An interconnect system connects two drawers of a redundant computer system, wherein each drawer contains a redundant node of the computer system. A first signal source and a first signal preventer are operatively associated with a first drawer of the two drawers. A second signal source and a second signal preventer are operatively associated with a second drawer of the two drawers. Each of the two drawers has a connection interface that includes a plurality of terminals connected to a redundant node of the drawer. A redundant system may be provided by connecting the connection interfaces with a connector. The connecter is further configured to connect the first signal source to the second signal preventer, and the second signal source to the first signal preventer, thereby signaling each drawer that the computer system may be operated in a redundant mode. If the connector is disconnected, the connection between the first signal source and the second signal preventer, and between the second signal source and the first signal preventer, are also disconnected, thereby signaling each drawer that the computer system cannot be operated in a redundant mode.

1. Field of the Invention
The present invention relates to redundant computer systems for computer servers and the like, and more particularly, to a system and method for interconnecting redundant systems.
2. Description of Related Art
Redundant systems are appropriate for various computing applications. As used herein, redundancy refers to duplication of electronic elements to provide alternative functional channels in case of failure, and a redundant node or element is one that provides this redundancy. A redundant system is a system containing redundant nodes or elements for primary system functions.
In a redundant computing system, two or more computers are utilized to perform a processing function in parallel. If one computer of the system fails, the other systems are capable of handling the processing function, so that the system as a whole can continue to operate. Redundant computing systems have been designed for many different applications, using many different architectures. In general, as computer capabilities and standards evolve and change, so do the optimal architectures for redundant systems.
For example, a standard may permit or require that the connectivity architecture for a redundant system be Ethernet-based. One such standard is the PCI Industrial Computer Manufacturers Group (PICMG) PSB Standard No. 2.16, about which more information may be obtained at www.picmg.com. In an Ethernet-based system, redundant nodes of the system communicate using an Ethernet protocol. Such systems may be particularly appropriate for redundant server applications. A redundant server comprises two or more separate computer servers (herein called "drawers") connected by a suitable interconnect.
It is desired, therefore, to provide a redundant system suitable for use with an Ethernet-based connectivity architecture, and with other connectivity architectures. It is further desired to provide a system and method for interconnecting drawers of the redundant system. The system and method should support operation of the drawers in a redundant mode. That is, if one drawer of the system experiences a failure, the other drawer or drawers of the system should be able to assume the processing function that has been lost by the failure, via an interconnection. At the same time, the system and method should provide that if the interconnection fails (i.e., if there is a "connection failure"), it is immediately detected by each affected drawer. The connection failure may then be reported, and the affected drawers may operate in a non-redundant mode until the connection failure can be repaired.

System and method for interconnecting nodes of a redundant computer system


A wedge-ribbed belt supports an elevator car in a cantilevered mode and engages a drive pulley of a drive mounted at the head of an elevator shaft. The belt has a running surface facing the drive pulley with a plurality of ribs and grooves extending in parallel in a longitudinal direction of the belt. The ribs and grooves can be triangular-shaped or trapezium-shaped in cross section. A plane of the drive pulley is arranged vertically and at right angles to a car wall at a counterweight side of the elevator car.

The present invention relates to elevator systems having flat belts supporting the elevator car.
Elevator systems of the kind according to the present invention usually include an elevator car and a counterweight which are movable in an elevator shaft or along free-standing guide devices. The guide device for the elevator car in that case consists on the one hand of guide rails which are arranged in a fixed position in the elevator shaft at one side of the elevator car and on the other hand of car guide rails fastened to a side of the elevator car. For producing the movement, the elevator system includes at least one drive with at least one respective drive pulley which by way of support and drive means supports the elevator car and the counterweight and transmits the necessary drive forces to these.
The support means or drive means are termed support means in the following description.
In the case of conventional elevator systems, steel cables with a round cross-section are usually used as support means. However, flat, belt-like support means are increasingly used for more modem systems.
An elevator system according to the cantilever principle with flat-belt-like support means is described in the technical article "Hannover Messe: Neue Idee von ContiTech-Hubgurte für Aufzüge" (ContiTech initiativ, January 1998).
The article discloses an elevator for automobile body works in which a guide device, which comprises two guide columns, with integrated counterweight is present on one side of an elevating platform. At the upper end the two guide columns are connected together by a platform on which a drive motor is arranged, which acts by way of two drive pulleys on two flat support means strands by which the elevating platform and the counterweight can be moved upwardly and downwardly along the guide columns. In each instance one of the flat-belt-like support means is connected, on the side of the elevating platform facing the guide device, with the platform and extends from this support means fixing point vertically upwards to the side, which faces the elevating platform, of the periphery of the associated drive pulley, loops around this through 180° and then runs vertically downwards to a second support means fixing point present at the counterweight.
A drawing in the mentioned technical article indicates that with use of the same technique a passenger elevator car can also be moved instead of the elevating platform.
For simplification, in the following there is used, instead of different expressions for the form of elevator receiving means, only the term "elevator car" which refers exclusively to load receiving means in a "cantilever arrangement".
An elevator system as described in the foregoing has, thanks to the use of flat-belt-like support means, the advantage that drive pulleys as well as deflecting rollers and support rollers can be used with a substantially smaller diameter than would be allowed in the case of use of a conventional wire cable. As a consequence of the smaller drive pulley diameter the drive torque required at the drive pulley is reduced, whereby a drive motor with smaller dimensions can be used. Due to this and thanks to the generally smaller support means pulley diameter, particularly space-saving elevator systems can be realized.
However, such elevator systems have certain disadvantages.
As a consequence of the small drive pulley diameter and because, in the case of the use of flat belts as support means known measures for improving traction capability, for example undercutting of the cable grooves at the drive pulleys for round support means, are not usable, the problem can arise in the case of a relatively large weight ratio between fully laden and empty elevating platform or elevator car that the traction forces transmissible between drive pulley and flat-belt-like traction means are not sufficient.
In addition, it is known that in the case of use of flat-belt-like support means without profiling the running surface, significant problems arise with lateral guidance of the support means on the drive pulley and, if they should be present, deflecting rollers and support rollers. Experience has shown that there is the risk that the support means rubs so strongly against the lateral boundary discs, which are usually present at the drive pulleys, deflecting rollers and support rollers, that the support means are damaged.


A voltage controlled oscillator includes a resonant circuit having a choke coil, a variable-capacitance diode, coupling capacitors, a resonant capacitor, a resonator, and a bypass capacitor. An amplifying circuit includes a buffer amplifying transistor, an oscillating transistor, bias resistors, Colpitts capacitors, bypass capacitors, a coupling capacitor, a choke coil, a resonant capacitor, and a resonant inductor which is an inductor element. A bias resistor has one end electrically connected to the base of the oscillating transistor and has the other end electrically connected to the ground via the resonant inductor having one end electrically grounded.

1. Field of the Invention
The present invention relates to a voltage-controlled oscillator, a composite module, and a communication apparatus.
2. Description of the Related Art
FIG. 6 is a circuit diagram of a conventional voltage-controlled oscillator 1. The voltage-controlled oscillator 1 includes a resonant circuit 2 and an amplifying circuit 3. The resonant frequency of the resonant circuit 2 changes according to a control voltage Vc applied to a control terminal 4. The amplifying circuit 3 oscillates a signal based on the resonant frequency of the resonant circuit 2 and amplifies the signal.
Referring to FIGS. 7 and 8, the circuits 2 and 3 of the voltage-controlled oscillator 1 typically have various electronic components (described below) mounted on or provided inside a circuit substrate 10, which is produced by integrally firing multilayered ceramic sheets having circuit patterns or ground electrodes printed thereon. In FIGS. 7 and 8, the circuit substrate 10 includes a control terminal 4, a driving power terminal 5, an output terminal 6, inter-layer connecting terminals 7 to 9, and a ground terminal G. The circuit substrate 10 further includes wiring patterns 12a to 12e, a via hole 11a, and a through-hole 11b. In addition to the components described above, the circuit substrate 10 includes on its upper surface other wiring patterns, via holes, and through-holes, which are not shown in FIGS. 7 and 8.
The resonant circuit 2 includes a choke coil L1, a variable-capacitance diode D1, coupling capacitors C9 and C10, a resonant capacitor C11, a resonator (strip line or microstrip line) SL2 which defines an inductor element, and a bypass capacitor C12.
The amplifying circuit 3 includes a buffer amplifying transistor Tr1, an oscillating transistor Tr2, bias resistors R1, R2, R3, and R4, Colpitts capacitors C4, C5, C6, and C7, bypass capacitors C1 and C3, a coupling capacitor C2, a choke coil (strip line or microstrip line) SL1, a resonant capacitor C8, and a resonant inductor (strip line or microstrip line) SL3 which defines an inductor element.
Japanese Unexamined Patent Application Publication No. 11-74727 discloses another well-known voltage-controlled oscillator, which has a different circuit from that according to preferred embodiments of the present invention. In this voltage-controlled oscillator, the emitter of a transistor is connected to the ground not only via a capacitor and a bias resistor, but also via a resonator connected to a node between the bias resistor and the capacitor.
Referring again to FIG. 6, the bias resistor R3 in the amplifying circuit 3 has one end electrically connected to the base of the transistor Tr2 and the other end directly connected to the ground. One approach for connecting the bias resistor R3 to the ground is via the wiring pattern 12a that is provided on the circuit substrate 10, as shown in FIG. 7, so as to electrically connect the bias resistor R3 to the ground terminal G.
This approach, however, prevents chip components from being mounted in an area S1 because the area S1 overlaps the wiring pattern 12a. Therefore, this approach is not appropriate for compact design of the voltage-controlled oscillator 1. Another disadvantage of this approach is that the space available for a microstrip line is reduced, which makes it difficult to form the resonator SL2 as a small-loss microstrip line.
Another approach, as shown in FIG. 8, is to form the through-hole 11b inside the circuit substrate 10 such that the through-hole 11b electrically connects the bias resistor R3 to a ground electrode (not shown in the figures) on the lower surface of the circuit substrate 10. This approach eliminates the need for forming the wiring pattern 12a on the circuit substrate 10, thus allowing a chip component such as the bias resistor R1 to be mounted in the area S1.
Unfortunately, this approach has a disadvantage in that the area for the resonator (strip line or microstrip line) SL2 inside the circuit substrate 10 is restricted by the through-hole 11b, which prevents an area S2 from being utilized, as shown in FIG. 9. Thus, this approach is also not appropriate for compact design of the voltage-controlled oscillator 1. In particular, the resonator SL2 defined by a strip line requires the formation of the via hole 11a for electrically connecting between strip lines on the surfaces and the inner layers of the circuit substrate 10, thus further restricting the component layout and internal layer patterns.

This patent is subject to a terminal disclaimer.

Voltage-controlled oscillator, composite module, and communication apparatus


A field emission device with an emitter on a first layer of material and an anode on a second layer of material, separated by a predetermined distance, with a sealed region therebetween. Changes in pressure external to the sealed region producing movement and consequent changes in the predetermined distance between the first and second layers, which change in distance produces a change in current between the emitter and anode. The change in current representing the change in differential pressure.

Differential pressure transducer devices are known in the art. Such prior art devices typically employ mechanical or semiconductor properties to translate a detected differential pressure variation into an electronic signal such as a voltage signal.
Differential pressure transducers of the prior art suffer from a number of operational restrictions. Mechanical differential pressure transducers are generally physically too large to be directly compatible with circuit integration, and are typically slow to respond to pressure variations.
Semiconductor-based differential pressure transducers may be realized in a form typically smaller than the mechanical differential pressure transducer devices. However, semiconductor-based differential pressure transducers are generally still too large to conveniently incorporate into an integrated structure. Additionally, the response time of prior art semiconductor-based differential pressure transducers is too slow for many applications.
Accordingly, there exists a need for a new differential pressure transducer which overcomes at least some of the shortcomings of the devices of the prior art.


A method for computing an exact solution for an electronic state of a substance by performing a first principle calculation using a computer, the method is characterized in that evaluating a deviation of an approximate value obtained by local density approximation or generalized gradient approximation from the exact solution of the electronic state to be obtained using an energy functional determined by an electronic density, a space derivative for the electronic density and fluctuations of physical quantities; and computing the exact solution by solving an optimization problem being defined by the energy functional.

Conventionally, there is a calculation theory called a first-principle calculation theory of estimating physical or chemical properties (hereinafter called properties) of a material according to a basic principle of quantum mechanics. As this kind of calculation theory, there is a calculation theory based on a density functional theory, in which properties, such as mechanical properties including elasticity, conductive properties including superconductive properties, a dielectric property and a magnetic property, are reproduced with relatively high accuracy, and a computation scale is in an implementable range. This calculation theory is already applied to material design, and there are numerous examples with its estimation accuracy verified through experiments (for example, see "Keisanki Material Design Nyumon (Introduction to computational material design)" edited by Hideaki Kasai, Hisazumi Akai, Hiroshi Yoshida, Osaka University Press (2005)).
As computation techniques based on a density functional method, a plurality of techniques are known, such as generalized gradient approximation (GGA), GW approximation, GW+Γ approximation and LDA+U approximation, regarded as techniques for solving problems caused by local density approximation (LDA).
However, each of the above-mentioned computation techniques has a problem of not giving a method for reaching a real solution (exact solution). In other words, until now, there is not a self-consistent calculation theory of reaching a real solution while a single-electron basis set being given by LDA in high accuracy is utilized.
On the other hand, the present inventor has proposed a fluctuation reference determination method as an effective many-electron calculation based on a multi-configuration reference density functional method (for example, see WO 2007/141942). With this method, an extended Kohn-Sham equation for reproducing a fluctuation variable (correlation function) having a positive definite property, such as local density fluctuations, in addition to one-electron density is given, whereby the reproduction accuracy of physical quantities can be raised to arbitrary accuracy. With this computation technique, total energy, one-electron density and a specific fluctuation variable of a material are reproduced simultaneously through the determination of the lowest energy state of a model Hamiltonian. Furthermore, by using a model system and its stable solution as initial values, a time-development equation for reproducing total energy, one-electron density and canonical correlation function is given, and a highly-accurate first principle electronic state computing method for reproducing the external field responses (responses to dynamic deformation and electromagnetic field application) of a material is given.
However, the effective many-electron computation based on the aforementioned multi-configuration reference density functional method is a computation technique that inevitably requires reference calculation, such as a Quantum Monte Carlo Method, a Transcorrelated Method, a Configuration Interaction Method, a Perturbation calculation/Green's function Method or an Effective Potential Method. For this reason, the reproduction accuracy of physical quantities depends on the calculation accuracy of the reference calculation, and a calculation technique reaching a real solution beyond the calculation accuracy of the reference calculation is not given.

Electronic state computing method, electronic state computing device, and recording medium


Process for the preparation of n-butylamines where n-butenylamines are firstly prepared by reacting 1,3-butadiene in the form of a 1,3-butadiene containing mixture obtained during the cracking of petroleum fractions or during the dehydrogenation of LPG or LNG or from GTL technology with a primary amine and/or a secondary amine under hydroaminating conditions, and the resulting butenylamine(s) are then reacted in a second process stage under hydrogenating and transalkylating conditions.

The present invention relates to processes for the preparation of n-butylamines and to the n-butenylamines which form as intermediate in this process.
n-Butylamines serve as starting materials for the preparation of surfactants, textile and flotation auxiliaries, bactericides, corrosion and foam inhibitors, additives for pharmaceuticals, and as antioxidants for fats and oils.
Alkylamines, such as butylamines, can be prepared by the hydrogenation of corresponding nitrites or nitro compounds, by the reductive amination of corresponding aldehydes and ketones and by the amination of corresponding alcohols.
The lower alkylamines (C1-15-alkylamines), such as, for example, also butylamines (e.g. C4-C15-butylamines, such as n-butylamine, butylmethylamines, butylethylamines, butylisopropylamines and dibutylamines), are prepared industrially, in particular, by the amination of the corresponding alcohol or of the corresponding carbonyl compound with ammonia, a primary or secondary amine over metal catalysts which are e.g. supported, under hydrogenating conditions (see e.g.: Ullmann""s Encyclopedia of Industrial Chemistry, Vol. A 2, 5th Ed., page 4).
Alternatively, alkylamines, e.g. butylamines, can also be prepared over acidic phosphate catalysts from corresponding alcohols (see e.g. U.S. Pat. No. 4,582,904 (Air Products)).
A further alternative for the preparation of alkylamines, such as e.g. butylamines, consists in the addition of NH3 or amines onto olefins in the presence of acidic catalysts, such as e.g. zeolites, see e.g. EP-A-132 736), in the presence of basic catalysts, such as e.g. metal amides, in particular alkali metal and alkaline earth metal amides (see e.g. B. W. Howk et al., J. Am. Soc. 76, page 1899ff (1954); R. Stroh et al., Angew. Chem. 69, 124ff (1957)), amides of subgroup IV (see e.g. D. Steinborn et al. (Z. Chem. 29 (1989), page 333ff) or alkali metal alkoxides, or in the presence of transition metal complex compounds (see e.g. U.S. Pat. No. 3,758,586).
EP-A-752 409 (DE-A-195 24 240) describes a process for the preparation of amines by hydroamination of olefin-containing mixtures obtained during the cracking of petroleum fractions, over zeolites, alumosilicates, phosphates, mesoporous oxides, Pillard clays, amorphous oxides or phyllosilicates. In particular, use is made here of butadiene-free C4 hydrocarbon mixtures (page 3, lines 10-12; Examples).
The processes listed above for the preparation of alkylamines have the following disadvantages:
The use of alcohols (e.g. ethanol), aldehydes, ketones and nitriles as starting materials for the preparation of alkylamines, such as butylamines, is significantly less economical on the basis of their costs than the use of corresponding olefins (e.g. ethene).
The use of olefins as starting material for the alkylamine preparation is accordingly desirable, but has hitherto been burdened with the following disadvantages (cf. e.g.: M. Beller et al., Chem. Rev. 98, 675f (1998) 675; R. Taube, xe2x80x9cReaction with Nitrogen Compoundsxe2x80x9d in B. Cornils and W. A. Hermann: xe2x80x9cApplied Homogeneous Catalysis with Organometallic Compoundsxe2x80x9d, VCH Weinheim, 1996, pages 507 to 520, and E. Haak et al., Chemie in unserer Zeit (1999), 297 to 303, in particular the summary on p. 302):
aa) The addition, under basic and heterogeneous catalysis, of amines onto olefins in the presence of metal oxide catalysts is possible, according to Kakuno et al., J. Catal. 85 (1984), page 509ff, with primary and secondary alkylamines, and conjugated dienes, such as butadiene or isoprene.
ab) The addition, under weakly basic catalysis, of amines onto olefins with alkali metal alkoxide as catalyst is, according to Beller et al., Angew. Chem. 110 (1998), page 3571ff, only successful in the case of aromatically conjugated amines and styrene as olefin component.
ac) In the case of the NaNH2- or KNH2-catalyzed addition of NH3 onto olefins, as is described e.g. in B. W. Howk et al., J. Am. Chem. Soc. 76 (1954), 1899-1902 and R. D. Closson et al., U.S. Pat. No. 2,750,417, the space-time yields of desired alkylamines are very low even at high temperatures and olefin pressures amide.
ad) G. P. Pez (U.S. Pat. No. 4,336,162 and 4,302,603) describes a solution approach to the problem given in ac) by changing to the corresponding Rb and Cs amides or by using a eutectic of NaNH2 and KNH2. In the first case, industrial realization is precluded because of the extremely high cost of the catalyst, and in the second case the space-time yields of desired alkylamines are still too low.
b) Over acidic catalysts, such as e.g. zeolites, the addition of NH3 onto olefins, ammonia generally being used in a high excess based on the olefin, does not proceed in every case with such good selectivities and yields for a certain alkylamine as, for example, in the case of isobutene (see e.g. DE-A-3634247).
xe2x80x83The hydroamination of olefins with secondary amines in the presence of acidic catalysts again generally proceeds in poorer yields and with poorer selectivities than the corresponding hydroamination with ammonia or primary amines.
c) The transition metal complex-catalyzed hydroamination of olefins is generally possible in good yields only with secondary alkylamines (e.g.: Brunet, Gazzetta Chimica Italiana, 127, 1997, pages 111 to 118, page 112, left-hand column).
The two earlier German applications No. 10030619.5 from Jun. 28, 2000 and No. 10041676.4 from Aug. 24, 2000 describe a process for the preparation of alkylamines where, in a first process stage, an olefin is reacted with ammonia, a primary amine and/or a secondary amine under hydroaminating conditions, and then the resulting hydroamination product(s) is/are reacted in a second process stage under transalkylating conditions. The use of 1,3-butadiene in the form of a 1,3-butadiene-containing mixture obtained during the cracking of petroleum fractions or during the dehydrogenation of LPG or LNG or from GTL technology as olefin component is not disclosed herein.
A disadvantage of many processes for the preparation of amines from olefins is that the isolation of pure olefins or mixtures of pure olefins from mixtures obtained during the cracking of petroleum fractions is complex and expensive.
The complex separation of 1,3-butadiene from the C4 cut is described, for example, in K. Weissermel and H. -J. Arpe, Industrielle Organische Chemie [Industrial Organic Chemistry], 4th edition 1994, VCH Verlagsgesellschaft, page 76.
It is an object of the present invention to find, while overcoming the disadvantages of the prior art, an alternative, economical and flexible process for the preparation of n-butylamines which permits the preparation of a desired n-butylamine or two or more desired n-butylamines with high space-time yield and selectivity.
We have found that this object is achieved by a process for the preparation of n-butylamines which comprises firstly preparing n-butenylamines by reacting 1,3-butadiene in the form of a 1,3-butadiene-containing mixture obtained during the cracking of petroleum fractions or during the dehydrogenation of LPG or LNG or from GTL technology with a primary amine and/or a secondary mind under hydroaminating conditions and then reacting the resulting butenylamine(s) in a second process stage under hydrogenating and transalkylating conditions.
The 1,3-butadiene-containing mixtures preferably originate from the following sources:
a) C4 cuts which are produced on an industrial scale during the thermal or catalytic cleavage of petroleum fractions, such as, for example, petroleum spirits, in particular naphtha (steamcracking; see e.g. K. Weissermel and H. -J. Arpe, Industrielle organische Chemie [Industrial Organic Chemistry], 4th edition 1994, VCH Verlagsgesellschaft, pages 70-76);
b) hydrocarbon streams from the dehydrogenation of LPG or LNG, preferably C4 cuts therefrom, where the C4 fraction of the LPG stream is separated off from the LPG stream before or after the dehydrogenation. A LNG stream with high C1 and C2 can here be converted beforehand into C4, for example via an MTO process.
Here, LPG means liquefied petroleum gas. Such liquefied gases are defined, for example, in DIN 51 622. They generally comprise the hydrocarbons propane, propene, butane, butene and mixtures thereof which are formed in oil refineries as secondary products during the distillation and cracking of petroleum, and in the processing of natural gas during the separation of petroleum spirit. LNG means liquefied natural gas. Natural gas consists primarily of saturated hydrocarbons which have varying compositions depending on their origin and are generally divided into three groups. Natural gas from pure natural gas deposits consists of methane and a small amount of ethane. Natural gas from petroleum deposits additionally comprises relatively large amounts of high molecular weight hydrocarbons, such as ethane, propane, isobutane, butane, hexane, heptane and secondary products. Natural gas from condensate and distillate deposits comprises not only methane and ethane, but also, to a considerable extent, higher-boiling components having more than 7 carbon atoms. For a more detailed description of liquefied gases and natural gas, reference is made to the corresponding keywords in Rxc3x6mpp, Chemielexikon, 9th edition.
The LPG and LNG used as feedstock includes, in particular, field butanes, as the C4 fraction of the xe2x80x9cmoistxe2x80x9d fractions of natural gas, and of petroleum accompanying gases is called, which are separated off from the gases by drying and cooling to about xe2x88x9230xc2x0 C. in liquid form. Low-temperature or pressure distillation thereof gives the field butanes, the composition of which varies depending on deposits, but which generally comprise about 30% isobutane and about 65% n-butane.
Suitable processes for the dehydrogenation of hydrocarbons are described, for example, in DE-A-100 47 642. In addition, for the dehydrogenation of alkanes, reference may be made to U.S. Pat. No. 4,788,371 WO 094/29021, U.S. Pat. No. 5,733,518, EP-A-0 838 534, WO 96/33151 or WO 096/33150.
The abovementioned MTO here means methanol-to-olefin. It is related to the MTG process (methanol-to-gasoline). This is a process for the dehydration of methanol over a suitable catalyst, giving an olefinic hydrocarbon mixture. Even C1 feedstreams can thus, for example, be converted, via methanol and the MTO process, into olefin mixtures from which the C4 fractions can be separated off by suitable methods. For example, separation can take place by distillation. For the MTO process, reference may be made to Weissermel, Arpe, Industrielle organische Chemie, 4th edition, 1994, VCH-Verlagsgesellschaft, Weinheim, p. 36 et seq..
The methanol-to-olefin process is also described, for example, in P. J. Jackson, N. White, Technologies for the conversion of natural gas, Austr. Inst. Energy Conference 1985.
c) C4 cuts from GTL Technology (GTL=gas to liquid), for example the Fischer-Tropsch synthesis.
d) All mixtures of the abovementioned hydrocarbon streams.
The preferred C4 cuts have the following composition (in % by weight):
1) C4 cracker cut:
1,3-butadiene: 25-60, preferably 35-50, particularly preferably 40-45,
butenes (isobutene, 1-butene, trans-2-butene, cis-2-butene): 35-70, preferably 40-60,
butanes (n-butane, isobutane): 3-12, preferably 5-10,
alkynes (vinylacetylene, 1-butyne): 0-4, preferably 0- less than 2, particularly preferably 0- less than 1;
others (e.g. 1,2-butadiene, C5 components such as pentanes): 0-2, preferably 0-1.
A typical C4 cracker cut composition (in % by weight) is e.g.:
2) Hydrocarbon mixture from the dehydrogenation of n-butane:
1,3-butadiene: 3-40, preferably 5-30, particularly preferably 7-15;
butenes (1-butene, trans-2-butene, cis-2-butene): 25-70, preferably 35-60;
n-butane 25-70, preferably 35-60;
alkynes (vinylacetylene, 1-butyne): 0-1, preferably 0-0.5, particularly preferably 0-0.2;
others (e.g. 1,2-butadiene): 0-1, preferably 0-0.5.
A typical composition (in % by weight) of C4 cut from an n-butane dehydrogenation is e.g.:
3) Hydrocarbon mixture from the dehydrogenation of field butanes:
1,3-butadiene: 1-20, preferably 2-15, particularly preferably 3-10;
butenes (1-butene, trans-2-butene, cis-2-butene, isobutene): 45-85, preferably 55-80;
butanes (n-butane, isobutane): 10-50, preferably 15-40;
others 0-1, preferably 0-0.5.
A typical composition (in % by weight) of C4 cut from an n-butane dehydrogenation is e.g.:
Particular preference is given to using a C4 cut which comprises less than 2% by weight, in particular less than 1% by weight, of hydrocarbons which have a pKa value of less than 30, according to the MSAD scale.
Such hydrocarbons are e.g. 1-butyne and vinylacetylene.
[Definition of the MSAD scale (xe2x80x9cMc Ewen-Streitwieser-Applequist-Dessy scalexe2x80x9d) e.g. in D. J. Cram, Fundamentals of Carb Chemistry, Acad. press, 1965].
Surprisingly, using the process according to the invention, it is possible, in the reaction of the primary or secondary amine with the mixture containing 1,3-butadiene and further olefins, to react the amine with an olefin selectivity, based on all of the olefins in the mixture, of more than 90%, in particular more than 95%, very particularly more than 98%, with the 1,3-butadiene to give the corresponding n-butenylamine as hydroamination product. Thus, virtually only the 1,3-butadiene from the 1,3-butadiene-containing mixture reacts.
Particular preference is given to choosing the reaction conditions (see below) such that the 1,3-butadiene is removed completely (i.e. in an amount greater than 98%, in particular greater than 99%) from the 1,3-butadiene-containing mixture.
The constituents of the 1,3-butadiene-containing mixture used which remain after the reaction has been carried out can, following separation and optional purification, be further processed and used elsewhere. For example, these constituents which remain can be passed back to a steamcracker again.
If the constituents of the 1,3-butadiene-containing mixture used which remain after the reaction has been carried out still comprise small amounts of 1,3-butadiene, these constituents can be returned to a 1,3-butadiene partial hydrogenation stage (K. Weissermel and H. -J. Arpe, Industrielle orsanische Chemie, 4th Ed. 1994, VCH Verlagsgesellschaft, page 76, 2nd paragraph).
In particular, the constituents of the 1,3-butadiene-containing mixture used which remain after the reaction has been carried out can, where removal of the 1,3-butadiene is complete as a result of the reaction, be further processed, following their separation, as raffinate I.
Such a raffinate I obtained according to the invention consists of n- butane, iso butane, 1-butene, cis-2-butene, trans-2-butene, isobutene, less than 1% by weight, in particular less than 0.5% by weight, very particularly 0-0.1% by weight, of 1,3-butadiene, 0-0.1% by weight of alkynes and optionally a further radical (e.g. traces of C5 components).
Prior to the further processing of the constituents of the 1,3-butadiene-containing mixture used which remain after the reaction has been carried out, these constituents may be purified by treatment with an acidic ion exchanger, an acidic heterogeneous catalyst (e.g. zeolite, acidic mixed oxide, xcex3-aluminum oxide), with dilute acid (extractive), or by distillation. This treatment removes, for example, any basic components still present, such as amine impurities.
In this respect, the process according to the invention is also a process for the preparation of a 1,3-butadiene-free mixture (i.e. 1,3-butadiene content of less than 1% by weight, in particular less than 0.5% by weight, very particularly less than 0.1% by weight), e.g. raffinate I, from the corresponding 1,3-butadiene-containing mixture obtained during the cracking of petroleum fractions or during the dehydrogenation of LPG or LNG or from GTL technology (e.g. a C4 cut).
Depending on the chosen reaction conditions (see below), it is possible for some of the 1-butene present in the 1,3-butadiene containing mixture to also react with the primary and/or secondary amine. Since this likewise leads to desired n-butylamines, this xe2x80x9csecondary reactionxe2x80x9d is not disadvantageous.
Primary and secondary amines which can be used in the process according to the invention, or mixtures thereof, are generally amines of the formula
in which
R1 is hydrogen (H), alkyl, in particular C1-C20-alkyl, alkenyl, in particular C2-C20-alkenyl, cycloalkyl, in particular C3-C20-cycloalkyl, alkoxyalkyl, aminoalkyl, monoalkylaminoalkyl, dialkylaminoalkyl, aryl, aralkyl
and R2 is alkyl, in particular C1-C20-alkyl, alkenyl, in particular C2-C20-alkenyl, cycloalkyl, in particular C3-C20-cycloalkyl, alkoxyalkyl, aminoalkyl, monoalkylaminoalkyl, dialkylaminoalkyl, aryl, aralkyl, and
R1 and R2 together may be a saturated or unsaturated C3- to C9-alkylene chain which may be interrupted by an O, S or N heteroatom, in particular together may be a xe2x80x94(CH2)jxe2x80x94Xxe2x80x94(CH2)kxe2x80x94 group, where j and k=1 to 4 and X=CH2, CHR3, oxygen (O), sulfur (S) or NR3, where R3=H or C1-C4-alkyl.
Examples of primary amines according to formula II are methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, tert-butylamine, n-pentylamine, cyclopentylamine, isopentylamine, n-hexylamine, cyclohexylamine, n-octylamine, n-decylamine, 1-phenylethylamine, 2-phenylethylamine, allylamine, 2-dimethylaminoethylamine and 2-methoxyethylamine.
Examples of secondary amines according to formula II are dimethylamine, diethylamine, di-n-propylamine, diisopropylamine, di-n-butylamine, pyrrolidine, piperidine, hexamethylenamine, piperazine and morpholine.
The catalyst used in the preparation of n-butenylamines by reacting 1,3-butadiene in the form of a 1,3-butadiene-containing mixture obtained during the cracking of petroleum fractions with a primary or secondary amine is an alkali metal, a metal monoalkylamide or metal dialkylamide, a metal amide corresponding to the amine used or a transition metal complex compound.
Alkali metals, in particular Na and K, very particularly Na, are preferred as catalysts.
The alkali metal reacts in situ with the primary and/or secondary amine and the 1,3-butadiene to give the corresponding alkali metal amide.
With regard to the metal amide catalysts, metal dialkylamides are preferred over metal monoalkylamides.
The metal monoalkylamides and metal dialkylamides generally have the formula MNR4R5 (M=monovalent metal), M(NR4R5)2 (M=divalent metal), M(NR4R5)3 (M=trivalent metal) or M(NR4R5)4 (M=tetravalent metal), where
R4 has the meanings according to the radical R1 and R5 has the meanings according to the radical R2, and R4 and R5 may also together be a saturated or unsaturated C3-C9-alkylene chain which may be interrupted by an O, S or N heteroatom (as defined for R1 and R2), in particular may together be a xe2x80x94(CH2)jxe2x80x94Xxe2x80x94(CH2)kxe2x80x94 group (as defined for R1 and R2) (see above).
The metal amides particularly preferably have the formula MNR1R2, M(NR1R2)2, M(NR1R2)3 or M(NR1R2)4, in which, accordingly, the radicals R correspond to those of the primary and/or secondary amine used.
As metal component (M) in the metal monoalkylamide and metal dialkylamide catalysts, preference is given to metals of groups IA, IIA, IIIB and IVB (Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, Sc, Y, La or a lanthanide element, Ti, Zr or Hf), in particular Li, Na, Mg, Ca and K, very particularly Na and K.
Examples of such metal alkylamides are NaHNEt, NaNEt2, KHNEt, KNEt2, LiHNEt, LiNEt2, LiN(iso-C3H7)2, NaN(iso-C3H7)2, NaN(n-C4H9)2, NaHN(iso-C3H7), NaHN(isopentyl), Mg(NEt2)2, Ca(NPr2)2 and Zr (NEt2)4.
In the case of the hydroamination of di-n-butylamine with the 1,3-butadiene-containing mixture, NaN(n-BU)2 and KN(n-Bu)2 are particularly preferred, and in the case of that of n-butylamine with the 1,3-butadiene-containing mixture, Na(H)N(n-Bu) and K(H)N(n-Bu) are particularly preferred.
These metal amides are prepared as described in Houben-Weyl, Methoden der organischen Chemie [Methods of Organic Chemistry], 4th edition, Volume XI/2 (nitrogen compounds II and III), Verlag Thieme, Stuttgart, p. 182ff, in U.S. Pat. No. 4,595,779, WO 93/14061, DE-A-21 17 970, DRP 615,468, GB-A-742 790, DE-A-26 13 113, U.S. Pat. No. 2,750,417, J. Wollensak, Org. Synth. 43 (1963), page 45ff, or C. A. Brown, J. Am. Chem. Soc. 95(3) (1973), page 982ff, by reacting metal with the corresponding amine in the presence of an unsaturated compound such as, for example, butadiene, isoprene, naphthalene, pyridine or styrene, by reacting a metal amide or hydride with the corresponding amine or by reacting an organometallic compound, such as, for example, n-BuLi, MeLi, PhNa, Et2Mg or Et4Zr, with the corresponding amine.
The transition metal complex compound used as catalyst is generally a complex compound of a metal of group IIIB, IVB or VIII of the Periodic Table of the Elements.
Examples thereof are the rhodium or iridium compounds described in U.S. Pat. No. 3,758,586, such as (cyclooctadiene)2RhCl2, RhCl3, RhBr3 and IrCl3, for the reaction of secondary aliphatic amines,
the ruthenium and iron compounds described in U.S. Pat. No. 4,454,321, such as RuCl3*xH2O, Ru(cyclopentadienyl)2, [Ru(NH3)4(OH)Cl]Cl*2 H2O, Fe(CO)5, Fe2(CO)9, H2Fe(CO)4, Fe(butadiene) (CO)3, Fe(CO)5/tri-n-butylphosphine, Fe(CO)5/triphenyl phosphite, for the reaction of primary or secondary amines,
the platinum and palladium compounds cited in the overview article by Th. E. Mxc3xcller and M. Beller in Chem. Rev. 1998, Vol. 98, No. 2, pages 675 to 703, on pages 679 to 680, such as PtX42xe2x88x92 (X=Clxe2x88x92, Brxe2x88x92),
the lanthanum, neodymium, samarium and lutetium compounds cited in the abovementioned overview article by Th. E. Mxc3xcller and M. Beller on pages 681 to 684, such as Cp*2Lnxe2x88x92E (Cp*=pentamethylcyclopentadienyl or tetramethylcyclopentadienyl with bridge to the second tetramethylcyclopentadienyl ligand, Ln=La, Nd, Sm or Lu, E=H, CH(SiMe3)2 or N(SiMe3)2), and
the platinum, ruthenium, hafnium, zirconium, iridium and tantalum compounds cited in the abovementioned overview article by Th. E. Mxc3xcller and M. Beller on pages 684 to 686, such as Pt(PEt3)2(H)(NHPh), IrCl(C2H4)2(PEt3)2 and Cp2Zr(H)[N(t-Bu)(SiHMe2)].
The process for the preparation of the n-butenylamines can be carried out as follows:
1,3-butadiene (I) in the form of a 1,3-butadiene-containing mixture obtained during the cracking of petroleum fractions or during the dehydrogenation of LPG or LNG or from GTL technology, preferably in the form of a 1,3-butadiene-containing mixture with a composition as described above, is reacted with a primary amine and/or a secondary amine under hydroaminating conditions (hydroamination).
The reaction generally takes place according to the following reaction scheme.
In the case of the reaction of the 1,3-butadiene-containing mixture with a secondary amine, an n-butenylamine IIIa results as tertiary amine in the hydroamination stage.
In the case of the reaction of the 1,3-butadiene-containing mixture with a primary amine, either an n-butenylamine IIIa results as secondary amine (R1=H) or a di-n-butenylamine IIIb results as tertiary amine, or a mixture thereof, depending on the reaction conditions chosen in the hydroamination stage.
To simplify the above scheme, it has been assumed that in the hydroamination of the 1,3-butadiene, the resulting olefinic double bond is neither in the a position, nor in the xcex2 position, nor in the xcex4 position, relative to the nitrogen in III (corresponding to an imine or enamine or homoallylamine, respectively). However, in this process stage, it is entirely possible for double bond isomerization to occur under the basic conditions.
Very particularly preferred amines are mono- and dialkylamines, such as monoethylamine, diethylamine, n-butylamine, di-n-butylamine and isopropylamine.
The hydroamination products starting from the 1,3-butadiene and n-butylamine are n-butenyl-n-butylamine and di-n-butenyl-n-butylamine, and, starting from the 1,3-butadiene and di-n-butylamine, di-n-butyl-n-butenylamine.
a) Alkali Metal and Metal Amide Catalysis
The reaction of the 1,3-butadiene-containing mixture with the amine in the presence of the metal amide (hydroamination stage) can be carried out analogously to the description in G. P. Pez et al., Pure and Appl. Chem. 57(12), 1917-26 (1985), R. D. Closson et al., J. Org. Chem. 22 (1957), 646-9, G. M. Whitman et al., U.S. Pat. No. 2,501,556), D. Steinborn et al., Z. Chem. 29 (1989), 333-4, D. Steinborn et al., Z. Chem. 26 (1986) 349-59 and H. Lehmkuhl et al., J. Organomet. Chem. 55 (1973), 215-20.
The reaction of the 1,3-butadiene-containing mixture with the amine in the presence of the metal amide can also be carried out in the presence of small amounts of ammonia (less than 1 mol % based on the amine(s) used) (cf. analogous to DE-A-21 17 970).
The preparation of the metal amide and the catalytic hydroamination of the 1,3-butadiene-containing mixture can also be carried out in a xe2x80x9cone-pot synthesisxe2x80x9d, i.e. simultaneously.
For this, use is made of an organometallic compound, e.g. BuLi, and the amine, e.g. di-n-butylamine, or (preferably) an alkali metal, e.g. Na, and the amine, e.g. di-n-butylamine.
The alkali metal is preferably used here in dispersed and/or suspended form, in particular in a particle size (diameter) of from 0.1 to 1000 xcexc(micrometers). The preparation of such alkali metal dispersions or suspensions is carried out in accordance with methods known to the person skilled in the art, e.g. by appropriate action of shear forces, such as e.g. stirring or ultrasound. (Cf. e.g. xe2x80x9cOrganikumxe2x80x9d [Organic Chemistry], 2nd reprint of the 15th edition, page 584, VEB Verlag 1981).
The metal amide can be converted into metal hydride during the reaction by xcex2-elimination or the action of H2 as described in DE-A-26 13 113; in the case of the xcex2-elimination, an imine arises in parallel in the process. This can be converted back into a metal amide and H2 under the action of a primary or secondary amine, in accordance with DE-A-26 13 113, C. A. Brown, J. Am. Chem. Soc. 95(3) (1973), 982ff or C. A. Brown, Synthesis (1978), 754ff, meaning that the metal hydride can be regarded as a type of xe2x80x9crest formxe2x80x9d of the metal amide and, for the purposes of the present invention, is therefore to be equated with the metal amide.
In addition, complexing agents may be present as solvents both during the preparation of the catalyst and also during the hydroamination reaction.
Thus, e.g. J. F. Remenar (J. Am. Chem. Soc. 120 (1988), 4081ff), H. Lehmkuhl et al. (J. Organomet. Chem. 55 (1973), 215ff) and D. Steinborn et al. (Z. Chem. 29 (1989), 333ff) describe the use of N,N,Nxe2x80x2,Nxe2x80x2-tetramethylethylenediamine, N,N,Nxe2x80x2,Nxe2x80x3,Nxe2x80x3-pentamethyldiethylenetriamine, N,N,Nxe2x80x2,Nxe2x80x2-tetramethylcyclohexanediamine and tetrahydrofuran as complexing agent.
In addition, amines with two or more aminic N atoms per molecule, such as, for example, N,N,Nxe2x80x2,Nxe2x80x2-tetraethylethylenediamine, N-permethylated or N-perethylated tetraethylenetetramine up to N-permethylated or N-perethylated polyimine having molar masses up to 500 000 daltons, ethers and polyethers, such as e.g. diglymes, triglymes and the corresponding homologs, terminally capped polyolsxe2x80x94e.g. PEG, PPG, polyxe2x80x94THFxe2x80x94, and complexing agents with aminic N and etheric O atoms in the molecule, such as e.g. 3-methoxyethylamine, 3-(2-methoxyethoxy)propylamine or N,N,Nxe2x80x2,Nxe2x80x2-tetramethyldiaminodiethyl ether, may be present.
The procedure generally involves dissolving or suspending the catalyst [or the corresponding alkali metal or the corresponding metal hydride or the corresponding organometallic compound (e.g. n-BuLi), in each case as catalyst xe2x80x9cprecursorxe2x80x9d] in a primary and/or secondary amine, particularly preferably in a secondary amine.
The catalyst may be present as a solution, a suspension, or in supported form on a typical catalyst support, such as e.g. SiO2, A12O3, TiO2, ZrO2, activated carbon, MgO, MgAl2O4. The catalyst is preferably in the form of a solution or suspension, particularly preferably a solution.
The hydroamination of the 1,3-butadiene-containing mixture can be carried out batchwise, semicontinuously or continuously.
In the first case, the 1,3-butadiene-containing mixture is added to catalyst and amine and reacted. In the second case, the 1,3-butadiene-containing mixture is metered into the reaction mixture. In the third case, catalyst, amine and 1,3-butadiene-containing mixture are metered in continuously.
Preference is given to a molar ratio of 1,3-butadiene-containing mixture: secondary amine of 3:1 to 1:10, particularly preferably 1:1 to 1:2.
Preference is given to a molar ratio of 1,3-butadiene-containing mixture: primary amine of 6:1 to 1:5, particularly preferably 2:1 to 1:1.
The reaction is carried out, preferably with stirring, at 0 to 250xc2x0 C., in particular at 20 to 150xc2x0 C. and particularly preferably at 40 to 120xc2x0 C.
The reaction can be carried out under the pressure which arises under the chosen conditions (autogenous pressure). Generally, the pressure while the reaction is being carried out is from 0 to 200 bar above atmospheric, in particular 2 to 100 bar, very particularly 3 to 30 bar.
Suitable reactors are all typical reaction apparatuses, e.g. stirred reactors, loop reactors, bubble columns, packed bubble columns, cascaded bubble columns and stirred columns.
After the reaction, the product is separated off from the catalyst, e.g. by distillation, rectification, filtration, membrane filtration, washing with water or adsorption.
Catalyst (metal amide or metal hydride) which has not undergone protolysis can then be recycled.
b) Transition Metal Complex Compound Catalysis
The reaction of the 1,3-butadiene-containing mixture with the primary and/or the secondary amine can be carried out, for example, as described in the literature given above in the discussion of the transition metal complex compounds.
The reaction can be carried out continuously, batchwise or semi-batchwise.
In the batchwise procedures, the catalyst is introduced together with the amine. After the reaction temperature has been reached, the 1,3-butadiene-containing mixture is injected in. When the pressure has decreased (measure of the reaction), the product or product mixture is distilled off.
Excess 1,3-butadiene and unreacted amine can be recycled.
In the batchwise procedure the catalyst, together with the product mixture, can be conveyed out of the reactor via the bottom and worked up separately.
The reaction can be carried out in a stirred reactor.
In the case of the continuous procedure, the reaction can be carried out in a bubble column. Here, the 1,3-butadiene-containing mixture is blown from below through the mixture of catalyst and product solution. The solution can then be removed from the catalyst by distillation or the catalyst can be removed from the product solution by means of a membrane. Alternatively, the catalyst does not need to be removed but can be passed directly to the work-up or to the next process stage, provided it does not cause interference there.
Second Process Stage
Following the reaction of the 1,3-butadiene-containing mixture with the primary and/or secondary amine under hydroaminating conditions, the resulting hydroamination product(s) is(are) reacted in a second process stage under transalkylating conditions.
Variant a)
The process products of the transalkylation in this second process stage are again n-butenylamines. The composition of the reaction discharge of this transalkylation stage differs from that of the preceding hydroamination stage by the fact that, inter alia, the n-butenylamines obtained as products are present in a different molar ratio relative to one another.
This second process stage is preferably carried out in the presence of a transalkylation catalyst.
Preferred temperatures for this amine transalkylation stage are 80 to 400xc2x0 C.
The reaction discharge from the first hydroamination stage can, usually following removal of the catalyst (as described above in each case), be used directly in this second process stage.
However, it is also possible to firstly separate off the n-butenylamine(s) as hydroamination product(s) from the reaction discharge of the first hydroamination stage which is/are desired for this second process stage (as described above in each case), and then to use it/them in this second process stage.
Advantageously, for the second process stage, ammonia and/or amines can also be passed to the feed, and/or ammonia and/or amines from the reaction discharge can be passed (returned) to this second process stage.
In a preferred embodiment, the product mixture obtained in the second process stage (transalkylation stage) is separated into (a) product(s) which is/are returned to the first process stage (hydroamination stage), and/or (a) product(s) which is/are returned to the second process stage (transalkylation stage), and the desired n-butenylamine(s).
The reaction of the hydroamination product/products obtained in the first process stage in the second process stage under transalkylating conditions can be carried out, for example, as described in Houben Weyl Volume XI/1, Nitrogen compounds II, 1957, Georg Thieme Verlag Stuttgart, pp. 248-261.
Accordingly, the amine transalkylation (xe2x80x9camine exchangexe2x80x9d) can be carried out in the presence of transalkylation catalysts, such as acids, zeolites, metal salts, iodine, dehydration catalysts, hydrogenation/dehydrogenation catalysts or else in the absence of catalysts.
Acids suitable as transalkylation catalyst are, for example, hydrohalic acids (such as HCl), phosphoric acid, sulfanilic acid or sulfonic acids (such as p-toluenesulfonic acid).
Zeolites suitable as transalkylation catalyst are, for example, faujasites, such as X, Y and USY zeolites, erionite, chabazite, mordenite, offretite, clinoptiolite, pentasiles such as ZSM-5 and ZBM-10, ZSM-11, ZSM-12, MCM-22, MCM-41, MCM-48, MCM-49, MCM-56, EMT, SSZ-26, SSZ-33, SSZ-37, CIT-1, PSH-3, NU-85, beta and the boron-containing forms, such as, for example, ZBM-11, H-boron-ZSM-5, H-boron-beta, H-boron-ZSM-11, and the gallium- or titanium-containing forms. They are characterized by a high number of catalytically active centers, combined with a large surface area.
These zeolites differ in type and in the nature of the aftertreatment following their preparation (e.g. thermal treatment, dealuminization, acid treatment, metal ion exchange, etc.).
Examples of suitable zeolites are given in U.S. Pat. No. 4,375,002, 4,536,602, EP-A-305 564, EP-A-101 921 and DE-A-42 06 992.
Also suitable are the zeolites known from EP-A-133 938, EP-A-431 451 and EP-A-132 736, which are borosilicate, gallosilicate, alumosilicate and ferrosilicate zeolites, which may optionally be doped as described with alkali metals, alkaline earth metals and transition metals.
Also suitable are, for example, the beta zeolites known from CA-A-2 092 964, which are defined as crystalline alumosilicates of certain composition with a pore size of more than 5 xc3x85.
Preference is given to using metal- or halogen-modified beta zeolites, as described, for example, in DE-A-195 30 177.
Also particularly suitable are zeolite catalysts of the pentasil type having a SiO2/Al2O3 molar ratio of greater than or equal to 10, as are disclosed in EP-A-132 736.
Metal salts suitable as transalkylation catalyst are, for example, zinc or iron halides, such as zinc chloride, iron(II) chloride or iron(III) chloride.
Dehydration catalysts suitable as transalkylation catalyst are, for example, manganese(II) oxide/activated carbon, alumosilicates, Al2O3, TiO2 or ZrO2.
As transalkylation catalyst, preference is given to hydrogenation and dehydrogenation catalysts.
In this connection, the presence of hydrogen is advantageous to maintain the catalytic activity. Alternatively, the hydrogenation or dehydrogenation catalyst can be freed from deposits by reduction with H2 at regular intervals.
Particularly suitable hydrogenation and dehydrogenation catalysts are catalysts which contain, as catalytically active constituents, elements chosen from the group consisting of copper, silver, gold, iron, cobalt, nickel, rhenium, ruthenium, rhodium, palladium, osmium, iridium, platinum, chromium, molybdenum and tungsten, in each case in metallic form (oxidation state 0) or in the form of compounds such as, for example, oxides, which are reduced to the corresponding metal under the process conditions.
The catalytically active constituents copper, silver, gold, iron, cobalt, nickel, rhenium, ruthenium, rhodium, palladium, osmium, iridium, platinum, chromium, molybdenum and/or tungsten are generally present in the catalytically active mass of the catalyst in overall amounts of from 0.1 to 80% by weight, preferably 0.1 to 70% by weight, particularly preferably 0.1 to 60% by weight, calculated as metal in oxidation state 0.
Preference is given to catalysts which contain, as catalytically active constituents, elements chosen from the group consisting of copper, silver, nickel, ruthenium, rhodium, palladium, platinum, chromium and molybdenum, in particular chosen from the group consisting of copper, cobalt, nickel, in each case in metallic form (oxidation state 0) or in the form of compounds, such as, for example, oxides, which are reduced to the corresponding metal under the process conditions.
More preference is given to catalysts which contain the catalytically active constituents copper, silver, iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium and/or platinum and a support material, preferably chosen from the group consisting of aluminum oxide, zirconium dioxide, titanium dioxide, carbon and/or oxygen-containing compounds of silicon.
The catalytically active mass of these catalysts preferably used in the process according to the invention comprises the catalytically active constituents copper, silver, iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium and/or platinum generally in overall amounts of from 0.1 to 80% by weight, preferably 0.1 to 70% by weight, particularly preferably 0.1 to 60% by weight, calculated as metal in oxidation state 0.
Furthermore, the catalytically active mass of these preferably used catalysts comprises the support materials aluminum oxide (Al2O3), zirconium dioxide (ZrO2), titanium dioxide (TiO2), carbon and/or oxygen containing compounds of silicon, calculated as SiO2, generally in coverall amounts of from 20 to 99.9% by weight, preferably 30 to 99.9% by weight, particularly preferably 40 to 99.9% by weight.
Particular preference is given to catalysts with the active compounds Cu, Co, Ni and/or Pd, in particular Cu, Co and/or Ni. These can be used as unsupported catalysts or as supported catalysts.
Very particular preference is given to Cu-containing catalysts which, as has been recognized according to the invention, are more selective because of their comparatively low ethane and methane formation.
Examples thereof are copper alloys, metallic copper, e.g. in the form of copper gauze, and Cu catalysts with a Cu content of from 2 to 70% by weight of Cu, calculated as CuO, on a support, preferably with 10 to 55% by weight of Cu, calculated as CuO, on a support. Preferred support materials may be aluminum oxide (Al2O3), zirconium dioxide (ZrO2), titanium dioxide (TiO2), carbon and/or oxygen-containing compounds of silicon.
For example, catalysts disclosed in EP-A-382 049 whose catalytically active mass prior to treatment with hydrogen comprises
20 to 85% by weight, preferably 70 to 80% by weight, of ZrO2, 1 to 30% by weight, preferably 1 to 10% by weight, of CuO, and in each case 1 to 40% by weight, preferably 5 to 20% by weight, of CoO and NiO, for example the catalysts described in loc. cit. on page 6 and having the composition 76% by weight of Zr, calculated as ZrO2, 4% by weight of Cu, calculated as CuO, 10% by weight of Co, calculated as CoO, and 10% by weight of Ni, calculated as NiO, can be used in the process according to the invention.
In addition, the catalysts disclosed in EP-A-963 975 whose catalytically active mass prior to treatment with hydrogen comprises
22 to 40% by weight of ZrO2,
1 to 30% by weight of oxygen-containing compounds of copper, calculated as CuO,
15 to 50% by weight of oxygen-containing compounds of nickel, calculated as NiO, where the Ni:Cu molar ratio is greater than 1,
15 to 50% by weight of oxygen-containing compounds of cobalt, calculated as CoO,
0 to 10% by weight of oxygen-containing compounds of aluminum and/or manganese, calculated as Al2O3 or MnO2, respectively, and does not comprise oxygen-containing compounds of molybdenum, for example catalyst A disclosed in loc. cit., page 17, and having the composition 33% by weight of Zr, calculated as ZrO2, 28% by weight of Ni, calculated as NiO, 11% by weight of Cu, calculated as CuO and 28% by weight of Co, calculated as CoO, can be used in the process according to the invention.
In addition, catalysts disclosed in EP-A-514 692 whose catalytically active mass prior to treatment with hydrogen comprises 5 to 100% by weight of an oxide of copper and nickel in the atomic ratio from 1:1 to 10:1, preferably from 2:1 to 5:1, and zirconium oxide and/or aluminum oxide, in particular the catalysts disclosed in loc. cit. on page 3, lines 20 to 30, whose catalytically active mass prior to treatment with hydrogen comprises 20 to 80% by weight, particularly 40 to 70% by weight, of Al2O3 and/or ZrO2, 1 to 30% by weight of CuO, 1 to 30% by weight of NiO and 1 to 30% by weight of CoO, can be used in the process according to the invention.
Preferably, catalysts disclosed in DE-A-19 53 263 and comprising cobalt, nickel and copper and aluminum oxide and/or silicon dioxide with a metal content of from 5 to 80% by weight, in particular 10 to 30% by weight, based on the overall catalyst, where the catalysts comprise, calculated on the metal content, 70 to 95% by weight of a mixture of cobalt and nickel and 5 to 30% by weight of copper, and where the weight ratio of cobalt to nickel is 4:1 to 1:4, in particular 2:1 to 1:2,
the catalysts disclosed in EP-A-696 572 whose catalytically active mass prior to reduction with hydrogen comprises 20 to 85% by weight of ZrO2, 1 to 30% by weight of oxygen-containing compounds of copper, calculated as CuO, 30 to 70% by weight of oxygen-containing compounds of nickel, calculated as NiO, 0.1 to 5% by weight of oxygen-containing compounds of molybdenum, calculated as MoO3, and 0 to 10% by weight of oxygen-containing compounds of aluminum and/or manganese, calculated as Al2O3 or MnO2, respectively, for example the catalyst disclosed in loc. cit., page 8, having the composition 31.5% by weight of ZrO2, 50% by weight of NiO, 17% by weight of CuO and 1.5% by weight of MoO3,
the catalysts disclosed in EP-A-284 919 and of the formula MxMgy(SiO2).nH2O, in which M is a divalent, reducible metal atom from the group consisting of Cu, Fe, Co and Ni, x and y are numbers which together can reach the value 1.5, and n, after drying and expressed in % by weight, is between 0 and 80, for example the catalyst described in loc. cit. in the example, comprising 35% CuO, 9% MgO and 38% SiO2, and the catalyst described in EP-A-863 140 on page 3, comprising 45 to 47% by weight of CuO, magnesium silicate from about 15 to 17% by weight of MgO and 35 to 36% by weight of SiO2, approximately 0.9% by weight of Cr2O3, approximately 1% by weight of BaO and approximately 0.6% by weight of ZnO,
the catalysts disclosed in DE-A-24 45 303 which are obtainable by heat-treating a basic copper- and aluminum-containing carbonate of the composition CumAl6(CO3)0.5mO3(OH)m+12, where m is any value, including fractions, between 2 and 6, at a temperature of from 350 to 700xc2x0 C., for example the copper-containing precipitation catalyst disclosed in loc. cit., Example 1, which is prepared by treating a solution of copper nitrate and aluminum nitrate with sodium bicarbonate and subsequently washing, drying and heat-treating the precipitate, and
the supported catalysts disclosed in WO 95/32171 and EP-A-816 350, comprising 5 to 50% by weight, preferably 15 to 40% by weight, of copper, calculated as CuO, 50 to 95% by weight, preferably 60 to 85% by weight, of silicon, calculated as SiO2, 0 to 20% by weight of magnesium, calculated as MgO, 0 to 5% by weight of barium, calculated as BaO, 0 to 5% by weight of zinc, calculated as ZnO, and 0 to 5% by weight of chromium, calculated as Cr2O3, in each case based on the total weight of the calcined catalyst, for example the catalyst disclosed in EP-A-816 350, page 5, comprising 30% by weight of CuO and 70% by weight of SiO2, can be used according to the invention.
The hydrogenation or dehydrogenation catalysts used as transalkylation catalyst in the process according to the invention can be prepared by processes described in the prior art, and some of them can also be obtained commercially.
In the case of the preparation of supported catalysts, no limitations of any kind exist with regard to the method of applying the active components, such as, for example, nickel, cobalt and/or copper and optionally further components, to the support material used.
Particularly suitable application methods are impregnation and precipitation, e.g. as described in the earlier German application No. 10041676.4 from Aug. 24, 2000, pages 26-28.
Variant b)
In a preferred embodiment, following the reaction of the 1,3-butadiene-containing mixture with the primary and/or secondary amine under hydroaminating conditions, the resulting hydroamination product(s) is/are reacted in a second process stage under transalkylating and hydrogenating conditions.
If the reaction in the second process stage is carried out under transalkylating and simultaneous hydrogenating conditions, in particular in the presence of hydrogen and a transalkylating hydrogenation or dehydrogenation catalyst, the n-butenylamines present in the hydroamination discharge from the first process stage and optionally further unsaturated organic nitrogen compounds, i.e. organic nitrogen compounds which either have an olefinic Cxe2x95x90C double bond (e.g. as in enamines) or are imines, can be hydrogenated to the correspondingly saturated n-butylamines.
Preferred transalkylating hydrogenation or dehydrogenation catalysts here are the same hydrogenation and dehydrogenation catalysts as have already been described above for variant a).
The hydroamination discharge from the first process stage comprises e.g., in addition to the n-butenyl function in the n-butenylamines, further unsaturated functions if the amine used in the first process stage was a correspondingly unsaturated amine. Imines can arise as a result of double-bond isomerization or as a result of xcex2-elimination from metal alkylamides.
Examples of such unsaturated amines having an olefinic Cxe2x95x90C double bond are: allylamine, 1-amino-2-butene, 1-amino-3-butene, 1-amino-4-pentene.
To carry out the second process stage in the presence of the hydrogenation or dehydrogenation catalyst (variant a) and b)), a preferred procedure involves passing the product or product mixture from the first reaction stage (hydroamination stage), or the n-butenylamine or enriched n-butenylamine originating from the work-up of the first process stage (hydroamination stage) continuously over the transalkylation catalyst, or transalkylating and optionally hydrating it batchwise.
In the case of a continuous procedure, the transalkylation catalyst is incorporated into a tubular reactor or tube-bundle reactor.
In the case of a transalkylating dehydrogenation/hydrogenation reactor and the procedure in the presence of H2 (variant b), the catalyst can, if desired, be reduced beforehand with hydrogen, although it can also be introduced directly in the presence of the product and hydrogen.
The hydrogen pressure (variant b) can be chosen between 0 bar and 300 bar, preferably between 1 and 250 bar.
For a reaction in the gas phase, the pressure is generally 1 to 70 bar.
For a reaction in the liquid phase, the pressure is generally 70 to 250 bar.
The temperature (variant a and b) is generally 80 to 400xc2x0 C, in particular between 100 and 350xc2x0 C., preferably between 120 and 250xc2x0 C., very particularly preferably between 150 and 230xc2x0 C.
Depending on the temperature chosen, a thermodynamic equilibrium of the n-butenylamines or n-butylamines, according to the process, plus, possibly, ammonia is established which is dependent on the ratio of nitrogen to the butyl or butenyl groups. The more sterically demanding the amines, the lower the proportion of the corresponding tertiary n-butenylamine or n-butylamine.
The space velocity of starting material over the catalyst can be between 0.05 and 2 kg of starting material per liter of catalyst and per hour (kg/l*h), preferably between 0.1 and 1 kg/l*h, particularly preferably between 0.2 and 0.6 kg/l*h.
The molar ratio of the n-butenylamines or n-butylamines (the xe2x80x9ctransalkylation reagentsxe2x80x9d) can vary within wide ranges depending on the desired product mix.
In the case of a batchwise transalkylation, the catalyst can be introduced together with the starting material for the second process stage, and the desired amount of transalkylation reactant can be added thereto or replenished. The mixture is then heated to the desired temperature (see above).
Following decompression, the discharge can be worked up by customary methods, e.g. distilled.
In a particular process embodiment, the product mixture obtained in the second process stage (transalkylation and hydrogenation) is separated into (a) product(s) which is/are returned to the first process stage (hydroamination), and/or (a) product(s) which is/are returned to the second process stage (transalkylation and hydrogenation), and the desired n-butylamine(s).
According to the invention, it is also possible to prepare n-butylamines by firstly preparing n-butenylamines as already described by reacting 1,3-butadiene in the form of a 1,3-butadiene-containing mixture obtained during the cracking of petroleum fractions or during the dehydrogenation of LPG or LNG or from GTL technology with a primary amine and/or a secondary amine under hydroaminating conditions and subsequently reacting the resulting hydroamination product(s) in a second process stage under transalkylating conditions, and reacting said n-butenylamines in a further process stage under hydrogenating conditions.
This further process stage under hydrogenating conditions can be carried out e.g. as already described above by corresponding reaction of the n-butenylamine(s) in the presence of a hydrogenation or dehydrogenation catalyst and hydrogen.
The radicals R1 to R5 in the formulae II and III are, independently of one another:
R1, R3, R4:
hydrogen (H),
R1, R2, R4, R5:
alkyl, in particular C1- to C20-alkyl, preferably C1- to C12-alkyl, particularly preferably C1- to C8-alkyl, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, isohexyl, n-heptyl, isoheptyl, n-octyl and isooctyl,
alkenyl, in particular C2- to C20-alkenyl, preferably C2- to C12-alkenyl, particularly preferably C2- to C8-alkenyl, such as vinyl and allyl,
cycloalkyl, in particular C3- to C20-cycloalkyl, preferably C3- to C12-cycloalkyl, particularly preferably C5- to C8-cycloalkyl, such as cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl,
alkoxyalkyl, in particular C2-30-alkoxyalkyl, preferably C2-20-alkoxyalkyl, particularly preferably C2-8-alkoxyalkyl, such as methoxymethyl, ethoxymethyl, n-propoxymethyl, isopropoxymethyl, n-butoxymethyl, isobutoxymethyl, sec-butoxymethyl, tert-butoxymethyl, 1-methoxyethyl and 2-methoxyethyl, particularly preferably C2- to C4-alkoxyalkyl,
aminoalkyl, in particular C1-20-aminoalkyl, preferably C1-8-aminoalkyl, such as aminomethyl, 2-aminoethyl, 2-amino-1,1-dimethylethyl, 2-amino-n-propyl, 3-amino-n-propyl, 4-amino-n-butyl, 5-amino-n-pentyl, N-(2-aminoethyl)-2-aminoethyl and N-(2-aminoethyl)aminomethyl,
monoalkylaminoalkyl, in particular C2-30-monoalkylaminoalkyl, preferably C2-20-monoalkylaminoalkyl, particularly preferably C2-8-monoalkylaminoalkyl, such as methylaminomethyl, 2-methylaminoethyl, ethylaminomethyl, 2-ethylaminoethyl and 2-isopropylaminoethyl,
dialkylaminoalkyl, in particular C3-30-dialkylaminoalkyl, preferably C3-20-dialkylaminoalkyl, particularly preferably C3-10-dialkylaminoalkyl, such as N,N-dimethylaminomethyl, (N,N-dibutylamino)methyl, 2-(N,N-dimethylamino)ethyl, 2-(N,N-diethylamino)ethyl, 2-(N,N-dibutylamino)ethyl, 2-(N,N-di-n-propylamino)ethyl and 2-(N,N-diisopropylamino)ethyl,
aryl, such as phenyl, 1-naphthyl and 2-naphthyl, preferably phenyl,
aralkyl, in particular C7- to C20-aralkyl, preferably C7- to C20-aralkyl, preferably C7- to C12-phenalkyl, such as phenylmethyl, 1-phenylethyl, 2-phenylethyl,
R1 and R2, R4 and R5:
together are a saturated or unsaturated C3- to C9-alkylene chain which may be interrupted by an O, S or N heteroatom, such as e.g. xe2x80x94(CH2)3xe2x80x94, xe2x80x94(CH2)4xe2x80x94, xe2x80x94(CH2)5xe2x80x94, xe2x80x94(CH2)6xe2x80x94, xe2x80x94(CH2)7xe2x80x94 and xe2x80x94CHxe2x95x90CHxe2x80x94CHxe2x95x90CHxe2x80x94,
together are in particular a xe2x80x94(CH2)jxe2x80x94Xxe2x80x94(CH2)k group, where j and k, independently of one another, =1, 2, 3 or 4 and X=CH2, CHR3, oxygen (O), sulfur (S) or NR3,
where R3=H or C1- to C4-alkyl, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl,
such as e.g. xe2x80x94(CH2)2xe2x80x94NHxe2x80x94(CH2)2xe2x80x94, xe2x80x94(CH2)2xe2x80x94NCH3xe2x80x94(CH2)2xe2x80x94, xe2x80x94(CH2)2xe2x80x94Oxe2x80x94(CH2)2xe2x80x94.


The invention relates to a system and a method for training a number of neural networks, by determining a first training data record, wherein the training data have a particular accuracy, generating a number of second data training records by perturbing the first training data record with a random variable, and training each of the neural networks with one of the training data records. A prognosis and an estimation of the prognosis error can be carried out by means of such a system.

The invention relates to a method for training neural networks, to a method for prognosis by means of neural networks and to a system for determining a prognosis value and its error.
A large number of possible applications for neural networks are known from the prior art. Neural networks are used for data-driven modelling, for example for physical, biological, chemical and technical processes and systems, cf. Babel W.: Possible uses of neural networks in industry: pattern recognition with the aid of supervised learning methods—with examples from traffic and medical technology, Expert Verlag, Renningen-Malmsheim, 1997. In particular, the fields in which neural networks can be used include process optimization, image processing, pattern recognition, robot control and medical technology.
Before a neural network can be used for the purposes of prognosis or optimization, it has to be trained. The weightings of the neurons are in this case usually adjusted by an iterative method with the aid of training data, cf. Bärmann F.: Process modelling: modelling of continuous systems with neural networks, the NN-tool Internet site, www.baermann.de and Bärmann F.: Neural networks. Lecture text. Technical College of Gelsenkirchen, School of Physical Technology, Department of Neuro-Information Technology, 1998.
DE 195 31 967 discloses a method for training a neural network with the nondeterministic behaviour of a technical system. The neural network is in this case incorporated into a control loop so that, as it is output quantity, the neural network outputs a manipulated variable to the technical system and the technical system generates, from the manipulated variable delivered by the neural network, controlled variable which is delivered to the neural network as an input quantity. Noise with a known noise distribution is superimposed on the controlled variable before it is delivered to the technical system.
Other methods for training neural networks are known from DE 692 28 412 T2 and DE 198 38 654 C1.
A method for estimating the prognosis error is known from EP 0 762 245 B1. Here, a plurality of neural networks having different training parameters (e.g. different initialisation) are trained with the original data. The prognosis error is obtained by comparing the discrepancies of the prognosed quantities. A disadvantage of this method is that the estimation of the prognosis error is not influenced by information about the measurement accuracy of the measurement data used for the training.
A method for estimating the reliability of a prognosis output by a neural network is furthermore known from the prior art: Protzel P., Kindermann L., Tagscherer M., Lewandowski A.: "Estimation of the reliability of neural network prognoses in process optimization", VDI Report No. 1526, 2000.


A high efficiency laminar flow burner system for proving a stream of heat energy including a supply input module for providing fuel and laminar streams of air to a combustion manifold. The combustion manifold includes an air-fuel mixing system, a stoichiometric unit, and a refractory unit each coupled to one another. A first combustion stream is established at the air-fuel mixing chamber system as fuel exits an injector device at direction perpendicular to the laminar air intake stream. A laminar air intake stream traveling from the supply input module and along the staging passageway passes through a stoichiometric unit body at a plurality of air intakes to meet with the first combustion stream within to define a second combustion stream for introduction from the stoichiometric unit to the refractory unit. The refractory unit thus defines a third combustion stream as the second combustion stream travels across a refractory passageway.

1. Field of the Invention
The present invention generally relates to combustion systems for enhancing efficiency as streams of laminar air and fuel mix. More particularly, but not by way of limitation, the present invention relates to a combustion system for generating an optimized combustion stream by directing a stream of preconditioned laminar air mixed with a fuel through a combination of stoichiometric combustion staging arrangements and refractory units.
2. Description of Related Art
The general concept of low nitrogen-oxide (NOx) burners is to produce a flame that provides heat energy though a high efficiency combustion process with minimal waste products arising from the combustion, namely oxides of nitrogen of which form the basis for environmental pollution such as acid rain and smog. The resulting heat energy is used in a variety of industrial applications such as for boilers in energy generation; for furnaces employed in applications requiring high heat such as smelting metals, distilling chemicals, petrochemicals and gas; paper manufacturing; and for flaring oil and gas wells. Similarly, such "high efficiency" burners seek to minimize a combination of other combustion waste products in addition to NOx such as oxides of carbon (COx) and total hydrocarbons (THC) among others to comply with federal and international governmental requirements especially for global warming prevention as well as to conserve natural resources by maximizing the burn efficiency of the requisite raw materials for combustion.
Presently, many high efficiency burners require various swirling techniques to maximize the efficiency of a high efficiency burner. Swirling is a widely used mixing process for homogenizing an air fuel mixture in the combustion process by which atomized fuel is introduced into a turbulent stream of air. However, various swirling techniques are often non-uniformly applied across the entire combustion chamber. Detrimentally, fuel and air can become drawn apart from the air fuel mixture to thereby compromise combustion efficiency as well as to spread waste fuel throughout the combustion chamber which requires routinely taking the high efficiency burner out of commercial operation to perform preventative maintenance for structural damage. Moreover, turbulent or swirled air provides an aerodynamic drag-effect that generally interrupts the rate at which air is initially supplied to a combustion chamber, and therefore consequently decreasing the operational efficiency of the burner. Furthermore, costly and often bulky low-waste emissions monitoring equipment are integrated with effluent towers of current high efficiency burner systems to ensure operational efficiency. Additional costs incur as emissions monitoring equipment shorten the operational time of such burners to ensure overall operation within low-waste emission requirements.
Unfortunately, there is no known device or method for successfully providing a "high efficiency" combustion system for leaving negligible waste products for sustained use with industrial applications without use of swirling techniques or derivations of swirling techniques. Therefore, a need exists for a system and method for generating an optimized combustion stream by directing a stream of preconditioned laminar air with a fuel through a combination of stoichiometric combustion staging arrangements and refractory units. There is also a need for a system and method for quickly and accurately increasing combustion efficiency for a various applications through linking a series of interchangeable reaction efficiency modules to the system. Many other problems and disadvantages of the prior art will become apparent to one skilled in the art after comparing such prior art with the present invention as herein described.


A compensated control circuit includes a combination module that generates a control variable based on n signals and a process module that generates an output signal based on an input signal and the control variable wherein n is a positive integer.

The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Referring now to FIG. 1, an amplifier 10 includes a first module 12 that can be characterized by a first transfer function z=f1(x), where x is an independent variable such as frequency, current, voltage, and the like, and z is an output signal. The amplifier 10 includes a second module 14 that can be characterized by a second transfer function y=f2(z), where y is a dependent variable such as frequency, current, voltage, and the like. At least one of the first function f1 and the second function f2 may be non-linear and/or dependent on a third independent variable, such as time, temperature, and the like. Therefore, it can be challenging to calibrate or otherwise predict an overall total transfer function y=f(x) of amplifier 10 as the third variable changes.
Referring now to FIG. 2A, a programmable gain amplifier 20 is shown that behaves in accordance with generic amplifier 10 of FIG. 1. A programmable current source 22 corresponds to first module 12 and generates a programming current Igm based on an input signal Vcontrol. A differential amplifier 24 corresponds to second module 14 and has a gain A=vout/vin that is based on the programming current Igm. FIG. 2B shows a functional block diagram of programmable gain amplifier 20.
Referring now to FIG. 2C, a first plot 30 shows an unscaled characteristic curve of programmable current source 22 and a second plot 32 shows an unscaled characteristic curve of differential amplifier 24. First plot 30 shows that if all other variables are held constant, then the programming current Igm is more sensitive to temperature changes at higher temperatures T than at lower temperatures T. Second plot 32 shows that if all other variables are held constant, then the gain A is more sensitive to temperature changes at lower temperatures than at higher temperatures. The opposite characteristics of these temperature sensitivities can make it challenging to control the gain of amplifier 20 as its temperature varies.


The present invention relates to use of a transglutaminase in the preparation of a medicament for inhibiting angiogenesis. Preferably, the transglutaminase is a human tissue transglutaminase. Advantageously, the medicament is for treating cancer, rheumatoid arthritis, retinopathy and/or psoriasis. Additionally, the invention relates to compositions comprising a transglutaminase in an amount sufficient to inhibit angiogenesis.

Angiogenesis, the sprouting and development of new blood vessels from pre-existing ones, is a fundamental process that occurs in embryonic development and tissue remodelling (Folkman, J., 1995, Nat. Med. 1, 27-31). The development of the neovasculature requires the proliferation and migration of endothelial cells, and their interaction with other cell types including fibroblasts and pericytes to form complex three-dimensional cord-like structure that contain endothelial monolayers surrounding the lumen of the vessel (Risau, W., 1997, Nature 386, 671-674). The mechanisms controlling angiogenesis are not completely understood, but it is likely that the progression and development of new blood vessels is regulated at multiple control sites, and involves growth factors (Meyer, M et al, 1999, EMBO J. 18, 363-374), proteases (Kubota, Y., et al., 1988, J. Cell Biol. 107, 1589-1598), the extracellular matrix (Preissner, K. T., et al., 1997, Thromb. Haemost. 78, 88-95), and the expression of cell-surface receptors (Bazzoni, G., et al., 1999, Curr. Opin. Cell Biol. 11, 573-581). The identification of factors that regulate and control angiogenesis is of increasing clinical importance since inappropriate or insufficient angiogenesis is central to a number of pathological conditions, including the development of solid tumours, rheumatoid arthritis and psoriasis (Folkman, J., 1995, Nat. Med. 1, 27-31).
The search for molecules that modulate angiogenesis is of emerging clinical importance, particularly with respect to solid tumor therapy. Specific inhibition of angiogenesis has the potential to revolutionise cancer therapy, by starving tumours of their blood supply (O'Reilly, M. S., et al., 1997, Cell 88, 227-285), and this approach to cancer therapy led to the discovery of the anti-angiogenic peptides endostatin (O'Reilly, M. S., et at., 1997, Cell 88, 227-285) and angiostatin (O'Reilly, M. S., et al., 1996, Nat. Med. 2, 689). Modulation of angiogenesis also presents the possibility of new treatments for other pathological conditions that rely on vascular remodelling.
Transglutaminases are an important class of protein crosslinking enzymes that catalyze protein aggregation reactions in blood coagulation (Greenberg, C. S., et al., 1991, FASEB J. 5, 3071-3077), skin maturation Thacher, S. M. & Rice, R. H., 1985, Cell 40, 685-695) and the clotting of seminal secretions (Dubbink, H. J., et al., 1999, Lab. Invest. 79, 141-150). The most widespread member of the family is the cellular form of the enzyme, tissue transglutaminase (tTGase), which is expressed in varying amounts in many cell types. Like the well-characterized plasma TGase (blood coagulation factor XIIIa) (Greenberg, C. S., et al., 1991, FASEB J. 5, 3071-3077) and keratinocyte TGase (Thacher, S. M. & Rice, R. H., 1985, Cell 40, 685-695), tTGases are calcium-dependent enzymes that catalyze the formation of crosslinks proteins via ε(γ-glutamyl) isopeptide bonds and the incorporation of polyamines at certain glutamine residues (Greenberg, C. S., et al., 1991, FASEB J. 5, 3071-3077).
However, tTGase is unique in the transglutaminase family of enzymes in that is able to bind and hydrolyze GTP and ATP (Achyuthan, K. B. & Greenberg, C. S., 1987, J. Biol. Chem. 262, 1901-1906), and to bind to fibronectin (Achyuthan, K. E., et al., 1995, J. Immunol. Methods 180, 67-79). The enzyme is predominantly located in the cytosol, although tTGase has also been reported to exist in the nucleus (Lesort, M., et al., 1998, J. Biol. Chem. 273, 11991-11994), at the cell surface and in the extracellular matrix (Martinez, J., et al., 1994, Biochemistry 33, 2538-2545). Tissue TGase is highly expressed in endothelial cells (Greenberg, C. S., et al., 1987, Blood 20, 702-709) and its activity at the surface of such cells is thought to enhance basement membrane stabilisation, cell spreading and cell adhesion (Martinez, J., et al., 1994, Biochemistry 33, 2538-2545, Greenberg, C. S., et al., 1987, Blood 20, 702-709, Kinsella, M. G. & Wight, T. N., 1990, J. Biol. Chem. 265, 17891-17896, Jones, R. A., et al., 1997, J. Cell Sci. 110, 2461-2472, Gaudry C. A., et al., 1999, Exp. Cell Res. 252, 104-113). However, the overall significance of the high amount of enzyme in this cell type and its biological function is poorly understood.
Antisense studies in the endothelial-like cell line ECV304 have demonstrated that tTGase-deficient cells exhibit severely impaired cell adhesion (Jones, R. A., et al., 1997, J. Cell Sci. 110, 2461-2472), and ECV304 cells transfected with a chimeric form of the enzyme that contains a Protein kinase Cε-epitope tag show strong tTGase staining at cell adhesion sites that co-distribute with the β1-integrin (Gaudry C. A., et al., 1999, Exp. Cell Res. 252, 104-113).
Recently, a study by Haroon et al (Haroon, Z. A., et al., 1999, FASEB J. 13, 1787-1795) has demonstrated that tTGase is expressed and active in rat dermal wound healing and angiogenesis. By examining biopsy punch wounds throughout the healing process, tTGase antigen and activity were observed at sites of neovascularisation and in the provision of fibrin matrix in the wound bed 24 hours after injury. Tissue TGase antigen levels increased four- to five-fold at three days after wounding and were ultimately degraded. In this study, it was also found that endothelial cells, macrophages and skeletal muscle cells express tTGase and that the addition of exogenous recombinant tTGase led to an increase in vessel length density.
On the basis of studies such as those by Haroon et al, which highlight a role of TGase in promoting angiogenesis, skilled persons have sought TGase inhibitors as therapeutic agents for inhibiting angiogenesis.

Transglutaminase for inhibiting angiogenesis


A practical orbit raising method and system wherein a satellite quickly escapes the Van Allen radiation belts and payload mass and mission life are maximized. A satellite is launched that contains high thrust chemical propulsion thrusters, high specific impulse electric propulsion thrusters and a solar array. The satellite quickly escapes the Van Allen radiation belts by firing the high thrust chemical propulsion thrusters at apogees of intermediate orbits, starting from the transfer orbit initiated by a launch vehicle, to successively raise the perigees until the perigee clears the Van Allen radiation belts. The payload mass and mission life are maximized by firing high specific impulse electric propulsion thrusters to raise the satellite to near synchronous orbit, while steering the thrust vector and solar array to maintain the sun's illumination on the solar array. The chemical and/or electric propulsion thrusters are then fired to achieve geosynchronous orbit.

The present invention relates generally to satellites, and more particularly, to systems and methods that raise the orbit of a satellite to geosynchronous orbit.
The assignee of the present invention manufactures and deploys spacecraft that orbit the earth. For satellites that are placed in geosynchronous orbit, the Van Allen radiation belts pose hazards for the satellite caused by radiation, and the like.
U.S. Pat. No. 5,595,360 entitled "Optimal Transfer Orbit Trajectory Using Electric Propulsion" addresses orbit raising maneuvers of satellites. Such prior art orbit raising techniques limit orbit maneuvers in terms of location and attitude to achieve and maintain the orbital semi-major axis near the geosynchronous value so that the satellite can be continuously observed from a single ground station. U.S. Pat. No. 5,716,029 entitled "Constant Sun Angle Transfer Orbit Sequence and Method Using Electric Propulsion" discloses a technique that adjusts the inertial attitude periodically while maintaining a fixed direction of electric propulsion thrust firing throughout each orbit. Prior art techniques also do not steer the thrust vector while also steering the satellite's attitude during the orbit to maintain the sun's illumination on the solar arrays of the satellite during orbit raising maneuvers. Steering the thrust vector maximizes efficiency of the delivered thrust thus minimizing fuel and time to achieve the desired final orbit.
Therefore, it would be advantageous to have improved systems and methods that raise the orbit of a satellite to geosynchronous orbit. It would also be advantageous to have improved systems and methods to minimize exposure of the satellite to the hazards of the Van Allen radiation belts.

Practical orbit raising system and method for geosynchronous satellites