and the gases are again passed through the final absorption column thus achieving not only high conversion efficiency for SO2, but also enabling production of a higher concentration of sulfuric acid. The industrial production of sulfuric acid involves proper control of temperatures and flow rates of the gases as both the conversion efficiency and absorption are dependent on these. See also Lead chamber process Notes References The Repertory of Patent Inventions, no. 72 (April 1831), page 248. (Anon.) (1832) "English patents: Specification of the patent granted to Peregrine Phillips, Jr. of Bristol, in the county of Somersetshire, Vinegar Maker, for an improvement in manufacturing Sulphuric Acid. Dated March 21, 1831." Journal of the Franklin Institute, new series, vol. 9, pages 180-182. Ernest Cook (March 20, 1926) "Peregrine Phillips, the inventor of the contact process for sulphuric acid," Nature, 117 (2942) : 419–421. Lunge, Theoretical and Practical Treatise on the Manufacture of Sulphuric Acid and Alkali, with the Collateral Branches, 3rd ed., vol. 1, part 2 (London, England: Gurney and Jackson, 1903), page 975 External links Chemical processes Vanadium Sulfur Catalysis