acid rain, and particulates which cause visible air pollution and have deleterious effects on human health. Technology Several different technological methods are available for the purpose of carbon capture as demanded by the clean coal concept: Pre-combustion capture – This involves gasification of a feedstock (such as coal) to form synthesis gas, which may be shifted to produce a and -rich gas mixture, from which the can be efficiently captured and separated, transported, and ultimately sequestered, This technology is usually associated with Integrated Gasification Combined Cycle process configurations. Post-combustion capture – This refers to capture of from exhaust gases of combustion processes. Oxy-fuel combustion – Fossil fuels such as coal are burned in a mixture of recirculated flue gas and oxygen, rather than in air, which largely eliminates nitrogen from the flue gas enabling efficient, low-cost capture. The Kemper County IGCC Project, a proposed 582 MW coal gasification-based power plant, was expected to use pre-combustion capture of to capture 65% of the the plant produces, which would have been utilized and geologically sequestered in enhanced oil recovery operations. However, after many delays and a cost runup to $7.5 billion (triple the initial budget), the coal gasification project was abandoned and as of late 2017, Kemper is under construction as a cheaper natural gas power plant. The Saskatchewan Government's Boundary Dam Integrated Carbon Capture and Sequestration Demonstration Project will use post-combustion, amine-based scrubber technology to capture 90% of the emitted by Unit 3 of the power plant; this will be pipelined to and utilized for enhanced oil recovery in the Weyburn oil fields. An early example of a coal-based plant using (oxy-fuel) carbon-capture technology is Swedish company Vattenfall’s Schwarze Pumpe power station located in Spremberg, Germany, built by German firm Siemens, which went on-line in September 2008. The facility captures and acid rain producing pollutants, separates them, and compresses the into a liquid. Plans are to inject the into depleted natural gas fields or other geological formations. Vattenfall opines that this technology is considered not to be a final solution for reduction in the atmosphere, but provides an achievable solution in the near term while more desirable alternative solutions to power generation can be made economically practical. Other examples of oxy-combustion carbon capture are in progress. Callide Power Station has retrofitted a 30-MWth existing PC-fired power plant to operate in oxy-fuel mode; in Ciuden, Spain, Endesa has a newly built 30-MWth