Combating Global Warming—Reducing CO₂ Emissions from Coal-Fired Power Plant

Abstract

The threat of global warming is sufficient to warrant ‘least regrets’ measures to reduce emissions of greenhouse gases, in particular through increased efficiency in energy production and use. British Coal has set up a programme to contribute to the international responses to the threat. It is concentrating on investigating options for removing carbon dioxide from fossil-fuelled power plants in case expensive fallback options become necessary. Screening of the options commenced with flowsheeting studies which estimated the thermal efficiency of a number of process schemes. These screening studies concluded that carbon dioxide (CO2) control could be retrofitted to existing coal-fired power stations, but that the new generation of gasification-based systems is more promising. CO2 separation could be more easily integrated into advanced power plants as they operate at high pressure, resulting in increased CO2 partial pressure which reduces the energy penalty associated with the separation. The CO2 would need to be exported as a liquid stream for storage in exhausted oil or gas fields. Costs of such power plants and CO2 disposal options have been developed. These studies suggest that, using proven technology, the cost of electricity would rise by about 42 per cent. If novel gas separation systems based on membranes can be developed, the increase in electricity cost could be limited to around 34 per cent. This paper discusses the options and presents the results of costing studies.

Materials for separation membranes in hydrogen and oxygen production and future power generation

“…CO 2 sequestration is a critical stage for ensuring a net ecological advantage in utilising hydrogen as a fuel. Without carbon sequestration, hydrogen generation from fossil fuels will do little to abate global CO 2 emissions, which have been established as a significant contributor to global warming [11]. By separating or capturing CO 2 in a concentrated form, it can then be compressed and transported before being stored indefinitely in geological formations, the ocean, as mineral carbonates or being used in industrial processes [12,13].…”

Critical Assessment 4: Challenges in developing high temperature materials

“…The ‘least-regret’ strategy 1 of using high efficiency systems for addressing green house gas emissions also appears to be one of the least expensive strategies. In the USA, fossil fuels will likely continue to generate >70 of electricity and >90 of transportation for the next two decades.…”