IS NUCLEAR POWER ALSO THE KEY TO ECONOMICALLY CLEAN COAL GASIFICATION?

摘要

Reducing the amount of carbon dioxide emitted to the atmosphere is a major goal and an imperative need for most of the world's nations, even for those nations such as the USA who are not Kyoto Treaty signatories. A response by the current USA administration is to develop a national transportation economy for automobiles based upon efficient, environmentally sound fuel cells. However, hydrogen is a secondary fuel requiring a primary energy source for production. Nuclear power (or renewables such as hydroelectric, wind or solar) must be the source of the primary energy required to produce hydrogen from water, if the overall energy system is to be free of carbon dioxide emissions to the atmosphere. The dissociation of water leaves oxygen as a major byproduct. Currently, there are no existing commercial markets for the large quantities of oxygen that would result from a US transportation economy based upon hydrogen fuel cells. However, Integrated Coal Gasification Combined Cycle (IGCC) power plants operating on pure oxygen for both gasification and combustion produce no greenhouse gas releases. This highly desirable feature results from the combustion output being only water and carbon dioxide. Pure CO_2 can be relatively easily captured and delivered to a sequestration site. Also, hazardous trace metal compounds (e.g., Hg, As, Pb, Sn, Sb, Se, U, Th, etc.) that would ordinarily be emitted to the atmosphere could be captured as solids, for environmentally acceptable disposal.