Calcium oxide sorbent process for bulk separation of carbon dioxide. Quarterly progress report 20, April 1994--June 1994

摘要

This research project is investigating the technical feasibility of a high-temperature, high-pressure (HTHP) process for the bulk separation of CO(sub 2) from coal-derived gas. The original contract for two years was awarded in September 1989 as a result of solicitation number DE-RA21-89MC26040 entitled Novel Concepts for Bulk Separation of Gases in Coal Gasification Systems. Two no-cost extensions without a change in the statement of work extended the performance period by six months to March 1992. At that time a two-year contract extension with an enlarged scope of work and additional funding was approved so that the research was re-scheduled to end in March 1994. A third no-cost extension for seven months was approved during the previous quarter so that the project completion date is now October 1994. Phase I research, in which an electrobalance reactor was used to establish the technical feasibility of the regenerable sorbent process, was completed in March 1992 and results have been fully described in earlier quarterly reports. In Phase 1, the calcination and carbonation characteristics of three calcium sorbents were studied as a function of calcination and carbonation temperature and pressure, mol fraction CO(sub 2) in the carbonation gas, and carbonation background gas composition. Desirable reaction conditions required for high reactivity and good sorbent durability were determined. Multicycle tests consisting of as many as ten complete calcination and carbonation cycles were completed. Indirect evidence which suggested that the water-gas shift reaction occurred simultaneously with CO(sub 2) removal was found. Occurrence of the simultaneous reactions created the possibility of a direct one-step process for the manufacture of hydrogen from coal-gas while at the same time separating a concentrated stream of CO(sub 2).