Sorption-enhanced hydrogen production for pre-combustion CO_2 capture

摘要

Sorption-enhanced steam reforming of methane is a process, in which steam reforming reaction is carried out in the presence of a CO2 sorbent. The removal of CO2 from the reaction zone shifts the equilibrium to the product side and makes it possible to perform the reaction at much lower temperatures. In an experiment using potassium carbonate promoted hydrotalcite as CO2 adsorbent in combination with a steam reforming catalyst, it was shown that the average methane conversion over a adsorption cycle was more than 95%. Subsequently, the sorbent was regenerated with steam and this was repeated for 500 cycles without deterioration of the performance. Systems analysis shows that efficiency penalties can be as low as 5.5 percent point, provided that steam used in the regeneration step is kept low.