Advanced Hydrogen Transport Membranes for Vision 21 Fossil Fuel Plants

Hydrogen from coal gasification: An economical pathway to a sustainable energy future

“…Although initially thought to be promising, these membranes have been found to be susceptible to degradation from the presence of both sulfur and CO. However, Eltron Research has recently reported metal alloys that have shown very high hydrogen fluxes at temperatures around 400 8C (Roark et al, 2002). In fact, the performance of the material at this stage of development rivals that of the ORNL K25 membrane.…”

Calcium Looping Process for Enhanced Catalytic Hydrogen Production with Integrated Carbon Dioxide and Sulfur Capture

“…However, ceramic membranes have a very low H 2 permeability, and the intermediate temperature composites in spite of having a high H 2 flux are difficult to fabricate and are very susceptible to poisoning. The cermet membranes are superior to the other two classes of membranes, but again they are susceptible to poisoning and are expensive . Ma and Lund have reported the investigation of a Pd membrane reactor system packed with HTS catalyst .…”

“…These reactors also suffer from inhibition effects of CO 2 , which reduces the yield of H 2 from 90% to 50% . In addition, membranes cannot completely remove H 2 from the mixture and suffer from a considerable pressure drop across them . Any remaining H 2 in the main stream would dilute the CO 2 and would lead to poor process economics.…”

“…The cermet membranes are superior to the other two classes of membranes, but again they are susceptible to poisoning and are expensive. 9 Ma and Lund have reported the investigation of a Pd membrane reactor system packed with HTS catalyst. 10 For optimum performance these reactors require two stages and an S:C ratio of 3.…”

“…10 membranes cannot completely remove H 2 from the mixture and suffer from a considerable pressure drop across them. 9 Any remaining H 2 in the main stream would dilute the CO 2 and would lead to poor process economics. High temperature CO 2 membranes have been developed which operate in the same temperature range as that of the water gas shift reaction.…”