Sorbent for Enhanced Water-Gas Shift

For the last 10-12 years, the development of sorption-enhanced fuel conversion has mainly focused on the further improvement of sorption-enhanced water-gas shift using hydrotalcite-based sorbents. Starting with the sorption-enhanced steam reforming work of Air Products, hydrotalcite-based materials were identified as potentially attractive sorbents for a pressure swing-based sorption-enhanced water-gas shift reactor system. 

In theFP7 CAESAR project [9], sorbent development focused on addressing these issues with the hydrotalcite-based sorbent. The objectives here were to increase the cyclic capacity, to reduce the amount of steam needed for regeneration, to increase the mechanical strength of the sorbent pellets and finally to reduce the specific sorbent cost. The key issue was to develop a HTC-based sorbent material that did not form notable amounts of MgC03 

As a result of all the improvements, the K-Mg30 sorbent had substantially lower steam consumption for the regeneration resulting in a steam/C02 ratio of 1.6 at the test conditions used. Consequently, the efficiency penalty was reduced almost 50% from 13% points (K-Mg70) to about 7.6% points (K-Mg30) for a 95% CO2 capture ratio in an NGCC [31]. 

In addition to the efforts to improve the performance of potassium-promoted hydrotalcite sorbents, new alumina-based sorbents have been screened via high throughput testing on their applicability in the SEWGS process [33], 

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