(221e) Hydrogen Generation Using Fixed-Bed Adsorption-Enhanced Natural Gas Reformer

Absorption enhanced reforming (AER) process is a steam reforming process carried out in the presence of CO2 absorbers. The CO2 absorption drives the steam reforming and water-gas-shift equilibrium to achieve higher CH4 conversion at lower temperatures. Instead of conventional multi-step SMR process (including reforming and water gas shift reactors), AER needs only a single-step to achieve high H2 purity (about 95% compared to about 75% for conventional SMR). Hence, it is anticipated that this technology can be used for numerous hydrogen production applications such as fuel cell power plants, internal combustion engines, refinery and other industrial applications. In a fixed bed approach, the CO2 absorbers are utilized during reforming and need to be regenerated in a fixed interval. CO2 adsorption is exothermic and provides the heat for endothermic steam reforming reaction. Regeneration is an endothermic process and requires heat to release CO2 from the material. Also the process requires an intermediate cooling step following regeneration to efficiently absorb CO2 during reforming. Therefore, the AER process involves cycles of reforming, regeneration and an intermediate cooling step. In this paper, general operation of this cyclic process is presented with an emphasis on various methods of regenerating the bed. Experimental results are also provided along with reactor construction details. Details are also presented on the effect of regeneration process on overall system efficiency. Acknowledgement: This project which is partially funded by DOE under contract DE-FC36- 03GO13102 is acknowledged.