Harnessing Ammonia as a Hydrogen Carrier for Integrated CO2 Capture and Reverse Water-Gas Shift

초록

In this paper, a concept of integrated CO2 capture and reverse water-gas shift (ICCrWGS) process was proposed using NH3 as the H-2 carrier. The CO2 efficiency and total thermal energy consumption for the conventional rWGS, ICCrWGS using H-2 (H-2-ICCrWGS) and NH3 (NH3-ICCrWGS), were calculated. ICCrWGS using H-2 and NH3 was conducted over the thermally stable Ni/CaZr dual-function materials (DFMs). NH3 decomposition, CO2 capture capacity, CO2 conversion, and CO selectivity were addressed at different reaction temperatures, and the optimal temperature was determined to be 650 degrees C. The Ni/CaZr DFMs exhibited stable CO2 capture capacity and CO productivity during ICCrWGS using the NH3 carrier. A carbonate spillover mechanism for CO production over the Ni/CaZr DFMs in NH3-ICCrWGS was proposed using in situ diffuse reflectance infrared Fourier transform spectroscopy. It was found that CO is produced from the bridged bidentate carbonate route in the Ni-CaO interface.

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