Zr-Modified Ni/CaO Dual Function Materials (DFMs) for Direct Methanation in an Integrated CO<sub>2</sub> Capture and Utilization Process
Seong Bin Jo, Jin Hyeok Woo, Tu Thi Phuong Nguyen, Ju Eon Kim, Ju Eon Kim, Tae Young Kim, Ho-Jung Ryu, Byungwook Hwang, Jae Chang Kim, Jae Chang Kim, Soo Chool Lee, Kandis Leslie Gilliard‐AbdulAziz
Abstract
An integrated CO 2 capture and direct methanation (ICCM) system has recently gained significant attention as a promising process to produce value-added chemicals. Compared to conventional CO 2 capture and utilization, ICCM is a simplified process that directly converts captured CO 2 without purification at lower thermal inputs. One of the primary limitations is the deactivation of the sorbent and the embedded catalysts after several thermal cycles. In this study, we formulated thermally stable macroporous structured Ni/CaO dual function materials (DFMs) by incorporating a Zr stabilizer. The textural properties, porosity, CO 2 capture performance, and catalytic activity of Zr-modified Ni/CaO (Ni/CaZr) were assessed. In situ DRIFTS was used to investigate the possible intermediates and reactions during the ICCM. It was found that CH 4 is produced from the formate and methoxy intermediates route on the CaO surface and the CO intermediate route on the Ni surface. Ni/CaZr had improved thermal stability with the best CO 2 capture capacity (13–14 mmol of CO 2 /g), CH 4 productivity (13–14 mmol of CH 4 /g), CO 2 sorption, and desorption kinetics at 500 °C. The benefit of adding Zr for ICCM enhanced the macroporous structures, which enhanced the CO 2 mass transport and prevented the sintering of Ni and CaO.