Continuous CO2 abatement via integrated carbon capture and conversion over Ni-MgO-Al2O3 dual-functional materials
Xingbo Wang, Deng Hu, Yingdong Hao, Lina Zhang, Nannan Sun, Wei Wei
Abstract
Massive emission of CO 2 is one of the main contributors to global warming, and CO 2 capture, utilization and storage (CCUS) was proposed as an indispensable option for carbon reduction. Recently, integrated carbon capture and conversion (ICCC) was regarded as a potential approach to lower the cost of CCUS, and development of efficient dual-functional materials (DFMs) is among the top priority in the area. Herein, Ni-MgO-Al 2 O 3 DFMs were prepared by calcination of Ni-impregnated Mg-Al layered double hydroxide (MgAl-LDH), as such, the pre-loaded Ni species was actively involved in the decomposition of MgAl-LDH, therefore the synergy and balance of the adsorption and catalytic functionalities for ICCC can be promoted in the resulted DFMs. The optimized sample (20NiMgAl(5 0 0)) showed excellent ICCC performance. At 300 °C, continuous abatement of CO 2 from simulated flue gas (15 vol.%CO 2 /N 2 ) was achieved with an excellent efficiency of 280 L·h −1 ·kg −1 . Composition analysis of the effluent gas demonstrated that over 97 % CO 2 in the feed could be captured, and over 95 % of the captured CO 2 was converted to CH 4 with ∼ 100 % selectivity. Full retention of the adsorption capacity was observed for 10 adsorption-methanation cycles, and the post-reaction characterization of the DFMs indicated little structure change. This work may pave a way to the practical application of the ICCC technology, and also inspire other integration approaches between CO 2 capture and the following mitigation technologies.