Ru/K2CO3-MgO catalytic sorbent for integrated CO2 capture and methanation at low temperatures

In this study, we have developed a Ru/K2CO3-MgO (Ru/KMg) catal-sorbent for integrated CO2 capture and methanation (ICCM) at low temperatures. The Ru primarily existed as a K2RuO3 phase, which was not observed after reduction at 400 degrees C. In addition, the crystallite size of Ru0 is smaller than that of Ru/MgO because Ru species as K2RuO3 phase, instead of RuO2, is dispersed well throughout the MgO support material. Here, the CO2 capture and regeneration properties of Ru/KMg catal-sorbents after carbonation at different temperatures (60, 120, 150, and 320 degrees C) were studied under N2 or H2 conditions, respectively. The optimal carbonation temper-ature was 150 degrees C when considering 100% CO2 conversion to CH4. 20 consecutive cycles of ICCM were conducted at 150 degrees C for carbonation (10 vol% CO2 and 10 vol% H2O) and 320 degrees C for methanation (90 vol% H2). The results showed stable CH4 productivities of 1.07-1.19 mmol CH4/g with 100% CH4 selectivity and 96.2%-101.3% CH4 yield.

Automated summary

In this study, a Ru/K2CO3-MgO (Ru/KMg) catal-sorbent was developed for integrated CO2 capture and methanation (ICCM) at low temperatures. The Ru primarily existed as a K2RuO3 phase, and the crystallite size of Ru0 was smaller than Ru/MgO due to better dispersion throughout the MgO support material. The optimal carbonation temperature for achieving 100% CO2 conversion to CH4 was found to be 150 degrees C. The ICCM experiments conducted at 150 degrees C for carbonation (10 vol% CO2 and 10 vol% H2O) and 320 degrees C for methanation (90 vol% H2) showed stable CH4 productivities with 100% selectivity and 96.2%-101.3% yield.