CO 2 adsorption on Cu-BTC to improve the quality of syngas produced from supercritical water gasification

One outstanding advantage of supercritical water gasification (SCWG) coupled with CO 2 capture and storage (CCS) technology is to realize the conversion of bio-waste into hydrogen-rich syngas. In this study, metal organic frameworks of copper benzene-1,3,5-tricarboxylate (Cu-BTC) were synthesized via solvothermal method with different synthesis time and used as adsorbent for capturing CO 2 from SCWG model syngas. The effect of synthesis time, adsorption temperature, and adsorption pressure on CO 2 adsorption capacity of Cu-BTC was evaluated using analysis of variance (ANOVA). The Pareto chart showed that adsorption pressure had significant effect on CO 2 adsorption capacity, and the surface plot indicated that CO 2 adsorption capacity increased with higher adsorption pressure and lower adsorption temperature. Cu-BTC with 48-h synthesis time had the largest specific surface area (1737 cm 2 /g) and pore volume (0.73 cm 3 /g), and it exhibited the highest CO 2 capacity of 19.83 mmol/g and 13.56 mmol/g at 0 °C and 25 °C, respectively. The adsorption results showed that CO 2 concentration in multi-component gas decreased from 48.75 to 12.9%, and H 2 concentration increased from 38.75 to 75.45%. Therefore, Cu-BTC has the potential for removal of CO 2 from SCWG syngas, and more work is necessary to further improve the adsorption capacity and selectivity. Graphical abstract