CO2 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 CO2 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 CO2 from SCWG model syngas. The effect of synthesis time, adsorption temperature, and adsorption pressure on CO2 adsorption capacity of Cu-BTC was evaluated using analysis of variance (ANOVA). The Pareto chart showed that adsorption pressure had significant effect on CO2 adsorption capacity, and the surface plot indicated that CO2 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 CO2 capacity of 19.83 mmol/g and 13.56 mmol/g at 0 degrees C and 25 degrees C, respectively. The adsorption results showed that CO2 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 CO2 from SCWG syngas, and more work is necessary to further improve the adsorption capacity and selectivity.