Kilogram-scale production and pelletization of Al-promoted CaO-based sorbent for CO2 capture

Excessive emission of anthropogenic CO2 has facilitated greenhouse effect since the industrialized and modernized society, causing serious problems to both environment and human society. To alleviate this, Al-promoted CaO-based solid sorbents were produced on kilogram scale per batch via a simple and facile co-precipitation technique, in which Al served as an inert support and achieved an improvement on CO2 sorption performance of the sorbents. Preparation conditions of the mass-produced sorbents were optimized, including Ca/Al molar ratio, precursor concentration of calcium, coprecipitating temperature and time, which acted as critical roles in co-precipitation process. A 6-kg sorbent powder with favorable CO2 capture performance has been synthesized successfully at one batch. In addition, pelletization of the kilogram-scale produced sorbent powder was also executed utilizing extrusion-spheronized granulation methods. And a typical binder material (pseudo-boehmite) with peptizing agent (nitric acid) was incorporated to ameliorate nano-porous structure and mechanical reliability of sorbent pellets. The sorbent pellets, fabricated using the kg-scale produced powder, displayed a final CO2 sorption capability of 5.4 mol-CO2/kg-ads and great anti-attrition resistance (0.14 wt%/h) after 30 adsorption/desorption cycles up to 40 h.