CO2 sorption and desorption efficiency of Ca2SiO4

Reduction of CO2 emissions especially for power plants is inevitable. Highly-efficient solid sorbent for CO2 has been demanded so far. In this work, Ca2SiO4 was synthesised from CaCO3 plus SiO2 at 800 °C under essential inert gas atmosphere, then the product was characterised via XRD analysis. Ca2SiO4 can absorb CO2 fast at a broad temperature gap ranging from 500 °C to 800 °C. Reaction in CO2 sorption and desorption of Ca2SiO4 was found to be reversible. CO2 sorption efficiency increased with increasing temperature within the temperature range below 800 °C, reaching a peak of 45.68%, and it decreased when the temperature exceeded 850 °C. The optimal temperature for the reaction is 800 °C. CO2 sorption–desorption efficiency descended with rising cycle time. The decaying rate is averagely about 1.92% per cycle with 40 min or so. Ca2SiO4 could maintain its original block shape during the cycle processes. The spent Ca2SiO4 can be replaced due to low cost and easy preparing techniques.