Amine-Modified Silica Zeolite from Coal Gangue for Co2 Capture

Abstract

Coal gangue is a solid waste produced in coal mining. China is a large coal producing country, which produces a large amount of coal gangue every year but lacks utilization. In this work, MCM-41 and amine-modified MCM-41 were prepared from coal gangue for CO 2 capture. MCM-41 were prepared at different pH (8, 9, 10) and different calcination temperatures (450°C, 500°C, 550°C) and the effect of pH and temperatures were investigated. Polyethyleneimine (PEI) was loaded onto MCM41 at different loadings (30%, 40%, 50%, 60%) to improve its CO 2 capture performance. The CO 2 adsorption capacity and cyclic stability of amine modified MCM-41 were also measured. The results showed that as the pH increased, the specific surface area of MCM-41 increased. 450°C was considered as the optimal calcination temperature. PEI loading improves the CO 2 capture performance of MCM-41. As the PEI loading amount increased from 0 to 60%, the CO 2 adsorption capacity showed an improvement from 0.125 to 1.742 mmol g -1 . After 5 cycles, its CO 2 uptake capacity still remained 70%.

Keywords: Coal gangue, CO2 capture, MCM-41, amine modification