Adsorption of Carbon Dioxide from Gas Streams via Mesoporous Spherical-Silica Particles

摘要

A relatively new mesoporous silica sorbent for environmental protection applications (i.e., mesoporous spherical-silica particles [MSPs]), was modified by N-[3-(trimethoxysilyl)propyl]ethylenediamine (EDA) solution and was tested for its potential in the separation of carbon dioxide (CO_2) from flue gas. The CO_2 adsorption capacity of MSP and MSP(EDA) increased with temperature from 20 to 60 ℃ but decreased with temperature from 60 to 100 ℃. The mechanism of CO_2 adsorption on both samples is mainly attributed to physical interaction regardless of temperature change. The MSP(EDA) have good adsorption performance as compared with EDA-modified zeolite or granular activated carbon conducted in this study and many types of silica sorbents reported in the literature. The cyclic CO_2 adsorption showed that spent MSP(EDA) could be effectively regenerated at 120 ℃ for 25 min and CO_2 adsorption capacity of MSP(EDA) was preserved duringrn16 cycles of adsorption and thermal regeneration. These results suggests that MSP(EDA) are efficient CO_2 sorbents and can be stably used in the prolonged cyclic operation.