烟道气低浓度二氧化碳的变压吸附法富集研究

Low concentration carbon dioxide enrichment from flue gas by pressure swing adsorption

建立了3塔变压吸附分离装置,对烟道气中的低浓度二氧化碳(体积分数12%左右)的富集进行了实验研究,考察了吸附压力和吸附时间、置换压力和置换时间及解吸压力对产品气浓度和回收率的影响。结果表明:基于硅胶的PSA技术能够对炉窑尾气中的低浓度二氧化碳气体进行浓缩;吸附压力和吸附时间对变压吸附回收浓缩烟道气中低浓度的二氧化碳有着重要的影响,为了得到较高浓度的二氧化碳气体,吸附压力不能太低,不同的吸附压力下有着不同的最佳吸附时间;一定条件下提高置换气的流量和压力会提高二氧化碳气体的浓度,但是回收率会下降。

A three-bed pressure swing adsorption（PSA） separative device is established and the enrichment processes of low concentration CO2 from flue gas are studied. The influence of adsorption pressure and time, purge pressure and time, and desorption pressure on the concentration of CO2 and recovery are investigated. The results show that： （1）The PSA technology based on silica gel can be used to enrich the carbon dioxide from flue gas, （2）The adsorption time and pressure have great effects on the enrichment of carbon dioxide and the adsorption pressure should not be too low to get higher concentration of carbon dioxide. （3）There are optimal period of time of adsorption at different adsorbing pressures. （4）Under certain conditions, to increase the purge time and pressure will increase the concentration of carbon dioxide,but the recovery will be decreased. These results way be meaningful to capture low concentrated CO2 from flue gas.