Removal Of Low Concentration Carbonyl Sulfide And Carbon Disulfide From Carbon Dioxide By Adsorption

Recovery of CO2can reduce the green-house effect and provide the carbon resources. However, some organic sulfurs like carbonyl sulfide(COS)and carbon disulfide(CS2) which could cause equipment corrison and poison the catalysts downstream, which are hard to be removed from a CO2stream for the low concentration and similar properties to CO2. Up to now, the typical catalysts were hard to meet the requirement of S content in food grade CO2. Therefore, the removal of low concentration COS from a CO2stream shows very important for production and utilization of food grade CO2. In this present, we invisitigated desulfurization performance of a series of adsorbents, and the main works were shown as below:(1) Investigated the removal of CS2in low concentration from N2stream, using different substrates modified with different transition-metal ions. The results show that Y zeolites modified with Ag+played a better performance of the removal of CS2. CS2was converted into COS in the removal process, using HY modified with Ag+(2) Adsorbent Ag/NaY prepared to removal low concentration COS from a CO2stream and identify the optimal operation conditions in a fixed-bed adsorption apparatus. The results revealed that the adsorbents prepared by incipient wetness impregnation method shows the well stability of Ag content; the optimium adsorption temperature, AgNO3loading amount and regeneration temperature are50℃,4%and250℃, respectively. The breakthrough adsorption capacity of COS decreases to below50%after the fifth regeneration.(3)This study investigated the performance of adsorbent Ag/NaZSM-5in the removal of low concentration COS from a CO2stream. Effects of the conditions on preparation of adsorbents, adsorption and desorption were intensively investigated. Results proved that the adsorbent Ag/NaZSM-5(x)-80-250showed the better performance in the desulfuration of COS, where optimal value of x was5-10; the adsorption performance of the adsorbent on COS could not be enhanced by addtion of3wt.%CO2O3, CeO2and ZnO; Some Ag" turned into Agn81clusters after Ag/NaZSM-5adsorbed COS, and the new absorption bands were observed at1315cm-1and623cm-1. The adsorbent can be fully regenerated using the hot air at450℃, and the adsorption capacity remained stable even after eight cycles of regeneration.