물분해 수소제조를 위한 SI cycle에서의 EMIm[EtSO_4]를 이용한 SO_2/O_2 분리공정

Abstract

SO_2 has been absorbed and separated selectively by an ionic liquid from SO_2/O_2 mixture decomposed from sulfuric acid during the thermochemical SI cycle for the water splitting. In order to design and operate high pressure SO_2/O_2 separation system, the solubility of SO_2 in [EMIm]EtSO_4 (1-ethyl-3-methylimidazolium ethylsulfate) has been measured by Magnetic Suspension Balance at high pressure and temperature. Based on the measured solubility, a pressurized separation system was set up and operated. 194 L/h of SO_2(SO_2:O_2=0.65:1) has been separated with 99.85% of O_2 at the vent of absorption tower, which is 22.7% of the theoretically ideal capacity of the system. This discrepancy results from the reduced contact between the gaseous SO_2 and the ionic liquid. Increased SO_2 supply, scale-up of the absorption column, and a faster ionic liquid circulation speed were suggested to improve the separation capacity.