Study of influential parameters on H2S conversion efficiency of LO-CAT bubble column reactors: a statistical approach

LO-CAT is one of the best and economical processes commonly used for removal of hydrogen sulfide from lean-H2S acid gases. Prediction of H2S conversion efficiency in LO-CAT bubble columns is of great importance for design and scale up of these types of reactors. Effects of four factors including gas and liquid superficial velocities through the bubble column, the concentration of Fe3+ in solution entering the reactor, and feed gas H2S content on the H2Sm conversion efficiency of the LO-CAT reactors are investigated by the method of central composite orthogonal design (CCOD) of experiments. The reactor performance has been previously formulated using the mixing cell model. This mathematical model is used for prediction of H2S conversion in the reactor at different operating conditions constructed based upon the CCOD. Analysis of variance (ANOVA) is employed to study the signification of the four mentioned factors and their interactions. A statistical model including the main factors and their binary interactions is proposed for the H2S conversion in the reactor. It is found that H2S conversion efficiency of the reactor is considerably enhanced by the Fe3+ concentration in the entering solution; however, the conversion is sharply suppressed by the feed gas superficial velocity in the reactor. In addition, a reasonable curvature is observed for the H2S removal as a function of the liquid superficial velocity. Furthermore, as compared to the other three factors, H2S content of the feed gas has a lesser effect on the performance of the reactor.

Keywords:

LO-CAT process , Central composite design , H2S removal , Design of experiments , Bubble column reactors