Activities of copper oxide and Cu-V and Cu-Mo mixed oxides for H2S removalin the presence and absence of hydrogen and predictions of a deactivation model

Considering the importance of high-temperature removal of H2S from industri al gases, sorption studies were carried out on copper oxide and Cu-V and Cu -Mo mixed oxides in the absence and presence of hydrogen in a fixed-bed rea ctor. Experiments were carried out in a wide temperature range between 300 and 700 degreesC. A significant amount of SO2 was produced with CuO sorbent in the absence of hydrogen. In the case of mixed oxide sorbents, SO2 forma tion was detected even in the presence of hydrogen. On the basis of the exp erimental concentration profiles of H2S, SO2, and H2O measured in the react or effluent and XRD results for the solid products, reaction sequences were proposed in reducing (in hydrogen) and nonreducing atmospheres. A deactiva tion model proposed for such noncatalytic gas-solid reactions gave excellen t predictions of the H2S breakthrough curves. Sorption rate parameters obta ined in the absence of hydrogen were found to be larger than the correspond ing values in the presence of hydrogen. Partial reduction of CuO prior to t he sorption of H2S in the presence of hydrogen is the major reason for this observation.