Analysis And Research Of Deactivation Factors Of Catalyst For Methanol Synthesis From Syngas

Catalyst for methanol synthesis from syngas has high activity but is prone to be deactivated,and that is a general problem in the current industrial production process.The main reasons for the deactivation of catalyst is impurities which cause the poisoning of the catalyst in the synthesis gas,the high temperature leading to the thermal deactivation of the catalyst,the deposition of the catalyst and the unreasonable operation of the enterprise.At present,the analysis of deactivation of the catalyst is mainly limited to the study of the mechanism of one kind of deactivation.The deactivation of the catalyst is not analyzed comprehensively and the main factors leading to the deactivation of the catalyst are not analyzed.Only by comprehensively analyzing the factors that lead to the change in the structure of the active components of the catalyst we can take measures to improve the process to avoid or reduce the degree of deactivation of the catalyst.The activity of catalyst for methanol synthesis from syngas in one enterprise in our province descended very fast,and that greatly reduced the service life of catalyst,affected the production of methanol,and greatly reduced the cost of production.Therefore,we use X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD)and the temperature programmed oxidation-mass spectrometry(TPO-MS)to analyze and determine the deactivation type of the catalyst.combining with the conditions of the conditions in the actual production of the catalyst we determine the laboratory simulation conditions of the catalyst poisoning and simulate the deactivation process of the catalyst and analyze the most important factor affecting catalyst deactivation.The details are as follows:1 ? The detection data of the synthesis gas and the detection data of the deactivated catalyst,and the XPS,XRD and TPO-MS spectrogram were analyzed.The results showed that the deactivation type of the methanol catalyst was poisoninginactivation.The results showed that CuS,ZnS,CuCl2,ZnCl2,CuSO4,CuCO3,Zn(OH)2 were formed by the reaction of methanethiol,ethanethiol,hydrogen sulfide,sulfur dioxide,hydrogen chloride and carbonyl iron in syngas with the active components of the catalyst,resulting in the ruin of active components of catalyst and the deactivation of catalyst.2?The influence of the reaction conditions on the methanol catalyst activity were studied and the laboratory simulation conditions of methanol catalyst combining with the conditions of use in the actual production of the catalyst were determined.We determined that the optimum reductive temperature of the catalyst was 175? and the reaction temperature of methanol is 225? and the reduction time of catalyst was 10 h,and the particle size of catalyst was 20~40 mesh.3?The methanol catalyst,sulfur poisoning and carbonyl iron poisoning process under the condition of laboratory simulation were simulated and analyzed.According to the change of sulfur,chlorine and iron content in the catalyst,we found that the catalyst in the presence of sulfur poisoning,chlorine poisoning and iron poisoning,the activity decreased by 51.5%,18.5% and 8% respectively of the catalyst at the top of the synthesis tower.The activity decreased by 18.9%,9.4% and 17.5% respectively of the catalyst at the bottom of the synthesis tower.Thus,we determined that the main substance that causes the inactivation of the methanolic catalyst is sulfide.According to the synthesis of sulfide species and its content,we can see that the main factors leading to methanol catalyst poisoning inactivation are syngas containing mercaptan,ethanethiol.