Studies On Syngas Conversation To Aromatics And Hydrogenation Of Carbon Dioxide To Propane Over Bifunctional Catalysts

In recent years,with the increasing shortage of petroleum resources and the increasing demand for alkenes,aromatics and other basic chemical materials,the production of alkenes,aromatics and other chemicals by non-petroleum routes has become a research focus.Syngas obtained from coal gasification,methane reforming of natural gas,shale gas and biogas,could be a feasible way to be converted into chemicals.On the other hand,the massive emission of carbon dioxide brings about serious environmental problems.Therefore,the conversion of CO2 into high-value chemicals and liquid fuels is also concerned.In recent years,a series of advances have been made in the synthesis of olefin,aromatics from syngas and hydrogenation from carbon dioxide.In this paper,two kinds of bifunctional catalysts are developed based on the research idea of reaction coupling to realize the highly conversion of syngas and carbon dioxide into the target products:Aromatics from syngas and C2+hydrogenation from carbon dioxide.We have designed a kind of sol-gel prepared ZnO-ZrO2 solid solution oxide,and H-ZSM-5 zeolite powder grinding.Under the condition of 380℃,5 MPa,3000 ml gcat1 h-1,H2/CO=2/1,the catalyst has achieved 37%CO conversion rate,68.0%aromatics selectivity,with 42.6%CO2 selectivity and 0.6%methane selectivity.The spacetime yield(STY)yield of total aromatics was as high as 0.23g goxide-1 h-1.In this paper,by comparing different methods of ZnO-ZrO2 oxide synthesis,it is found that ZnO-ZrO2 oxide prepared by sol-gel method and dried by ethanol supercritical method has more outstanding performance than other synthesis methods,and it is characterized that the oxide prepared by sol-gel method has the largest specific surface and the smallest particle size.However,the content of Zn in the oxide has a great impact on CO conversion and aromatics selectivity in the products.The close combination of oxide and Zeolite not only promotes the CO conversion rate,but also improves the aromatics selectivity.In view of the present works of CO2 hydrogenation C2+hydrocarbons,low selectivity of single products has become a problem.we have designed a kind of ZnGa2O4 and H-MOR double bed coupled bifunctional catalyst.Under the condition of 330℃,3MPa,3000 ml gcat-1 h-1,H2/CO2=3/1,the catalyst has achieved 10.7%CO2 conversion rate and a 74.1%selectivity of single propane product,as well as a total LPG selectivity of 87.6%.This offers a new idea for the highly selective of single C2+hydrocarbon product from the hydrogenation of CO2.The acidity of 8MR/12MR in MOR has different effects on the product selectivity under different reaction atmosphere.