Study Of Syngas Methanation Based On Ni/MCM-41 Catalyst

According to China’s "rich coal poor oil little gas" energy characteristics, and due to the destruction of the living environment and the natural environment pollution, haze in many of our major cities staged an urgent need for a clean and sustainable energy efficiency as a primary energy consumption goods, in order to reduce pollution primary fossil fuels on the environment. However, methane gas as a low carbon, clean, efficient energy, just to meet the urgent demand for clean domestic sustainable and efficient energy.Domestic natural gas production growth lags behind demand growth. Furthermore, relying on the rich coal resources in China’s Xinjiang region, to develop coal gas, not only in line with the development direction of clean utilization of coal, but also to ensure an effective supplement gas supply. The methanation catalyst is the key coal to natural gas, and therefore, according to the characteristics of the current methanation catalyst, methanation catalyst to be addressed urgently the efficiency and heat issues.This article is based on Ni/MCM-41 research synthesis gas methanation performance, respectively, by adding a catalyst mainly alkaline earth metal additives, precursors of different heat treatment, as well as amino-modified carrier MCM-41 was prepared, and the catalyst activity, selectivity and stability of the different inquiry.Hydrothermal synthesis of MCM-41 prepared by the legal system and the use of ion exchange added Ca, Mg alkaline earth metal attached to the surface of the catalyst MCM-41, and catalysts prepare by the impregnation method to load 10wt% of Ni. The catalysts under 1.5MPa, 30000 mL·g-1·h-1, n（H₂）:n（CO）=3 conditions to research catalytic properties. And Ni/MgO-MCM-41 and Ni/CaO-MCM-41 catalytic activity of the catalyst is much higher than the of Ni/Z-MCM-41 at lower temperatures（ie, 250 ℃）. The catalyst after a series of characterization found that Ca²⁺, Mg²⁺ is added primarily as a structural aid of the role of the nickel particles is relatively small uniformly distributed on the support surface, and enhances the surface interaction of nickel particles and the carrier and, secondly, Ca²⁺, Mg²⁺ influence of the pH of the active sites of the catalyst, weakly basic active sites on the Ni/MgO-MCM-41 and Ni/CaO-MCM-41 catalytic activity play a beneficial effect.10wt% Ni/MCM-41 precursor prepares by impregnation method with MCM-41 as the carrier, the precursor via two different ways to prepare a catalyst by microwave heat treatment and general baking heat treatment. After the active test, we found MW-Ni/MCM-41 catalyst by microwave treatment of activity is more than 95% at 250℃, 1.5MPa, 30000 mLg-1h-1 the conditions, whereas under the same conditions of the calcination treatment Ni/MCM-41 catalyst the basic activity is almost 0%. And stability test at 450℃, 1.5MPa, 30000 mLg-1h-1 condition through 100 h, and we found MW-Ni/MCM-41 carbon monoxide conversion rate basically stable at 98%, whereas Ni/MCM-41 conversion of carbon monoxide rate from 94% down to 76%. And XRD, TPR, TEM, XPS catalyst characterized by results show that microwave heat treatment enables the load on the catalyst of nickel particles finer, more uniform dispersion. Size and morphology of the nickel particles and the carrier ordered mesoporous structure of MCM-41 affects the low-temperature activity of the catalyst and the highest activity, more dispersed Ni particles are supported on MCM-41 and the higher surface area and pore surface in such catalyst with better thermal stability.Amino-modified carrier surface of MCM-41, and then 20wt% Ni/NH₂-MCM-41 catalyst is prepared by impregnation. And compared with 20wt% Ni/MCM-41 without amino-modified performance test, Ni/NH₂-MCM-41 catalyst under 1.5 MPa, 12000 mL g-1h-1 the reaction conditions, the activity is almost 100% at the range of 300-450℃, and methane selectivity is about 95%. Low temperature（250℃） catalytic activity of the reaction is higher than 96%, while the same temperature for the Ni/MCM-41 of which the catalytic activity is almost 0%. After two catalysts at 1.5 Mpa.12000mLg-1h-1,550℃and 200 h stability test conditions were found that Ni/NH₂-MCM-41 catalyst activity stable at around 99%, without any significant decline trend. However, Ni/MCM-41 catalyst activity decreased from 97% to 89%. And through a series of catalyst characterization and found that amino-modified Ni/NH₂-MCM-41 catalysts have small and uniform distribution of nickel particles on the support surface, and with the strong support interactions, nickel particles are suppressed to grow up at high temperatures, and have anti-sintering effect.