Research On The New Type Of Coal Direct Liquefaction Disperse Iron Series Catalyst

Direct coal liquefaction catalyst can reduce the severity of the reaction conditions, promote the yield of liquefied oil, reduce the production costs of coal liquefaction and improve the competitiveness of coal liquefaction industry. Direct coal liquefaction iron-based catalyst cost-effective, research and application is very extensive, but the iron-based catalyst activity relative to other nickel-molybdenum catalyst activity is low, thus increasing the activity of the iron-based catalyst is the focus of the study. The smaller the particle size of the catalyst, the more easily dispersed, and the more full contact with the coal, the better the reaction between,reduce the iron-based catalyst particle size and increase the degree of dispersion is one of the effective means to improve the catalytic efficiency;at the same time,using the method for modifying additives to improve the physical and chemical properties of the catalyst, especially to improve the low activity of iron-based catalyst is an effective method.In this dissert, taking FeSO4·H2O as the iron source, NH3·H2O as the precipitating agent, a series of highly dispersed iron series catalyst was prepared under the of various pH and temperature conditions by precipitation-air oxidation method and the experimental results as following:(1) The different pH conditions had great influence on the microstructure of the catalysts, and when the pH less than 7, the main crystal phase of catalysts are FeOOH, and When the pH more than 7, phase gradually to ?-Fe2O3 transformation; the specific surface area and pore volume increases with the increase of pH, and reach the maximum when the pH is 7.(2) With the increasing of reaction temperature, the crystalline phase transition of catalyst is from ?-FeOOH to a-FeOOH gradually, then to ?-Fe2O3, and specific surface area of the catalyst is also decreased, and coal liquefaction oil yield of shangwan coal also gradually reduced, but when the temperature reaches 60?, the liquefaction oil yield increases.(3) Introduction of Si, Al, Ca, Zr, Ni and Co element into catalyst, could modify catalysts, and the oil yield increased by 0.7?2.7%, and Ni, Co and Fe produce synergies and improve the activation capacity of Fe. Mg is not, and Cu, La inerting the catalyst and reduces the oil yield.(4) Introducing different silicon and aluminum content mainly influence the selectivity of the catalysts, Si and Al can increase the specific surface area of catalysts and reducing particle size, the introduction of Si content is less than 5% can obviously improve the oil yield, and only the introduction of Al content in 10?15% has the best liquefaction oil yield.