Study On Highly Dispersed Iron Catalyst For Coal/oil Co-processing

This thesis was mainly targeted at the study of highly dispersed iron catalyst for coal/oil co-processing. Two catalyst precursors and two catalyst preparation methods (catalyst dispersion in oil and catalyst impregnation on coal) were used in this study in order to discuss the effect of catalyst for Coal/oil co-processing. Then the catalysts were applied in the Neimeng lignite+THN liquefaction system, Shenhua bitumite+THN liquefaction system and Neimeng lignite and Du-84 heavy oil co-processsing system, also the analysis and characterization with catalyst and liquefaction product were discussed, in order to inspect the intrinsic link between changes of coal, solvent, catalyst and product components. The main conclusions were as following:It was found that the catalytic effect of the highly dispersed iron catalysts on Neimeng lignite displayed better than on Shenhua bitumite by comparing the catalytic effects of the catalysts on the different coals, solvents in the reaction systems. It was found that the liquefaction of Neimeng lignite was more thoroughly in the catalytic role. THN as a hydrogen solvent promoted more coal liquefaction than Du-84. As for the two catalyst preparation methods (catalyst dispersion in oil and catalyst impregnation on coal), the catalytic effect of the impregnated catalysts was better than that of dispersed catalysts. As for the two precursors of Fe, the catalytic effect of Fe2+ was much better than that of Fe3+.By XRD and SEM-EDX analysis, it was found that the impregnated iron catalysts existing on coal surface were amorphous, highly dispersed and the catalyst phase components were mainly FeOOH. Since the combination of iron-sulfur compounds was found from iron and sulfur atoms on coal surface, thus the impregnated catalysts may be mixtures of FeOOH and iron-sulfur compounds. After liquefaction reaction, the catalysts were mainly in the form of iron-sulfur compounds in the liquefaction residue.At last, in Neimeng lignite and Du-84 heavy oil co-processsing system, the catalytic effect of impregnated and dispersed catalyst under different conditions was systematic investigated, and the effect of catalyst on the the properties and compositions of product was discussed in order to discove the catalytic mechanism of the catalyst in the reaction system. In addition, two catalyst preparation methods (catalyst dispersion in oil and catalyst impregnation on coal) were improved in this study. Partly impregnated catalyst and methanol-dissoluble dispersed catalyst were prepared in order to discuss the adaptability with the reaction system.