Catalysis of pyrite on coal liquefaction has been investigated with a 5 L batch-autoclave. The following conclusions are obtained. (1) Pulverized pyrite exhibits high catalytic activity for asphaltene hydrogenating reaction so that high oil yield and high grade solvent having high hyodrogen donatability are obtained in the coal liquefaction system. (2) It is inferred that oxidation of pulverized pyrite slows down the transformation rate to pyrrhotite which exhibits high catalytic activity on coal liquefaction reaction. (3) Sulfur addition to pulverized and oxidized pyrite increases the catalytic activity for asphaltene cracking reaction, but it is not effective for asphaltene hydrogenating reaction . Sulfur addition is supposed to have different effect from pulverization for the catalytic activity of pyrite.
In China the acid rain problem due to SOx from the coal combustion facility has been serious after 80's. It is important to devolop the economical and effective desulfurization process to solve the acid rain problem in China. In this study a new dry desulfurization process producing useful fertilizer as a byproduct has been proposed and studied. The reactant gas of NH3, SO2, and NO2 was supplied into the reactor packed with fly ash or an activated ash where the reaction occurred on the surface of the packed particle. The product of the reaction was analyzed by X ray diffraction (XRD) and other qualitative analysis, the weight change of the packed material after the reaction was measured to calculate the removal rate of SO2. The result showed that the ammonium sulfate could be formed at 110°C when the activated ash was used as the packed material, a coexistence of NO2 improve the removal rate of SO2 significantly and ultra fine (NH4) 2SO4 particles could be newly formed on the flake-like (NH4) 2SO4 surface.
A surface reaction occurs at a certain surface temperature when the catalyst is heated up in a reactive mixture. If homogeneous ignition does not occur, a steady state is observed because the heat produced by the surface reaction is balanced with the heat loss caused by convection, conduction and radiation. The steady temperature is defined as the temperature at the steady state. This paper treats the pressure effects on the surface reaction. Hydrogen and oxygen are used as reactants and nitrogen as an inert gas. The height, width and length of the combustion chamber are 76 mm, 140 mm and 140 mm, respectively. A spherical Pt catalyst sample of 1.5 mm in diameter is sustained in the chamber with two wires of 0.1 mm in diameter. As results, there is a maximum steady temperature at a certain equivalence ratio (ERmax) and ERmax increases with total pressure. At the steady state, it can be approximated that the heat release is evaluated by the mass transfer which includes the effect of natural convection. The experimental results could be explained qualitatively by the approximation.