A Study On Hydrogenation Of Hydrogen Donor Solvent In The Coal Direct Liquefaction Process

The direct coal liquefaction technology is a technology that converts organic matter into liquid oil under the conditions of high temperature,high pressure and hydrogen using hydrogen donor solvent.The hydrogen donor solvent not only plays the role of dissolving,diluting,swelling and dispersing the coal particles,but also has the function of providing and transferring active hydrogen.The hydrogen donor solvent with better hydrogen donating performance can effectively improve the conversion rate and liquid oil yield of the coal direct liquefaction process,thus improving the hydrogen supply performance of the hydrogen donor solvent is very important to improve the economic benefits of the device.In this paper,naphthalene and phenanthrene were used as the model compounds of hydrogen donor solvent,and n-tridecane was used as solvent for the reaction solution.The hydrogenation experiment of naphthalene and phenanthrene was studied in a constant temperature fixed-bed reactor in the direct coal liquefaction process by using NiMo/Al2O3 as the catalyst.NiMo/Al2O3 is a single functional hydrogenation catalyst.It occurs only hydrogenation when naphthalene and phenanthrene were fed separately,and the hydrogenation depth is deep.After analyzing the product composition,respective reaction models are proposed and the relevant models are calculated by Powell method.The optimization results are better.When the feed is the mixture of naphthalene and phenanthrene,it occurs also hydrogenation reaction.Due to the difference in the number of aromatic rings of naphthalene and phenanthrene compounds,it will lead to competitive adsorption between the compounds.The equilibrium composition of the reaction was simulated using Aspen Plus software.The kinetic parameters of the naphthalene phenanthrene mixed system were calculated by the BFGS algorithm with the average deviation of 6%.According to the analysis,phenanthrene will inhibit the hydrogenation of naphthalene to a certain extent,and the hydrogenation depth of naphthalene and phenanthrene can be controlled by lowering the reaction temperature and increasing the space velocity to obtain hydrogen donor solvent with better hydrogen-supply performance.This paper studies the hydrogenation behavior of hydrogen donor solvent in the direct coal liquefaction process,which provides a reference for improving the hydrogen supply capacity of hydrogen donor solvents and further improving the economic benefits of coal liquefaction plants.