The Influence Of Increasing The Aromatics Concentration In Recycle Solvent On Coal Hydro-liquefaction

Coal Hydro-liquefaction is a kind of clean coal conversion technology which transforms coal to liquid fuels and chemical raw materials,in the condition of high temperature,high pressure,hydrogen and catalyst.Shenhua coal direct liquefaction process is the process with a set of independent intellectual property rights,and also has a process characteristic using part of heavy liquefied hydrogenation oil of as recycle solvent.It was found that saturated cyclic hydrocarbon moiety was produced during the hydrogenation for solvent,and hydrogen-donating ability of the saturated hydrocarbon is poor.Therefore we need to improve the content of the aromatic component in the recycled solvent which has strong capacity of hydrogen.The object we study is produced by National Engineering Laboratory BSU plant operation in Shenhua Coal to Liquid Co.,Ltd.Shanghai Institute,and its aromatic content is improved by liquid-liquid extraction process.First,a single-stage extraction test using GC-MS,GC characterizations methods establishes liquid-liquid solvent extraction equilibrium parameters and elects two solvents furfural and N-methylpyrrolidone with H2O suitable for recycle solvent extraction,then the extraction basic rules and parameters are mastered.By three countercurrent extraction simulation method,the operating temperature of 35?40?,solvent ratio(solvent:raw)of 1:1 under conditions of verified three equivalents of a theoretical plate extraction column,the aromatic content of raw materials increased from 55.7wt%to 88.3wt%with an extraction yield of 34.6wt%.Small autoclave coal liquefaction test is studied with the extraction products,and it's found that the liquefied oil yield increased 3.2 percentage points,coal conversion increased 1.8 percentage points,when recycle solvent(middle temperature)aromatic content was increased from 55.7%to 88.3%.It's concluded the effects of the aromatic content increase of recycle solvent on improving coal conversion and oil yield,and little help to aquatic rates and gas yield.Thus it's directly verified that aromatic concentrate increase in recycle solvent contributes to Shenhua coal liquefaction process.