Study On Moderate Liquefaction Process Of Shenfu Coal With ZnCl₂/Organic Solvents

Coal is one of the most important energy in China,and coal-to-liquids technology hasbecome one of the most important strategy which can ease the crisis of China’s oil supply andenergy security. The development of direct liquefaction in our country have matured andachieved a technical breakthrough at present.However,generally,the direct liquefaction hasstringent austerity conditions,so its technology investment is large and its cost ishigh.Therefor,it has very important practical meaning to develope new coal-liquid technologywith efficient and moderate conditions.Zinc chloride catalytic liquefaction is a new method for producing the value-added liquidfuels directly from coal under mild conditions.This paper focuses on researching the influenceof organic solvents,the pressure of hydrogen,solvent（mL）/coal（g）,ZnCl₂（g）/coal（g）,reactiontemperature,additive such as4%zinc,4%KI,4%MOS2,4%CoCl2and10%H2O on results ofliquefaction with Shenfu ash free coal,under the moderate conditions of230℃³50℃,0²MPa,it also focuses on researching the influence of reaction time on oilyield,asphaltene yield and preasphaltene yield.According to the results,the mechanism ofzinc chloride catalytic liquefaction was discussed primarily. In this study,the gaseous productand liquid product were characterized and analyzed by gas chromatography and gaschromatography-mass spectrometry respectively,the solid residue were characterized andanalyzed by SEM and quality analysis.At last,the organic solvents and zinc chloride wererecycled in this study.The results showed that the tetralin’s liquefaction rate to Shenfu ash free coal is highestamong the organic solvents used,which also verified again the tetralin has better ability ofhydrogen-donate and hydrogen-transfer.With the increase of hydrogen pressure,the totalconversion rate and oil yield were increased,and the hydrogen pressure had a larger influenceon low temperature than higher temperature.At the conditions of atmosphericpressure,300℃,organic solvent is tetralin,organic solvents（mL）/coal（g） is4,when the ZnCl₂（g） /coal（g） up to1from0,the total conversion rate increases to48.11%from6.47%,whichsuggests that the zinc chloride has a large effect on the liquefaction process.With the increaseof the organic solvents（mL）/coal（g）,the total conversion was increased,but the increase marginis dropped.At the conditions of265℃, hydrogen pressure is1Mpa,used organic solvent istetralin,organic solvents（mL）/coal（g） is2,ZnCl₂（g）/coal（g） is1,with the reaction time up to150min from50min,the total conversion increases to67.42%from46.24%,the oil yieldincreases to61.36%from39.31%,but the asphaltene yield and preasphaltene yield had atendency of drop,which suggests that,with the increase of reaction time,there is still a part ofthe small molecule oil were extracted out from the coal,at the same time, another part ofmacromolecular asphaltene and preasphaltene were split into small molecules oil.The above research results show that zinc chloride catalytic liquefaction can get higherconversion and oil yield under wild conditions,which provide a new promising technology formoderate liquefaction of coal in China.