Study On The Hydrogenation Liquefaction Of Coal With The Hydrogen Source Of H₂S

According to the characteristic of rare oil and gas resources but rich in coal resource inour China, coal-to-oil has become the significant strategy to compensate the shortage ofpetroleum resources, of which the direct coal liquefaction is one of the most effective ways.The traditional process of direct coal liquefaction has the disadvantages of requiring verystrict conditions and high investment costs, and a low single-pass utilization ratio of hydrogen,which greatly limit their application in industry. In order to improve the liquefactionprogresses, reduce the expenses, the feasibility of shenfu coal liquefaction with H₂S as thehydrogen source was studied using a high pressure batch autoclave.We investigated the factors influenced on the conversion of coal liquefaction includedthe proportion of H₂S in hydrogen source and kind of catalysts, then analyzed both thedistribution of S in the liquefaction oil and residual and the composition of the oil. Resultsshowed that the liquefaction condition was getting mild and the conversion increased invarious degrees when H₂S as the whole or part of hydrogen source, and when the proportionof H₂S in hydrogen source was in the range of20%⁵0%, the conversion was increased from62%to about70%; Besides, FeS showed a higher catalytic activity than the other meta llicoxide with the hydrogen source of H₂S only.After the elemental analysis and industrial analysis, we found that C and H contentdecreased, in the liquefaction residue, and heteroatom N content reduced significantly, incontrast, both the content of S and ash increased apparently. When H₂as the hydrogen sourcealone, S content in its oil was0.005%, and for H₂S, S content reached up to0.052%, whichwas a bit higher, but higher than the state of standard oil sulfur content. The GC/MS analysisof the liquefied oil obtained from the liquefaction implied that it was composed by thearomatic compounds, such as benzene, naphthalene, indane and their derivatives. In addition, the effect of polyethylene glycol dimetyl ether （NHD） dissolved H₂S in thechemical factory on the conversion was investigated in the presence of the catalyst. Resultsshowed that under the conditions of FeS as catalyst, NHD as hydrogen source and a massratio of NHD with tetralin of1:3, the highest conversion could reach22.50%, which indicatedthat NHD is feasible to act as the hydrogen source, which need to do further investigations.