The Study On Properties Of Shengli Lignite Liquefaction And Its Co-liquefaction With Corn Straw

This paper investigated the properties of Shengli lignite(SL)liquefaction and its co-liquefaction with corn straw(CS),the effect of reaction system and catalyst on the liquefaction properties of SL.The synergistic effect on co-liquefaction of SL and CS had also been explored under the H2/THN.The results were as follow.Adding H2O into the H2/THN was benefit of the depolymerization for macromolecule cross-linked structure of coal under the supercritical condition,but wasn't in favour of improving the catalytic hydrogenation.Adding THN into the CO/H2O could increase the solubility of preasphaltene and asphaltene obviously.At the same time,the hydrogen transmition could improve the delivery from the reactive hydrogen to free radical.Increasing the loading content of CO in the CO+H2/H2O+THN reaction system could improve the productivity of reactive hydrogen during the liquefication process,which could improve the catalytic hydrogenation.The results of infrared spectroscopy and elemental analysis of liquefied product from different reaction systems indicated that mixture reaction system had better effect of the aromatic ring dealkylation for catalytic liquefaction of SL.Under different reaction systems,adding some alkali in the iron-based catalyst could decrease polycondensation of preasphaltene and asphaltene in the liquefaction product,which led to the surface carbon deposition of iron-based catalyst reduced.Under the H2/THN reaction system,the promotion order of alkali was as follow,Na2CO3>NaOH>KOH>K2CO3.At the same time,when the value of?-FeOOH/Na2CO3 was 1:1,the promotion was better than others.The yield of oil increased 5.87%.There exits an obvious synergistic effect between SL and CS.With the increasing CS content,the synergistic effect increased.The synergistic effect of liquefied products depends on the difference of reaction temperature.The increased yield of asphaltene and preasphaltene is improved by synergistic effect at low temperature.Otherwise,at high temperature it presents on oil.From infrared spectroscopy,the free radicals of CS pyrolysis could promote the pyrolysis of macromolecule aromatic structure from SL.But the hydrogen reaction did not occur in this promoting process.The conversion of phenol substance in the preasphaltene partly results in the synergistic effect.