| The raw materials are Salix Psammophila and Shengli lignite in this experiment,the raw materials were liquefied in a sub-supercritical water-ethanol system.The effect of different factors on liquefaction was studied by single factor experiment.The liquefaction products and residues were characterized and analyzed by FTIR,SEM,XRD and thermogravimetric analysis.The effects of solvent ratio,reaction temperature,reaction time,quality of Salix Psammophila and catalyst on liquefaction of Salix Psammophila were investigated in subcritical water-ethanol system.The results showed that:(1)Under the conditions of water ethanol volume ratio 5:5,reaction time 60 min,reaction temperature 260? and Salix Psammophila 4 g,the liquefaction rate was 92.91%,the oil yield was 65.56%,and the asphalt yield was 4.14%.(2)Alkaline catalysts may be more beneficial to the fracture of chemical bonds during the liquefaction of Salix.(3)By means of FTIR,SEM,XRD and thermogravimetric analysis,it was found that in the process of liquefaction,the cellulose,hemicellulose and other wood structures in the Salix Psammophila were degraded and a series of compounds of the phenyl group and the benzene ring group were produced.The liquefying residue of Salix Psammophila contains a small amount of SiO2 and its crystallinity decreases.In the sub/super-critical water-ethanol system,the effects of reaction temperature,reaction time,the quality of Shengli lignite and the catalyst on the liquefaction of Shengli lignite were investigated.The results showed that:(1)Under the conditions of water ethanol volume ratio 5:5,reaction time 90 min,reaction temperature 350? and Shengli lignite 2 g,the liquefaction rate was 49.33%,the oil yield was 32.99%.(2)Adding FeS,Fe2O3,K2CO3,NaOH and t-BuOK to Shengli lignite liquefaction,it is concluded that FeS,Fe2O3 has little effect on Shengli lignite liquefaction.K2CO3,NaOH and t-BuOK indicate that alkaline catalysts are more beneficial to the degradation of Shengli lignite and inhibit the formation of macromolecular products.The addition of K2CO3 and t-BuOK can increase the liquefaction rate and oil yield more significantly,which may be due to the fact that potassium promotes the removal of methoxyl groups and the cracking of rings,thus increasing the liquefaction rate of Shengli lignite.(3)Through the infrared analysis of liquid products,it is concluded that the liquefied bio-oil contains ethers,aliphatic and aromatic compounds.FTIR,SEM and thermogravimetric Analysis of Shengli lignite and its Liquefaction residue,result that after liquefaction,Shengli lignite becomes a smaller molecule,the active molecule is reduced,and the residue is more difficult to decompose.In the sub/super-critical water-ethanol system,the effects of reaction temperature,reaction time,mass ratio of Shengli lignite to Salix on the co-liquefaction of Shengli lignite and Salix were investigated.The results showed that:(1)At the water-ethanol volume ratio of 5:5,sand willow,Shengli lignite 2 g each,reaction temperature 350?,oil yield and liquefaction rate 24.65%,72.43%,respectively.(2)when co-liquefaction,NaOH,K2CO3,t-BuOK,Fe2O3 and FeS are added,suggesting that FeS,Fe2O3,NaOH,t-BuOK and K2CO3 can promotes the co-liquefaction of Salix Psammophila and Shengli lignite,increase the liquefaction rate and bio-oil yield,and reduce the asphalt yield.catalytic effect:NaOH>K2CO3>t-BuOK>Fe2O3>FeS.(3)Infrared Analysis of liquefaction bio-oil of Shengli lignite and Salix Psammophila:Salix not only promotes liquefaction reaction of Shengli lignite,but also improves the quality of biological bio-oil.It is possible that the co-action of the sand willow and the Shengli lignite in the liquefaction process.FTIR,SEM and thermogravimetric analysis of the raw materials and their co-liquefaction residues:The degradation reaction occurs in the process of liquefaction,and the active group is reduced.The degree of cracking of the coal in the co-liquefaction residue is much higher than that of the coal liquefaction. |
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