Study On Normal Pressure Thermochemistry Liquefaction Of Rice Straw

As the resource of the petrifaction is gradually used up,the biomass which can be recycled to utilize is daily concerned by scientists in the whole world.The biomass via atmospheric pressure liquefying,degradating,brings out the valuable chemical raw material.And then reacting with other materials,it can product the polymer of polyurethane,epoxy resin,phenolic resin.The technic of the atmospheric pressure liquefaction only begins to develop recently.It should further study on the procedure and theory of liquefaction system,structure and component of liquefaction product and industrialized technique.The material of biomass is complicated with many ingredients,and the ingredients of diverse biomass are differ from each other,which make liquefaction complicated and go against the research of mechanism and improving specificity of reaction.It is difficulty and hotspot for liquefaction mechanism and separate product.Thereby, some researcher separate main ingredients from lignin biomass,then study the rule of chemical degradation.It was studied that factors of time,temperature,acid concentration and material ratio on residue ration by using different liquefacients(ethylene carbonate:EC,ethylene glycol:EG,diethylene glycol: DEG,polydiethylene glycol 400:PEG⁴⁰⁰),and analyzing effect of different liquefacient to obtain the perfect liquefaction conditions.The products have characterized by viscosity,molecular weight, and infrared ray analysis.As the differential factor on reaction by liquefying by diverse liquefacient,which both have virtue and defect,it is tried best to blend with one or another so that produce best characterization on liquefacient.It is concluded that:1.Rice straw was liquefied using ethylene carbonate in the presence of sulfuric acid as catalyst. Adding hydrogen peroxide(6%of the liquefaction reagent) had great influence on the percent residue,which is decreased by about 30%.Comparatively small amount of water addition was slightly effective for the liquefaction,and the percent residue was decreased from 55%to 33% adding 8%of the water at 150℃.Also,it was found that increased the ratio of solvent/rice straw to 6:1 or prolonged the time to 2 hour can significantly reduce the percent residue down to perfectly liquefying in present of 6%of hydrogen peroxide.The hydroxyl number and acid number were measured to ascertain the compositions in polyol polymerization,and the hydroxyl number and acid number were 116 mg KOH g^-1 and 1.4 mg KOH g^-1 respectively.2.Rice straw was liquefied using phenol in the presence of sulfuric acid as catalyst.Using GLY, EG,DEG,PEG⁴⁰⁰ respectively as liquefacients in some extent conditions,the residue ratio were 21.1%,41.6%,38.5%å’Œ51.6%.But EG,DEG,PEG⁴⁰⁰ blending with GLY(ratio:1:2 ) respectively liquefacient,the residue ratio decrease to 17%down in 60min.3.Rice straw was liquefied using phenol in the presence of sulfuric acid as catalyst.Using phenol. The best condition for liquefaction were:175℃,60min,phenol/rice straw ratio=3,H₂SO₄/rice straw=0.18,and the residue ratio is about 14%.It was found that phenol believe as best liquefacient by comparing to PEG⁴⁰⁰,DEG,GLY.When phenol blended with PEG⁴⁰⁰,DEG, GLY,The best condition for liquefaction were polyol/phenol ratio=5/10,the ratio almost reduced to 14%.