Efficient Liquefaction And Application Of Corn Straw Waste

In recent years,China has become the second largest energy producer and consumer.The energy structure can not be transformed significantly for the expanding of industrial market,and chemical fuel is still the main consumption energy.However,chemical raw material price fluctuations,and the long-term mining reserves declining.Thus,searching for some replace resources of the chemical materials is gradually becoming a global research focus.In this thesis,liquefied products were prepared from lignin,cellulose,lignocellulose respectively and solid heteropoly acid-phosphotungstic acid was used as the catalyst.The influences of liquefaction reagent ratio,liquefaction temperature,liquid-solid mass ratio,catalyst dosage and liquefaction time on the properties of the liquefied production were investigated.The experimental results showed that the optimal conditions of preparing bio-polyols with lignin were as follows:PEG400/Glycerol was 8:2(w/w);the liquefaction temperature was 140?;liquid-solid ratio was 5:1;the amount of catalyst was 0.5 g;liquefaction time was 60 min.The hydroxyl value of the prepared liquid product was 477.72 mgKOH/g,and the residue content was 0.89%.The optimal conditions of preparing bio-polyols with cellulose were as follows:PEG400/Glycerol was 8:2(w/w);the liquefaction temperature was 200?;liquid to solid was 5:1;the amount of catalyst was 1 g;the liquefaction time was 60 min.The hydroxyl value of the prepared liquid product was 447.11mgKOH/g,and the residue content was 8.75%.The experimental results showed that the optimal conditions of preparing bio-polyols with lignocellulose were as follows:PEG400/Glycerol was 8:2(w/w),the liquefaction temperature was 150?;the ratio of liquid to solid was 5:1,the amount of catalyst was 0.5 g,the liquefaction time was 60 min.The hydroxyl value of the prepared liquid product was 476.44 mgKOH/g,and the residue content was 9.86%.Then the bio-polyols prepared from different raw materials under the optimal conditions were used to modify polyurethane foams by replacing partial of industrial polyether polyols.The influences of the amount of triethylamine,the amount of water,the value of R,the amount of stannous octoate and the replacing percentage of liquefied product on the properties of the polyurethane foams were researched.The experimental results showed that the optimal conditions of synthetic lignin-based polyurethane foams were as follows:the amount of triethylamine was 0.65 g;the amount of water was 0.3 g;the value of R was 1.2;and the amount of the stannous octoate was 0.2 g;the best replacing amount of bio polyols was 10%,and the compressive strength of the foam was 89.5 kPa,the apparent density was 0.067g/cm3.The optimal conditions of synthetic cellulose-based bio-polymers were as follows:the amount of triethylamine was 0.15 g;the amount of water was 0.25g;the value of R was 1.4;and the amount of the stannous octoate was 0.35g;the best replacing amount of bio-polyols was 5%.And in this condition,the compressive strength of the polyurethane foam was 69.2kPa,and the apparent density was 0.91g/cm3.The optimal conditions of synthetic lignocellulose-based bio-polymers were as follows:the amount of triethylamine was 0.15g;the amount of water was 0.3 g;the value of R was 1.2;and the amount of the stannous octoate was 0.25 g;the best replacing amount of bio-polyols was 10%,and in this condition,the compressive strength of the polyurethane foam was 87.3 kPa,and the apparent density was 0.07g/cm.To protect the environment and reduce pollution,discovering alterlative chemical raw materials is urgent,and the development and utilization of biomass resources will become a hot and difficult point in the research.