| Camellia oleifera seed shell is the largest by-product before oil is pressed out of Camellia oleifera,which contains abundant hemicellulose,cellulose and lignin,which have high added value.The separation and extraction of single component is one of the methods of processing and utilization of by-products at present.The existing utilization technology is time consuming,energy consuming,high cost and low benefit,and can not be fully utilized,which limits the full utilization of Camellia oleifera by-products.By using liquefaction technology,Camellia oleifera seed shell and alcohol solution can be fully reacted,and the by-products of Camellia oleifera seed shell can be converted into compounds with high added value,which can reduce the pre-treatment work and reduce the cost.However,after the treatment of Camellia oleifera seed shell by alcohol liquefaction technology,a certain amount of residue will be produced,the content of lignin in the residue is high,and there are many active groups on the surface of the residue after alcohol liquefaction,which is more wasteful to be discarded directly.Therefore,this paper takes Camellia oleifera seed shell as the test object,studies its liquefaction mechanism in alcohol solution,optimizes its liquefaction process,and probes into the process optimization of liquefaction orientation conversion of Camellia oleifera seed shell alcohol to ethyl acetoacetate and the process optimization of preparing activated carbon from solid product-liquefaction residue,which provides a experimental reference for the study of:the all-round utilization of oil..processing by-products.The main research contents and results are as follows:(1)Study on the technology of oil tea seed shell and ethanol-water solution liquefactionResponse surface analysis showed that the concentration of ethanol and the amount of catalyst in the liquefaction process of Camellia oleifera seed shell had a significant effect on the liquefaction rate,and the ratio of material to liquid had a significant effect on the liquefaction of Camellia oleifera seed shell.The interaction between the ratio of material to liquid and the amount of catalyst was the most significant during the liquefaction of Camellia oleifera seed shell alcohol.The optimized process parameters are ethanol concentration of 64%,catalyst amount 0.9 mL,liquefaction time 1 h,material/liquid ratio 1:10,liquefaction temperature 220℃.Under this liquefaction condition,the liquefaction rate of Camellia oleifera seed shell is(70.65±0.48)%.(2)Mechanism of liquefaction of camellia oleifera seed shell with ethanol-water composite solventCamellia oleifera seed shell and alcohol solvent liquefaction,liquefaction products are mainly divided into liquid products and solid products.A GC-MS analysis was carried out on the separation of water-soluble substances and water-insoluble substances from aqueous solution.The results showed that esters,aldehydes,ethers,ketones,carboxylic acids,acids,alcohols,furans,phenols and other compounds were found in liquid products,mainly esters,aldehydes,acids,acids and ketones.Carbonyl compounds such as aldehydes,esters,acids and ketones could be effectively separated by extraction with different organic solvents;cellulose,hemicellulose and lignin can all produce alcohols and esters,but furans and other compounds are mainly converted from cellulose in camellia oleifera seed shell.phenolic compounds are characteristic products of lignin in camellia oleifera seed shell,while lignin participates in the reaction.mainly by Cβ-O bonds.The reaction of Camellia oleifera seed shell with alcohol solution liquefaction hemicellulose and lignin was preferred.FT-IR analysis and SEM characterization of liquefaction residue of Camellia oleiera seed shell,it was found that alcohol solvent effectively entered the powder of seed shell under different factors.(3)Optimization of Extraction Process for Ethyl Acetate from Camellia oleifera seed shell by LiquefactionUsing response surface analysis,The amount of catalyst and the number of heads in the process of producing ethyl acetoacetate from Camellia oleifera seed shell alcohol have significant effects on the preparation of ethyl acetoacetate,The effect of reaction temperature on it is not significant.The interaction between the amount of catalyst and the number of heads of Camellia oleifera seed shell has a significant effect on the preparation of ethyl levulinate,The interaction between the number and liquefaction temperature of Camellia oleifera seed shell,the amount of catalyst and the liquefaction temperature had a significant effect on the liquefaction rate of Camiellia oleifera seed shell.Optimized process conditions:60 mesh of raw material,Quantity of catalyst 2.3 ml、liquefaction temperature 195℃ liquefaction time 1h,Ethanol concentration 40.The crude extract of ethyl levulinate was(3.25±0.56)mL,this condition After distillation GC-MS the concentration of ethyl levulinate was 94.65%,The actual amount of ethyl levulinate extracted by the optimal process is(3.0732±0.53)mL.(4)Optimization of the Preparation of Activated Carbon from Oil Tea Seed Shell Liquefaction ResidueTo study the liquefaction residue of Camellia oleifera seed shell,Preparation of activated carbon.By investigating the effects of three single factors:the amount of activator(potassium carbonate),the activation temperature and the activation time on the preparation of activated carbon from the residue of Camellia oleifera seed shell,Response surface optimization model is S(comprehensive score)=0.85-0.045 A-0.093B 0.060C-0.056A B 0.012AC 0.079BC-0.24A2-0.023B2-0.19C2.Based on the one-time factor,The order of effect of three factors on the liquefaction rate of Camellia oleifera seed shell is as follows:activator addition>activation time>activation temperature,The effect of activator addition on the comprehensive score of iodine adsorption value and methylene blue adsorption value of activated carbon was the most significant.The optimum preparation conditions were as follows:addition of activator 2.05 g、activation temperature 650℃,activation time 2 h,An optimum value of 0.8961±0.36 under these conditions,The adsorption values and methylene blue adsorption values were 1097.23±0.35 mg/g and 138.66±0.86 mg/g.respectively... |
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