Preparation And Characterization Of Immobilized Hpws With Modified Cellulose And Its Application On Biodiesel Production From Yellow Horn Seed Oil

In this study,the key factor of biodiesel catalytic process which was the preparation of catalyst was studied.The modified cellulose which was a kind of renewable resources was used as the immobilized substrate.The cellulose was successfully prepared as modified cellulose beads and they were applied on the immobilization of HPW.After immobilization,the catalyst has high catalytic activity.Under optimized conditions,the conversion yield can reach more than 96%.Moreover,the catalyst can be separated rapidly and reused after immobilization.Thus,this project is of great practical significance for the development of biodiesel industry.The experimental works of this study are as follows:1.A novel negative pressure cavitation-microwave assisted extraction method wasproposed and applied on the extraction of yellow horn seed oil.In this study,a novel negative pressure cavitation-microwave assisted extraction method was proposed.The new method includes the both advantages of negative pressure cavitation extraction method and microwave extraction method.In the experiments,the extraction conditions was first studied by single factor experiment and then optimized by BBD test.The the kinetics were also studied by the first-order kinetics equation.The optimal parameters of negative pressure cavitation-microwave assisted extraction of yellow horn seed oil was as follow:extraction solvent 100%ethanol,microwave power 700 W,extraction temperature 63?,liquid to solid ratio 35:1 mL/g,negative pressure-0.07 Mpa,exttaction time:25 min.Under the optimal extraction conditions,the extraction yield of yellow horn seed oil was 52.07%.The HNPCE method has the advantages of time-saving,high extraction yields and green and environmental protection.Thus,the HNPCE method was suitable for the extraction of yellow horn seed oil.After analyzed,six components which was hexadecanoic acid,9,12-Octadecadienoic acid,9-Octadecenoic acid,cis-11-eicosenoic acid and 13-Docosenoic acid with relatively high content was determined.The amount of these fatty acid were 7.23%,42.85%,39.92%,3.14%,3.23%and 3.63%respectively.The main physicochemical properties of yellow horn seed oil were determined using GB/T standard methods.It indicated that there was little difference of the main physicochemical properties between yellow horn seed oil and soybean oil,rapeseed oil and peanut oil.So the yellow horn oil was suitable as an alternative raw material of biodiesel.2.The preparation of chemical modified cellulose beads and its application on theimmobilization of HPW.In this study,ILs were used as the solvent to preparation of cellulose beads.After that,the cellulose beads were first modified by SOCl2 and then modified by amine compounds with different amine groups.And then the HPWs were immobilized on cellulose beads by chemical bonding with amine groups.The immobilized catalysts were characterized by FTIR spectroscopy,scanning electron microscopy,X-ray diffraction.All this experiments showed that HPW was successfully immobilized on the cellulose beads.The loading content of HPW on cellulose-based immobilized heteropoly acid was determined by ICP atomic emission spectrophotometer.The contents of HPW were CB-EDA-HPW 5.50%,CB-EDTA-HPW 12.19%,CB-TETA-HPW 16.17%,CB-(AST-HPW)n 40.93%,respectively.3.The application of cellulose-based immobilized heteropoly acid and kinetics of catalysis on the biodiesel production.The four different cellulose-based immobilized HPWs were applied on the production of biodiesel.The conversion yield obtained by CB-(AST-HPW)n was very close to that by H2SO4 at the same conditions and it was higher than by other HPW immobilized catalysts.The optimal conditions of microwave-assisted biodiesel production from yellow horn oil by CB-(AST-HPW)n was as follow:Reaction temperature:60 ?Methanol/oil molar ratio:10:1Catalyst amount:4%oil massRecycle number:7Under the optimal conditions,the conversion yield reached more than 96%.The study also investigate the kinetics of biodiesel production by CB-(AST-HPW)n.It was found that the conversion yields(Y)and reaction time(t)exist Ln(l-Y)(kt function relation.The reaction rate constants k at 40 ?,50 0C and 60? were 5.97×10-3min-1,2.82×10-3 min-1 and 1.46×10-3 min-1,repectively.And after calculation,the activation energy was 14.68 KJ/mol.Meanwhile,the optional time was 40 min from the results of kinetics.4.The analysis of biodiesel sample composition and determination of physical and chemical propertiesAfter trans-esterification,the component of biodiesel was analyzed by GC-MS.Six components were found which were hexadecanoic acid methyl ester,octadecadienoic acid methyl ester,octadecenoic acid methyl ester,octadecanoic acid methyl ester,eicosenoic acid methyl ester and docosenoic acid methyl ester with the content of 5.59%,44.34%,28.76%,2.18%,9.95%and 4.28%,respectively.The main physicochemical properties of the biodiesel product preparaed from yellow horn oil were determined:viscosity(4.4 mm2/s),flash point(165?),acid value(0.07 mg KOH/g),sulfur content(0.04%),carbon residues(0.02%),and cetane number(56.1).Thus,from the viewpoints of environmental friendliness,costs,reusability and operational stability,this cellulose-based immobilized heteropoly acid represents an attractive alternative catalyst for the production of biodiesel.