Study On Production Process And Consumption And Emission Characteristics Of Cottonseed Oil Biodiesel

Object:Biodiesel were synthesized by cottonseed oil and methanol through transesterification. The reactionconditions were investigated on fatty acid methyl ester yield, and the optimized condition was obtainedthrough orthogonal experiments. The compositions of biodiesel were qualitatively analyzed, and thevarious physical and chemical parameters of blended fuel with biodiesel and diesel were determined.Moreover, the consumption and emission characteristics of blended fuel were studied. Through the abovestudies, suitable mixing ratio and excellent properties blended fuel were selected, and the feasible basis wasoffered for fully utilization of cottonseed oil.Methods:Cottonseed oil biodiesel was produced through base catalysis methods. Optimizing the reaction conditionswere obtained by single-factor and orthogonal experiments. The compositions of biodiesel werequalitatively analyzed by GC-MS. The various physical and chemical parameters of the blended fuel weredetermined by GB testing methods. The consumption and emission characteristics of blended fuel wereinvestigated by the engine bench test.Results:1. Acid value and saponification value of cottonseed oil were tested, the average molecular weight ofcottonseed oil were calculated. Acid value was0.25mg KOH/g, saponification value was199.68mgKOH/g, the average molecular weight was843.9. Because acid value was low, the method of base catalysiswas suitable.2. The cottonseed oil biodiesel were synthesized by base catalysis methods. Through single-factor andorthogonal experiments，the optimum reaction conditions were obtained, as follows: molar ratio ofmethanol to oil was6:1, amount of KOH was1.0%, reaction temperature was55℃, and reaction time was50min. In these influencing factors, the influence of amount of catalysis on fatty acid methyl ester yieldwas the greatest.3. The compositions of Cottonseed oil biodiesel were qualitatively analyzed by GC-MS. Thirty-fivecomponents were separated, in which twenty-three components were fatty acid methyl esters. The maincompositions of biodiesel were linole acid methyl ester and palmitic acid methyl ester，the content ofsaturated fatty acid methyl ester was27.37%and the content of unsaturated fatty acid methyl ester was72.63%.4. Different mixing ratio blended fuel with cottonseed oil biodiesel and diesel were used as research subjectand then the various physical and chemical parameters of the blended fuel were determined by GB testingmethods. The results showed that: some biodiesel’s parameters were distinctly higher than0#diesel’s，suchas density，viscosity sport，surface tension，flash point and acid value etal，so above mentioned parametersof blended fuel rose with increasing biodiesel mixing ratio. Determination of the main physical andchemical properties of cottonseed oil biodiesel: density(20℃)889.8kg·m3, viscosity sport(40℃)4.92mm2·s-1, flash point (closed)165℃, acid value0.58mgKOH·g-1, copper corrosiveness first level.5. Through the engine bench tests, the external characteristic analysis showed that the engine power tend todecrease with the increasing biodiesel content, while it was contrary to the consumption of fuel. Theemission of CO and the smoke density decreased in contrast to the increased emission of NOx and CO2.The emission of HC was lower than diesel in the low mixing ratio while higher in the higher mixing ratio.Revealed by the load-characteristic tests, in the case of the increasing of the load in the low and high speeds,the consumption of fuel increased, the emission of NOx increased little, the smoke density reduced obviously in the low speeds.Conclusion:1. The cottonseed oil biodiesel were synthesized by base catalysis methods. Through single-factor andorthogonal experiments，the optimum reaction conditions were obtained.2. The compositions of cottonseed oil biodiesel were qualitatively analyzed by GC-MS. In view ofcomposition, cottonseed oil biodiesel was fit for alternative fuel.3. The various physical and chemical parameters of the blended fuel were determined. Self-productcottonseed oil biodiesel complied with native standard of biodiesel. When the mixing ratio was lower than50%, the blended fuel had excellent properties.4. The consumption and emission characteristics of blended fuel were determined by the engine bench test.The appropriate mixing ratio of cottonseed biodiesel was10%.