Study On New Preparation Technology Of Bio-diesel From Oils

Bio-diesel is one of the ideal substitute energy resources. At present, the main hurdle, which restricts the development of bio-diesel in our country, is high cost. Producing bio-diesel with an economical way is the most important thing now. In this study, taken into account the interior composition of oil and fat such as rapeseeds oil, the part which can be synthesized industrial product will be industrialized first, the remainder will be used as bio-diesel. The issue of costing can be solved in the way. The main contents and results areas follow: 1. The extraction process was that the temperature was 90℃, the extraction time was 120 minutes. Rapeseed oils yield was 38.0% at above technology conditions. 2. Alkali, which employed as catalysis in the transesterification reaction, was more effective than acid. It was found that KOH is the best catalysis. The effect of alcohol-to-oil(mole),catalyst dosage,temperature and reaction time on the methyl ester yield was also discussed in the paper. By orthogonality experiment, It was indicated that the optimal process condition for the transesterification reaction of rapeseeds oil was methanol to oil molar ratio at 6:1,1% KOH(W%) of oil , reaction temperature was about 60℃, reaction time was about 90 minutes. It was showed that fatty acid methyl ester yield was over 98% at best technology conditions. 3. The recovery and refining technology of glycerol from the by-product of transesterification of rapeseed oil with methanol was researched. It was found that the best operation condition for the recovery and refining technology of glycerol was that the bottom layer of transesterification production was diluted with methanol, then was neutralized to pH=5.0-7.0 by adding H3PO4. The total yield of glycerol was up to 30% under these separation conditions. It was obtained, through computing by the means of density, that the glycerol purity in the end-product was 97%. Compared IR spectrum of self-made glycerol with standard glycerol, it was found that both of them were almost the same. 4. The dimmer yield was only 34% on condition that aluminum was employed as catalyst, reaction temperature was 240℃, and reaction time was 8h. 5. The cetane value improver of bio-diesel, isooctyl nitrate, was studied in this dissertation. The structure of isooctyl nitrate was analyzed through its IR spectrum. When compared IR spectrum of self-made isooctyl nitrate with standard isooctyl nitrate, it was showed that both of them were much at one. 6. Cetane value of bio-diesel was improved by adding the improver.Adding the isooctyl nitrate and peroxide to the bio-diesel, it was found that the cetane value of bio-diesel was not better but a little worse. On the contrary, when adding 20 percent alkene to the bio-diesel, it was obvious that the cetane value of bio-diesel improved from 52.7 to 62. 7. Tension and shearing of dimmer curing agent which made from fatty acid methyl ester dimmer and epoxy resin, was test. It can be found from the report that the tension and shearing of curing agent was above 10MPa, the average value of three samples was 12.49MPa, which achieved the standard value. So it would go into the market.