Study On The Quality Detection And Combustion Performance Of Biodiesel

In the present study, three kinds of feedstocks, the cottonseed oil, the waste oil and the soapberry(a woody oil plant with Fujian local characteristics), are selected to produce biodiesel. The study is developed in three aspects:The first, the process condition of the three different feedstocks for biodiesel production and their composition; Second, With the Near infrared spectroscopy(NIR) technique, detected the impurity in the biodiesel; Finally, mixed the biodiesel and the petroleum diesel for the test of diesel engine combustion. Specific work contents and conclusions as follows:Through the stock oil with methanol under the catalysis of KOH to produce biodiesel with transesterification reaction. Orthogonal experiment method was used to study the process condition of producing biodiesel, the optimum process conditions of three kinds of stock oil(the waste oil, the cottonseed oil and the soapberry oil), were determined. These three kinds of biodiesel are analyzed through gas chromatography-mass spectrometry (GC-MS) analysis method to get the detail fatty acid methyl ester composition and the corresponding contents. The analyzing results indicated that the methyl palmitate, the methyl linoleate, the methyl oleate are the main components of these three kinds of biodiesels. In addition, the content of unsaturated methyl esters in biodiesel of soapberry as high as 86.8%, higher than the other two biodiesel obviously, it helps to reduce the cold filter plugging point and improve the cold flow properties of biodiesel, so the soapberry is a woody energy very worthy to further development.Artificially, mixed with water and methanol to biodiesel, applied NIR technique with the partial least squares(PLS) to develop model of quantity analysis for detected water and methanol content in biodiesel respectively. Results showed that the correlation coefficient(R) of the calibration model were 0.9540 and 0.9783, the root mean square error of cross validation(RMSECV) were 97.98 and 0.1027, root mean square error of prediction were 97.95 and 0.1047, the prediction effect was better. Therefore, the NIR technique could complete the detection of water and methanol in biodiesel, by scan the sample only once, provided a new efficient detection means.An experiment on combustion performance was conducted on diesel engine test bench, the fuels used in the experiment were diesel blended with 5%(volume percent),10%,15% cottonseed oil biodesel and three kinds of biodiesel(MB5、FB5、 WB5) blended with 5%, combustion performance of biodiesel, through the dynamic performance, fuel economy and emissions, was investigated. Results showed that the output torque and output power, compared with 0# diesel, fall slightly with blend fuels, and the decline was limited; the fuel oil consumption almost the same as that of 0# diesel; the CO and smoke emission of blend fuels were lower than those of 0# diesel, and smoke emission drop especially; the NOx had increased or decreased with the change of the working condition, but the rangeability were small.Biodiesel blended with 0#diesel at low proportion for engine combustion, the impacts of the power performance and fuel economy were very small and could effectively improve the exhaust emissions. Biodiesel from different feedstocks blended with 0#diesel for diesel engine, the combustion performance were differently, and the WB5 relatively excellent performance, the preliminary results showed the biodiesel used in diesel engine is completely feasible, and the soapberry biodiesel was a very suitable alternative fuel, had a good application prospect.