Non-staple Raw Material Of Biodiesel And Diesel Engine Compound Additive On The Road Application Performance Impact

Facing with the Climate change and the energy shortage of the world, the applying of biodiesel, clean alternative fuel replacing petro-diesel, is a hot field of research with immense potential and has great scopes for creative job.Because of the wide range and diversity for the feedstocks and the drawback of high viscosity and double bonds, Biodiesel often applied in diesel engine at low blending rate. Me an while, the production of non-road engine in China is also the lagrgest of the world,the economic performance is normally bad and the the emission of NOx and PM are sepreately20%and36%of all the emission of engine.So, it is necessary to take measures to reduce the energy consumption and emission of non-road engine. This research focus on improving the combustion and emission characteristics,flow properties at low temperatures,viscosity,spray quality, and fuel consumption based on the molecular structure and make up of the biodiesel based on non-edible feedstock such as waste cooking oil, waste frying oil in KFC, rubber seed oil, coconut oil, jatropha seed oil and palm oil.Also, this thesis explore the technology to raise the fuel economy and reduce the NOx emission based on the fuel design theory, and finally analyze the impact on the low properties by the composition and the species of the additives using the knowledge of molecular structure from the microscope.Some species of biodiesel may cause slightly high NOx emission at some working con-ditions due to the high oxygen content of about10%,so this research try to create ways to reduce the NOx emission using the fuel design theory. This research concentrate on the test in a non-road diesel with3cylinders combusting different non-edible feedstocks, biodiesel with additives, biodiesel blends with methanol and ethanol and complex additives.This research explore the molecular structure of biodiesel and the characteristics of the cumbustion and emission considering the economic qualities.This thesis mainly studies the combustion process and emission characteristics of combustion pollutant after mixing petroleum with the rubber seed oil based biodiesel, coconut oil based biodiesel, Jatropha seed oil, waste cooking oil and wasted frying oil based biodiesel blends with diesel at different load condition, analysing the impact on the regular gas emission (HC, CO, NOx) and soot. The result indi-cate that every feedstock has its own advances such as the consumption of the CNNMEB100is lowest at1800r/min, the economic quality of the JPMEB100is secondly better and the BSFC of JPMEB100is the worst.The NOx emission of JPMEB100is lowest.and then CNNMEB100is the second-lowest. The HC emission of JPMEB100is lowest and CNNMEB100is the second-lowest.The soot of KFCMEB100is lowest and JPMEB100is second-lowest. The CO emission of CNNMEB100is the lowest, WCOMEB100is the second-lowest.The noise of the KFCME-B100is the lowest. The temperature of the exhaust emission for the RSMEB100is the lowest at low load condition, and WCOMEB100is the lowest at high load condition.The flow properties at low temperature of CNNMEB100is the best and the quality of KFCMEB100is the worst. SO, the combinative factors should be considered comprehensively in the selective process for the feedstock of biodiesel.This thesis proposed that the combustion of the biodiesel can be devided into four process. The first process is vaporization by absorbing the heat, and then H absorbed at the a C carbon atoms of the carbon double bonds produce·C,·H free radicals, the C-C bonds breaks at the β position of carbon double bonds changing to·C-HC=CH-C*-HC=CH-C*-HC=CH-C·,·C-HC=CH-C*-HC=CH-C·,·C-HC=CH-C·,·CH2-CH2-CH2-CH2-CHi,·C-(CO)-O-CH3free radical fragments.then the n bonds in double bonds break to cause addition or oxidation reaction in the second process. In the third process, the σ bonds in C=C,C=O bonds breaks. The fourth process is as following,the0=0, N=N breaks join into the reaction with the free radical fragments. The four process exists at different time.different space,intiating the chain reaction due to the different composition of fatty acid methyl ester of different feedstock-based biodiesel.The dissertation highly evaluates the impact of emissions of the typical additives on bio-diesel engine NOx. The study found that biodiesel blends with DTBP, EHN, TBHQ, methanol can reduce NOx emissions. Combined the free radicals reaction mechanism presented above, the study further analyzed the impact of economy and combustion characteristics of biodiesel fuel with cetane number improver, anti-oxidant, methanol, ethanol, pour point depressants. It found that antioxidants such as BHT&TBHQ, and its combinations such as BHT+BHA, with the cetane additive synergy could inhibit free radical reaction process, control the law of com-bustion, thereby reduce NOx. The experiments verify the hypothesis, adding antioxidants in-habits the process of free radicals. With cetane number improver, it further reduced the concen-tration of NOx emissions, and filter additives and conditions with dual effects of NOx reduction and efficient fuel consumption. In the meanwhile, antioxidant, alcohol, CFPP depressant were added in the non-edible feed stock based biodiesel together with the cetane improver as a mix-ture fuel to be combusted in the engine,then the impact on the improving oxidation resistance and low temperature fluidity were studied.Biodiesel tends to crystallize at a low temperature and precipitation, which blocks filter-s and affects the reliability of engine operation. The researching focus on the solution state of crystallized fatty acid ester in the physical phenomena, the degree of supersaturation, the phase-change driving force in the crystallization of solution, the stacking structure of the fatty acid methyl ester molecule, the formation of crystallization nuclei in the process of biodiesel crys-tallization,thermodynamic and kinetic characteristics of the grain growth. The study revealed the biodiesel composition of the crystallization mechanism and petroleum diesel crystallization characteristics in different blending states (B5, B20, B50, B100). It also discovered the function of S FAMEC≤14short-chain fatty acid methyl ester molecules in the low-temperaure fluidity e-valuation system and proposed the new ideas the same function of S FAMEc≥2o long-chain fatty acid methyl ester molecules worth having the equal consideration. On this basis, the study added cold flow improvers to improve low temperature fluidity of the biodiesel, analyzed the effect of antioxidants, cetane number improver, alcohols synergistic on the low temperature fluidity of biodiesel. The results provide the theoretical basis and test values for selecting feedstocks and improve the low temperature fluidity of biodiesel in cold environments and also provide guiding significance of blending biodiesel and diesel in a large scale, and fixing standard of its storage and transpotation.