Biodiesel And Emulsion Fuel Production From Rice Bran Oil And Properties As Fuel

Recently,biodiesel has been receiving increasing attention due to its less polluting characteristics and because it is a renewable energy resource as against the conventional diesel,which is a fossil fuel leading to a potential exhaustion.The main hurdle to the commercialization of biodiesel is the cost of raw materials.However,use of cheap and abundant feedstock may result in substantial reduction in the biodiesel production cost.Rice bran is an important by-product in rice processing.The rice contains 6～10 wt%of bran which contains 16～32 wt%oil.Due to the presence of an active lipase in the bran,FFA content in crude rice bran oil is higher compared to the other edible oil.Because of this reason,rice bran oil is not considered as edible oil.Even though the bran produced is used as poultry and cattle feed,to ensure its quality is difficult.Using rice bran oil as feedstock of biodiesel not only gives full play to the advantage in abundant bran resources but also improves the quality of feed.The biodiesel(RBME)was prepared from rice bran oil.The properties of rice bran oil,the technological conditions of transesterification and the preparation process of emulsion fuel were researched.The study on the performance and emissions of the biodiesel and the emulsion fuel was conducted in a DI engine.Main contents of the research were as fallows:1.Physical and chemical characteristics and fatty acid composition of rice bran oil were studied.The study results showed that oleic,linoleic and palmitic acids were three major FA in rice bran oil.Molecular structure of biodesel product was similar to diesel,ideal for alternative fuel substitution. Acid value of the rice bran oil was high,so it needs to deacidfy before making biodiesel. 2.The transesterification of rice bran oil with methanol,in presence of base catalyst,by means of mechanical stirring in order to obtain RBME fuel was studied.The study results showed that the optimal conditions of the conversion rate were:ratio of methanol to oil,6,reaction temperature, 60℃,dosage of catalyst,0.9%,reaction time,45min,but the optimal conditions of the yield rate were:ratio of methanol to oil,6,reaction temperature,50℃,dosage of catalyst,1%,reaction time,45min.The conversion rate and the yield rate were 98.6%and 91.2%,respectively.3.The transesterification of rice bran oil with methanol,in presence of base catalyst,by means of low frequency ultrasound in order to obtain biodiesel fuel was studied.By using ultrasounds the reaction time was much shorter(15～20min)than for mechanical stirring.The quantity of required catalyst is lower than for mechanical stirring.At 40 kHz ultrasounds the reaction time was shorter,but the yields were lower than at 28 kHz.The differences in the product yield were mainly due to difficulties through washing.4.Fuel properties of RBME were studied and compared according to ASTM D6751-02 and DIN V51606 standards for biodiesel.Most fuel properties comply with the limits prescribed in the aforementioned standards.The consequent engine test was shown a similar power output compared with regular diesel,but consumption rate was slightly increased. Emission tests have shown a marked decreasing in CO,HC,and PM, however with a slight increasing in NOx.5.The mutual solubility and the physicochemical properties of the diesel-RBME-ethanol blend fuel were investigated,and the power and fuel economy and emission characteristics of the diesel engine were measured under the condition of burning diesel fuel and the diesel-RBME-ethanol blend fuel.The results showed that the solubility and fuel properties were improved when added RBME in diesel—ethanol blend fuel.But the solubility of blend fuel was not good when the temperature is lower than 0℃.6.The influence of diesel-RBME-ethanol blend fuel oxygen content on diesel engine exhaust emissions was investigated.The CO and HC emissions decreased with the oxygen content increasing when the oxygen content was lower than the oxygen content of RBME.With the content of ethanol increasing,though the oxygen content increased,the CO and HC emissions increased.At all time,with the fuel oxygen content increasing, the NOx emissions continued increased,but the soot emissions continued decreased.7.Using Span80 and Tween80 as emulsifier,the preparation process of RBME-water emulsion fuel were researched.The results showed that the optimal conditions of preparing W/O emulsion fuel were:dosage of emulsifier,0.9%,temperature,30℃,ratio of oil to water,9:1,stirring intensity,3000r/min,mixing time,15min,HLB value,4.The optimal HLB value of preparing O/W/O emulsion fuel was in the range from 6 to 9. When the content of water was over 10%,the viscosity of emulsion fuel was too high to be used in diesel engine.8.The power and fuel economy and emission characteristics of the diesel engine were measured under the condition of burning diesel fuel and the RBME -water emulsion fuel.The consequent engine test was shown a slightly low power output compared with regular diesel,but consumption rate was slightly increased.However,if the 10vol%of water is taken out of the calculation for the consumption,then the emulsion fuel has less consumption than neat RBME.Emission tests have shown a decreasing in CO,HC,soot,and NOx.9.Using Span80,Tween80 and soybean phospholipids as emulsifier, the preparation process of RBME-water emulsion fuel were researched. The compound emulsifier made from soybean phospholipids and chemical synthesis emulsifier has the similar emulsifying capacity with neat chemical compound emulsifier,but has higher emulsifying capacity than the single chemical synthesis emulsifier.When the compound emulsifiers had the same HLB value,the influence of emulsifier type on emulsifying capacity was not marked.As soybean phospholipids been added in emulsion fuel,the negative influence on fuel properties was not found.To sum up,this research showed that it is feasible to prepare biodiesel and emulsion fuel from rice bran oil.The development of making biodiesel from rice bran oil has great practical significance to develop cyclic economy and new energy,ruduce pollution and protect environment.This study gave the theoretic and experimental base to advance the industrialization of biodiesel.