Experiment Study On Viscosity Reduction And Emission Performance Of Acidic Oil Biodiesel

As a kind of green and renewable energy, it is of great strategic meanings for our country to develop biodiesel to alleviate energy crisis,mitigate environmental pollution and promote sustainable growth of economy. The subject mainly does experimental study on physical and chemical properties of acidic oil biodiesel,methods of reducing viscosity of acidic oil biodiesel and how to reduce NOX emissions of diesel engine when it uses acidic oil biodiesel and blended fuels composed of petroleum diesels and acidic oil biodiesel.The article takes measurement on physical and chemical properties of acidic oil biodiesel such as viscosity,solidifying point,density,flash point,boiling range, and calculate the cetane index according to density and boiling range. The results indicates that compared with 0~# petroleum diesels, acidic oil biodiesel's viscosity,density,flash point are higher, flash point,boiling range are equivalent, and cetane index is lower.In the experiment that reduces acidic oil biodiesel's viscosity, three methods include magnetic field,ultrasonic and combined action caused by both magnetic field and ultrasonic are adopted. Reducing viscosity by magnetic field contains two ways: magnetization on standing and flowing magnetization. The test results indicates that in the experiment magnetization on standing reduction rate of viscosity is in proportion to magnetic induction and time, and the rate can reach 6% when they are 580 mT and 6 h. In the flowing magnetization test, it can be known throw orthogonal test and variance analysis the best rate of viscosity reduction can reach 5.32% when parameters are that magnetization is 40 s, sample temperature is 40℃and magnetic induction is 600 mT. In the viscosity reduction test by ultrasonic, it can be known throw orthogonal test and variance analysis the best rate of viscosity reduction can reach 6.92% when parameters are that time is 40 s, ultrasonic intensity is 70 W/cm2, ultrasonic frequency is 1.25 MHz, and sample temperature is 40℃. Viscosity of biodiesel is still lower than that before it is treated though viscosity rise again along with extension of time after it is treated. In the viscosity reduction test by combined action composed of magnetic field and ultrasonic, it can be known throw orthogonal test and variance analysis the best rate of viscosity reduction can reach 7.88% when parameters are that magnetic induction is 420 mT, ultrasonic intensity is 70 W/cm2, time is 30 min and sample temperature is 40℃.Emission characteristics experiment of blended fuels which are composed of 0~# diesel and acidic oil biodiesel and experiment of reducing NOX emission when diesel engine consumes acidic oil biodiesel and its blended fuels are conducted throw bench testing system for engines. It can be known by emission characteristics experiment of blended fuels composed of 0~# diesel and acidic oil biodiesel: compared with 0~# diesel, smoke emission of blended fuels declines but NOX emission rises. Two ways are adopted in the experiment to reduce NOX emission when diesel engine uses biodiesel and its blended fuels: blending ethanol with biodiesel and changing fuel supply advance angle of diesel engine, and following conclusions can be got: compared with B100, E5B95 can reduce both smoke and NOX emissions of diesel engine but with no remarkable effect on its dynamics and economy, so using blended fuels that are made up of ethanol and biodiesel is good way for diesel engine to reduce NOX emission; decreasing fuel supply advance angle is efficient to reduce NOX emission, and based on overall consideration on emissions,dynamics and economy factors it can be known that the best fuel supply advance angle ranges between 14°CA and 17°CA when diesel engine consumes E5B95.