Study On Production Of Biodiesel From Wasted Oils And Fats

Cleansing energy sources is gaining more and more attention as an attractive fuel due to the depleting of fossil fuel resources and environmental protection.The expert actively explores and develops replacing fuel and regenerative energy from the start of environmental protection and resource strategy, biodiesel is one kinds of among them. The cost problem of material is the key factor that restricts the development of biodiesel line. So seeking one kind of cheap material is one of the direction to study, too. Waste oils and fats will meet the need to synthesize biodiesel because of its sleazy price and broad source. Waste oils and fats used to synthesize biodiesel, are not only able to resolve the problem that the impact of waste oils and fats to safety of food, but also to the problem of exorbitant cost of material. The waste oils and fats are selected and used to produce biodiesel by combining deacid value and esterification technology. The conclusions are as follows:1 The impurity and moisture content in waste oils and fats get very good controlling by filtration, dehydration and decoloring, decolor rate is up to 35.27%. The effect on deacid value was investigated by single factor experimentation base on the characteristic of resin, the B type resin exhibited the best effect on acid value. The parameters of deacid value technology were: reaction temperature 60℃, reaction time 3h, 16% resin(resin weight/ waste oils and fats weight), methanol-to-oil molar ratio 9:1. The regeneration method of resin by the following three steps: (1) diping the resin into distilled water containing 5% NaCl for 5h, (2) then diping it into distilled water containing 5% HC1 for 5h, (3) regenerating with distilled water containing 5% NaOH for 5h, resin exhibited stabilization catalytic activities after 12 time regeneration. The reaction time is comparatively long in the shaking-up flask, resin will be loss in the process of the resin regeneration and separation, operation process is relatively complicated.2 Based on the factor experiment, using continuous reaction system, a quadratic rotation-orthogonal combination design and response surface method was used to study and analyse the effects of reaction temperature, methanol-to-oil molar ratio, height of resin and velocity of sample flow on rate of deacid value. The results were as follow:(1) All the four factors significantly affected the rate of deacid value, and the sequence was reaction temperature > methanol-to-oil molar ratio > height of resin > velocity of sample flow. The interaction of reaction temperature and velocity of sample flow had negative effects on the rate of deacid value.(2)On the optimized conditions, namely reaction temperature 53.49～56.71℃, methanol-to-oil molar ratio 12.05:1～13.29:1, height of resin26.79 cm～30.15cm and velocity of sample flow0.298 mL/s～0.305 mL/s, the percent of rate of deacid value was more than 96.29% on the possibility of 95% and above.3 The single factor experimentation was used to obtain the biodiesel synthesis technique which put the contents of methyl ester and rate of yield as the target. And the parameters to producing biodiesel containing 98.0% methyl ester were: reaction temperature 60℃, reaction time 40min, methanol-to-oil molar ratio 12:1, 1.0% NaOH (resin weight/ waste oils and fats weight)., less than 0.3 % moisture content, middle blending speed was used in the reaction process.4 The whole technology was established for the synthesizing of biodiesel with waste oils and fats. By means of gas chromatography, main components of biodiesel were methyl myristate (C14:0), methyl palmitate (C16:0), methyl palmitoleate(C16:1), methyl stearate(C18:0), methyl oleate(C18:1), methyl linoleate(C18:2), methyl arachidonate(C20:0), methyl linolenate(C18:3), methyl erucate (C22:1). The total contents of methyl ester reach 98.11 %.The performance index of biodiesel reached EN II standard.