Preparation Of Biodiesel From Zanthoxylum Bungeanum Seedoil Bycarbon Based Solid Acid Catalyst

Biodiesel, as a green renewable energy source, is biodegradable, burning less pollutants etc., has attracted worldwide attention for the replacement of fossil diesel. Whereas, the sources of raw materials restrict the development of biodiesel, especially in our country, using edible oils as raw materials are not allowed, so it is very important to find a kind of non-edible oil or herbaceous (ligneous) oil which is cheap and can be used in industrial production. Zanthoxylum bungeanum seed, as a by-product of zanthoxylum bungeanum, itcontains 27%-31% oil, a wide range of source, but its application is very few. Therefore, using ZSO as a raw material to produce biodiesel, not only can increase the utilization of zanthoxylum bungeanumseed, but also can alleviate the crisis of shortage of fossil fuels. However, due to the high acid value of ZSO, the pretreatment is needed to reduce the amount of free fatty acids (FFAs). The commonly used in esterification reaction is a number of homogeneous acid catalyst, whichhavedisadvantages of corrosion of equipment, cannot be reused and other issues. So it has become a hot research topic to design a catalyst which has low price, good activity and can be reused.In this paper,a carbon based solid acid catalyst was prepared by carbonized and sulfonated with glycerol as carbon source, and the catalyst was employed to catalyze the esterification reaction of ZSO and methanol. The effects of methanol to oil molar ratio, catalyst amount, reaction temperature and reaction time on esterification reaction were investigated by single factor experiment. And using orthogonal experiments to determine the optimumconditions of reaction, the results showed that the catalystpossesses desired activity, and under the optimum conditions:methanol to oil molar 40:1, catalyst amount of 10.0 wt.%, reaction temperature 75℃, reaction time 3.5 h, the acid value of ZSO reduced from 73.75 mgKOH/g to 1.63 mgKOH/g, which satisfied the requirement of the following alkali-catalyzed transesterification process for biodiesel production.On the above basis, ZSO was employed as carbon source to prepare a solid acid catalyst. The prepared solid acid was employed to catalyze the esterification reaction of ZSO. The effects of methanol to oil molar ratio, catalyst amount, reaction temperature and reaction time on esterification reaction were studied by single factor experiment, and orthogonal experimentswere used to determine the optimumconditions of the reaction. The results showed that the catalyst exhibited excellentcatalytic properties in the reactions and under the optimum conditions:methanol to oil molar 30:1, catalyst amount of 12.0 wt.%, reaction temperature 60℃, reaction time 4.5 h, the acid value of ZSO reduced to 1.76 mgKOH/g, which satisfied the requirement of the next stepof alkali-catalyzed transesterification for biodiesel production.Using the solid acid catalyst derived from ZSO as the catalyst, the simultaneous esterification and transesterification reaction to prepare biodiesel in one step was studied.The effects of methanol to oil molar ratio, catalyst amount, reaction temperature and reaction time on the reaction were investigated by single factor experiment, and orthogonal experimentswere used to optimize the reaction conditions.The results showed that the yield of biodiesel was 96.30% under the optimum conditions:methanol to oil molar 30:1, catalyst amount of 8.0 wt.%, reaction temperature 160℃, reaction time 3.0 h.The amplification experiment was carried out byone-step methodof preparing biodiesel, and the quality of biodiesel was evaluated by national standards. The results showed that the main physical and chemical properties of biodiesel were satisfied with the standard of biodiesel (BD100) (20828-2015 GB/T).