| With the rapid development of science technology and social economy,we are more and more dependent on energy.China is a huge energy consumption country,the contradiction between the increasing energy demand and the decreasing energy reserves is more and more serious.In addition,traditional fossil energy is non-renewable and is harm to environment.Therefore,it is very important for us to look for a clean and renewable energy to alternative conventional fossil energy.Biodiesel is get more and more attention for it's a new renewable clean energy,it is non-toxic,renewable and biodegradable.In this paper,the waste cooking oil is chosen to be the material of biodiesel production by basing on the national condition of China.On one hand,the cost of production could be reduced effectively.On the other hand,it is a good way to avoid the refined waste cooking oil being sell to food market,which could do really harm to consumer.By referencing previous studies of at home and abroad,the inclusion complex CsPW-CB[7]of cucurbit[7]uril(CB[7])and Cs2.5H0.5PW12O40(CsPW)is prepared by two steps and used to catalyze the biodiesel production from waste cooking oil.The result of experimental data analysis shows that the experimental consideration in this paper is practicable.The main subjects of the study are as following.(1)First of all,the inclusion complex CsPW-CB[7]was prepared in two steps.Cs2.5H0.5PW,2O40 was prepared with phosphotungstic acid(H3PW12O40)and cesium carbonate(Cs2CO3),and the cucurbit[7]uril was prepared with glycoluril and paraformaldehyde.Then the inclusion complex CsPW-CB[7]was synthesized with CsPW and CB[7]under supersonic at an amount of substance ratio of 1:1.Finally,the X-ray diffraction and FT-IR were employed to characterize CsPW,CB[7],CsPW-CB[7]and the physical mixture of CsPW and CB[7].(2)Secondly,response surface methodology was used to optimize the operating parameters on the conversion rate.In addition,the maximum conversion rate could reach 95.1%under the optimum experimental conditions:catalyst of 2 wt%,methanol/oil molar ratio of 11:1,reaction time of 150 min and temperature of 70 ?.Also,based on the coded parameters,the quadratic regression model with determined coefficients was presented.In addition,the model is significant according to the ANOVA analysis and residual plots.(3)Thirdly,the transesterification kinetic was calculated at a string linearity of R2>0.99.It has been observed that the rate constant for transesterification reactions increased from 0.0104 to 0.0185 min-1 with an increase in the temperature from 55 to 70 °C.In addition,the activation energy of the reaction was calculated as 36.0 kJ/mol,and the frequency factor A was calculated from the intercept to be 8.64 min-1.(4)In the end,the reaction product was confinned to be biodiesel with FT-IR and GC/MS,and the proportion of fatty acid methyl ester could reach 96.8%.What's more,the physicochemical properties of the product could match the ASTM D6751 and GB/T25199-2010 standard.CB[7]owns the characteristics of hydrophilic outer shell and hydrophobic cavity,which could form an inclusion of CsPW.And the inclusion complex showed high efficiency to catalyze biodiesel production form waste cooking oil.An high conversion rate could obtained with a mild condition. |
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