Study On The Preparation Of Bio-Based Lubricating Oil From C18 Methyl Ester Catalyzed By Potassium Carbonate And Its Properties

With the increasing awareness of human environmental protection,traditionalmineral lubricants have poor biodegradability,which has attracted more and more attention.Therefore,the development of biodegradable lubricants to replace traditional mineral lubricants is an inevitable trend in the future.In this experiment,biodiesel was used as raw material to produce bio-based lubricant,with methanol removed by nitrogen purge instead of traditional vacuum coupled with liquid nitrogen cooling method.This technique would greatly reduce the energy consumption.In addition,potassium carbonate was used as the catalyst,which could achieve similar catalytic effect and avoid acid washing and water washing.This process would greatly reduce the wastewater emission.The main contents of this study include:1.C18 methyl ester with purity over 99.5%obtained by vacuum distillation of biodiesel was used as raw material to prepare trimethylolpropane fatty acid ester by transesterification reaction with trimethylolpropane?TMP?in the presence of potassium carbonate catalyst.The effects of molar ratio of fatty acid methyl ester and TMP,nitrogen flow rate,reaction temperature and catalyst dosage on transesterification were investigated.The results showed that the yield of TFATE was over 98%at the following conditions:molar ratio of C18 methyl ester to TMP was3:1–4:1,stirring speed was 400 r/min,nitrogen flow rate was 600 m L/min,reaction temperature was 200?,catalyst dosage was 1.5 wt%of C18 methyl ester.Under the optimal conditions,the yield of TFATE reached higher than 98%after 4 h.2.The kinetics of transesterification of fatty acid methyl ester with trimethylolpropane was studied.By establishing the kinetic equation and using MATLAB software to calculate the concentration of each component under different experimental conditions,the reaction rate constants of each reaction in the process of transesterification at different temperatures were obtained.With the increase of temperature,the reaction rate constants of each reaction increased,and the activation energy of each reaction was further calculated.In addition,the kinetic model of transesterification between C18 methyl ester and TMP can be used to predict the transesterification process.3.The properties of the product,including density,kinematic viscosity,acid value and iodine value,condensation,oil film strength were determined.The optimum conditions are as follows:density 0.91 g/cm³,kinematic viscosity 52.6 mm²/s?40??,acid value 0.54 mg KOH/g,iodine value 106.3 g I₂/g,condensation point–30?,oil film strength 588 N,friction coefficient 0.089.All the indexes are up to or better than those of the products reported in the market or literature.