Study On Catalytic Conversion Of Bio-based Dimethyl Oxalate And Succinic Anhydeide And Their Mechanism

The utilization of fossil fuels thrived the development of industry and technology,therefore matured the modern society.However,energy crisis and global contamination were simultaneously caused by it.In recent years,biomass,as a renewable resource,has attracted much attention and became a new opportunity for human development due to its characteristics as abundant,carbon neutral,and environmental benign.Traditional methods for biomass conversion were less satisfied due to the severe pollution and low efficiency.Thus,to develop new methods for the conversion of biomass derivatives is very important.This study aimed to develop green and efficient methods to convert biomass derivatives to chemical materials.The study is categorized as two parts:?1?the hydrothermal production of Ethylene glycol?EG?via biomass-derived dimethyl oxalate?chapter 2?;and?2?the catalytic production of?-butyrolactone?chapter 3?and succinimide?chapter 4?via succinic anhydride.The specific research contents and results are as follows:Chapter 2 focuses on the production of ethylene glycol from bio-based dimethyl oxalate under hydrothermal conditions,in which common metals were used as reducing agents and transition metals as well as metal oxides were used as catalysts.The effect of reaction temperature,time,pressure and the amount of catalyst on the ethylene glycol yield was optimized,and the optimal reaction conditions were obtained.It turned out that when 7 mmol Cu₂O was used as the catalyst,and 30 mmol Zn was used as the reductant to react with dimethyl oxalate under 250 ^oC for 2 h,a95%ethylene glycol yield could be obtained.Based on the analysis results of liquid products and solid samples,the reaction pathway for the formation of ethylene glycol from dimethyl oxalate under hydrothermal conditions was proposed.Chapter 3 studied the feasibility of using bio-based succinic anhydride for the production of?-butyrolactone.NiNPore was used as the catalyst for the first time and hydrogen is used for succinic anhydride hydrogenation.The effect of different solvents and the performance of various catalysts were studied.A better?-butyrolactone yield of 39%was obtained and the possible reaction mechanism was proposed.Chapter 4 studied the feasibility of catalytic production of succinimide via bio-based succinic anhydride with NiNPore as the catalyst.By adding ammonia sources,succinimide was synthesized from succinic anhydride,and the effect of different catalysts was studied.It turned out that NH₃.H₂O was an effective ammonia source and a higher yield of 91%was obtained.