Direct reduction of seven benzoic acids to alcohols via sodium borohydride-bromine （NaBH4-Br2） reagent was developed. The isolated yields for the seven acids to reduce reached 60.6-90.1%. This new synthesis route ha...Direct reduction of seven benzoic acids to alcohols via sodium borohydride-bromine （NaBH4-Br2） reagent was developed. The isolated yields for the seven acids to reduce reached 60.6-90.1%. This new synthesis route has the advantages of simple of application, low cost, mild nature, and satisfactory yields.展开更多
Benzoic acid residue is solid waste produced from the production of benzoic acid by oxidizing toluene.Because it contained important chemical raw materials such as benzoic acid,benzyl benzoate and fluorenone,it is nec...Benzoic acid residue is solid waste produced from the production of benzoic acid by oxidizing toluene.Because it contained important chemical raw materials such as benzoic acid,benzyl benzoate and fluorenone,it is necessary to recover them from the residue.In this work the technique featured with high efficiency evaporation and vacuum distillation was developed to obtain total recovery and utilization of the benzoic acid residue.By controlling the operation temperature at 260℃ and the pressure of 16kPa in the rising and falling film evaporators,heavy components separated efficiently from the residue can be polymerized and the light components consisting of 63% of the residue entered into a benzoic acid vacuum distillation column.Keeping the temperature of polymerization at(280±10)℃,coumarone resin was produced after adjusting the softening point according to the market requirements.Vacuum distillation was operated under the following conditions:top temperature at 186℃,top pressure of 16kPa,bottom temperature at 240-250℃,reflux ratio being 3︰1.Benzoic acid of 98% purity was distilled out from the column as a side stream and the bottom product was crude benzyl benzoate.By the developed technique,the benzoic acid residue was splitted into three products,benzoic acid,crude benzyl benzoate and coumarone resin without any surplus waste.展开更多
A large amount of residue including benzoic acid, benzyl benzoate and fluorenone can form in the production of benzoic acid by oxidizing toluene. To recycle the resources and reduce secondary pollution, the treatment ...A large amount of residue including benzoic acid, benzyl benzoate and fluorenone can form in the production of benzoic acid by oxidizing toluene. To recycle the resources and reduce secondary pollution, the treatment of benzoic acid residue was carried out to obtain the three purified materials by flash-vacuum distillation combination method, and the influence of the operating parameters, such as the top pressure, reflux ratio and top and bottom temperatures was investigated to obtain the best operating conditions. The experimental results show that the benzoic acid purity can reach 97% through distillation under the following conditions： the top pressure is 1 600 Pa, the bottom temperature is 190--200℃, the top temperature is 130--135℃, and reflux ratio is 5：1. The best operating conditions for benzyl benzoate distillation column are： the top pressure is 400 Pa, bottom temperature is 250-- 260 ℃, the top temperature is 150--160 , and reflux ratio is 5：1. The benzyl benzoate purity can reach 95%, and the fiuorenone purity can reach 92 %. When refined by melt crystallization, the benzoic acid purity can be improved up to 99.6%, and the purities of benzyl benzoate and fluorenone are both above 95%.展开更多
文摘Direct reduction of seven benzoic acids to alcohols via sodium borohydride-bromine （NaBH4-Br2） reagent was developed. The isolated yields for the seven acids to reduce reached 60.6-90.1%. This new synthesis route has the advantages of simple of application, low cost, mild nature, and satisfactory yields.
文摘Benzoic acid residue is solid waste produced from the production of benzoic acid by oxidizing toluene.Because it contained important chemical raw materials such as benzoic acid,benzyl benzoate and fluorenone,it is necessary to recover them from the residue.In this work the technique featured with high efficiency evaporation and vacuum distillation was developed to obtain total recovery and utilization of the benzoic acid residue.By controlling the operation temperature at 260℃ and the pressure of 16kPa in the rising and falling film evaporators,heavy components separated efficiently from the residue can be polymerized and the light components consisting of 63% of the residue entered into a benzoic acid vacuum distillation column.Keeping the temperature of polymerization at(280±10)℃,coumarone resin was produced after adjusting the softening point according to the market requirements.Vacuum distillation was operated under the following conditions:top temperature at 186℃,top pressure of 16kPa,bottom temperature at 240-250℃,reflux ratio being 3︰1.Benzoic acid of 98% purity was distilled out from the column as a side stream and the bottom product was crude benzyl benzoate.By the developed technique,the benzoic acid residue was splitted into three products,benzoic acid,crude benzyl benzoate and coumarone resin without any surplus waste.
文摘A large amount of residue including benzoic acid, benzyl benzoate and fluorenone can form in the production of benzoic acid by oxidizing toluene. To recycle the resources and reduce secondary pollution, the treatment of benzoic acid residue was carried out to obtain the three purified materials by flash-vacuum distillation combination method, and the influence of the operating parameters, such as the top pressure, reflux ratio and top and bottom temperatures was investigated to obtain the best operating conditions. The experimental results show that the benzoic acid purity can reach 97% through distillation under the following conditions： the top pressure is 1 600 Pa, the bottom temperature is 190--200℃, the top temperature is 130--135℃, and reflux ratio is 5：1. The best operating conditions for benzyl benzoate distillation column are： the top pressure is 400 Pa, bottom temperature is 250-- 260 ℃, the top temperature is 150--160 , and reflux ratio is 5：1. The benzyl benzoate purity can reach 95%, and the fiuorenone purity can reach 92 %. When refined by melt crystallization, the benzoic acid purity can be improved up to 99.6%, and the purities of benzyl benzoate and fluorenone are both above 95%.
