稀酸大液比水解生产糠醛的研究

STUDY ON HYDROLYSIS FOR FURFURAL PRODUCTION WITH DILUTE ACID AND HIGH LIQUID-SOLID RATIO

Smallscale experiments for furfural production from corn cobs, schemed according to orthogonal list L9(34), and using dilute acid and high liquid-solid ratio (HLSR) were conducted. By studying the factors as hydrolytic pressure (temperature), acid concentration, liquid-solid ratio and reaction time, which affect the furfural yield, optimum bydrolytic conditions were chosen. Furthermore, comparisons of the catalytic activity between sulphuric acid and the mixture of sulphuric-phosphoric acid, effects between low liquid-solid ratio (LLSR) and HLSR were made and accordingly, the economical benefit of HLSR process was initially evaluated. Technics of H2SO4 recovery was also investigated. Results show that the furfural yield obtained under the best conditions reaches to 17. 82% of dry corn cobs, or 80. 93% of theoretical furfural content in raw material. Compared the results with those of the two LLSR processes, the yield increased by 2. 51 % and 6. 70% respectively. The cost of corn cobs and sulphuric acid for manufacturing one ton furfural can be reduced to 75. 10 and 332. 20 yuan respectively (according to 1985' price).