两相水合熔盐体系中杂交狼尾草水解制备糠醛和乙酰丙酸

以杂交狼尾草为原料,先经甲苯-乙醇抽提,在硫酸浓度为0.05 mol/L的酸性溴化锂溶液中,加入邻苯二甲酸二乙酯为有机相,形成溴化锂水合熔盐-邻苯二甲酸二乙酯两相体系,将原料置于两相体系中水解反应制备糠醛和乙酰丙酸.考察了温度、酸浓度、反应时间、有机相体积等工艺条件对糠醛和乙酰丙酸得率的影响.实验结果表明:以硫酸浓度0...

Preparation of Furfural and Levulinic Acid from Hybrid Pennisetum Hydrolysis in Biphasic Hydrated Molten Salt System

Hybrid Pennisetum was used as raw material and extracted firstly by toluene-ethanol. Diethyl phthalate was used as the organic phase and added to the acidic lithium bromide solution with the sulfuric acid concentration of 0.05 mol/L to form lithium bromide hydrated molten salt-diethyl biphasic system. And then, the raw materials were placed in the biphasic system for hydrolysis to produce furfural(FF) and levulinic acid(LA). The effects of temperature, acid concentration, reaction time and organic phase volume on the yield of FF and LA were investigated.The experimental results showed that when the system was an acidic lithium bromide solution with the sulfuric acid concentration of 0.05 mol/L, the solid-to-liquid ratio of the extracted Pennisetum to the acidic lithium bromide volume was 1:20(g: mL), the volume of the diethyl phthalate was 20 mL, 1 g of the extracted Pennisetum was used as raw material, the reaction temperature was 160 ℃, and the reaction time was 120 minutes, the yield of FF was 65.17%, and the yield of LA was 10.48%. Under the same conditions, when the acidic lithium bromide volume was 30 mL and the organic phase volume was 10 mL, the yield of FF was 60.74%, and the yield of LA was as high as 41.30%. More than 80% of FF was dissolved in the organic phase, and more than 90% of LA was dissolved in the hydrated molten salt phase. The technology could realize the synchronous preparation and effective separation of FF and LA, and could effectively reduce production costs and shorten the process flow, which provided a reference for the simultaneous preparation of furfural and levulinic acid from cellulosic biomass.