纤维素高值化利用制备微晶纤维素

High Value-added Utilization of Cellulose: Microcrystalline Cellulose Preparation

关键词:  微晶纤维素  Fe³⁺  选择性酸水解  还原糖

Key Words:microcrystalline cellulose  Fe³⁺  selective acid hydrolysis  reducing sugar

摘要:以溶解浆为原料，通过Fe³⁺作为催化剂酸水解、分离、纯化制备微晶纤维素（MCC）粗产品。确定最优的稀酸水解浓度和Fe³⁺浓度，同时对水解残液成分进行初步分析。最终水解条件为，水解温度80℃，Fe³⁺浓度0.3 mol/L，水解时间60 min，HCl浓度2.0 mol/L。对制备的MCC分析与表征结果表明，MCC主要成分为纤维素，其晶型结构仍为纤维素Ⅰ型，结晶度为73.0%，与原料相比增加了18.2个百分点，聚合度下降至100左右；所得的MCC质均长度集中分布在200~400 μm之间；水解残液中还原糖得率为1.56%。

Abstract:Application of metal Fe³⁺ catalytic acid hydrolysis, separation and purification to prepare crude microcrystalline cellulose from dissolving pulp was introduced. The optimal dilute acid hydrolysis concentration and Fe³⁺ concentration were determined, and a preliminary analysis was carried out on the ingredients of hydrolysis residual liquid. The optimal hydrolysis parameters were: hydrolysis temperature 80℃, Fe³⁺ concentration 0.3 mol/L, hydrolysis time 60 min, and hydrochloric acid concentration 2.0 mol/L. The results showed that the main composition of MCC was cellulose with crystalline structure ofⅠtype, the crystallinity was 73.0%, which increased by 18.2 percentage points compared with raw material 54.8%,and the degree of polymerization reduced to around 100; and the weighted mean length of MCC distribution was between 200~400 μm; the yield of reducing sugar in the hydrolysis residual liquid was 1.56%.