浓磷酸预处理废弃棉织物回收葡萄糖和涤纶的优化

为了实现废弃棉织物的高效资源化利用,采用浓磷酸预处理,将棉纤维转化为葡萄糖,并回收高纯度涤纶.以磷酸浓度、磷酸与原料液固比、预处理温度和时间为研究对象,以涤纶回收纯度、葡萄糖收率为考察指标,采用中心组合设计(CCD),建立响应面模型对预处理工艺参数进行优化.并确定了最佳的浓磷酸预处理工艺条件为:磷酸质量分数85%,液固比15:1,预处理时间7 h,预处理温度50℃.在此条件下涤纶回收纯度可达100%,葡萄糖收率可达79.0%,且实验验证值与模型预测值较为接近,模型精度较高.此外,再生纤维素不经干燥直接酶水解,葡萄糖收率可被进一步提高至83.0%.

Optimization of concentrated H3PO4 pretreatment on waste cotton-based textiles for glucose and polyester recovery

In order to utilize waste cotton-based textiles efficiently, the concentrated H3PO4 pretreatment was employed to facilitate glucose production from cotton fibre, and recover polyester as well. Central composite design (CCD) was applied to optimize the main parameters, including H3PO4 concentration, the ratio of H3PO4 and textiles, pretreatment temperature and duration, to achieve the highest purity of the recovered polyester and glucose recovery. Results indicated that the optimized pretreatment conditions can be determined as follows: H3PO4 concentration of 85%, the ratio of H3PO4 and textiles of 15:1, pretreatment duration of 7 h, and pretreatment temperature of 50℃. According to the optimized conditions, the purity of the recovered polyester can reach 100%, and 79.0% glucose recovery can be achieved. The experimental results for verification were very close to the predicted data indicating the fitted models were accurate. In addition, glucose recovery can be further improved to 83.0% when the regenerated cellulose was directly enzymatically hydrolyzed without being dried.