Conversion to Biodegradable Polylactic Acid and High Speed Methane Fermentation of Paper Manufacture Sludge with Sub-Critical Water Treatment

为研究造纸污泥亚临界水处理零排放资源化技术，采用小型间歇式反应器对造纸污泥进行了亚临界和超临界水处理，考察了温度和反应时间对污泥产物及其数量的影响。在亚临界区，可溶性产物在570 K附近出现最大量。反应时间在5-20分钟内足够。在水相中，存在糖如纤维二糖、葡萄糖、果糖和赤藓糖以及有机酸如乙醇酸、乳酸、甲酸、乙酸、乙酰丙酸和丙酸。我们还使用滤纸，这是纯纤维素，亚临界水处理，以比较上述。在此基础上，本文进一步利用商品化的离子交换树脂和自行研制的壳聚糖吸附剂，探索了纸浆污泥亚临界水处理产物的经济分离方法。对单组分和多组分体系的平衡、吸附速率、穿透曲线和洗脱曲线进行了详细的实验和理论研究。我们发现这些组分可以通过使用吸附剂进行分离。我们测试了用亚临界水处理纸浆污泥以大幅加快甲烷发酵速率的可能性。我们使用乙酸水溶液作为模型溶液和通过用亚临界水处理纸浆污泥获得的溶液，并且明确了在甲烷发酵之前的亚临界水处理使发酵速率增加10倍。

The objective of this work is to develop zero emission conversion technologies of paper manufacture sludge to resources or energy with sub-critical water treatment.Pulp sludge was processed with sub-critical and supercritical water using a small batch reactor, and the effect of temperature and reaction time on the products and their amounts were tested. The soluble products showed maximum amounts around 570 K in sub-critical region. The reaction time was enough in 5-20 minutes. In water-phase, sugar such as cellobiose, glucose, fructose, and erythrose and organic acids such as glycolic acid, lactic acid, formic acid, acetic acid, levulinic acid, and propionic acid existed. We also used filter paper, which was pure cellulose, for sub-critical water treatment to compare the above. According to these detail experiments, the reaction mechanism was proposed.Furthermore, using commercial ion exchange resins and the chitosan adsorbent, which we developed, we tried to develop economical separation method of the products obtained by sub-critical water treatment of pulp sludge. Equilibria, adsorption rate, breakthrough curves, and elution curves for single component systems and multi-component systems were experimentally and theoretically investigated in detail. We found that these components could be separated by using the adsorbents.We tested the possibility of speeding up the methane fermentation rate drastically by treating pulp sludge with sub-critical water. We used an aqueous acetic acid solution as a model solution and the solution obtained by treating the pulp sludge with sub-critical water and made clear that the sub-critical water treatment before methane fermentation increased the fermentation rate 10 times.