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

本研究的目的是开发利用亚临界水处理技术将造纸污泥零排放转化为资源或能源的技术。采用小批式反应器对纸浆污泥进行亚临界水和超临界水的处理，考察了温度和反应时间对产物及其数量的影响。亚临界区可溶性产物在570k左右含量最高。反应时间5-20分钟就足够了。在水相中，存在纤维素二糖、葡萄糖、果糖、红血球等糖类和乙醇酸、乳酸、甲酸、乙酸、乙酰丙酸、丙酸等有机酸。我们还使用纯纤维素滤纸进行亚临界水处理，对上述进行比较。根据这些详细的实验，提出了反应机理。在此基础上，利用自行研制的工业离子交换树脂和壳聚糖吸附剂，对纸浆污泥亚临界水处理产物进行经济分离。对单组分体系和多组分体系的平衡、吸附速率、突破曲线和洗脱曲线进行了详细的实验和理论研究。我们发现这些成分可以通过吸附剂分离。试验了用亚临界水处理纸浆污泥可大幅度提高甲烷发酵速率的可能性。我们以醋酸水溶液为模型溶液，用亚临界水处理浆料污泥得到的溶液，明确甲烷发酵前的亚临界水处理使发酵速率提高了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.