涂料废渣水热减量及其产物特性

Hydrothermal reduction of paint residue and properties of products

采用水热技术处理涂料废渣,考察了水热温度、反应时间、含水率和投碱量对涂料废渣减量及其产物特性的影响,并用SEM、元素分析对涂料废渣进行表征。实验结果表明:随着水热温度的升高及时间的延长,涂料废渣减量效果及水热液中COD、TN浓度不断增加,固体产物的热值也随之增加,而含水率对涂料废渣减量的影响不大;随着碱投加量的增加,涂料废渣减量效果和水热液中COD、TN浓度逐渐提高,固体产物的热值呈不规则变化。水热温度220℃、水热时间4 h、含水率77.5%、投碱量0.17 g(NaOH,投加量以每克干物质(DS)计)为涂料废渣减量的最佳反应条件。在最优条件下,总减量率和干重减量率分别为79.1%和52.1%,含水率为47.2%。水热固体产物热值较高,可以作燃料为其他工艺提供热能。

In this paper, the use of hydrothermal technology was introduced to treat with the paint residue. The influence of hydrothermal reaction temperature, time, water content and alkali dosage on the reduction efficiency of the paint residue was studied. The characteristics of the solid and liquid products after hydrothermal treatment were investigated through SEM and elemental analysis. The experimental results showed that with the increase of hydrothermal reaction temperature and time, the reduction efficiency of the paint residue and the concentration of COD and TN in the hydrolysate increased. In addition, the calorific value of the solid hydrothermal product also improved. However, the moisture content showed no significant impact on the reduction efficiency of the paint residue. With the increase of alkali dosage, the reduction efficiency and the concentration of COD and TN in the hydrolysate gradually increased with irregularly calorific value change of the solid product. In conclusion, the optimum reaction conditions for the paint residue reduction are as follows： hydrothermal treatment temperature of 220 ℃, hydrothermal time of 4 h, moisture content of 77.5 % and alkali dosage of 0.17 g（NaOH, per gram of DS）.Under these conditions, the total weight reduction rate and dry weight reduction rate of paint residue are 79.1% and52.1%, respectively, and the moisture content after treatment is 47.2%. The solid product by hydrothermal treatment exhibits high calorific value, which could be used as fuel to provide heat energy for other thermal processes.