厨余垃圾水热炭化处理技术研究进展

Research Progress on Hydrothermal Carbonization Treatment Technology of Kitchen Waste

我国厨余垃圾处理正面临着从“基于混合”向“基于分类”的重大转型,厨余垃圾的减量化、资源化和无害化已经成为城市环境治理的重大问题。水热炭化(HTC)技术可将厨余垃圾转化为类似褐煤的水热炭、工艺水和少量气体,达成治理目标。HTC过程中起主要作用的是脱水和脱羧反应,羟基大量去除,H/C和O/C降低,疏水性能提高,物料煤化。反应温度和停留时间是HTC过程的主要影响因素。HTC工艺可依据是否存在闪蒸环节分为两类,与厌氧结合是一种发展趋势。厨余垃圾HTC的产物水热炭具有较高的热值,污染物含量也相对较低,用作燃料将是其资源化利用的主要途径。共水热炭化(Co-HTC)和微波辅助是HTC技术发展的新方向,将有助于提升水热炭品质和降低成本。最后总结了制约厨余垃圾HTC工业化应用的问题及挑战。

Kitchen waste treatment is facing the major transformation from“mixing-based”to“classification-based”in China.The reduction,recycling and harmlessness of kitchen waste has become a major issue in urban environmental governance.The hydrothermal carbonization(HTC)technology can achieve the governance goal by converting kitchen waste to lignite-like hydrochar,process water and a small amount of gas.The main role in HTC process are dehydration and decarboxylation reactions,hydroxyl groups are largely removed,the H/C and O/C ratio are reduced,the hydrophobic performance is improved,and material is coalified.The reaction temperature and residence time are the main influencing factors in HTC process.The HTC process can be divided into two kinds based on whether it has flash vaporization and its combination with anaerobic is a development trend.The hydrothermal carbon of HTC product of kitchen waste has a higher calorific value and a relatively low pollutant content,therefore it will be the main way of its resource utilization by using as fuel.Co-hydrothermal carbonization(Co-HTC)and microwave assistance are the new development directions of HTC technology,which will help to improve the quality of hydrochar and reduce its costs.Finally,the problems and challenges restricting the industrial application of HTC in kitchen waste were summarized.