摘要
垃圾热解半焦是垃圾在无氧环境中升温热解后的固体产物,其熔融处置有助于实现废弃物彻底无害化和减量化。为探究分类和资源回收对垃圾热解半焦熔融的影响,对混合垃圾进行分类和分选,获得9组不同组成的垃圾,再分别制备其热解半焦和半焦灰分,研究它们的熔融特性。结果发现,分类前后的垃圾及垃圾回收某种可燃物后热解半焦的热值为14.83~23.87 MJ/kg,回收塑料等可燃物组分会影响半焦灰分含量从而使半焦热值发生变化。垃圾分类后半焦灰分的熔融温度有所升高,不同半焦灰分的4个特征熔融温度在1180~1300℃之间波动。纸类物质的回收会使半焦灰分熔融温度降低,纺织类物质回收的影响不明显。垃圾分类前回收塑料会使半焦灰分熔融温度降低,而分类后回收塑料类物质会使半焦灰分熔融温度升高,这是因为它们携带的灰分影响了半焦灰分的酸碱比与硅铝比。垃圾热解半焦的燃烧放热量远远大于其半焦灰分熔融的吸热量,热解半焦在环境温度1150℃下停留30 min时,会因燃烧放热直接完成熔融过程,而同样条件下半焦灰不能完成熔融,说明半焦直接熔融温度低且熔融速度更快。本研究结果将为生活垃圾气化熔融技术的工业化应用提供参考。
Municipal solid wastes(MSW)pyrolysis char is the solid product from waste pyrolysis at high temperature in oxygen-free atmosphere.Its melting disposal is helpful to realize the complete harmlessness and reduction of MSW.To explore the effect of waste classification and resource recovery on the melting of MSW pyrolysis char,the mixed waste was classified and sorted to obtain nine groups of waste with different compositions,then their pyrolysis char and char ash were prepared respectively to study their melting characteristics.The results showed that the heat value of pyrolysis char from the nine groups varied from 14.83 to 23.87 MJ/kg.The recovery of plastics and other combustibles could affect the content of pyrolysis char ash and its heat value.After waste classification,the ash fusion temperature(AFT)of pyrolysis char increased,and the four melting characteristic temperatures of different pyrolysis char ash fluctuated between 1180~1300℃.The recycling of paper would reduce the AFT of pyrolysis char ash,while the influence of textile materials recycle was not obvious.Recycling plastics before waste classification would decrease the AFT of pyrolysis char ash,while recycling plastics after classification would increase the AFT of pyrolysis char ash,because the ash carried by plastics affected the ratio of acid-base ratio and Si/Al ratio of pyrolysis char ash.The heat released from the combustion of the waste pyrolysis char was far greater than the heat absorption of pyrolysis char ash melting.When the pyrolysis char stayed at 1150℃for 30 minutes,the pyrolysis char can be completely melted due to the heat released from combustion,while the pyrolysis char ash could not melt under the same condition,which indicated that the direct melting temperature of pyrolysis char was lower and its melting speed was faster.The results of this study would provide guidance for the application of MSW gasification and melting technology.
作者
潘伟
陈德珍
王国雲
俞海淼
PAN Wei;CHEN Dezhen;WANG Guoyun;YU Haimiao(Thermal&Environmental Engineering Institute,Tongji University,Shanghai 200092;Shanghai Engineering Technology Research Center of Multi-source Solid Wastes Co-processing and Energy Utilization,Shanghai 200092)
出处
《环境卫生工程》
2022年第2期37-44,共8页
Environmental Sanitation Engineering
基金
上海市科委国际合作项目(20230712900)。
关键词
垃圾分类
资源回收
热解半焦
热值
熔融
半焦灰分
waste sorting
resource recovery
pyrolysis char
calorific value
fusion
pyrolysis char ash
