低温烘焙下城市生活垃圾与烟煤的混燃特性

Co-combustion Characteristics of Bituminous Coal and Municipal Solid Waste Under Torrefaction

为了探讨垃圾与煤的混燃特性,选取城市生活垃圾(MSW)和烟煤(BC)为研究对象,通过热重分析法研究烘焙温度、掺混比例、升温速率对样品燃烧特性的影响,并采用Kissinger-Akahira-Sunose(KAS)法计算样品的活化能。结果表明:MSW经220℃,260℃和300℃低温烘焙后,热值都有所提升,随着烘焙温度上升,其质量产率和能量产率逐渐降低,挥发分析出与燃烧区间逐渐减小,固定碳燃烧区间逐渐增大;MSW-260与BC掺混能有效改善烟煤的燃烧特性,提高混合样的燃烧速率;升温速率上升会产生热滞后现象,MSW-260与BC混合燃烧各反应阶段向高温侧移动,且升温速率越快偏移越明显。综合动力学分析以及燃烧特性参数分析来看,在保证资源高利用率和良好的燃烧状况条件下,MSW-260与BC混燃质量比可以选用5∶5。

In order to discuss the co-combustion characteristics of waste and coal,municipal solid waste(MSW)and bituminous coal(BC)were selected as the research objects,and the effects of torrefied temperature,blending ratio and heating rate on the combustion characteristics of samples were studied by thermogravimetric analysis.The Kissinger-Akahira-Sunose(KAS)method was used to calculate the activation energy of the samples.The results show that after MSW is torrefied at 220℃,260℃and 300℃,the calorific value has increased,the torrefied temperature rises,its mass yield and energy yield gradually decrease,the precipitation and combustion interval of volatile matter gradually decrease,and the combustion interval of fixed carbon gradually increases;the blending of MSW-260 and BC can effectively improve the combustion characteristics of bituminous coal and increase the combustion rate of the mixed sample;the increase of heating rate causes thermal hysteresis,and the combustion of MSW-260 and BC mixed sample moves to the high temperature side in each reaction stage,and the faster the heating rate,the more obvious the deviation.The results indicate that based on the comprehensive dynamics and correlation analysis of combustion characteristic parameters,under the conditions of ensuring high resource utilization and good combustion conditions,the mass ratio of mixed combustion of MSW-260 and BC can be selected as 5∶5.