餐厨垃圾厌氧沼渣在不同温度下的热解特性

Pyrolysis Characteristics of Anaerobic Biogas Residue of Food Waste at Different Temperatures

城市干湿垃圾分类后,餐厨垃圾经厌氧消化被用于沼气的制造,沼渣是其副产品.为研究沼渣热处理/燃烧技术,通过热重与热裂解-气相色谱质谱联用实验分析了厌氧沼渣的热解规律.结果表明:沼渣中有机组分热解存在两个吸收峰,两峰值位置在200~300℃.200~300℃低温下沼渣热解气中以碳数C9~C18的有机物为主;中温500℃下C19及以上有机物比例由19%提高至31%;高温700℃下C8及以下有机物由6%提高至27%.说明在高温下样品表面会发生热解二次反应.400℃沼渣灰中含有Na、K、Cl,在高温下会释放.750℃的热天平峰值是灰中CaCO_(3)热解失重.沼渣热解产物中,烃、酸的热解主要发生在低温下,醇的热解主要在中温下进行,含N有机物的充分释放发生在高温下.

With urban dry and wet waste classification adopted,kitchen waste is used for anaerobic biogas pro-duction,in which biogas solid residue is the by-product.To develop the heat treatment technology of biogas resi-due,the pyrolysis process of biogas residue was studied experimentally with the use of TG and Py-GC/MS.The results show that:There exist two pyrolysis peaks in thermal gravimetric figure of biogas residue,which lie within the temperature range of 200—300℃.The volatile gas at 200—300℃consists mainly of organic com-pounds with the carbon number of C9—C18.The organic compounds with the carbon number of C19 and above increase from 19%at 200℃to 31%at 500℃.The organic compounds with the carbon number of C8 and below increase from 6%at 200℃to 27%at 700℃.It indicates that secondary pyrolysis reactions occur on the sample surface at higher temperature.The ash content of biogas residue at 400℃contains Na,K and Cl,which are re-leased at higher temperature.A little CaCO_(3) in ash is decomposed at around 750℃.For the pyrolysis products,the release of hydrocarbon and acid mainly takes place at lower temperature.The pyrolysis of alcohol mainly takes place at 500℃.The release of N-containing organic matter tends to occur at higher temperature.