摘要
以棉花秸秆和木屑为研究对象,设定不同的燃烧工况,在管式炉中进行燃烧并采集碳烟物质,采用TEM、EDS、GC-MS等检测方法对生物质燃烧过程中生成碳烟的物化特性进行研究,并根据检测结果对碳烟生成机理进行分析和推测。检测及分析结果表明,碳烟颗粒典型形貌有胶囊状、球状、链状、网状等。燃烧工况影响燃烧过程使碳烟颗粒表现出不同的微观形貌。碳烟生长过程中伴随着颗粒的碰撞和凝并,形成形貌复杂的链状或网状颗粒聚团。生物质燃烧中碳烟主要由纤维素热裂解生成,成分包括糠醛类、酚类、醛类、呋喃、烷烃、烯烃等含碳化合物。推测碳烟生成机理为,在生物质燃烧过程中,纤维素发生化学键的断裂与重排,生成CO、CO2和残炭分子碎片等,而残余碳基再通过重整、脱水、碳化、断键等反应生成各种醛类、酮类等产物,醛类、酮类化合物之间通过缩聚、环化反应生成苯环结构,再进一步转化为苯酚、甲苯等化合物。
Cotton stalk and wood scraps were burnt in a tube furnace to generate soot under different combustion conditions. Soot particles were sampled and detected by TEM, EDS and GC-MS to study their physicochemical properties, then the formation mechanics of soot during biomass burning was deduced. The results show that the typical morphological structures of soot are capsule-like, spherical, catenulated and reticular. Combustion conditions enfluence the burning process and result in the different morphology of the soot. The soot particles collided and coagulated during nucleation and growth of soot, which leads to formation of complicated clustered particles. During biomass burning the soot is mainly generated from pyrolysis of cellulose, which contains furfurans, phenols, aldehydes, furans, alkanes and alkenes. The formation mechanics of soot has been speculated. During burning of biomass, the chemical bonds of cellulose fractured and restructured, which generate CO, CO2, residual carbon molecule fragments, and so on. Then residual carbon goes on a series of reactions such as reforming, dehydration, carbonization and bond-breaking to generate aldehydes and ketones. And these compounds polymerized and cyclized to form benzene ring structure, and further converted to toluenes and phenols.
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
2013年第10期1184-1190,共7页
Journal of Fuel Chemistry and Technology
基金
国家自然科学基金(51176047)
河北省自然科学基金(E2012502048)
中央高校基本科研业务费(11MG52)
关键词
生物质燃烧
碳烟
物化特性
生成机理
biomass buring
soot
physicochemical properties
formation mechanics
