以焦炉上升管内壁结焦炭层块为研究对象, 采用X射线荧光光谱仪(XRF)、 X射线衍射仪(XRD)、 傅里叶红外光谱仪(FTIR)和激光共聚焦拉曼光谱仪(Raman)对结焦炭层的元素组成, 以及各结焦炭层的矿物组成、 组成结构和分子结构进行测试。 分析从结焦炭层块外表面向内表面过渡的各结焦炭层的差异性, 揭示焦炉上升管内壁结焦机理。 结果表明焦炉上升管内粉尘中Fe, S和Cr极易催化荒煤气中蒽、 萘等稠环芳烃化合物成炭, 在焦炉上升管内壁形成炭颗粒沉积, 为焦油凝结挂壁提供载体, 在荒煤气温度降至结焦温度时易结焦积碳。 结焦炭层均含有芳香层结构, 随着结焦炭层从外表面向内表面过渡, 各结焦炭层的面层间距(d002)逐渐降低、 层片直径(La)先降低后增加、 层片堆砌高度(Lc)和芳香层数(N)先稳定后增加。 结焦炭层石墨化过程是由结焦炭层内表面向外表面进行, 主要包括其片层外缘的羧基和部分C—O结构的降解剥离, 从而形成高度规整的共轭结构。 结焦炭层块中C元素是以结晶碳与无定型碳的混合物形式存在。 以上研究为解决焦炉上升管内壁结焦及腐蚀问题, 提高换热器换热效率, 有效回收焦炉荒煤气显热, 降低焦化企业能耗提供实验基础和理论依据。

In this research, the coke layer on the surface of ascension pipe is investigated, and X-ray fluorescence spectrometer (XRF), X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR) and Laser confocal Raman spectrometer (Raman) are applied to investigate mineral composition of the coke, component structure and molecular structure of different coke layer. The research focuses on the differences of coke layer from outer surface to inner surface, and further reveals coking mechanism of ascension peipe heat exchanger. The research displays that the elements of ferrous, sulfur and chromium in dust can catalyst polycyclic aromatic hydrocarbons (anthracene, naphthalene et. al) in raw gas to form carbon particles and deposite on the surface of ascension peipe, providing carrier for tar condensation when the temperature decreases to coking temperature. All of the coke layers contain aromatic structure, and from outer surface to inner surface, the aromatic lamellas spacing (d002) gradually decreases, the value of diameter (La) firstly decreases then increases, and the stck high (Lc) and layer number (N) are stable first then increase. The graphitizing process of the coking layer is from inner layer to outer layer, and —COOH and C—O structures on the edge of the aromatic layers degrade and peel out to form highly regular conjugate structure. The C element in the coke layer is in the form of mixture of crystalline carbon and amorphous carbon. The above research provides experimental and theoretical basis for solving problems of coke and corrosion of ascension pipe, improving heat exchange efficiency, effectively recovering sensible heat of raw gas and decreasing energy consumption of coking enterprises.