煤炭地下气化焦油析出特性

Formation and characterization of tar from underground coal gasification

基于煤地下气化模型试验,研究不同气化工艺条件下焦油的产率变化,探讨气化工况对焦油析出特性的影响.结果表明,焦油产率主要受气化温度及水蒸汽注入量影响,气化温度升高及水蒸汽存在强化了焦油的裂解过程.最佳气化工况条件下,煤气有效组分含量最高,焦油产率最低.采用GC-MS对地下气化焦油,地面气化焦油及焦炉高温焦油组分进行对照分析得:地下气化焦油主要由多环芳烃和酚类化合物组成.多环芳烃绝大部分为萘、蒽、菲及其衍生物,酚类化合物主要为苯酚、甲酚、二甲苯酚等低级酚,焦油中脂肪烃及杂原子化合物较少.现场试验与模型试验焦油族组分对比表明,煤气出口温度是影响焦油组成的重要因素,焦油中重组分百分含量随煤气温度降低而降低.与地面气化焦油及焦炉高温焦油组成对比表明,地下气化焦油与地面鲁奇加压气化焦油性质接近.

The various law of tar yield and characterization of tar were investigated under different process conditions based on underground coal gasification model experiments. Results show that temperature and steam content are important factors impacting tar yield. Elevated tempera ture and water vaper can promote tar cracking. Tar yield is lowest while the effective component is in the highest amount under the optimum condition. Bying GC-MS, Tar from UCG is in abundance of polycyclic aromatic hydrocarbons and phenols, in which aromatic hydrocarbons mainly contain naphthalene, anthracene, phenanthrene and their derivatives while phenolic compounds mainly Contain phenol, cresol and xylenol etc. The group composition comparison between tar from field test and model test show that well head temprature is an important factor impacting the tar composition. Further more, content of heavy components in tar is lower due to lower well head temprature. The composition and characteristics of tar from UCG is similar with those from Lurgi.