采用富氧空气/水蒸气两阶段气化工艺,用自行研制的煤炭地下气化模拟试验系统,对内蒙褐煤进行地下气化模型试验,并收集气化后的煤气洗涤水。之后对煤气洗涤水的有机组分、挥发酚和氨氮进行检测,考察内蒙褐煤地下气化对地下水可能造成的污染。由结果可知:不同气化阶段煤气洗涤水的有机组分相似,均以酚类物质为主,酚类物质体积分数最高可达有机组分的76.82%。其次为多环芳香烃和杂环化合物,还含有少量的单环芳烃和脂肪烃,几乎不含卤代烃;水蒸气气化阶段煤气洗涤水中的多环芳烃和酚类化合物均比空气气化阶段的多,氨氮和挥发酚的浓度变化也符合这一规律。表明水蒸气气化剂对地下水的污染可能更严重。
The underground gasification model test of Neimeng lignite was carried out by applying two-stage coal gasification( oxygen-enriched steam) gasifier designed by ourselves. The gas was washed by deep groundwater in the process of gasification. Then the organic components,volatile phenol and ammonia of gas washing water were tested to detect the groundwater pollutions from UCG. The results show that the organic components of gas washing water are similar at different gasification stage. The phenolics compounds are given priority,and the volume fraction of which can be up to 76. 82%. The second ones are polycyclic aromatic hydrocarbon and heterocyclic compounds,and a little of mononuclear aromatics and aliphatic hydrocarbons are also tested in washing water. There are little halogenated hydrocarbon. The contents of polycyclic aromatic hydrocarbons and phenolic compounds in gas washing water with steam as the gasification agents are higher than those of oxygen-enriched gasification. The changes of the concentration of ammonia and volatile phenol also comply with the law,which show that the steam gasification agent for groundwater pollution should be more serious.