工艺条件对煤液化油中酚类化合物的影响研究

STUDY ON THE EFFECTS OF PROCESS CONDITIONS ON PHENOLIC COMPOUNDS IN DIRECT COAL LIQUEFACTION OILS

煤炭直接液化油中含有种类丰富且数量可观的酚类化合物,研究影响酚类含量和组成的因素,对于深入研究煤液化产物中酚类化合物的生成机理具有重要的理论意义和实践意义.考察了煤液化过程中反应温度、催化剂及添加高分油三种工艺条件对煤液化油（41℃-220℃）中酚类含量分布的影响.结果表明：随着反应温度升高和催化剂加入都能增加煤液化油中总粗酚产率,而添加高分油方式则不太明显;另外,升高反应温度和添加高分油两种方式可以促进高级酚类中间体发生裂解、脱烷基及脱羟基等二次反应向生成分子量更小、结构更简单的低级酚类进行转化,而通过催化剂的加入可以抑制部分高级酚类向低级酚类的转化.

High-abundance content-rich phenolic compounds are formed in the direct coal liquefaction oil. It is crucial to investigate the factors that determine the contents and compositions of phenolic compounds, in order to understand better the mechanism how phenolic compounds are produced. In this paper, we study the effects of three process conditions, including reaction temperature,catalyst and addition of high boiling point oil, on the content distribution of phenolic compounds in a boiling 41 ℃-220 ℃ coal liquefaction oil. We have found out that both the addition of catalyst and the increase of reaction temperature lead to the enhanced yield of crude phenol while addition of high boiling oil has insignificant effect. In addition, both the increase of reaction temperature and addition of high boiling oil help convert high-level phenolic intermediates to lower-molecular-weight, simpler-structure, low-level phenols by means of cleavage, hydrodealkylation, and dehydroxylation. In contrast, the addition of catalyst greatly inhibits the transformation from higer phenols to low-grade phenolic.