化学法改性煤沥青脱除苯并芘的研究

Removal of benzopyrene from coal tar asphalt by chemical method

  • 摘要: 在管式反应器中采用苯甲酸、聚乙二醇、固体古马隆树脂(S)、液体古马隆树脂(L)为添加剂来降低煤沥青中有害物质苯并芘的含量,以期使得煤沥青可绿色化应用。采用紫外-可见分光光度计分析煤沥青中苯并芘含量。考察了反应温度、反应时间、添加剂添加量、催化剂等工艺条件对添加剂脱除煤沥青中苯并芘的影响。结果表明,不同工艺条件能降低煤沥青中苯并芘的含量。在优化条件下,不同添加剂对苯并芘脱除率由高到低依次为:液体古马隆树脂、聚乙二醇、苯甲酸和固体古马隆树脂。分析其反应机理,这与催化剂的酸性相关,发生亲电取代反应。结果表明,液体古马隆树脂(L)在催化剂存在下对煤沥青中苯并芘脱除率可达73.0%,显示了良好的应用前景。

     

    Abstract: For the friendly environmental application of coal tar pitch, the benzoic acid, polyethylene glycol, solid coumarone resin (S) or liquid coumarone resin (L) were selected as a modifier to lower the content of harmful benzopyrene in coal tar pitch by chemical reaction in a tube furnace. The benzopyrene content was detected by an ultraviolet-visible spectrophotometer, and the influence of reaction temperature, reaction time, modifier contents and catalyst types on the benzopyrene content was investigated. The results show that the technical condition has an intimate relationship with the decrease of benzopyrene content owing to the electrophilic substitutive reaction at the existence of acidic catalyst. All modifiers tested have obvious effects on the decrease of benzopyrene content. Under the optimum conditions, the removal rates of benzopyrene by different additives decrease in proper sequence of liquid coumarone resin, polyethylene glycol, benzoic acid and solid coumarone resin. The highest benzopyrene removal rate of 73.0% is obtained by using liquid coumarone resin, showing a promising application prospect.

     

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