| With the intensification of environmental pollution and the reduction of fossil fuel reserves,people continue to deepen their understanding of the importance of sustainable development.Industrial production is developing in the direction of green,clean and environmental protection.Washing oil is one of the fractions of coal tar.Indole and quinoline,as the high value-added components,separation and utilization from washing oil have extremely high economic value.However,the traditional separation method has serious pollution and harsh conditions.Therefore,the research on the separation method of indole and quinoline is of great significance for the effective use of washing oil.The components of the wash oil are complex and diverse.In this paper,the main components are selected to prepare simulated wash oil for extraction experiments.Imidazole-based ionic liquids and adsorbents are used as new extractants to separate indole and quinoline from the wash oil.Separation experiments were carried on solid adsorbent,and ultraviolet spectrum was carried out on the components analysis of simulated washing oil,and the feasibility of using ultraviolet spectrophotometry to qualitatively and quantitatively determine the components was explored.The preliminary conclusions of this article are as follows:（1）The optimal conditions for the indole extraction experiment of the studied ionic liquid are determined as:extraction time 40 min,extraction temperature 60 oC,volume of ionic liquid and simulated wash oil is 1:5,1-butyl-3-methyl The extraction rate of imidazole tetrafluoroborate to indole reached 96.3%,and the extraction rate of 1-butyl-3-methylimidazole hexafluorophosphate to indole reached 97.2%.Through infrared data analysis,Materials Studio quantitative calculation and polarity analysis,the action mechanism of ionic liquid extraction of indole is analyzed.The analysis shows that the high extraction rate of ionic liquid for indole is the result of the combined effect of hydrogen bonding force and polar force.（2）The highest extraction rate of quinoline using adsorbent silica gel is96.0%,and the best extraction conditions are selected:the mass ratio of ionic liquid to simulated wash oil is 1.5:1,silica gel pore size is 20-30?,silica gel particle size The effect of quinoline extraction is small.In addition,when using ZSM-5 molecular sieve,the extraction rate of quinoline is the best when the agent-to-oil mass ratio is 1.5:1,reaching 88%,but when using artificial zeolite to extract the simulated wash oil,quinoline has no obvious selectivity.The comparison of the extraction rates of quinoline by the three adsorbents is:silica gel ZSM-5 molecular sieve artificial zeolite.（3）Under the optimized extraction experiment conditions,silica gel,ZSM-5 molecular sieve,artificial zeolite and[Bmim][BF4]ionic liquid were immobilized to prepare immobilized ionic liquid.The selectivity of indole is not very obvious,and the extraction rate is relatively reduced to less than 40%,the effect is not ideal,and the extraction rate of indole and quinoline for single ionic liquid[Bmim][BF4]and separate adsorbent and Selective.（4）Use ultraviolet spectrophotometer to detect and analyze the components in the simulated wash oil,and select three substances in the wash oil:naphthalene,quinoline and acenaphthene for the mixed quantitative determination experiment,and compare the measurement results with the gas chromatography detection results.The relative standard deviation of naphthalene is below 7%,and the relative standard deviation of quinoline and acenaphthene is relatively high.This paper proposes a new separation and detection method for indole and quinoline in wash oil fractions in coal tar,which will provide new research directions for green and efficient separation of high value-added chemicals. |
