Study On The Solvent Extraction Process Of Phenolic Compounds In Distillate Oil

Phenolic compounds,because of its particular structure,which can be used as intermediate for organic synthesis and which is also an important chemical row materials.Phenolic compounds have a very high economic value.Developing the technology of extracting phenolic compounds from phenol oil not only can enrich the source of phenolic compounds,but also can improve the oil.The technology has important economic and social value.At present,alkaline cleaning method is wildly used in the industry,which consumes a lot of strong acid and alkali in the course of operation,produces the serious corrosion of equipment.In the process,a lot of waste water contained phenol is produced,which pollute the environment seriously.This result cannot meet the requirement of green chemical industry.Solvent extraction method is used in this paper.I selected the proper extract and a new phenolic extraction process is developed.The whole process had high extraction rate,did not produce phenol wastewater,no acid and alkali,no corrosion equipment,solvent recovery simple,high recovery rate,easy to achieve industrialization.Based on the principle of similarity compatibility,the method of cavity effect and bond energy data is used to select several extraction agents.Combining with the experimental results and analyzing the physical properties of each solvent,MEA is suitable as phenolic extractant.Taking MEA as extractant,single factor experiment is carried out.The optimal operating conditions are as follows:the ratio of MEA to oil is 0.4,the extraction temperature is 25?,and the extraction time is 8 min.The extraction rate of phenolic compounds was more than 80%when the phenol oil was extracted with the MEA,which contained oil of 10%.The extraction effect of MEA on phenol is better than that of cresol.The content of toluene in phenol oil has little effect on the extraction of phenolic compounds.The effects of extraction modes and extraction stages on the extraction process are as follows:When the total amount of solvent and extraction stages are the same,the countercurrent extraction effect is better than the cross-flow extraction.Under the condition of five-stage countercurrent extraction,the extraction rate of phenolic compounds can reach98.97%.The extractant in the extraction phase was recovered by reduced pressure distillation.The entrapped extractant in the raffinate phase is recovered by washing with water and dehydrating at atmospheric pressure.The recovery of the solvent reached 99.97%under the conditions of the operating pressure of 6kPa and reflux ratio of 5.The MEA content was97.69%in top product.The four-stage cross-flow extraction was carried out under the optimal extraction conditions of 0.8:1(V_water:V_oil)at room temperature of 25?.The MEA content in the residual oil is as low as 0.08%.The MEA aqueous solution obtained by washing with water was subjected to atmospheric distillation to obtain product which contented 99.57%of MEA.