Industrial Test Of Coking Benzene Refining By The Halogenated Method

The halogenation method for the refining of coking benzene has been developed in this paper. As a novel technology, it consists of three systems,including the refining of benzene and thiophene derivatives, the refining of toluene and the recovery of acetone. Industrial test of coking benzene refining by the halogenation method were studied.In the industrial test process, materials and distillates from each column were needed to analysis. We have developed the detection methods of the high sulfur compounds, low sulfur compounds and hydrocarbons used gas chromatography based on the requirements of Industrial produce,providing technical support for the industrial processes to ensure Industrial test carry out smoothly.It need to optimize the key parameters when laboratory research apply to industrial production.In the 4th chapter,the non-aromatic hydrocarbon(NAH) in the coking benzene were removed by azeotrope distillation technology by using acetone as entrainer. The amount of acetone and the related parameters of acetone recovery were determined. Results of the simulation test showed that:(1)Industrial simulation test was carried out by azeotrope distillation technology by using acetone as entrainer, when the amount of acetone was added 10 wt% of the feed rates of T202, NAH can be completly removed from mixed materials.(2)Triangular phase diagram show that : Flow rate ratio of extractant and T202 column top material is 1, extraction number of theoretic stages is 4. Flow rate ratio of extraction solvent and raffinate is 3.In the 5th chapter, the industrial test were investigated.Results of the industrial test show that:(1)Operating data of the T202 showed that :When the mass fraction of acetone add to 8wt%-13wt%,the concentration of NAH in the benzene can be reduced to below 0.1wt% through distillation.(2)Carbon disulfide can be removed cleanly by azeotrope distillation technology by using acetone as entrainer(3)The thiophene can be converted into their derivatives by means of halogenation reaction. Thiophene can be converted into 2-bromothiophene and 2,5-dibromothiophene in 2 hours by applying KMnO4+NaBr as halogenated agents at Ph≈1.Furthermore thiophene derivatives are worthy to recycle.(4)Methylthiophene also can be converted into their derivatives by means of halogenation reaction The reaction of methylthiophene was completed in 8.5 hours at the same conditions.(5)The high added value of 2-bromothiophene could be recovered at 56℃-66℃and 2,5-dibromothiophene recovered at 99℃-113℃ by using vacuum distillation under-0.087 Mpa to-0.091 Mpa.The purity of thiophene derivatives were above 98%The key technical parameters and practical experience of coking benzene refining were achieved through this industrial test. It has laid a solid foundation for the next stage of industrial test.