282929 Increased Productivity of Industrial Plant of Benzene Reforming

Tuesday, October 30, 2012
Hall B (Convention Center )
Dasha Smirnova, Resource-Saving Technologies, Saint-Petersburg State Institute of Technology (Technical University), St Petersburg, Russia

The study examined industrial plant of benzene reforming, which is part of the existing refinery. The device is intended for the production of aromatic hydrocarbons - benzene and toluene - from virgin gasoline fraction 62-105 ° C.

Purpose - Implementation of resource-saving technologies by improving the performance of the separation complex of catalysate of reforming, which is part of the existing facility, and increase the release of benzene when used with existing manufacturing equipment and energy resources.

The complex consists of three separate processing units - the unit of stabilization of catalysate, the unit of liquid extraction and the unit of secondary rectification. The raw materials other than gasoline fraction from the installation of the primary distillation of crude oil can be fed fractions containing benzene and toluene from the plant of summary xylenes.

To analyze the process and optimization calculations the model of the separation complex was developed in the program ASPEN HYSYS. We calculated the optimal structural and operational parameters of the separation system. It was established that in order to increase the load capabilities of the complex is necessary to optimize the separation of the two processing units - the unit of stabilization of catalysate and the unit of secondary rectification.

We shown The possibility and ways of extracting from the catalysate reforming of additional C6 + hydrocarbons  in the unit of catalysate stabilization, as well as the ability of existing facilities to provide increased load on the block on 7 tone per hour. It will increase production of marketable products, in particular benzene.

The  compliance with the quality of products of the block of liquid extraction after changes in stabilization process was confirmed in the model. The research results are confirmed in the course of industrial tests on the current industrial plant. The block of stabilisation was transferred up to the  proposed scheme of operation  on the basis of the experimental test.

To optimize the block  of secondary rectification we identified factors affecting the quality of products, which are divided into two groups - the parameters of control of column of benzene separation(heat flow rate in cubic meters of the column, flow rate and temperature of irrigation), and raw material parameters (flow rate of benzene in the feed stream, the ratio of benzene / toluene  in the feed stream). We established the main reason for the violation of separation in the column, namely overload of  the unit by vapor in the case of increasing the proportion of benzene in the feed stream.

The analysis of the effectiveness of the operation of the process of benzene separation was done. To select the most effective position of  sensor  the term of "width of working range" is introduced. It refers to a range of values of the controlled parameter (in this case, temperature) at which the following restrictions on the production quality.

We developed An algorithm for optimization of technological modes of the block, as well as a prediction algorithm which allows to calculate the composition of raw secondary distillation unit and to develop appropriate technological parameters of the regime accordingly under change the flow of stable catalysate after the block  of stabilization.

Thus, the proposed system of measures has increased the volume of benzene by 15% in compliance with quality requirements and restrictions on the work of production equipment. Results of the study introduced in the industrial process.

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