CATALYTIC CRACKING METHOD WITH RECYCLING OF OLEFIN FRACTION EXTRACTED BEFORE GAS SEPARATION SECTION IN ORDER TO INCREASE PROPYLENE OUTPUT

摘要

FIELD: oil and gas industry.SUBSTANCE: this invention is referred to production of benzene and simultaneous production of propylene catalytic cracker (FCC) comprised of the main reactor (1) operating in upflow (upflow riser) or in downflow (downflow riser) and processing heavy charge (CH1), and eventually an auxiliary upflow riser (2) operating in more severe conditions than the main reactor (1) and processing lighter charge (CH2), at that according to the method besides processing of the main charge (CH1) and eventually lighter charge (CH2), the fraction consisting mainly of olefin molecules C4, C5 and C6 is processed, moreover the above olefin fraction corresponding to the flow of intermediate stage (22) is extracted at the level of intermediate stage of wet gas compressor being a part of gas cleanup section (SRG) coupled to FCC, and the above olefin fraction C4, C5 and C6 corresponding to the flow of intermediate stage (22) is introduced before the main charge (CH1) through inner tube of the above main reactor (1), which is ended 1-0.5m before the level of the main charge injectors (CH1).EFFECT: improvement of the method efficiency.10 cl, 1 dwg, 10 tbl, 5 ex