FIELD: chemistry.
SUBSTANCE: invention relates to method of producing separate xylol isomer from initial raw material flows, which contain aromatic C8 compounds, aromatic C9 compounds and heavier aromatic compounds. Method includes: (a) distillation process, which includes application of two xylol columns, separating aromatic C8 compounds from aromatic C9 compounds and heavier aromatic compounds, contained in, at least, one raw material flow with lower boiling temperature and in, at least, one raw material flow with higher boiling temperature, and said, at least, one raw material flow with higher boiling temperature has higher content of aromatic C9 compounds and heavier aromatic compounds in comparison with, at least, one raw material flow, which has lower boiling temperature, distillation process includes distillation of, at least, one flow of initial raw material, which has higher boiling temperature, in first xylol column at first pressure for separation of first flow of aromatic C8 compounds from first flow of aromatic C9 compounds and heavier aromatic compounds, and distillation of, at least, one flow of initial raw material, which has lower boiling temperature, in second xylol column at second pressure for separation of second flow of aromatic C8 compounds from second flow of aromatic C9 compounds and heavier aromatic compounds, value of second pressure being higher than first pressure, flow of product, discharged from the top pf second xylol column exchanges heat with reboiler of first xylol column; (b) process of separating xylol isomer for removal of separate xylol isomer from one or both of first and second flows of aromatic C8 compounds by introduction of one or both flows of aromatic C8 compounds and desorbent flow into adsorption process with obtaining first mixture, which contains separate xylol isomer and desorbent, and second mixture, which contains raffinate and desorbent; (c) process of desorbent extraction with separation of first mixture of (b) stage by distillation of first mixture in extract column at working pressure, constituting, at least, 300 kPa to obtain flow, which contains separate xylol isomer, and flow of desorbent, and return of desorbent flow into process of xylol isomer separation, with flow, discharged from the top of first xylol column of stage (a) providing supply of heat to extract column reboiler.
EFFECT: application of claimed invention provides additional possibilities for energy-saving within the limits of installation due to exchange of heat with involved in xylol extraction technical means interrelated, which are connected with them.
10 cl, 1 ex, 6 dwg
