The invention relates to a
combination method for increasing the yield of p-
xylene in
aromatic hydrocarbon production, which mainly ensures that the problems of low concentration of p-
xylene in mixed xylenes, large
aromatic hydrocarbon processing circulating amount, high requirements on reaction raw materials,
high energy consumption and the like in
aromatic hydrocarbon production are solved. The technical scheme of the method is as follows: mixed raw materials separated from a reforming unit are adopted; C-9 aromatic
hydrocarbon and a third flow of
benzene, which are separated from the reforming unit, enter into a
benzene and C-9 aromatic
hydrocarbon alkyl transfer unit so as to be subjected to dealkylation reaction to generate a second flow of
benzene, a second flow of
toluene and a second flow of C-8 aromatic
hydrocarbon;
toluene selectivity disproportionated reaction is carried out in all
toluene selectivity
disproportionation units to generate C-8 aromatic hydrocarbon containing p-
xylene and benzene flows, thus obtaining a third flow of C-8 aromatic hydrocarbon, a third flow of toluene and a third flow of benzene, wherein the third flow of benzene is returned to the toluene selectivity
disproportionation units; the C-8 aromatic hydrocarbon and the second flow of C-8 aromatic hydrocarbon, which are separated from the reforming unit are mixed and then delivered to an absorptive separation unit so as to obtain a fifth flow of C-8 aromatic hydrocarbon; and the third flow of C-8 aromatic hydrocarbon and the fifth flow of C-8 aromatic hydrocarbon are delivered to a
crystallization separation unit so as to obtain a fourth flow of C-8 aromatic hydrocarbon and pure p-xylene, wherein the fourth flow of C-8 aromatic hydrocarbon is returned to the absorptive separation unit. The problems of the prior art can be solved, and the
combination method can be used for p-xylene industrial production.