Separation method of aromatic compounds comprising simulated moving bed xylene mixture pre-treatment process and additional xylene isomerization process
Disclosed is a method for separating aromatic compounds using a simulated moving bed adsorptive chromatography, comprising a sulfolan process that is a non-aromatic compound removing process, a benzene/toluene fractionation process, an aromatic compound fractionation process, a selective toluene disproportionation process, a transalkylation process, a simulated moving bed para-xylene separation process and a xylene isomerization process, wherein the method is characterized by further comprising a simulated moving bed xylene mixture pre-treatment process and an additional xylene isomerization process. The separation method of aromatic compounds according to the present invention can make significant improvement in para-xylene and benzene production in the overall process, as compared to the conventional aromatic compound separation process.
1. A method for separating aromatic compounds using a simulated moving bed adsorptive chromatography, comprising:
removing a non-aromatic compound from a mixture of aromatic compounds having 7 or less carbon atoms in a sulfolan step;
fractionating benzene/toluene;
fractionating an aromatic compound which separates aromatic compounds having 8 or more carbon atoms;
selectively disproportinating toluene;
transalkylating;
separating para-xylene with a simulated moving bed para-xylene separation step; and
isomerizing xylene;
wherein,
a resultant of the sulforan process is inputted to the benzene/toluene fractionation step,
the toluene from the benzene/toluene fractionation step is inputted to the selective toluene disproportionation step and the transalkylation step,
a resultant of the selective toluene disproportionation step is inputted again to the benzene/toluene fractionation step,
resultants of the benzene/toluene fractionation step and the transalkylation step are inputted to the aromatic compound fractionation step,
a xylene mixture from the aromatic compound fractionation step is inputted to the simulated moving bed para-xylene separation step, and
the xylene mixture from the simulated moving bed para-xylene separation step is inputted to the xylene isomerization step, and wherein,
the method further comprises a simulated moving bed xylene mixture pre-treatment step and an additional xylene isomerization step, wherein the simulated moving bed xylene mixture pre-treatment step is applied between the aromatic compound fractionation step and the simulated moving bed para-xylene separation step, and the xylene mixture from the simulated moving bed xylene mixture pre-treatment step is inputted to the additional xylene isomerization step.
2. The method for separating aromatic compounds according to claim 1 , wherein the xylene mixture pre-treatment step and the additional xylene isomerization step comprise the following steps:
(1) inputting a part of the xylene mixture that is to be inputted to the simulated moving bed para-xylene separation step, to the simulated moving bed xylene mixture pre-treatment step;
(2) inputting the xylene mixture containing 80% by weight or more para-xylene in the resulted product obtained from the simulated moving bed xylene mixture pre-treatment step, to the simulated moving bed para-xylene separation step, and the remaining portion of the xylene mixture is inputted to the additional xylene isomerization step;
(3) re-inputting the resulted product obtained from the additional xylene isomerization step to the aromatic compound fractionation step.
3. The method for separating aromatic compounds according to claim 2 , wherein a portion of the resulted products from the additional xylene isomerization step which are to be inputted to the the aromatic compound fractionation step (3), is inputted to the benzene/toluene fractionation step.
4. The method for separating aromatic compounds according to claim 1 , wherein the toluene is additionally supplied to the selective toluene disproportionation step.
5. The method for separating aromatic compounds according to claim 1 , wherein the xylene mixture is additionally supplied to the aromatic compound fractionation step.
6. The method for separating aromatic compounds according to claim 2 , wherein the toluene is additionally supplied to the selective toluene disproportionation step.
7. The method for separating aromatic compounds according to claim 3 , wherein the toluene is additionally supplied to the selective disproportionation toluene step.
8. The method for separating aromatic compounds according to claim 2 , wherein the xylene mixture is additionally supplied to the aromatic compound fractionation step.
9. The method for separating aromatic compounds according to claim 3 , wherein the xylene mixture is additionally supplied to the aromatic compound fractionation step.