Production and recovery of para-xylene
US4118429A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 26, 1977 |
| Grant date | Oct 3, 1978 |
| Priority date | — |
| Expiry date | Sep 26, 1997 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C7/163
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A C.sub.8 -aromatic hydrocarbon mixture containing para-xylene is subjected to adsorption-separation in contact with a crystalline aluminosilicate adsorbent which selectively retains para-xylene. Raffinate therefrom, being a para-xylene deficient C.sub.8 -aromatic concentrate, is isomerized in contact with a catalytic composite containing a Group VIII noble metal component to form additional para-xylene. Isomerization conditions employed to produce the para-xylene, also effect the formation of olefinic material. To prevent the adverse effect which olefins exhibit toward the efficiency and capacity of the zeolitic adsorbent, the isomerization effluent is subjected to hydrotreating at conditions which provide a liquid-phase operation and saturate olefins without saturation of the C.sub.8 -aromatics. The hydrotreating is effected in contact with a substantially non-acidic catalytic composite comprising a Group VIII noble metal component.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.