Process for producing maleic anhydride
US4760153A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 24, 1986 |
| Grant date | Jul 26, 1988 |
| Priority date | — |
| Expiry date | Mar 24, 2006 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01J2523/00
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An improved process for producing maleic anhydride which comprises catalytically oxidizing benzene with a molecular oxygen-containing gas in the vapor phase in a multitubular heat-exchanger-type reactor. The process is characterized in that PA1 a catalyst-packed layer of the reactor is divided into a gas inlet side layer and a gas outlet side layer, PA1 the activity of the gas inlet side layer is controlled by adding at least one component selected from the group consisting of potassium, cesium, thallium and rubidium as a promoter or by decreasing the amount of phosphorus pentoxide (P.sub.2 O.sub.5) to be added in the catalytically active substance containing vanadium pentoxide, molybdenum trioxide and sodium oxide, and PA1 the activity of the gas outlet side layer is increased by decreasing the amount of at least one component selected from the group consisting of potassium, cesium, thallium, rubidium, magnesium, calcium, strontium and barium or by not adding such a component from that in the catalyst, or by increasing the amount of phosphorus pentoxide (P.sub.2 O.sub.5) from the gas inlet side catalyst.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.