EP0384652A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Process for preparing carboxylic acids
Assignee: BP PLC
•
Filing: 1990-02-15
•
Granted: —
•
Expires: 2010-02-15
Abstract
Abstract An improved liquid-phase process for preparing carboxylic acids having (n + 1) carbon atoms by rhodium catalysed carbonylation of an alcohol having n carbon atoms is provided. The process is particularily suitable for preparing acetic acid from methanol in commercial carbonylation reactors operating at steady-state with a low standing quantity of water (eg 0.5 to 5% by weight). The improvement lies in carrying out the carbonylation in the presence of an iodide stabiliser (eg lithium iodide) and a Group VI B metal costabiliser. The process can optionally be carried out in the presence of hydrogen.
Inventors
- 👤 Michael David Jones
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 20:13
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/10; C07C51/12
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
150 words
A liquid-phase process for preparing a carboxylic acid having (n + 1) carbon atoms by reaction of carbon monoxide with an alcohol having n carbon atoms in the presence of a rhodium catalyst at elevated temperature and pressure which process comprises feeding the alcohol and/or an ester of the alcohol and the carboxylic acid together with carbon monoxide to a carbonylation reactor and removing the carboxylic acid from the carbonylation reactor characterised in that the carbonylation reactor contains during the course of the process a liquid reaction medium comprising: (a) at least a finite quantity of water, (b) a catalyst stabiliser selected from iodide salts which are soluble in the reaction medium at the temperature of the reaction, (c) a Group VIB metal costabiliser, (d) the iodide derivative of the alcohol, (e) the ester of the carboxylic acid and the alcohol, (f) a rhodium catalyst, and (g) the carboxylic acid.
Claim 2
Dependent Claim
150 words
A liquid-phase process for preparing a carboxylic acid having (n + 1) carbon atoms by reaction of carbon monoxide with an alcohol having n carbon atoms in the presence of a rhodium catalyst at elevated temperature and pressure which process comprises feeding the alcohol and/or an ester of the alcohol and the carboxylic acid together with carbon monoxide to a carbonylation reactor and removing the carboxylic acid from the carbonylation reactor characterised in that the carbonylation reactor contains during the course of the process a liquid reaction medium comprising: (a) at least a finite quantity of water, (b) a catalyst stabiliser selected from iodide salts which are soluble in the reaction medium at the temperature of the reaction, (c) a Group VIB metal costabiliser, (d) the iodide derivative of the alcohol, (e) the ester of the carboxylic acid and the alcohol, (f) a rhodium catalyst, and (g) the carboxylic acid.
Claim 3
Dependent Claim
22 words
A liquid-phase process as claimed in claim 1 characterised in that the carboxylic acid is acetic acid and the alcohol is methanol.
Claim 4
Dependent Claim
27 words
A liquid-phase process as claimed in claim 2 characterised in that the level of water is 0.5 to 5% of the total weight of the reactor contents.
Claim 5
Dependent Claim
31 words
A liquid-phase process as claimed in claim 3 characterised in that the level of methyl acetate in the reactor is 1 to 6% of the total weight of the reactor contents.
Claim 6
Dependent Claim
19 words
A liqiud-phase process as claimed in claim 4 characterised in that the catalyst stabiliser is an alkali metal iodide.
Claim 7
Dependent Claim
24 words
A liquid-phase process as claimed in claim 5 characterised in that the Group IV B metal costabiliser is either a molybdenum or tungsten costabliser.
Claim 8
Dependent Claim
31 words
A liquid-phase process as claimed in claim 6 characterised in that the Group IV B metal costabiliser is a low valent molybdenum or tungsten salt or a molybdenum or tungsten carbonyl.
References Cited (Backward Citations)
GB2121794A
Cited
EP0161874A1
Cited
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.