Process for preparation of alpha, beta-unsaturated acids
AssigneeAmoco Corporation
InventorsGary P. Hagen, Ruth A. Montag
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Abstract
Catalyst and process are disclosed for the improved preparation of alpha, beta-unsaturated acids. The catalyst comprises a porous silica gel component and a Group IA alkali metal component, which is present in an amount of from 200 to 20,000 parts per million and optionally another component such as tin (IV) oxide, and mixtures thereof. The process comprises reacting formaldehyde and an aliphatic carboxylic acid in the presence of said catalyst while maintaining catalyst activity and selectivity during the process by addition of a source of the alkali metal component.
Claims14
In a process for making an alpha, beta-ethylenically unsaturated carboxylic acid by contacting formaldehyde and a saturated monocarboxylic acid at vapor-phase condensation conditions over a particulate catalyst comprising a minor amount of alkali metal ion and a major amount of porous silica gel, wherein said catalyst loses said alkali metal ion with consequent decrease in catalyst activity, the improvement consisting of maintaining said catalyst activity by incorporating a volatile or soluble compound of said alkali metal ion in a gaseous feed stream to said process, said feed stream containing at least said saturated monocarboxylic acid, and depositing at least some alkali metal ion contained in said gaseous feed stream on said catalyst.
Dependencies are inferred from the claim text.