Patent ID: 7348443

Claim:
A process for the preparation of one or more partial oxidation products, one or more partial ammoxidation products, or both, of at least one olefinic hydrocarbon A′, comprising A) subjecting, in a first reaction zone A, at least one paraffinic hydrocarbon A to a partial dehydrogenation, oxydehydrogenation, or both, to form a product mixture A which comprises at least one paraffinic hydrocarbon A and at least one olefinic hydrocarbon A′ formed by the partial dehydrogenation, oxydehydrogenation, or both, B) optionally separating from the product mixture A at least a portion of the components other than the paraffinic hydrocarbon A and the olefinic hydrocarbon A′ to form a product mixture A′, and feeding either the product mixture A, when said separating is not carried out, or the product mixture A′, when said separating is carried out, to an oxidation, ammoxidation, or both, zone B and, subjecting the olefinic hydrocarbon A′ to partial oxidation, ammoxidation, or both, to form a product mixture B which comprises at least one partial oxidation, ammoxidation, or both, product B of the at least one olefinic hydrocarbon A′, C) separating partial oxidation, ammoxidation, or both, product B from the product mixture B in a working-up zone C and recycling at least a portion of the at least one paraffinic hydrocarbon A in the product mixture B into the reaction zone A and D) intermittently not operating at least a part of the reaction zone A wherein, while at least a part of the reaction zone A is not operating, the oxidation, ammoxidation, or both, in zone B is further carried out and a production loss of the at least one olefinic hydrocarbon A′ while at least a part of reaction zone A is not operated is at least partly compensated by feeding at least one olefinic hydrocarbon A′ originating from a source other than the reaction zone A, and optionally one or more paraffinic hydrocarbons A originating from a source other than the reaction zone A, to the oxidation, ammoxidation, or both, zone B and then recycling at least a portion of the at least one paraffinic hydrocarbon A present in the product mixture B of the oxidation, ammoxidation, or both, zone B, as paraffinic recycle hydrocarbon A, not via the reaction zone A, into the oxidation, ammoxidation, or both, zone B.