Patent GB-668867-A (GB)
Title: Process for the partial oxidation of organic compounds in the presence of cuprous oxide catalysts and the oxygenated compounds so produced
IPC: C07C47/00
Filed: 1949-06-13
Abstract: Relates to a continuous process for the partial oxidation of an oxidizable organic compound by reaction with oxygen in the presence of a solid catalyst containing cuprous oxide which comprises passing a gaseous mixture comprising the organic compound and oxygen or an oxygen-containing gas into contact with the catalyst at a predetermined pressure, temperature and composition of the gaseous mixture, whereby the organic compound is oxidized to an organic product of partial oxidation and catalyst deactivation occurs, separating from the catalyst or gaseous mixture comprising the product of partial oxidation, perodically substantially decreasing or interrupting the flow of oxygen or oxygen-containing gas to the catalyst, while maintaining the other conditions of operation substantially unchanged, or periodically substantially increasing the temperature of the catalyst and/or decreasing the pressure of the gaseous mixture in contact with the catalyst while maintaining the other conditions of operation substantially unchanged, and after each period of decreased or interrupted flow of oxygen or oxygen-containing gas restoring said flow to the catalyst or after each period of operation at the new temperature and/or pressure restoring those conditions extant before the change was effected. The catalyst may be used in any form, i.e. in fixed, mobile, pseudo-liquid or fluidized beds.  As well as reactivating the catalyst the process p  also results in increased overall activity and stability of the catalyst.  Temperatures generally range from about 150 DEG  to about 650 DEG  C.  Any pressure may be used when altering the oxygen flow but those above about 20 atmos. are usually avoided.  A pressure of 3 to 10 atmos. is used when pressure and/or temperature changes are made.  The cuprous oxide may be used alone or supported on conventional materials.  Inert diluents, e.g. steam, nitrogen or carbon dioxide, may be present.  The magnitude of the pressure drop depends on reactants and operating conditions, but drops of up to 15 atmos. are indicated.  Increases in temperature given are 50 DEG  or 150 DEG  C. in a reaction at about 350 DEG  C. These changes may be represented in magnitude by (T1/T0)2/(P1/P0) 1/3 , where T0 and T1 are respectively the operating and reactivating temperatures and P0 and P1 the corresponding pressures and specified values for the ratio are 1.1 to 4.0, preferably 1.2 to 2.5.  In this embodiment catalyst may be removed from the reaction zone reactivated in a second zone by treatment with a separate stream of gaseous reactants of the same composition but at the varied conditions and returned to the process.  The method may be used for oxidizing hydrocarbons to yield aldehydes, ketones, carboxylic acids, oxy-acids or oxo-acids, alcohols and epoxy compounds, or aldehydes to carboxylic acids, carboxylic acids to oxy- or oxo-acids, or alchols to more highly oxidized derivatives thereof.  Specified reactions are propylene, isobutylene and straight-chain butylenes to acrolein, methacrolein and methyl vinyl ketone respectively, and methyl ethyl ketone, mixed amyl ketones and methyl isobutyl ketone to diacetyl, methyl ethyl glyoxal and methyl isopropyl glyoxal, respectively. Details are given for the production of acrolein from propylene and methyl ethyl ketone to diacetyl and graphs are provided showing the effect of successive treatments on catalyst activity.  Details are also given of suitable apparatus for effecting the reaction. Specifications 547,743, 586,754, 633,334 and 640,383 are referred to. The Specification as open to inspection under Sect. 91 relates to the use as catalyst of any heavy metal capable of existing in the form of more than one oxide and many of such metals and their oxides are specified.  This subject-matter does not appear in the Specification as accepted.