Method for oxidising hydrocarbons into acids
AssigneeRhodia Polymide Intermediates
InventorEric Fache
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Abstract
The present invention relates to a process for oxidizing hydrocarbons, in particular branched or unbranched saturated aliphatic hydrocarbons, cycloaliphatic or alkylaromatic hydrocarbons to acidic or polyacidic compounds. The invention relates more particularly to the oxidation, with an oxidizing agent containing molecular oxygen, of cyclohexane to adipic acid, in the presence of organic acid of lipophilic nature and in the absence of adipic acid. The separation and recycling of the unoxidized cyclohexane, the oxidation intermediates and the catalysts are easier than in the presence of acetic acid.
Claims22
Process for oxidizing substituted or unsubstituted, saturated aliphatic or cycloaliphatic hydrocarbons or alkylaromatic hydrocarbons to acids or polyacids in a liquid medium by an oxidizing agent comprising molecular oxygen, characterized in that one of the constituents of the liquid medium is an acidic organic compound which is of lipophilic nature.
Process according to one of the preceding claims, characterized in that the weight percentage of lipophilic acidic compounds in the liquid medium is between 1% and 99% by weight relative to the total weight of the liquid medium.
Process according to one of the preceding claims, characterized in that the lipophilic acidic compound is chosen from the group comprising hexanoic acid, heptanoic acid, octanoic acid, 2-ethylhexanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, stearic acid (octadecanoic acid) and the permethyl derivatives thereof, 2-octadecylsuccinic acid, 2,5-di-tert-butylbenzoic acid, 4-tert-butylbenzoic acid, 4-octylbenzoic acid, tert-butyl hydrogen orthophthalate, naphthenic or anthracenic acids substituted with alkyl groups, preferably of tert-butyl type, fatty acids and substituted phthalic acid derivatives.
Process according to one of the preceding claims, characterized in that the oxidation is carried out in the presence of a catalyst.
Process according to one of the preceding claims, characterized in that the oxidation is carried out in the presence of a compound chosen from the family comprising nitriles, hydroxyimide compounds and halogenated compounds.
Process according to one of the preceding claims, characterized in that the hydrocarbon to be oxidized is chosen from the group comprising cyclohexane and cyclododecane.
Process according to one of the preceding claims, characterized in that, after oxidation, the phases of the liquid medium are separated by settling into at least one organic phase formed by the unoxidized hydrocarbon, the lipophilic acidic compound, the said organic phases being recycled into a further oxidation and the acid produced being extracted from the aqueous phase.
Process according to one of the preceding claims, characterized in that the catalyst comprises cobalt as catalytically active element.
Dependencies are inferred from the claim text.