| 摘要 |
It has been discovered that the naphthenic acids present in crude oil are carboxylic acids, characterised by being one (or more) aliphatic or naphthenic ring having an associated alkyl group, which is ended by a carboxylic acid group. The naphthenic acids produce atypical corrosion phenomena, given that they can cause a localised attack without the presence of water at temperatures between 473 K and 693 K, hindering the processing of this type of crude oils in refineries. The invention relates to a catalytic hydrogenation process that permits the selective removal of naphthenic acids present in heavy and extra heavy crude oils with a low production of hydrogen sulphides, in particular in crude oil that has not previously been fractionally distilled. The catalyst is formed by an aluminium and/or magnesium-aluminium spinel-type support having active Fe-Mo phases. In addition, the applicant has discovered that the hydrogenation process using Fe and Mo catalysts and/or mixtures thereof surprisingly permits an acid number of 1 mg KOH/g to be reached in crude oils with TAN greater than 4 gm KOH/g, reducing unwanted reactions in the process and prolonging the useful life of the catalyst via the low deposition of metal sulphurs. |
