Process for the destruction of porphyrin metallo complexes and for reducing the porphyrin metallo complex content in mineral oils

摘要

Porphyrin-metallo complexes contained in mineral oils are decomposed by treatment with an alkali metal, an alkaline earth metal, magnesium, aluminium, or a hydride of one of the said metals. Such complexes occur only in insignificant amounts in North American oils but are present in objectionable amounts in South American and Middle East oils; they are chiefly complexes of vanadium, nickel, copper and iron. Preferred treating conditions are 93 to 349 DEG C. using 0.02 to 2% wt. of the metal or hydride based on the oil. The treatment may be conducted in the vapour or liquid phase and the contact time required may be reduced by carrying out the treatment in the presence of an oxygen-containing gas, e.g. air. The oil may be recovered from the reaction products by extraction, adsorption, filtration, centrifuging, ion exchange or distillation. In examples, the following treating agents are used:-white mineral oil dispersions of sodium, sodium hydride, and calcium hydride; metallic sodium; and powdered aluminium. In one example the reaction products are removed by consecutive washes with 2% NaOH, 5% H2SO4 and 5% aqueous ethylene diamine tetraacetic acid and in another by filtration.