A process for the conversion of a asphaltenes, sulfur -, nitrogen - and oxygen compounds, as well as metallic impurities in low-boiling products containing heavy oil

摘要

Heavy hydrocarbon oils contaminated by asphaltenes and metallic impurities are contacted with hydrogen in a first stage in the presence of a solid catalyst containing at least one metal selected from Groups V(B), VI(B) and VIII, at 370-440 DEG C. and 68-204 atmos., reacting at least a high boiling portion of the effluent from the first stage with hydrogen in a second stage at a temperature of 413-468 DEG C., and higher than that in the first stage, in the presence of some of the same catalyst as used in the first stage, and returning high boiling oil from the second stage to the first stage. The first stage may be effected in partly vapour phase in a fluidized bed. Stripped catalyst may be recycled from the second to the first stage. The catalyst may be nickel oxide-molybdenum oxide on a silica-alumina carrier, or the catalyst may be carrier-free and suspended in the oil, being the product of thermal decomposition of an oil-soluble compound of the metal, for example a carbonyl, acetylacetonate or xanthate. This catalyst may be recirculated in suspension in heavy oil from the second to the first stage.