Two phase hydroprocessing

a method wherein the need to circulate hydrogen through the catalyst is presented. This is done by mixing and / or vaporizing the hydrogen and the oil to be treated in the presence of a solvent or diluent in which the hydrogen solubility is "high" in relation to oil supplies. The type and amount of diluent added, as well as the reactor conditions, are arranged so that all the hydrogen needed in hydrotreatment reactions is available in solution. The solution oil / diluent / hydrogen can then be supplied to a flow reactor with the catalyst sealing effect where the oil and hydrogen reacts. introducing additional hydrogen is needed, avoiding therefore to hydrogen recirculation and the operation dropwise reactor bed. Thus, large trickle bed reactors can be replaced with much lower tubular reactors.