Low sulphur fuel oil prodn. - by blending hydrodesulphurized vacuum gas oil and hydrodesulphurized deasphalted residuum

摘要

Fuel oil contg. 1.0 wt. % S is produced from asphaltic hydrocarbonaceous charge stock contg. 150 ppm metals by (a) sepg. the charge stock in a vacuum distillation zone to form a vacuum gas oil fraction free from asphaltics and a vacuum residuum asphaltenic fraction; (b) reacting the vacuum gas oil fraction and H2 in a lst catalytic reaction zone contg. hydrodesulphurisation catalyst, to convert sulphurous cpds. into H2S and hydrocarbons, under conditions including a catalyst bed temp. of 600-880 degrees F and a press. of 500-1500 psig., (c) deasphalting at least part of the vacuum residuum fraction with a solvent in an extraction zone to form a solvent-rich liq. oil phase contg. 30-100 ppm by wt. of metals and a solvent-lean asphaltene concentrate; (d) reacting at least part of the liq. -oil phase from (c) with H2 in a second catalytic reaction zone, to convert sulphurous cpds. into H2S and hydrocarbons, under conditions including a press. of 500-1500 psig. and a catalyst bed temp. of 620-900 degrees F and =20 degrees F higher than the temp. in the lst reaction zone, the catalyst in the 2nd zone has a pore vol. 0.5 cc/g. and comprises a GpVlB and a Gp VIII metal on Al2O3; and (e) recovering a fuel oil prod. contg. 1.0 wt. % S by blending the desulphurised gas oil with the desulphurised liq. oil from (d).