Partial oxidation of sulfur-containing solid carbonaceous fuel

In a process for the simultaneous partial oxidation and desulfurization of a sulfur and silicate-containing comminuted solid carbonaceous fuel comprising, basis solid fuel, 0.2 to 6.0 wt. % sulfur and 0.1 to 30 wt. % of silicate compounds including iron silicate the improvements comprising:

• (1) reacting in the free-flow unobstructed down-flowing vertical refractory lined reaction zone of a partial oxidation gas generator a feed mixture comprising said solid carbonaceous fuel and first and second types of supplemental calcium-containing material with a controlled amount of free-oxygen containing gas and a temperature moderator so that an equilibrium oxygen concentration is provided in the gas phase in the reaction zone with a partial pressure which is less than about 10.sup.-9 atmospheres, the O/C atomic ratio is in the range of about 0.3 to 1.5, the H.sub.2 O/solid carbonaceous fuel weight ratio is in the range of about 0.03 to 0.70 the total atoms of calcium in the reaction zone is in the range of about 1.0 to 3.0 times the atoms of sulfur in the solid carbonaceous fuel plus the atoms of silicon in the ash, and about 90 to 99.8 wt. % of the carbon in said solid carbonaceous fuel is converted into carbon oxides, thereby producing a hot raw effluent gas mixture comprising H.sub.2, CO, CO.sub.2, at least one gas selected from the group consisting of H.sub.2 O, N.sub.2, CH.sub.4, H.sub.2 S, COS and A, and entrained molten slag including calcium sulfide, iron sulfide, and the silicates of calcium and iron;
• the partial oxidation and desulfurization reactions take place at a temperature which is above about 1900.degree. F. and about 10.degree. to 100.degree. F. above the fluid temperature of the slag which has a viscosity in the range of about 1.0, to 2,000 poises, the pressure is in the range of about 2 to 250 atmospheres, and wherein substantially no elemental iron is produced, and at least about 10 to 99 wt. % of the sulfur in the solid carbonaceous fuel in the reaction zone is converted into said calcium sulfide and iron sulfide particulate matter which leave the reaction zone along with the silicates of calcium and iron in said molten slag and the remainder of the sulfur is converted into sulfur-containing gaseous products;
• and wherein said first type of supplemental calcium-containing materials is selected from the group consisting of calcium oxide, calcium hydroxide, calcium carbonate, calcium acetate, calcium formate, calcium hydride, calcium nitrate, calcium chloride, and mixtures thereof;
• said second type of supplemental calcium-containing material is selected from the group consisting of calcium fluoride, calcium borate, and mixtures thereof;
• and of the total amount of said first and second supplemental calcium-containing material added from about 0.01 to 12.0 weight percent is supplied as said second supplemental calcium-containing material and the remainder comprises said first supplemental calcium-containing material;
• (2) cooling and cleaning the hot raw effluent gas mixture from (1) by contacting said effluent gas mixture with a liquid hydrocarbonaceous fuel cooling and scrubbing agent, thereby producing a slurry comprising slag and calcium sulfide in liquid hydrocarbonaceous fuel;
• (3) steam stripping said slurry and separating a gaseous mixture comprising steam and H.sub.2 S;
• and (4) recycling the sulfur-depleted slurry to the front end of the process for use in preparation of fresh feed mixture to the partial oxidation gas generator.