Process for the partial oxidation of liquid hydrocarbonaceous fuels

In a partial oxidation process for producing gaseous mixtures comprising H.sub.2 and CO, and at least one material from the group H.sub.2 O, CO.sub.2, H.sub.2 S, COS, CH.sub.4, N.sub.2, NH.sub.3, and Ar, and entrained particulate carbon by the partial oxidation of a liquid hydrocarbonaceous fuel with a freeoxygen containing gas optionally with a temperature moderator in a free-flow, noncatalytic refractory lined, gas generator at a temperature in the range of about 1800.degree. to 3000.degree. F. and a pressure in the range of about 1 to 250 atmospheres, including preheating the reaction zone of said gas generator at atmospheric pressure by introducing fuel gas into said reaction zone by means of a preheat burner and by the complete combustion of said fuel gas with air, stopping said flow of said fuel gas and air and removing said preheat burner from the gas generator, replacing said preheat burner with an annulus-type main burner, the improvement comprising removing said preheat burner from the gas generator when said reaction zone reaches a temperature in the range of about 1832.degree. to 2012.degree. F.;

• introducing air or compressed air in excess of stoichiometric into said reaction zone by way of one passage of said main burner and continuously passing fuel gas through another passage of said main burner, heating said reaction zone by complete combustion of said fuel gas and air at a pressure in the range of about 0.5 to 1.0 atmospheres, connecting said main burner pressure tight to said reaction zone and continuing heating said reaction zone at a pressure in the range of about 0.5 to 250 atmospheres until the temperature required for ignition of the autothermal partial oxidation reaction of the liquid hydrocarbonaceous fuel and free oxygen containing gas in the presence of a temperature moderator in the range of about 2192.degree. to 2642.degree. F. is reached;
• stopping the flow of said streams of fuel gas and air and passing a stream of liquid hydrocarbonaceous fuel optionally in admixture with a temperature moderator through the same passage in said main burner that formerly carried said fuel gas, and passing a stream of free-oxygen containing gas optionally in admixture with a temperature moderator through the same passage in said main burner that formerly carried said air;
• and mixing said streams together to form a mixture, and igniting said mixture at atmospheric pressure and bringing said reaction zone up to operating pressure to produce said gaseous mixtures.