Thermochemical regeneration with soot formation

A method of carrying out combustion in a furnace, comprising

• (A) combusting fuel in a furnace to produce gaseous combustion products, and
• (B) alternately (1) (i) passing gaseous combustion products from the furnace into and through a cooled first regenerator to heat the first regenerator and cool said gaseous combustion products,
• (ii) passing at least a portion of said cooled portion of gaseous combustion products from said first regenerator, and hydrocarbon fuel, into a heated second regenerator,
• (iii) reacting the gaseous combustion products and the fuel in the second regenerator in an endothermic reaction under conditions effective to form a mixture of syngas comprising hydrogen, carbon monoxide, and soot which is entrained in the syngas, wherein the mixture contains 0.1 to 20 grams of soot per cubic meter of the mixture, and thereby cooling the second regenerator;
• and
• (iv) passing said syngas and entrained soot from said second regenerator into said furnace and combusting the syngas and entrained soot in the furnace with one or more oxidant streams injected into said furnace;
• and
• (2) (i) passing a portion of the gaseous combustion products from the furnace into and through a cooled second regenerator to heat the second regenerator and cool said portion of the gaseous combustion products,
• (ii) passing at least a portion of said cooled portion of gaseous combustion products from said second regenerator, and hydrocarbon fuel, into a heated first regenerator,
• (iii) reacting the gaseous combustion products and the fuel in the first regenerator in an endothermic reaction under conditions effective to form to form a mixture of syngas comprising hydrogen, carbon monoxide, and soot which is entrained in the syngas, wherein the mixture contains 0.1 to 20 grams of soot per cubic meter of the mixture, and thereby cooling the first regenerator, and
• (iv) passing said syngas and entrained soot from said first regenerator into said furnace and combusting the syngas and entrained soot in the furnace with one or more oxidant streams injected into said furnace;
• wherein said hydrocarbon fuel is natural gas and the molar ratio of the portion of said cooled portion of gaseous combustion products from said first regenerator passed into a heated second regenerator and said hydrocarbon fuel is less than 0.5:1.