Thermochemical regeneration with fuel additions

A method of carrying out combustion in a furnace, comprising

• (A) combusting fuel in a furnace to produce gaseous combustion products which contain oxygen;
• and
• (B) alternately
• (1) (i) passing a portion of the gaseous combustion products out of the furnace into a first chamber, feeding hydrocarbon fuel into the first chamber, and reacting the hydrocarbon fuel in the first chamber with oxygen present in the gaseous combustion products to reduce the concentration of oxygen in the first chamber and to produce a gaseous reaction mixture containing oxygen and from zero up to 20,000 ppm of carbon monoxide;
• (ii) passing the gaseous reaction mixture out of the first chamber into and through a cooled first regenerator to heat the first regenerator and cool said gaseous reaction mixture;
• (iii) passing at least part of said cooled gaseous reaction mixture from said first regenerator, and fuel, into a heated second regenerator and, in the second regenerator, reacting the gaseous reaction mixture and the fuel in an endothermic reaction in the second regenerator to form syngas comprising hydrogen and CO;
• and
• (iv) passing said syngas formed in the second regenerator into said furnace and combusting the syngas with one or more oxidant streams injected into said furnace;
• and
• (2) (i) passing a portion of the gaseous combustion products out of the furnace into a second chamber, feeding hydrocarbon fuel into the second chamber, and reacting the hydrocarbon fuel in the second chamber with oxygen present in the gaseous combustion products to reduce the concentration of oxygen in the second chamber and to produce a gaseous reaction mixture containing oxygen and from zero up to 20,000 ppm of carbon monoxide;
• (ii) passing the gaseous reaction mixture out of the second chamber into and through a cooled second regenerator to heat the second regenerator and cool said gaseous reaction mixture;
• (iii) passing at least part of said cooled gaseous reaction mixture from said second regenerator, and fuel, into a heated first regenerator and, in the first regenerator, reacting the gaseous reaction mixture and the fuel in an endothermic reaction in the first regenerator to form syngas comprising hydrogen and CO;
• and
• (iv) passing said syngas formed in the first regenerator into said furnace and combusting the syngas with one or more oxidant streams injected into said furnace.