Low NOx Combustion with Natural Gas

An improved method of gas firing on a glass furnace and reduced NOx emissions is outlined. This method involves the use of a cracker for NOx reduction. The cracker method of gas firing takes about 25% of the furnace natural gas consumption through a separate cracker to produce soot particles. This is then re-blended with the balance of 75% of gas, producing a "soot-rich" gas mixture. The combustion of soot-rich gas produces flame with increased luminosity and lower adiabatic flame temperature characteristics which is expected to reduce NOx emissions by 35% or more. Past, current and future plans involving the cracker program are discussed. Past experiments on a pilot unit indicate a very low soot yield (-2%) due to undesirable reforming reactions. Current and future cracker design includes a new modulative gas cracker concept that incorporates several new features which enhance thermal cracking with very little reforming.