OPTIMELT™ REGENERATIVE THERMO-CHEMICAL HEAT RECOVERY FOR OXY-FUEL GLASS FURNACES

The operation of glass furnaces with oxy-fuel combustion in combination with advanced heat recovery is a compelling low cost solution. Praxair has developed a new heat recovery technology for oxy-fuel fired furnaces in which regenerators are used in a similar way as conventional regenerators, which recover waste heat from the furnace flue gas. The OPTIMELT (TM) Thermo-Chemical Regenerator (TCR) technology uses the stored waste heat to reform a mixture of natural gas and recirculated flue gas to hot syngas, resulting in efficient heat recovery. The natural gas reacts endothermically in the hot checker pack with the water vapor and CO2 in the recycled flue gas, forming H-2 and CO as a hot syngas fuel. The OPTIMELT (TM) TCR system is simple and operated at atmospheric pressure without the need of catalysts or separate steam generation. It reduces fuel consumption of an oxy-fuel fired furnace by about 20% and offers an attractive conversion option for existing air-regenerator furnaces, with more than 30% fuel reduction compared to the air-fuel base case. This technology is currently being demonstrated on a 50 t/d commercial glass furnace at Pavisa. This paper introduces the operating principles of the TCR and highlights some milestones recently achieved at the demonstration site. Initial data from the TCR operation at the host furnace are presented and discussed.