The preheating of producer gas in regenerative furnaces 

GT V02 1961 023-034

Changes in producer gas composition  and heat content resulting from preheating have been  determined  on a number of industrial  furnaces. With regenerators of rectangular brick packing in which preheat  temperatures of over 1000°C are  obtained in normal  operation,  it is shown that decomposition of tar   vapours   increases rapidly at preheat temperatures above 900°C, and decomposition of fixed hydrocarbon gases above 1050°C. The thermal input  to the furnace  increases continuously with increasing preheat temperature, the gain in sensible heat far  outweighing the loss of chemical energy through soot  deposition. The only reason for  limiting  the preheat temperature  below the maximum attainable may be  the increasing loss of luminants from the gas associated with increasing temperature. In regenerators which gave lower preheat  temperatures in  normal  operation,  decomposition of hydrocarbons occurred at lower temperatures. It is suggested that  the relation  between preheat  temperature  and gas  composition  is dependent  upon the manner in which gas flows within   the   regenerator,   and   the lower gas  preheat temperature   associated   with   regenerators of lower thermal efficiency does not  necessarily give any advantage in reduced hydrocarbon decomposition. 

G. A. Sparham & D. W. Gill