Experimental and numerical study of applicability of porous combustors forHCl synthesis

Porous combustors have been studied intensively concerning the combustion o f natural gas. The advantages of combustion in porous inert media, such as low emissions, high power turndown ratio of typically 10:1 and compactness, can also be used for different chemical gas phase reactions, e.g. the HCl synthesis from H-2 and Cl-2. The advantages of porous reactors result from the heat transport properties of the porous medium, i.e. emissivity and con ductivity. Heat transport mechanisms and chemical reactions were implemente d in a numerical code in order to investigate the H-2/Cl-2 system. Importan t parameters of the reaction, e.g. the laminar flame speed and the adiabati c flame temperature, are higher for the H-2/O-2 reaction compared to the CH 4/air combustion. By studying the influence of H2O and HCl as inert compone nts it was shown by numerical investigations that the maximum temperature c ould be decreased to a level, which makes the usage of a porous reactor fea sible. A porous reactor for laboratory use was tested with O-2/CH4/N-2 comb ustion, which delivers even higher adiabatic temperatures and flame speeds than the H-2/Cl-2 reaction. Finally, experiments with H-2/Cl-2/HCl reaction were carried out and first results are presented. (C) 2001 Elsevier Scienc e B.V. All rights reserved.