A mixture (34) of a hydrocarbon feedstock with steam and/or carbon dioxide is preheated and adiabatically steam reformed giving a partially reformed gas (26) which is then, optionally after reheating, further steam reformed inannular catalyst regions (32) of a double tube reformer (14). The outer tubes...http://www.google.com.au/patents/US4985231?utm_source=gb-gplus-sharePatent US4985231 - Production of hydrogen-containing gas streams
