A method of producing liquid fuel and/or chemicals from a carbonaceous material entails combusting a conditioned syngas in pulse combustion heat exchangers of a steam reformer to help convert carbonaceous material into first reactor product gas which includes carbon monoxide, hydrogen, carbon dioxide and other gases. A portion of the first reactor product gas is transferred to a hydrogen reformer into which additional conditioned syngas is added and a reaction carried out to produce an improved syngas. The improved syngas is then subject to one or more gas clean-up steps to form a new conditioned syngas. A portion of the new conditioned syngas is recycled to be used as the conditioned syngas in the pulse combustion heat exchangers and in the hydrocarbon reformer. A system for carrying out the method include, a steam reformer, a hydrocarbon reformer, first and second gas-cleanup systems, a synthesis system and an upgrading system.