The process and system of the invention converts solid and liquid carbonaceous feedstock into electricity, steam, fuels, and carbon dioxide with minimal air emissions. Oxygen is partially consumed in a fuel cell then exhausted to a combustor of a Twin-Fluid Bed Steam Gasifier Unit (TFBSGU) where it is consumed in burning carbon contained in ash. After particulates are separated, the flue gas is expanded then cooled to recover power before returning to atmosphere or a bio-reactor. Synfuel leaving the TFBGSU is cooled in a heat recovery unit, producing steam and hot water. Carbon monoxide in this stream reacts with steam producing hydrogen and carbon dioxide. The stream is then cooled and compressed. The compressed gas passes through an acid gas removal system removing carbon dioxide and sulfur bearing compounds. Steam is added to the clean gas to prevent coking and the stream enters the anode space of the fuel cell.