METHODS FOR FEEDSTOCK PRETREATMENT AND TRANSPORT TO GASIFICATION

摘要

Methods for pretreating feedstock for gasification are provided. At least a portion of a coal based feedstock stream can be combined with at least a portion of a supercritical carbon dioxide stream within a pretreatment system to provide a treated feedstock stream. At least a portion of the treated feedstock stream can be passed to a gasifier to produce a synthesis gas stream of less than 50 % by volume carbon dioxide, at least 5 % by volume carbon monoxide and at least 1 % by volume hydrogen. At least a portion of the synthesis gas stream can be combusted to form an exhaust stream comprising carbon dioxide. At least a portion of the gasification byproduct stream can be purified and compressed to produce supercritical carbon dioxide. At least a portion of the supercritical carbon dioxide can be recycled to the pretreatment system via a supercritical carbon dioxide stream.