INTEGRATED PYROLYSIS AND ENTRAINED FLOW GASIFICATION SYSTEMS AND METHODS FOR LOW RANK FUELS

摘要

In one aspect, a gasification system for use with low rank fuel is provided The system includes a pyrolysis unit positioned to receive a feed of low rank fuel, the pyrolysis unit being configured to pyrolyze the low rank fuel to produce pytolysis gas and fixed carbon. The system also includes a gasifier configured to produce a syngas stream using the received fixed carbon, a cooler configured to receive and cool the syngas stream, and a first conduit coupled between the cooler and the pytolysis unit. The first conduit is configured to recycle at least a portion of the syngas stream to the pyrolysis unit such that the recycled syngas stream is mixed with the pyrolysis gas to produce a hydrocarbon- rich syngas stream containing gasification by-products. The system also includes a by-product recovery system coupled to the pyrolysis unit for removing the gasification by-products from the hydmcarbon-rich syngas stream.