A method of removing impurities from black water associated with a gasifier includes adding a flocculant to the black water to create a black water and flocculant mixture, settling the black water and flocculant mixture in a gravity settling device to separate the black water and flocculant mixture into clarified water, a froth phase, and a heavy phase, the froth phase comprising soot, water, and air or gas, the heavy phase comprising soot and water, drawing off the clarified water from the settled black water and flocculant mixture, collecting a dilute slurry comprising the froth phase and the heavy phase, and phase separating the dilute slurry in a high-speed centrifuge to provide additional clarified water and a concentrated slurry, wherein the black water is obtained from wet gas scrubbing of syngas.

The present invention relates to the processing of carbonaceous materials for, inter alia, hydrogen production. In particular, the invention relates to the production of hydrogen, for example, as input for industrial manufacturing applications or as a fuel source for the associated generation of electric power. In one form, the invention provides a method of producing hydrogen comprising the step of reacting a combination of solid carbonaceous material and a catalyst comprising alpha phase iron-based material adapted to produce an exothermic reaction with the solid carbonaceous material.

A system and a method for preparing hydrogen-rich syngas by taking biogas as a composite gasification agent for the gasification of biogas residue are provided. The system includes an anaerobic fermenter for biomass gradient, a solid-liquid separation device, a drying reactor, a gasification reactor, a condensing tower, and a syngas purifier; the anaerobic fermenter for biomass gradient is connected to the drying reactor through the solid-liquid separation device, to transport separated biogas residue to the drying reactor, and the drying reactor and the anaerobic fermenter for biomass gradient are connected to the gasification reactor, respectively, to jointly input biogas and a biogas residue dried into the gasification reactor for reaction; and the gasification reactor is connected to the condensing tower, to transport reaction products to the condensing tower, the condensing tower is connected with the syngas purifier, performing purification treatment on a gas cooled, to obtain the hydrogen-rich syngas.