Methods for treating an offgas containing carbon oxides

摘要

A method of treating an offgas includes purifying the offgas to remove particulate matter, water, undesirable gaseous components and inert gases to produce a dried carbon oxide gas feedstock, and converting at least a portion of carbon oxides in the dried carbon oxide gas feedstock into solid carbon. In other embodiments, a method includes passing a dried carbon oxide gas feedstock through a multi-stage catalytic converter. A first stage is configured to catalyze methane-reforming reactions to convert methane into carbon dioxide, carbon monoxide and hydrogen with residual methane. A second stage is configured to catalyze the Bosch reaction and convert carbon oxides and hydrogen to solid carbon and water.

主权项

1. A method of treating an offgas containing at least one carbon oxide gas, water vapor, and particulate matter to produce solid carbon from the carbon oxide gas, the method comprising:
purifying an offgas from at least one of an aluminum smelter or a steel smelter to remove at least a portion of particulate matter therefrom to produce an intermediate stream; condensing water vapor from the intermediate stream to produce a dried carbon oxide feedstock gas; mixing at least one reducing gas with the carbon oxide feedstock gas to form a reaction gas mixture; converting at least a portion of the carbon in the reaction gas mixture to solid carbon and a tail gas stream containing water vapor; and recycling at least a portion of the solid carbon to the at least one of the aluminum smelter or the steel smelter to form the offgas and at least one of a metal matrix composite, electrodes for electric arc furnaces, carbon raisers, or high purity carbon reducing agents.