CarboLoop: a novel concept of looping combustion of carbon

A novel concept of looping combustion/partial oxidation of carbon is presented. The underlying concept is the recognition of the feature of most carbons to extensively uptake oxygen upon exposure to air at moderate temperatures and to release surface oxides as carbon oxides (CO, CO2) when the oxidized fuel is brought to moderate-to-high temperature in an oxygen-free atmosphere. On this basis, continuous or semicontinuous processes of carbon looping combustion can be envisaged which are based on proper combination of carbon oxidation (under air-blown operating conditions) and desorption (in oxygen-free atmosphere) steps. The resulting processes enable the generation of highly concentrated CO2 effluents, much like conventional CLC processes. The soundness of the CarboLoop process is demonstrated by discontinuous experiments in which alternated oxidation (at 500°C) and desorption (at 700°C) steps were performed in a TG analyzer. Experiments were carried out using char from a bituminous coal. Carbon conversion degrees of about 50% were obtained after three cycles