Inhibition of carbon deposition using iron ore modified by K and Cu in chemical looping hydrogen generation

Abstract

Summary Chemical looping hydrogen generation based on iron is an innovative method to produce high purity hydrogen and capture CO2 simultaneously. However, carbon deposition of iron ore limits the development. The iron ore modified by K and Cu was employed to suppress the carbon deposition. Experiments were carried out to investigate the effects of the additive amount on carbon deposition and hydrogen purity via carbon release characteristics in a batch fluidized bed. The carbon deposition ratio decreased monotonically with the increasing amount of potassium, but the excess copper loading led to a rise in the ratio of carbon deposition instead. The carbon deposition ratio decreased by up to 84% after adding K and Cu, which is speculated to be closely related to the weight ratio of Fe on the oxygen carrier surfaces. The experimental results at different temperatures demonstrated that 850°C was suitable for the inhibition of carbon deposition and sintering. In addition, the mechanism of inhibition of carbon deposition was proposed in detail and illustrated that it was correlated to the covering of active sites and the reactivity enhancement. Moreover, the carbon deposition ratio of the modified oxygen carrier maintained stable during the cyclic experiments. Therefore, it is feasible to employ the iron ore modified by K and Cu as oxygen carrier to suppress carbon deposition in the chemical looping hydrogen generation.

Redox reactivity of titania‐doped YSZ‐promoted iron‐based oxygen carrier over multiple redox cycles for chemical looping reforming of methane and hydrogen production

“…The iron oxide redox pair is suitable for conversion of methane into syngas or hydrogen from the thermodynamic equilibrium and catalytic activity . The development of the oxygen carrier or thermodynamic analysis for the production of syngas or hydrogen from chemical looping have been intensively studied . The use of pure iron oxide as an oxygen carrier suffers from the decrease in the reactivity and the defluidization resulting from the sintering of iron oxide during the repeated redox cycling .…”

Kinetic and thermodynamic analysis of iron oxide reduction by graphite for CO2mitigation in chemical‐looping combustion

“…13 With the inherent carbon capture of CLC, recent studies have explored use of iron ore modified by potassium and copper as oxygen carriers in the generation of hydrogen. 14 In a life-cycle perspective, biomass is known to balance the CO 2 emissions which can significantly enhance the carbon capture capability of CLC by accounting the absorbed CO 2 in its growth stage. 15 Recently, the utilization of the woody shaving biochar was characterized by Hu et al 16 for the product conversion kinetics and structural evolution in an iron-based CLC.…”

Investigation of the relationship between electronic properties and reactivity of 3DOM LaFe 1 − x Co x O 3 for methane reforming to produce syngas

“…Previously, many kinds of metal oxides were selected as OCs for chemical looping process through preliminary experiments or thermodynamic calculations . Some of them showing good reactivity but low selectivity for the desired products, while some of them showing poor thermostability.…”

“…3 Previously, many kinds of metal oxides were selected as OCs for chemical looping process through preliminary experiments or thermodynamic calculations. [4][5][6][7][8][9][10][11][12][13][14][15] Some of them showing good reactivity but low selectivity for the desired products, while some of them showing poor thermostability. But it is generally believed that the mixed metal oxides have better reactivity and stability than the single ones.…”