Effect of Water-Gas Shift Reaction on Reduction of Iron Oxide Powder Packed Bed with H2-CO Mixtures

Abstract

Although the hydrogen reduction is thermally more disadvantageous than the CO reduction, it is advantageous that the reduction rate with H 2 is much larger than that with CO. In order to examine the effective use of hydrogen, the reduction of FeO 1.05 powder packed bed with H 2 -CO mixture was conducted, and the results were analyzed by a proposed model. The temperature, at which the reduction equilibria of FeO 1.05 with H 2 and CO equal, is determined to be 1 093 K from the present results. The apparent rate constants are determined to be 33, 8.6 and 15 for the reduction of FeO 1.05 with H 2 , CO and H 2 -CO mixture (V -H 2 : V -CO ϭ1 : 1), respectively. In the proposed model, when the water-gas shift reaction is taken into account, the additivity is established on the dependence of the rate constant of the reaction on the gas composition. When the water-gas shift reaction is not taken into account, the rate constant deviates negatively from the additivity. The apparent rate constants of the reduction determined in the present study take the middle values, and the contribution of the water-gas shift reaction is estimated to be 3 % against its equilibrium. In reducing FeO 1.05 with CO, the time when the sample is perfectly reduced is shortened by adding a small amount of H 2 , and the rate enhancement effect of H 2 on the gaseous reduction remarkably appears at 1 093 K. The effect originates in the proceeding of the water-gas shift reaction.

Kinetic Analysis of the Iron Oxide Reduction Using Hydrogen-Carbon Monoxide Mixtures as Reducing Agent

“…They found that the rate of reduction decreased as the concentration of CO increased in the gas mixture. Lin et al 8) 9) used the Rist's model to study the effect of water-gas shift reaction on the reduction of iron oxide powder packed bed with H 2 -CO mixtures.…”

Effect of waste plastics addition on the reduction of iron oxide by metallurgical coke

“…Blending of coke with HDPE therefore promotes the generation of hydrogen in the reaction environment. Hydrogen gas, apart from being a faster reducing agent than both carbon monoxide and solid carbon (Sohn and Fruehan, 2005;OnoNakazato et al, 2003), also enhances the rate of reduction of iron oxides by carbon monoxide (Ono-Nakazato et al, 2003)when it is added to a reaction system containing the latter.…”

Reduction of Magnetite Concentrate Particles by H₂+CO at 1673 K

“…However, most of the work has been done with pellets, briquettes, and iron oxide powder beds and thus at temperatures below ~1 400 K. [3][4][5][6][7][8] Much less work has been performed on the reduction rate of fine magnetite concentrate particles with mixtures of H2 and CO at temperatures above 1 473 K to be used in the process under development.…”