TH28844B - A process for the direct reduction reaction of granular materials containing iron, and a plant for carrying out such a process. - Google Patents

Abstract

with the method for the direct reduction reaction of iron-containing granular materials by making a fluid The reconstituted gas, at least partially devoid of CO2, is fed into the base-fluid reduction reaction region. to reduce the gas and will be removed in the same way as the upper gas. and at least part of the upper gas combined with the regenerated gas. It is used for the reduction reaction to save on the part of the plant that is impacted by the reducing gas. And to achieve savings in the form of costs of heating CH4 and N2 in addition to CO2 at least partially separated by absorption from 50 to 100% of the regenerated gas and from 1 to 100. % of gas from the top and the downstream gas separated from the regenerated gas and/or the upper gas by adsorption is used as the heating gas (Figure 1).

Claims (12)

1. A method for the direct reduction reaction of granular iron-containing materials in a multi-stage fluidized bed process where at least some of the reformed gas, free of CO2, is fed into the fluidized bed reduction zone to reduce the H2 and CO-containing gases, which are then similarly removed as the uptake gas. In this process, at least a portion of the uptake gas combined with the reformed gas is used for the direct reduction reaction. A characteristic feature is that, prior to CO2 removal, the reformed gas is significantly cooled by mixing with the uptake gas and CH4 and N2. In addition, at least some CO2 is removed by adsorption, preferably by centrifugal pressure adsorption, from 50 to 100% of the reformed gas and up to 100% of the uptake gas. The heated reducing gas and the terminal gas separated from the reformed gas and/or uptake gas by adsorption are used as heating gases. 2. The process under claim 1, which is characterized by the terminal gas separated from the reformed gas and/or the upstream gas by centrifugal pressure adsorption, is used to heat the reducing gas and/or as a heat source for the ongoing reforming process to produce the reformed gas. 3. The process under claim 1 or 2, which is characterized by the fact that prior to CO2 removal, the reformed gas is cooled to a temperature between 20 and 100°C, particularly between 30 and 50°C. 4. Any of the processes described in claims 1 through 3, characterized by the direct reduction reaction of the iron-containing granular material proceeding in a series of fluidized bed reduction zones, where the iron-containing granular material is gravity-driven from top to bottom in the fluidized bed zones, and reducing gases are moved from fluidized bed zone to fluidized bed zone in the opposite direction. The reducing gases used during the direct reduction reaction are removed from the top of the fluidized bed reduction zones and used as upstream gases mixed with reforming gases and used as reducing gases. 5. Any of the claims 1 through 4, which is characterized by the heating of the reducing gases to be accomplished in two steps, namely, in the first step (19) by heat exchange and in the second step (31) by partial combustion by a pathway through which at least part of the oxygen has been introduced into the reducing gases (Figure 2). 6. A plant for the operation of any of the processes under Reservations 1 through 5, which includes a number of fluidized bed reactors (1 through 4) for receiving iron-oxide material, a reducing-gas feed (18) which is directed to the fluidized bed reactor (1) and is first in the direction of material flow by the reforming gas (10), a reforming gas (13) which is separated from the reforming gas (10) and merged with the upper reducing gas (8) which is then reduced by the reforming gas and upper reducing gas and passed into the fluidized bed reactor (4) through the reducing-gas feed (18), and which includes a CO2 removal plant (16) characterized by the CO2 removal plant being constructed as a pressure-centrifugal adsorption plant. It is fed in along with the upper gas mixture, and the reformed gas is greatly cooled by the mixture, and pipes carry the CO2-free gas from the adsorption plant (16) to the heating pathway (19) and the terminal discharge pipe (16"), where the terminal gas, separated by the adsorption plant (16), is discharged to the heating pathway. 7. The plant under claim 6 is characterized by the adsorption plant (16) being bypassed by the upper gas-branch route (22), including an alternative bypass by the branch route (21) that brings reformed gas, separated from the reformed gas-branch route (13). 8. A plant under claim 6 or 7 which is characterized by the discharge pipe - end (16") being connected - flow to the heating path of the reformer gas (10). 9. Any plant under any of the claims 6 through 8 which is characterized by a terminal discharge pipe (16") being connected - flow to the heating pathway (19) for reducing gas. 10. Any plant under any of the claims 6 through 9 which is characterized by the gas feed pipes leading to the absorption plant being fitted with gas coolers (17). 11. One of the plants under claims 6 through 10 is characterized by a series of fluidized bed reactors (1 through 4) connected in sequence. The material containing -iron-oxide is removed from fluidized bed reactor (1) to fluidized bed reactors (2, 3, 4) through a conveyor (6) in one direction, and the reducing gas is moved from fluidized bed reactor (4) to fluidized bed reactors (3, 2, 1) through a connecting pipe (20) in the opposite direction, and within each fluidized bed reactor (1 through 4) is fitted with a cyclone for separating fine particles attached to the reducing gas. 12. Any plant under any of the claims 6 through 11 that is characterized by the arrangement of a heat exchanger (19) as a heating pathway for reducing the gas and the arrangement of a partial combustion pathway (31) in series with it for reducing the gas with an oxygen feed pipe (32) (Figure 2).