A plant complex may include a unit that produces CO.sub.2-containing gases, a gas conducting system for CO.sub.2-containing gases, a gas/liquid separation system, a reformer that is connected to the gas conducting system and where the CO.sub.2-containing gas reacts with H.sub.2 and/or hydrocarbons to give a CO— and H.sub.2-containing synthesis gas mixture. The reformer is connected to a reactor for producing higher alcohols in which the synthesis gas mixture reacts with H.sub.2 to give a gas/liquid mixture containing higher alcohols. For separating off the alcohols of the gas/liquid mixture, the gas/liquid separation system is connected to the reactor for producing higher alcohols.

A process for the production of sponge iron and a system for the production of sponge iron. The process includes the steps of: producing electrolytic hydrogen and oxygen by electrolysis of water; producing methanol by reacting the electrolytic hydrogen with carbon dioxide; storing the methanol; reforming the methanol using water and/or oxygen to provide carbon dioxide and released hydrogen; providing the released hydrogen as a component portion of a reducing gas to a direct reduction shaft; and reducing iron ore in the direct reduction shaft using the reducing gas to produce the sponge iron.

A method of starting a molten bath-based process for smelting a metalliferous material is disclosed. The method includes using the heat flux of water-cooled elements in lower parts of a smelting vessel to provide an indication of molten bath temperature during at least an early part of the start-up method and adjusting injection rates of oxygen-containing gas and/or carbonaceous material into the smelting vessel to control the molten bath temperature during start-up without exceeding critical heat flux levels and tripping the start-up method.

The invention relates to a control method for a secondary dust removal system in which a pipe network connects an induced draft fan to at least two suction points. The pipe network comprises a controllable exhaust air flap for each suction point, the position of said flap influencing the volumetric flow rate at the suction point. A mathematical model of the pipe network allows the method to energy-efficiently control the exhaust air flaps and the induced draft fan.

The invention relates to a plant complex for steel production comprising a blast furnace for producing pig iron, a converter steel mill for producing crude steel and a gas-conducting system for gases that occur in the production of pig iron and/or in the production of crude steel. According to the invention, the plant complex additionally has a chemical or biotechnological plant connected to the gas-conducting system and a plant for producing hydrogen. The plant for producing hydrogen is connected to the gas-conducting system by a hydrogen-carrying line. Also the subject of the invention is a method for operating the plant complex.

A process for operating an oxidizable combustion gas cleaning unit in a metallurgical plant, including the steps of: (a) passing an oxidizable combustion gas from a metallurgical reactor, in particular a blast furnace gas from a blast furnace, in a packed bed scrubber arrangement through a packed bed in countercurrent with a washing water or in a spray scrubber arrangement to remove cyanide compounds, in particular hydrogen cyanide, and to increase the removal of chloride compounds, in particular hydrogen chloride, from the combustion gas by solubilizing the cyanide and chloride compounds in the washing water, (b) collecting the washing water containing solubilized cyanide and chloride compounds at a bottom end of the packed bed or spray scrubber arrangement, and (c) collecting a cleaned oxidizable combustion gas at a top of the packed bed or spray scrubber arrangement, wherein a base is added to the washing water before step (a).

A process and a device for treating a flow of furnace gas with a pressure of more than 1 bar flowing through a channel. A powder agent, such as a powder comprising alkali reagents, such as lime, and/or absorbents, such as activated coal, is injected under an overpressure into the furnace gas flow via an injector which is positioned centrally within the channel. The powder agent may be fluidized. The pressure for injecting the powder may be adjusted by controlling the volume of fluidization gas vented via a venting outlet.

A method of manufacturing a steel product into at least two different steelmaking units wherein an expected level of CO2 emissions for the manufacturing of said product in each respective steelmaking unit is calculated.

A method to manufacture a global tonnage of steel products in at least two steelmaking units wherein expected level emissions are calculated and compared with pre-defined targets.

The invention is directed to a method for processing asbestos-containing steel scrap into useful products, which products can be handled in a safe manner. In accordance with the present invention the asbestos-containing steel scrap is melted in a furnace, which results in destruction of the asbestos fibers. It has been found possible to carry out such a process in an economically feasible manner. In accordance with the invention asbestos-containing steel is heated to high temperature so that the steel melts. As a result the asbestos will be converted into harmless material, which allows for safe handling and processing of the resulting products.