Patent DE-102008025119-A1 (DE)
Title: Method for utilizing process heat from carbonization of metal oxides under using carbon dioxide-containing gases, comprises mixing carbon dioxide-containing gas as gas stream and metal oxide in multi-level tubular reactor for carbonization
Inventor: JESCHAR RUDOLF
IPC: F24V30/00
Filed: 2008-05-26
Abstract: The method comprises mixing carbon dioxide-containing gas as gas stream and metal oxide in a multi-level tubular reactor for carbonization, which is carried out at maximum 600-100[deg] C below a decomposition temperature of the carbonate formed from the metallic oxide, and discharging the energy released from the exothermic carbonization reaction with a heat exchanger and then utilizing as a process heat. The metal oxide is used in the form of fine-grained solid or solid mixture with particle size of 50-100 mu m. The energy release of exothermic carbonization reaction is carried out in a reactor. The method comprises mixing carbon dioxide-containing gas as gas stream and metal oxide in a multi-level tubular reactor for carbonization, which is carried out at maximum 600-100[deg] C below a decomposition temperature of the carbonate formed from the metallic oxide, and discharging the energy released from the exothermic carbonization reaction with a heat exchanger and then utilizing as a process heat. The metal oxide is used in the form of fine-grained solid or solid mixture with particle size of 50-100 mu m. The energy release of the exothermic carbonization reaction is carried out in a reactor acting as a carbonator. A low calorific fuel gas or gas mixture with a high content of carbon dioxide is used as gas. The carbon dioxide content of respectively used gas or gas mixture is reduced by carbonizing the metal oxides under increasing its calorific value and is used as fuel gas with less carbon dioxide content. A combustion gas or combustion gas mixture or exhaust gas or exhaust gas mixture, which develops from the operation of burner systems or internal combustion engines, is used in the process. The carbon dioxide content of the used gases causes the carbonization of the metal oxides and the associated heat production and the emission of the gases ensures with the less carbon dioxide content. The metal oxide is introduced in the form of raw materials, which is accrued as cinders or ashes from the mining industry or other industrial processes or is obtained from igneous rock. The metal oxide is provided in a solid stream and is guided in a reverse flow for carbonization with the gas stream. The solid stream is heated in a flow direction in a first reactor (4), is carbonized in a second rector (6) formed as carbonator and is cooled in a third reactor (8). The gas stream is heated in the flow direction in the third reactor, is reduced in its carbon dioxide content in the second reactor and is cooled in the first reactor. The undetectable metal oxide from the carbonization reaction in the second reactor reacts with the humidity content of the supplied gas or with directly supplied water or water vapor to metal hydroxides in a fourth reactor between the second reactor and the third reactor in the flow direction of the solid stream, where the released energy is discharged and is used as the process heat. A catalyst is added to the metal oxide for the acceleration of the carbonization. An independent claim is included for a device for utilizing process heat from the carbonization of metal oxides under using carbon dioxide-containing gases.