Metallgesellschaft Aktiengesellschaft

Vereinigte Aluminium-werke Aktiengesellschaft

Lentjes Gmbh

Fujiang Lonjing Environment Technology Co., Ltd.

Metaligesellschaft Aktiengesellschaft

Fujian Lonjing Environment Technology Co., Ltd.

Sauer, Harald

Harald Sauer

Wolfgang Fennemann

Hans-Werner Schmidt

Bernd Thone

Martin Hirsch

Lothar Reh

Wolfram Schnabel

Roland Thome

Erhard Herrmann

Gunter Winkhaus

Dieter Moritz

Hans Werner Schmidt

Werner Weisweiler

Wenzel Von Jordan

Dieter Grone

Robert Mergler

Rolf Draf

Hansjörg Herden

Berthold Stegemann

Barbara Roth

The invention relates to a method for cleaning exhaust gases, in which an exhaust gas and a sorbent are combined in a fluidized bed reactor. In a subsequent filter system, solid matter is segregated, and thereafter, up to 99 per cent of the sorbent is re-channeled into the fluidized bed reactor, wherein the gas is subjected to a rotation around the flow axis in the fluidized bed reactor.

Method and device for cleaning exhaust gases by way of fluidized bed reactors

The invention relates to a process and a device for the removal of dust, HF, HCl, SO, SO, heavy metals, heavy-metal compounds, polyhalogenated hydrocarbons and polycyclic hydrocarbons from combustion flue gases by treating the pollutant-containing combustion flue gases with a sorbent in a circulating fluidized bed. The process is characterized in that the sorbent used is a mixture of Ca(OH), at least one naturally occurring zeolite and a carbon-containing substance, in that the treatment of the pollutant-containing combustion flue gases with the sorbent is carried out at from 120 to 180&#xb0; C. in the presence of water/steam, in that the reactor () of the circulating fluidized bed is operated at a gas velocity of from 2 to 10 m/s, a mean residence time of the solids particles in the case of a single pass of from 1 to 10 seconds, and a solids circulation rate of from 10 to 100, where the gas/solid suspension present in the reactor () has a mean suspension density of from 1 to 10 kg of solid/Nmof flue gas, and in that the removal of the loaded sorbent is carried out by filtration.

Process and device for cleaning combustion flue gases

The process of removing dust, sulfur compounds and nitrogen oxides from combustion exhaust gases, comprising mixing a combustion exhaust gas with ammonia; feeding Ca(OH).sub.2 and FeSO.sub.4 to a fluidized bed reactor containing mixed solids including fly ash, iron sulfates and calcium compounds, especially Ca(OH).sub.2, CaCO.sub.3, CaO, CaSO.sub.4 and CaSO.sub.3 ; supplying an ammonia-containing exhaust gas mixture to the fluidized bed reactor as a fluidizing gas; operating the fluidized bed reactor at a temperature between 300.degree. and 450.degree. C. to form a reacted exhaust gas; supplying the reacted exhaust gas to a multistage electrostatic precipitator having a first stage and additional stages; recycling solids collected in the first stage to the fluidized bed reactor; and recycling one portion of additional solids collected in the additional stages to the fluidized bed reactor and discharging another portion of the additional solids.

Process and apparatus for removing dust, sulfur compounds and nitrogen

For a treatment of the residues which become available as dry dust in the purification of exhaust gas and contain, inter alia, 5 to 12% by weight CaO and have a conductance in excess of 6000 .mu.S/cm, a process is proposed in which the residues are fluidized with purified exhaust gas in a circulating fluidized bed system consisting of a fluidized bed reactor, separator and recycling line and the CaO contained in the residues is reacted with the CO.sub.2 contained in the exhaust gases to form CaCO.sub.3.

Process of treating residues obtained by purification of exhaust gas

The dry slaking of lime is carried out continuously in a vessel from which an exhaust gas is removed. Hot gas, preferably a flue gas to be desulfurized, is added to the exhaust gas to prevent it from contacting the inner surface of the exhaust gas duct and thereby reduce the tendency for deposits in lines traversed by the exhaust gas.

Continuous process for the dry slaking of lime

A process of removing pollutants from exhaust gases in a circulating fluidized bed, in which solids are circulated through a fluidized bed reactor, separated in a separator and returned via a return line, to the reactor. The exhaust gas is introduced as a fluidizing gas into a fluidized bed which consists of two solid fractions differing in particle size, namely, a coarse-grained fraction having a particle size d.sub.p 50 in the range of 150 to 500 microns and a fine-grained fraction having a particle size d.sub.p 50 below 10 microns.

Process of removing pollutants from exhaust gases

A process for afterburning and purifying process exhaust gases, which contain combustible constituents, wherein the process exhaust gases and the oxygen-containing gases required for a combustion are separately supplied to a fluidized bed reactor of a circulating fluidized bed. In the fluidized bed reactor, the gas velocity is adjusted to 2 to 10 m/s (empty pipe velocity), the mean suspension density is adjusted to 0.1 to 10 kg/m.sup.3, the temperature is adjusted to 700.degree. to 1100.degree. C., and the stoichiometric ratio of gas-purifying agent having a particle size d.sub.p 50 of 30 to 200 .mu.m to pollutant contained in the process exhaust gas or formed by the combustion is adjusted to 1.2 to 3.0, calculated as Ca:S. The entrained solids in the gases from the fluidized-bed reactor are recycled to the reactor at a rate of at least 5 times the weight of solids contained in the fluidized bed reactor per hour.

Process of afterburning and purifying process exhaust gases

A method of recovering fluorine, e.g. as hydrogen fluoride, from wastes of aluminum electrolysis furnaces, chemisorbents, adsorbents or absorbents, etc. in which the fluorine-containing material is subjected to pyrohydrolysis in an expanded fluid bed and the HF-containing gas is subjected to condensation or scrubbing for the removal of the HF therefrom. According to the invention, the exhaust gases from the fluidized bed are cooled by direct contact with solids which can be circulated in a separate cycle and are themselves cooled in a cooler, e.g. by contact with gas which is to be fed to the expanded fluidized bed. The circulated solids thus allow recovery of the sensible heat of the gas without diluting it.

Process for producing hydrogen fluoride

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Frankfurt am Main, Germany

Harald Sauer