Metallgesellschaft Aktiengesellschaft

Bayer Aktiengesellschaft

Stadtwerke Munster Gmbh

Karl H Dorr

Hugo Grimm

Ulrich Heinrich Sander

Heinz Neumann

Waldemar Weber

Walter Blumrich

Hans J Konig

Gunter Lailach

Rudolf Gerken

Wolfgang Fennemann

Michael Tacke

Gustav Rowedder

Helmut Diekmann

Norbert Ohlms

Flue gases or other contaminated humid exhaust gases which contain SO.sub.3 are cooled by an indirect heat exchange in a heat exchanger to a temperature below the dew point temperature of sulfuric acid and are cooled further to a predetermined temperature in an SO.sub.3 condenser by means of dilute sulfuric acid, which is sprayed to flow in a countercurrent to the gas, whereby dilute sulfuric acid having a predetermined concentration is condensed. The gas leaving the SO.sub.3 condenser is scrubbed and cooled to a temperature from 40.degree. to 55.degree. C. in a fine scrubber by a treatment with a sprayed aqueous liquor. The exit gas is reheated to a predetermined temperature in a reheater by a treatment with sprayed dilute sulfuric acid from the SO.sub.3 and after the condensation of SO.sub.3 is passed through a filter. Dilute sulfuric acid from the reheater is sprayed into the SO.sub.3 condenser. The temperature of the gas in the reheater is so selected that the water which has been absorbed is not condensed but remains in the gaseous effluent. The exit temperature of the gas leaving the heat exchanger is approximately so selected that the temperature at which dilute sulfuric acid becomes available is approximately the same as the temperature of the gas in the reheater. The rate at which dilute sulfuric acid is sprayed is so adjusted that the dilute sulfuric acid withdrawn from the fine scrubber is at a temperature which is approximately the same as the required exit temperature of the gas leaving the SO.sub.3 condenser.

Process of purifying flue gases

Cleaned flue gases normally accumulate as steam-saturated gases with temperatures of from 40.degree. to 55.degree. C. after wet cleaning processes for the removal of sulfur and/or nitrogen compounds. Before being let off through a stack, however, these gases have to be heated to at least 72.degree. C. This invention relates to a process for reheating flue gases after wet cleaning.

Process for cleaning flue gases

A process for the production of sulfuric acid from wet sulfur dioxide containing gases is disclosed. The sulfur dioxide containing gas is initially purified and cooled, then predried with dilute sulfuric acid, finally dried with concentrated sulfuric acid, converted to sulfur trioxide catalytically and, the sulfur trioxide is absorbed in sulfuric acid. Preliminary drying removes more water than needed to maintain the water balance in the following process steps. A portion of the dilute acid from the preliminary drying is concentrated prior to recycle to the preliminary drying step and another portion of the acid from the preliminary dryer is added to the sulfur trioxide absorber to adjust the water balance in the acid circulating between the final dryer and the sulfur trioxide absorber.

Process of producing sulfuric acid

A process for the concentration of dilute phosphoric acid in a phosphoric acid process characterized by a plurality of separate phosphoric acid cycles when the phosphoric acid is concentrated in each cycle by a vacuum evaporation is described wherein the phosphoric acid cycles is heated by indirect heat exchange by heat of formation formed in a sulfuric acid contact process.

Process of strengthening dilute phosphoric acid

A catalytic reactor for converting sulfur dioxide to sulfur trioxide, suitable for high throughput rates of up to about 500,000 standard cubic meters per hour. The reactor includes a plurality of separate reaction chambers each containing catalyst trays connected in parallel in the gas flow path. The catalyst trays define gas spaces and alternate gas spaces are provided with inlets for supplying a partial stream of the sulfur dioxide containing gases which are divided in the gas spaces. The gas spaces adjacent to the gas spaces provided with inlets are provided with outlets for withdrawing partial streams of the gases which have passed through the catalyst trays.

Catalytic reactor having annular catalyst tray means

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Mainz, Germany

Karl H Dorr