Abstract: In a process and corresponding device for scrubbing acidic gases out of flue gases using adsorbent-containing suspensions, the flue gases are conveyed into a scrubber with narrowing channels and accelerated in a first stage in a direction opposite to the flow of suspension droplets and in a second stage in the same direction as the flow of liquid droplets, the suspension having already been broken down into droplets before or at the beginning of the acceleration section. Reflux of the suspension into the acceleration section is prevented by the shape of the channels. Flue gas and suspension droplets react and in the connecting first mist precipitator, the droplets are turned around 180° in the direction of gravitational forces.

Abstract: To recover the sodium-sulphur compounds following sodium-based pulp processing, e.g. the ASAM process or basic or acidic sodium sulphite processes, the waste liquor is burnt in a lye burning vat (1) with liquid slag extraction and the exhaust gases are subjected to multi-stage purification with dry fly-ash recovery and the gaseous sulphur compounds are also separated in a multi-stage washing process. The water-soluble components of the fly-ash are taken to the waste liquor to be burnt and thus the sulphur to be recovered in the slag is increased. The slag is dissolved in water and the dissolved sodium compounds are converted by multi-stage carbonisation with a part of the purified flue gas into sodium bicarbonate and H.sub.2 S. The H.sub.2 S is burnt and finally converted into sodium sulphite so that the desired lye for pulping cellulose can be made up from sodium sulphite and carbonate.

Abstract: A process is disclosed for extracting pure, coarse-grain silicic acid crystals from silicic acid-containing spent lye in cellulose production, comprising adding coarse-grain silicic acid to alkalized spent lye, lowering the pH of the alkalized spent lye to about 9 such that a sediment is formed, separating the sediment formed into coarse grain and fine grain silicic acid with little lignin and lignin-containing spent lye free from silicic acid, and separating the coarse grain and fine grain silicic acid with little lignin into course grain silicic acid and lignin. At least part of the course grain silicic acid separated is fed back to the alkalinized spent lye to be desilicified.

Abstract: The present invention is directed to a process for preventing the formation of dioxin and/or furan during combustion of composite combustible materials in a combustion chamber. The process includes passing the generated combustion gas in a flow from the combustion chamber to a dedusting device, cooled and purified while maintaining the SO.sub.3 content in the combustion gas flow from about 7 to about 500 mg/m.sup.3 and at a temperature of from about 300 .degree. to about 800.degree. C., The process allows at least surface regions of particles of meal dusts contained in the combustion gas to be converted to sulfates and thereby prevent formation of dioxins and furan. The invention also includes a steam generator for carrying out the process whose steel structures coming into contact with the combustion gases are either alloyed or coated with tungsten and/or vanadium on the combustion-gas side.

Abstract: Method of separating substances, notably SO.sub.2 and NO.sub.x where x is 1 or 2, from cooled flue gases, such as combustion exhaust gases containing low levels of impurities of the same. The gases are contacted with at least one substantially dry particulate absorbent including NaHCO.sub.3 which, at a release temperature below 400.degree. C., decomposes to form an activated absorbent including Na.sub.2 CO.sub.3 which serves to remove the harmful substances from the flowing gas.

Abstract: In order to achieve the removal of SO.sub.2 and NO.sub.x together with the entrained dust from the combustion product gases discharged from the combustion chamber of a steam generator in which sulfur-containing fuel, such as for instance lignite or brown coal is being burned, NH.sub.3 and/or NaHCO.sub.3 or chemical substances which release these compounds or react with the combustion product gases to form these compounds are introduced into the already partially cooled combustion product gases in the temperature region below 500.degree. C. upstream of a dry separator, such as for instance a cloth filter. The entrained ashes are to contain CaO or Ca(OH).sub.2 and/or Na.sub.2 CO.sub.3, especially from a previous desulfurization unit, prior to the introduction of the NH.sub.3 thereinto.

Abstract: Method and apparatus for separating at least one harmful substance such as SO.sub.2, HCl or NO.sub.x where x is 1 or 2, from combustion exhaust gases containing the same. The exhaust gases are contacted with at least one particulate adsorbent which, at a release temperature below 400.degree. C., releases at least one of water, ammonia, or carbon dioxide, for reaction with the harmful substances. This reactant leaves the adsorbent in activated condition. Thus, the reactant and activated adsorbent serve to remove harmful substances from the flowing exhaust gas.