Sanitary gas cleaning

Frequently the gas stream shall be treated for one or several components to be removed from it that could be harmful, nuisance or of interest to industry. Thus, carbon oxide (II) shall be removed from ammonia synthesizing gases prior to them being fed to synthesis column since CO poisons synthesis catalyst.

Components with offensive odor particularly organic nitrogen and sulfur compounds shall be removed from off-gases in areas with high population density and in residential areas.

Removal of solvents vapors (toluene, benzene, etc.) from off-gas of varnish-and-paint shops is very desirable, since they from one hand pollute the atmosphere, and from the other hand, their return to the process has considerable economic effect.Three methods are known for removal of gas components: Gas absorption with liquid, adsorption on solid matter surface, and chemical conversion into another harmless gas [10].

The latter method usually includes burning of organic substance in the flame or catalytic burning. Mechanism of these methods is based on gas diffusion to the surface of absorbing liquid or on solid adsorbent or catalyst diffusion into reaction area where the relevant chemical reaction occurs.

Sanitary gas cleaning is important for varnish-and-paint production, various purpose spray paint cabinets, stock-raising farms, poultry factories, meat-processing plants, galvanizing shops, candy manufactures, tobacco production, rubbish incinerators, etc.