1 - The development of adsorption technology

Abstract

Adsorption is the accumulation of concentration at a surface and is the consequence of interactive forces of physical attraction between the surface of porous solids and component molecules being removed from the bulk phase. During the twentieth century, adsorption technology survived as a means of purifying and separating both gases and liquids. The classical experiments of many scientists including Brunauer, Emmett and Teller, McBain and Bakr, and Langmuir throw light on the manner in which solids removed contaminants from gases and liquids. Industrial applications of adsorbents became common practice after the widespread use of charcoal for decolorizing liquids and, particularly, its use in gas masks during World War I (1914-18) for the protection of military personnel from poisonous gases. Adsorbents for the drying of gases and vapors included alumina, bauxite, and silica gel; bone char and other carbons were used for sugar refining and the refining of some oils, fats, and waxes; activated charcoal was used for the recovery of solvents, the elimination of odors, and the purification of air and industrial gases; fuller's earth and magnesia were found to be active in adsorbing contaminants of petroleum fractions and oils, fats, and waxes; base exchanging silicates were used for water treatment while some chars were capable of recovering precious metals. Finally, some activated carbons were used in medical applications to eliminate bacteria and other toxins. Equipment for such tasks included both batch and continuous flow configurations, the crucial consideration for the design of which was to ensure appropriate contact between adsorbent and fluid containing the component to be removed from gases and liquids.