An adsorption type desiccant. It is simply aluminium oxide in a solid and porous form, often known as alumina, or by its chemical composition, Al2O3, produced by thermal decomposition and subsequent activation of aluminium Tri hydroxide (gibbsite) it offers high surface area and high porosity matrix with good affinity towards polar compounds, especially water.
The activated alumina has a strong, resilient ability against the alkaline components. The alkaline components are Ammonia, Amines, and other organics, which have a high basicity level. It is also a strong opponent against moisture or water molecules. It is also a convenient choice for heat-restored dryers because of its versatile quality. It is also a low cost / economical option which also assists in achieving low-pressure dew points that range from -40degF up to 100degF (-40degC from -70degC).
Contrarily, the activated alumina has its disadvantages too. It is vulnerable to long-chain hydrocarbons: – they are heavy and strong. For example, the activated alumina is defenceless against air compressor oil vapours. These hydrocarbons accumulate on the surface of the alumina and block its porosity method. This lowers the water or moisture adsorption capability of activated alumina.