Cyclic Gas Separation Processes

Structured adsorbents in gas separation processes

“…The relative importance of internal and external resistances is expressed by the Biot number k f L/D where L is a characteristic dimension (particle diameter) and D the internal diffusion coefficient. The mass transfer Biot number for packed beds for most applications is in the range of 5-500 and hence the major resistance for mass transfer is within the particle [10]. Generally speaking, micropore diffusion resistance dominates over film and macropore resistances if…”

Sorption heat engines: Simple inanimate negative entropy generators

“…There is also a wide choice of adsorbents. Clay, zeolites, activated carbons, silica gel, and alumina (bauxite) are commonly used [1][2][3][4][5][6], and for special purposes specific minerals or materials may be more suitable.…”

“…The SHE1 can be used for demixing [4]. Information gain by compound identification is a key object in analytical chemistry, often achieved by detection after demixing/separation such as by chromatography [23].…”

“…The proposed sorption heat engine is based on adsorption and desorption, which are of large practical importance [1][2][3][4][5][6] but receive scant notice outside physics and engineering. The engine works by desorption at high temperature, with concomitant uptake of heat, and release of the adsorbate at high pressure (Figs 1-2).…”

“…The term 'negative entropy generator' is clearly applicable; 3. In geology, desorption of water and organics from clay minerals occurs on a large scale during subduction in the Earth's crust, a process driven by convection in the Earth's mantle; 4. In biology the engine may have played a role in the synthesis and desorption of the first biomolecules adsorbed on clay [7][8][9], and may thus have constituted an alternative source for the primordial soup proposed by Haldane in 1929 [10].…”