The core of adsorption regeneration of air separation equipment is to use the physical reversibility of adsorption to desorb the impurities such as HO, CO and hydrocarbons adsorbed on the adsorbent (molecular sieve and activated alumina) by changing the temperature, pressure or gas environment, so as to recover the adsorption capacity and realize recycling. Its thermodynamic basis is adsorption exothermic, desorption endothermic, temperature rise or pressure drop, which will significantly reduce the adsorption capacity of adsorbent and promote impurity desorption.
There are four main realization modes, and combined regeneration and heating regeneration are the most commonly used. The first is heating regeneration. Purge saturated adsorbent with 170-220 ℃ regeneration gas and switch adsorption after cold blowing. The regeneration is complete but the energy consumption is high; The second is depressurization regeneration. Impurities are desorbed through depressurization/vacuumization, no heat source, low energy consumption and limited regeneration depth; The third is combined regeneration, which combines heating, depressurization and purging, and gives consideration to depth and efficiency. It is the main flow mode of air separation; The fourth is waste heat regeneration. The air compressor is used to compress and heat the regenerated gas, with obvious energy saving effect.
