Adsorption Solutions, L.L.C.
Design of New Adsorption Units
Adsorption can be used to purify process streams and to separate components. If the amount of the contaminant that needs to be removed is not large, and if the contaminant loading on the adsorbent is high, it may make sense to use an adsorbent on a non-regenerated basis. The process stream flows through a bed of adsorbent for a long time after which the adsorbent is replaced. However, even a simple process such as this can have a problem. Adsorbents can act as catalysts. Sometimes the contaminant is removed, but a new trace component is created which causes problems to downstream operations.
Often the contaminant levels are high and the adsorbent needs to be regenerated during the use. This requires at least two adsorption vessels with one treating the process fluid, and the other being regenerated. The contaminant(s) from the process fluid are removed and put into the regeneration fluid. One of the design challenges is to use the proper fluid for regeneration and integrate the disposition of the spent regeneration fluid into the over-all plant operation.
Adsorbents are used in bulk separation processes such as iso/normal hydrocarbon separations and in air separation. To keep the adsorbent inventory manageable specific processing cycles and process steps are required.
Some of the steps in the design of a new adsorption unit involve:
- choice of adsorbent type and size
- selection of regeneration fluid type and quantity
- selection of process cycles
- disposition of spent regeneration fluid
- sizing of adsorber beds
- minimization of carrier fluid component co-adsorption
- functional design of adsorption vessels
- review of start-up procedures to avoid adsorbent damage