Adsorption Solutions, L.L.C.
Safety during Adsorbent Recharging
Periodically the adsorbent will need to be removed from the adsorption vessel and the vessel recharged with fresh adsorbent. The adsorbent will have collected components present in the process stream. Some of these components may be present in the process streams at very low levels and not even be detected by normal feed stream analysis. If there is a possibility that any of these components are toxic, or dangerous, the adsorbent needs to be purged free of these components before exposing the spent adsorbent to plant personnel. For instance, if the adsorbent has been in natural gas service it could contain benzene, H2S, as well as other toxic and flammable components.
The usual way to empty out the adsorption vessel is by gravity dumping through the bottom dump port. There are specialized material handling service companies that can vacuum out the contents under a nitrogen blanket. This avoids the safety concerns, but this service is expensive.
The adsorption vessel contents can be made safe for dumping by a number of techniques. These include: purging with hot/warm lean hydrocarbon gas, purging with hot/warm nitrogen, steaming the bed, and water flooding the bed. Purging becomes complicated if there is a flow distribution problem in the bed such as one caused by zones of agglomerated adsorbent. The preferred technique for making it safe will depend on what is available at the plant, and how sensitive the plant process is to water.
Installation is usually done by gravity dumping of the adsorbent into the vessel. There are also dense loading techniques available that help insure a more uniformly packed bed and increase the bulk density of the adsorbent allowing more adsorbent to be loaded into the vessel. However, dense loading will result in a higher pressure drop.
We can provide:
- Review of your adsorbent dumping plans
- Review of any inert bed support materials and ballast materials that you plan to use
- Review your adsorbent installation plans