• What can be the possible reason for foaming in HP amine absorber in Hydrocracker unit? Though we have a centrifugal separator upstream of Amine absorber we face foaming & at same time level in HP centrifugal separator in upstream remain NIL.



  • Marcello Ferrara, ITW S.R.L., mferrara@itwtechnologies.com

    This is a very common problem in amine absorbers. The causes of foaming can be multiple and often linked together: fouling, suspended solids, plugged trays, antifoam performance, off-spec inlet gas, hydrocarbons content, corrosion and erosion of metal components, low filtration/separation efficiency.

    Filtration can reduce some of them, but not filterable solids are also dispersed in the amine, as a result of amine degradation.

    All of the above causes are connected indeed with amine degradation and therefore to a high HSS content and related problems.

    Sometimes even at low HSS concentrations the fouling, foaming and corrosion problems may be not sustainable.

    Considering that all of the reclamation techniques have no impact on the existing fouling and HSS control methods (e.g. neutralization and solution purging/amine make-up) have almost no effect on HSS formation/build up, ITW technologies can give a holistic solution to the problem.

    The holistic ITW approach implies the use of different proprietary technologies, according to the following path:

    1) ITW Online Cleaning for cleaning the entire Unit.
    This implies circulation of a proprietary chemical, which will dissolve the existing fouling. The cleaning will take 24 hours on a feed-out/feed-in basis
    The Unit will resume production under clean conditions. This will be particularly beneficial for foaming control, in that the existing fouling has a major contribution to foam, namely: a) by creating delta P inside the absorber and thereby reducing the capacity; b) by creating a restriction inside the internals and thereby locally increasing gas velocity; c) by stabilizing the foam because some fouling will be suspended in the amine.

    2) HSS reduction on the circulating amine.
    Another proprietary chemical will be added (on a shot basis) to reduce the existing HSS in the amine.

    3) HSS formation prevention.
    After the previous steps the Unit will be clean and the circulating amine will have reduced HSS.
    At this point another proprietary chemical will be added on a continuous basis to prevent HSS formation.

    This will allow sustainable operations and reduce operating costs.


  • Paul Fearnside, Nalco Champion, pfearnside@ecolab.com

    What are this Units Heat Stable Salts content? Especially Thiocyanate and Formates? Corrosion by products from the Regeneration tower OVHD system can increase substantially, from ammonia bisulfide, if the ammonia content in the reflux water is not controlled to <10,000 ppm. Better yet to <8,000 ppm to take into account the unit variability. The ammonia content is directly controlled by the amount of reflux bleed water and subsequent fresh water make-up.



  • Mohammad Abdulrahman, Kuwait Integrated l Petroleum Industries Company, m.ghufran@kipic.com.kw

    Check the composition of the gas if there are more heavies than normal. HP Amine systems normally have more potential to foaming especially when more heavy hydrocarbons than usual find their way to the absorber.

    Operating parameters to be analysed as indicated in a previous answer.



  • Nathan Hatcher, Optimized Gas Treating, Inc., nate.hatcher@ogtrt.com

    Submicron aerosols can evade most mist elimination equipment. Some filter/coalescer vendors offer services to assess the effectiveness of your existing upstream separation equipment, which you might want to consider.

    Is the amine warmer than the inlet gas? Maintaining some differential temperature is helpful to avoid hydrocarbon vapor condensation inside the column.

    Does this contactor share lean amine with other treating services? If so, the oil polluter may be coming from an entirely different treater.

    If you can collect a sample of the overhead foam, extract and analyze the hydrocarbon content, this will provide a better idea of where the oil is coming from. The surface active hydrocarbon will be concentrated in the foam.