Q & A > Question Details
Our sulphur plant is two converter, three condenser designed for producing 180 mtpd sulphur with recovery of 96% and downstream TGTU for tail gas recovery. SRU have very frequent choking in condenser III. Deposits are very hard in nature and can not be removed even with hydrojet. This have made the condenser suseptible for leakages.
We operate SRU with acid gas from ARU. Amine is used in HCU and FG, LPG aboserbers treating LPG and FG from DCU and MSB, CDU. Solution is MDEA with concentration of 19%. Oil is also observed in amine and filtration system is not very effective. Amine could be source for initiation of problem in MCC but not able to understand the salt which is depositing in the condenser III. What could be the reason of salt deposits in condenser III?
 
Answers
06/06/2012 A: Lindsay McRae, Pall Corporation, Lindsay_McRae@pall.com
Hydrocarbon carryover from amine system into SRU is not only bad news for the SRU but likely to be contributing to amine plant issues as well. Our advice is to eliminte hydrocarbon ingress into the amine unit in the first place, and then carryover to the SRU can be virtually eliminated plus amine plant performance can be improved significantly also.
We would recomend to consider installting a high efficiency LG Coalescer on the offending amine absorber inlet to remove virtually all hydrocarbons including aerosol sized droplets. Conventional bulk separation equipment such as KO pot / mesh pad, cyclonic devices or horizontal filter-separators are often not effective to adequately protect amine units from hydrocarbon ingress
If hydrocarbon ingress into the amine system is coming from a number of sources, then LG coalescers may be installed on the sour gas at the inlet to each amine absorber or a rich amine coalescer can be used to remove virtually all liquid hydrocarbons. This technology is now commercially proven to remove the liquid hydrcarbons and reduce foaming, reduce amine losses to sweet gas or LPG and protect the SRU from trips as well.
31/05/2012 A: Egbert van Hoorn, Hocon B V, Egbertvh@hotmail.com
Hard depositions in a SRU like you are describing are normally the result of a combination of sulphur, catalyst fines and hydrocarbons. These deposits are normally very hard to remove like you indicated.
The combination of catalyst fines, hydrocarbons and sulphur also indicates significant operating problems. Catalyst fines do not normally occur with normal operation.
It is a bit of speculation, but it is possible that your SRU has seen several hydrocarbon upsets from the amine system. This results in high temperatures in the SRU.
A combination of high temperatures, off ratio operation and hydrocarbons can result in these deposits.
The MDEA strength in your system seem low.
A detailed survey of your system is required to give more detailed answers