// Project 2
- Finish your Analysis Below
- Write your summary and conclusion about these tasks
Process engineering investigated the foaming incident that took place on Gas Treating Unit. The investigation revealed that hydrocarbon liquid carry over to the unit is the root cause of the experienced foaming. The HC carryover was a result of transmitter failure to measure the level in the dew point K.O drum.
Below are the major findings from the foaming incident:
- Ambient temperature drops below the hydration point of the dew point HC mixture by several degrees during winter. Hydrate forms inside the chamber sample lines or the chamber itself which will block level transmitter taping.
- Since HC level cannot be measured, the HC fluid can rise in the drum causing carryover to the unit. HC mixed with the DGA solution increases the foaming tendency of the DGA solution.
- Lean DGA strength was 46.2% which lower than the acceptable range of 50-55%.
As a Process Engineer, provide your suggestions for the level of the drum and any suggestions for the DGA% level. In another case, the process engineering unit has investigated the DGA operation upset that took place . The upset, which included level and pressure instability in the unit’s vessels followed by major foaming, was caused by HC carryover from the upstream dew point system. The HC carryover took place after the dew point drum, was flooded due to faulty level transmitter reading. When the ambient air temperature drops during winter, the skin temperature of the transmitter’s sample lines drops well below the hydrate formation temperature of 70 °F causing slow build up and plugging of hydrates. The ambient air temperature reached 45 °F, which is 25 °F below the hydrate formation temperature. Provide your suggestions for Level transmitter and suggest any MOC required for the process. Write a letter to the operation foreman of the plant with your suggestions and make a copy for the higher managements. Find the sequence of events that took place during the incident as record by the log book:
Sequence of Events:
► 1/5@ 14:45: sour gas was admitted to the unit
► 1/5@ 13:00: contactor DP increased from O to 1.9 psi.
► 1/5@ 18:00: HC level in filter separator reached 100% and it was reduced to 6% at 23:00.
► 1/6@ 02:00: Tray 6 temperature was increased up to 220 F
► 1/6@ 02:45: feed rate was reduced in order to reduce the DP in the contactor