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Recent Questions
Date  Replies
19/03/2019 Q: Please share the detailed procedure of KMnO4 washing of Vacuum Column.
Can KMnO4 washing be done before steaming and hot water wash of column ?
Also, if KMnO4 washing is to be done after steaming and hot water wash then whether column is to be cooled to ambient condition.
Any requirement of cold / hot water wash of column after KMnO4 washing is completed ?
 
14/03/2019 Q: what is the role of DMDS in adding to the platformer unit feed?  
14/03/2019 Q: In the our hydrotreating naphtha plant total sulfur is increased more than .5 ppm (this is my specification) and this hydrotreated naphtha (HTN) used to Aromizing unit to produce Aromatics. As you know, in the furnace of CCR platformer DMDS is used to passivate furnace tubes ,but when total sulfur increase more than .5 ppm in the feed of CCR platformer we stop injection of DMDS in the feed of CCR platformer and the question is :
can we stop the injection of DMDS in the feed of CCR platformer in case of total sulfur increase more than 0.5 ppm in HTN?
does the increase of TS in HTN can do the role of DMDS in furnace tube ?
 
14/03/2019 Q: Our refinery has installed corrosion control system (filming and neutralizing amine injection) in our overhead distillation column system. However, since the water content isn't too high, we cannot have enough sample from water bootleg. Our Fe content in water bootleg sample is quite high (>100 ppm) with previous injection of filming amine is considerably high (up to 18 ppm). The chemical vendor suggested us to install wash water system. However, install wash water system may take longer period and we wonder if continue injecting amine is still effective without wash water system. Have anyone had this kind of experience and is there any suggestion to keep the corosion controlled without wash water system? (1)
06/03/2019 Q: How to remove pyrophoric material from FCC Reactor, if any, Does any refinery face such kind of issue during turnaround?  
Recently Answered Questions
Date  Replies
01/03/2019 Q: In a naphtha stabilizer, top tray (tray 46) temperature is controlled by the reflux and the bottom tray (tray 3)temperature is cascaded with the hot light gas oil flow (reboiler's hot medium). Top pressure (overhead vapor pressure not the OVHD drum pressure) is controlled by the removal of non-condensed vapors from OVHD accumulator. Here, when I increase the bottom tray temperature, top pressure is getting increased slightly (very minimum) and then OVHD vapor pressure is getting decreased faster. Can anyone explain this phenomenon? Note: Distillation tower - 48 trays column; OVHD product - LPG; Bottom product - Stabilized naphtha. (2)
14/03/2019 Q: Our refinery has installed corrosion control system (filming and neutralizing amine injection) in our overhead distillation column system. However, since the water content isn't too high, we cannot have enough sample from water bootleg. Our Fe content in water bootleg sample is quite high (>100 ppm) with previous injection of filming amine is considerably high (up to 18 ppm). The chemical vendor suggested us to install wash water system. However, install wash water system may take longer period and we wonder if continue injecting amine is still effective without wash water system. Have anyone had this kind of experience and is there any suggestion to keep the corosion controlled without wash water system? (1)
26/01/2019 Q: Linden based Hydrogen unit, NG is using as feed for hydrogen generation. There is a hydrogenation reactor with COMOX catalyst where hydrogenation reaction takes place after that desulfurization reaction in next reactor with ZNO catalyst. NG feed having no sulfur and we operate the hydrogenation reactor in line for many hours. Since there is no S in NG feed no H2S formation will occur in that reactor. Catalytic reaction will not occur. As per requirement, we take sometime RFG (refinery fuel gas) , which having sulfur content for Hydrogenation reaction in COMox based reactor. My question is this type of feed variation, deactivated catalyst may work after taking RFG feed or how we can make activate COMoX catalyst when NG feed in line alone. (1)
16/02/2019 Q: When our VDU column products, vacuum slop and vacuum residue were tested for H2S it showed H2S presence >10 ppm.What could be the possible reasons for high H2S?
We are maintaining VDU bottom level and temperature low to avoid cracking still H2S reported is high.Coil steam and Velocity steam were increased and kept 120% of the PFD values. Chances of exchanger leak was also checked and observed no leak.
(3)
15/02/2019 Q: I would like to hear your views on the factors that are the major causes of the increase in Wheel Chamber Pressure. To give you a background, we are currently experiencing an uptrend of wheel chamber pressure on our MANTURBO turbine almost reaching alarm values. Turbine steam flow has slightly increased also. Adjustment of exhaust pressure has yield into a slight decrease of WCP.
Base on our findings, we are leaning into fouling as one of probable causes of the increase of wheel chamber pressure. However, there was no axial movement of rotor or increase of bearing temp on the active side of the thrust bearing. Does increase of wheel chamber pressure always equates to movement of rotor and increase of bearing temp?
Furthermore, we cannot explain the observed trend of the WCP. Every time we reduce the feed rate, WCP also decreases. However we cannot explain why when we increase feed rate to its value prior reduction, (Ex. from 35 mbsd, to 25mbsd then return to 35 mbsd again) Wheel chamber pressure will be higher and have an uptrend increase! What do you think is the explanation with this observe trend?
As of the moment, we cannot afford to down the equipment and we do not have the necessary materials for overhauling. Can you guys share your thoughts on how can we lower the WCP? Or even just maintain pressure and prevent any further increase?
(1)
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