Q & A

Welcome to the ePTQ's Q&A: the technology Q&A for the refining, gas, biofuels and petrochemical processing industries.
You can browse existing questions and answers by topic or date or carry out a freetext search.
Using it is simple: try it out for yourself now.
And if you want to ask a question on any aspect of hydrocarbon process technology or plant, or answer a question that has been posed, just register and login. It will take you only seconds to do so.

We are excited to be Strategic Partner of the World Refining Association’s ERTC: Ask the Experts. This new event from the organisers of ERTC, the biggest and most important event for the European downstream industry, is the only event in Europe offering process and maintenance engineers a platform to ask their burning questions about the everyday challenges facing their plant and hear the practical solutions from industry experts.

This face to face interactive event, features experts from leading European refineries and technology providers; engineers will have the chance to hear unparalleled knowledge through interactive discussions such as fishbowl panels, Q&A Panels and Poster Sessions. Learn more here: asktheexperts.wraconferences.com  


Browse the Q & A
Search by Text Search By Date


Enter Search Criteria
 

Search by Date 

 
Search by Topics  

Recent Questions
Date  Replies
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?  
06/03/2019 Q: How to remove pyrophoric material from FCC Reactor, if any, Does any refinery face such kind of issue during turnaround?  
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.  
22/02/2019 Q: Do you have any ideas about the industry average of attained steam purity for steam turbines? Currently, we cannot meet the OEM requirement of steam purity, thus we are concerned that fouling might occur on our steam turbines.
 
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)
Recently Answered Questions
Date  Replies
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)
16/02/2019 Q: In our refinery Crude heater when open it we see moisture on whole pipe. Can you explain the possible cause for that? (1)
30/01/2019 Q: what is the maximum sulphur level in feed (Naphtha) that a platformer catalyst can handle without a hydrotreater? (1)
Post