Q & A

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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  

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Recent Questions
Date  Replies
02/07/2020 Q: In our catalytic reforming unit, DM water and CCl4 are used as dosing to keep the water and chloride balance within the prescribed limit. Material of both injection lines is stainless steel 304 whereas the main line of the feed (DSN) is carbon steel as per design. Line pressure and temperature of feed line are 24 kg/cm2 and 151deg C and both injection points are connected to the feed line. From a corrosion point of view, if i replace the injection line of DM water & CCl4 with carbon steel pipe will there be any problem ? If no then please give me the reason for using SS 304, or what type corrosion can take place in the injection line for DM water and CCl4?. Currently we are facing some leakage at the elbow weld joint. In addition, when we tried to repair by welding, again a leak/fissure was found just ahead of the welded point.  
28/06/2020 Q: The refinery I work in has a 40 year old hydrotreating reactor with a very high design minimum pressurization temperature (MPT) of 120degC. it always takes ages to clear the MPT before we can proceed to the next step in the unit startup. We run our 2x recycle gas compressors which are fixed volume reciprocating compressors, loaded to 200%. The question I would like to ask is: is it better to have higher purity H2 for heating up? Higher H2 purity would mean less mass flow at constant volume. However, H2 thermal conductivity is way higher than other gases such as N2 or CH4, C2H6. The other school of thought is to bring in less pure H2 source to boost the mass circulation.
This is probably a heat transfer question also. Would like to hear if anyone has done any research on this.
27/06/2020 Q: We have been facing issues in one of our sour water stripping units wherein we observe continuous plugging of the feed control valve to the stripper column with greenish black hard deposits. The temperature of sour water passing through this control valve is in the range 146-152 deg C. Could anyone suggest the testing we should carry out to understand this heavy deposit? Does anyone have experience with hard greenish black deposits in their sour water stripping units?  
26/06/2020 Q: In a multi-bed filter why is the larger particle size bed placed over the smaller particle size bed?  
26/06/2020 Q: During jet fuel manufacturing, conductivity improver and stability improver additives are added . During critical periods, the fuel requires prolonged storage times, around six to nine months. After this prolonged storage , does the fuel lose its stability? If so. why? Can the additives doped during manufacturing contribute to the instability of the fuel ?  
Recently Answered Questions
Date  Replies
21/06/2020 Q: In a hydroprocessing Unit, what factors determine location for adding washwater? I have seen two locations in my unit - one upstream of the air fin fan and one at the inlet of the last CFE. Where should I inject wash water? (5)
16/06/2020 Q: 1) What are the standard procedures to dispose of the catalyst dust (from regenerated and spent catalyst) from a CCR Platforming unit ?
2)Are there any adverse effects on the environment due to random disposal of the catalyst dust?
3) Is there any process to extract precious metal from the catalyst waste?

21/06/2020 Q: What are the effects of excess recycle gas flow with high purity at 95+ vol% on a hydrotreater unit? It's good for the catalyst but what are its effects on the process, especially on the furnace? (1)
10/06/2020 Q: i'm working in a LAB plant. For dehydrogenation of paraffins there are 2 standby reactors. After deactivation of the catalyst (about 45 days) we changed to another one. Now we want to use both reactors at the same time in parallel. We increased the paraffin flow rate from 50 t/hr to 60 t/h. The hydrogen flow rate also increased from 10 t/h to 11.5 t/h according to our equipments capacity. I think it'll raise our conversion and increase the catalyst lifetime. Is this possible?

07/06/2020 Q: in a SRU final condenser demister pad, dislocations occurred two times recently. Due to this the tail gas line to the TGTU filled with sulphur. What may be the reasons and remedies?
Also, in case of carryover of sulphur what ways are there for early removal of sulphur.