Q & A > Question Details
Current DP across the Naphtha Hydro-treating Reactor is 3 and it is giving peak frequently without giving a gradual increase of DP. Why is the pressure at the inlet of Reactor is suddenly increasing for the few second but coming down to previous position again? However, we are thinking Catalyst top bed is blocked by coke, iron scale and other metal contaminant. Besides, we are getting some Ash color and salt type dirt at the fine mesh filter at the suction of NHT compressor. So, i need to know what could be the probable composition of the dirt? For this, we assumed that it could be fouling product from the separator drum or dust of alumina ball from the bottom of Catalyst bed. Now we are facing frequent compressor changeover and cleaning of suction strainer. So, please share with me if anybody have similar kind of experience and help me to sort out what could be the composition of dirt.
 
Answers
11/02/2017 A: Virendra Kapoor, Petroleum Refining Consultants, vkkapoor9@yahoo.com
The deposits at strainer can be analysed & many refiners have done it successfully. It may be due to corrosion by ammonium salts, HCl in make up gas & foulants. Alumina fines or cat. fines or foulants need to be checked. Likewise momentary rise in Delta P could be due to hydrodynamic flow issues, feed issues or otherwise & need investigations.
27/01/2017 A: Austin Schneider, Crystaphase Products Inc, austin.schneider@crystaphase.com
This kind of analysis is all our company does. Crystaphase has been building custom filtration systems in hydroprocessing reactors for over 20 years.
We perform fouling/particle analysis in order to build efficient filtration systems inside the reactor. The analysis performed is important because, in addition to allowing for effective filtration design, good interpretation provides Crystaphase and refineries with an opportunity to identify a root cause. This can allow for a reduction in the overall magnitude of the fouling problem.
As for the determination between separator drum dust or alumina ball dust, we can make that distinction. When diagnosing this problem we will take a holistic view across the entire refinery. Any solution developed here should involve this understanding.
We will look at things like particle size distribution, elemental makeup, compound identification, and particle morphology.
We'd be happy to analyze these samples for you. To start the process you can go to www.crystaphase.com/analysis or you can email our group at technical@crystaphase.com.
27/01/2017 A: NS Murthy, Suez, murthy.ns.ext@suez.com
It looks to me some slug of water is entering thru feed to hydrotreater. Typically the feed to hydrotreater is sent directly from u/s unit. However, for reasons feed is supplied from tank farm, one has to critically examine the type of storage used. Ideally it shall be floating cum fixed roof to prevent moisture ingress.
It is also mentioned that there is repeated dirt accumulation in recycle gas compressor suction. Analysis of the dirt for water solubility, ultimate analysis, etc. will help to identify origin and possible control thereof.