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One of the PSU owners is asking for guarantees at the outlet of Propylene Recovery Unit (PRU). The basic design of this unit is in Consultant's scope. At present the poisons in feed such as Methyl Acetylene, Propadiene, Arsine, Phosphine and many others are not known. In fact feed composition is not known at all. However the poison levels in the product are fixed and are to be guaranteed. The propylene from PRU is routed to Polypropylene Unit. The feed to PRU comes from LPG treatment unit which in turn receives it from RFCC unit. Please advise whether it is wise to give guarantee of product at the outlet of PRU.
 
Answers
26/09/2017 A: Sridhar Balakrishnan, Bharat Oman Refineries Limited , laksrid@yahoo.com
Some analytical techniques are there by which you can quantify the poisons in feed. Like GC techniques like GC-AED other GC systems etc. These are sophisticated GCs which can quantify the feed poisons and can provide information.
19/09/2017 A: Eric Hennings, Technip Stone & Webster, EHennings@technip.com
We have vast experience in separation and safe, dependable removal of contaminants in polymer grade propylene (PGP). These apply to propylene from resid RFCC as well as conventional VGO FCCU and DCCU.
19/09/2017 A: Ralph Ragsdale, Ragsdale Refining Courses, ralph.ragsdale@att.net
Request a feed composition to be the basis of the guarantees. That composition needs to include the quantity of each impurity to be guaranteed. Assume all impurities will concentrate in the propylene product. For each impurity, guarantee no more than 120% of that amount. The guarantee language should include the phrase "if inherent in the feed."