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What can be the cause of coloration (yellowish green) in VGO Raffinate hydrotreater effluent?
 
Answers
08/09/2013 A: Virendra Kapoor, Petroleum Refining Consultants, vkkapoor9@yahoo.com
Polyaromatics such as coronene etc which are intermediate coke precursors formed during process impart yellowish color
01/09/2013 A: Sridhar Balakrishnan, Bharat Oman Refineries Limited , laksrid@yahoo.com
The colour of VGO feed will be of ASTM COLOUR 5.0 to 6.0 Dark amber to Dark Red, when it is hydrotreated the colour of the VGO product changes to Pale Lemon colour ASTM Colour 2.0. The colour of VGO Raffinate may be due to nitrogen species and some hydrocarbons .
22/08/2013 A: Alan Goelzer, Jacobs Consultancy, alan.goelzer@jacobs.com
More details are needed on the oil feed to VGO Hydrotreater Unit, key features of the reactor, operating conditions in the reactor, and VGO product qualities.
However, my first thought in the absence of above was that organic nitrogen is elevated in the oil feed, organic nitrogen removal is modest, and the balance of the organic nitrogen became "activated" into "color bodies".