Is there any commercial FCC process available in downer configuration? Hydrodynamics of Downer favours FCC process but still why there is very little information about downer FCC commercial units.
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26/03/2011
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BHANU PRASAD, IOCL, sgbhanu@yahoo.co.in
Millisecond Catalytic Cracking licensed by UOP is based on downflow, but have no knowledge of the success of this technology in increasing gasoline yield.
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12/01/2011
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keith bowers, B and B Consulting, kebowers47@gmail.com
The 'commercial' FCC process are very well developed and present minimal overall risk to an Owner/Operator. Yields, catalyst costs, product qualities, operating characteristics, details of mechanical design are extremely well developed and licensor predictions are reliable and usually conservative.
A completely different mechanical configuration would have to promise significant economic advantage, and have outstanding demonstration plant performance to entice an Owner (and the finance folks) to take the risks inherent in a new design and mechanical configuration. Circulation of the spent and regenerated catalysts are well managed and easily controlled in conventional FCC units and riser and control valve service intervals (which usually dictate run lengths) are over 5 years now. 'New' flow configurations will require some time (and more than a couple of surprises) to reach similar reliability. Moving FCC catalyst can cut through the internal refractory and steel pipe in hours if flow streamlines are not 'perfect' in the critical areas. CFD modeling of that 'system' to optimize mechanical design would be very difficult.
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12/01/2011
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Alan Goelzer, Jacobs Consultancy, alan.goelzer@jacobs.com
Personally, I believe that the multiple sequence of reactions involved in high conversion fluid catalytic cracking are favored by UPFLOW within the context of the following:
# Regenerator which both protects catalytic activity and achieves CRC = < 0.05 wt%
# Hydraulically engineered regen cat transfer line to Y junction
# Short dense flow riser segment where superheated steam and fuel gas provide lifting
# Mix Zone with array of advanced atomizing feed injectors [atomizing is very important]
# Lower upflow vertical riser reactor zone [perhaps 10 meters high]
# Upper upflow vertical riser reactor zone [perhaps 20 meters high]
# Optional MZOT secondary injection of lighter oils [per Goelzer invention now in public domain]
# Transfer into terminator [internal in reactor vessel or advanced external cyclone]
# Reactor vessel with advanced cyclones and advanced 'packed' stripping zone
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