Talk:Fluid catalytic cracking

The History section is being worked on

The History section will be ready in a few days. - Milton Beychok 20:13, 7 May 2008 (CDT)

Added the completed History section today. - Milton Beychok 03:00, 9 May 2008 (CDT)

barg

Milton what is barg? I know Pa, atm, and bar.--Paul Wormer 02:51, 10 May 2008 (CDT)

Paul, barg is "bar gauge". Bourdon tube pressure gauges display the pressure above atmospheric pressure. Thus, bar = barg + atmospheric pressure.

Just as engineers in the U.S. use psia and psig (meaning psia absolute and psi gauge), many if not most metric country engineers use bara and barg (meaning bar absolute and bar gauge). - Milton Beychok 09:54, 10 May 2008 (CDT)

slurry settler

In your diagram you have fuel oil go from the top of the slurry settler, but you write: The so-called clarified slurry oil is withdrawn from the top of slurry settler ... --Paul Wormer 03:00, 10 May 2008 (CDT)

As explained just below, the oil from the main fractionator bottom contains catalyst fines and for that reason is referred to as a slurry oil. It goes into the slurry settler where most of those fines settle into a thicker slurry which is recyled back to the catalyst riser along with the FCC feedstock. The clarified thinner slurry oil (containing much less catalyst fines) from the top of the settler is referred to as clarified slurry oil and is then routed into the refinery's fuel oil blending system ... or it may be routed into the feedstock of the refinery's delayed coking unit, where the fine would ultimately end up in the petroluem coke, if the refinery has a delayed coker. Does that "clarify" this point? :>) - Milton Beychok 10:27, 10 May 2008 (CDT)

fines

Are (or is) "fines" the same as "particulates"?--Paul Wormer 03:06, 10 May 2008 (CDT)

Paul, the catalyst particles undergo attrition and some of the catalyst gets grinded into smaller sizes that cannot be removed by the cyclones inside the reactor or regegenerator. Those smaller sized particles are called "fines". The fines that get into the main fractionator come out in the fractionator bottoms oil ... hence, the name slurry oil. The fines that get into the flue gas are ultimately removed in the ESP (electrostatic precipitator). Yes, fines are particulates, with "fines" being the industry usage for the attrited small catalyst particles and "particulates" being a generic term that is suitable for any kind of small solid material in the air or other gases. - Milton Beychok 10:10, 10 May 2008 (CDT)

Finished reading

Milton, I found it interesting and have one or two questions (see above).--Paul Wormer 03:22, 10 May 2008 (CDT)