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Dr. Jim Silva, Chemical Engineer at GE
·
·
He talked us through a real life problem and how he solved it:
o Trying
to produce a low-weight, electro-platable thermoplastic that could hold up to
temperatures of 180 C.
§ Wanted
to make a bisphenol into an organic salt that could then go on and be used to
make the polymer
§ Creating
the product required water but rest of process needed water-free organic salt
§ But
it was OK to have desired product floating in a non-aqueous solvent
o Scaled
up a lab process for one particular bisphenol and it worked fine
§ Needed
a dry product but it was full of water
§ So
add a large amount of boiling solvent
§ Sprayed
wet chemical into boiling solvent
§ Water
and vapor would evaporate, leaving desired salt behind in remailing solvent.
§ Some
of solvent would boil off too, but this was condensed by short path condenser
and then treated (not reused in process.) The loss of solvent was OK as it
wasn’t so much that the process became cost prohibitive.
o But
when they tried to repeat the process for a different biphenol (not bisphenol)
they got big chunks of salt caked to the walls, not fine particles suspended in
solvent.
o Analyzed
situation and discovered newer polymer was taking much longer to dry at a given
temperature so needed to make the new polymer at a much higher temperature, but
this meant way more solvent would boil off with the water. Way more!
o Came
up with a solution (details not listed in this outline)
·
Terms
o Thermoplastic
o Cellulose
o Bisphenol
o Biphenol
o R
group (as in HO-R-OH)
o Short
path condenser
o Thermos
gravitational analyzer
o Materials
balance
o Gibbs
phase rule – essentially that degrees of freedom or things you can adjust in a
process = number of phases minus number of components, plus two. So if T and P
are fixed, the relative proportions of the mixture are defined, cannot change.
o Partial
reflux condenser
o ppm
o electroplating
o Scale
and scaling of a process
o Chemistry
versus chemical engineering
o
·
Connections to other guests
o Linhardt (scaling, process simplification, cost effectiveness etc.) Others:
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