chemical physics of discharges - Argonne National Laboratory

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_. -. - L -J:,J.-;~~~L, ):as separator, and thence to a light oil scrubber.!
at~ave operations were investigated on both 8 bench ,
..:.- ;i;: ?L;,nt scale with the exception of cake crlcining which was
?cr:azn~2 oniy on bench scale, Variables investigated are discusred ,
I
... i.16 :oiAowing sections.
'racLDJ ,nd Oneratint! Variables for Deashed Coal
- I-
,I reviev of our work on solvent deashing indicated the
07crntiny. conditions necessary to optimize the process. These
Z L ~ be briefly summarized:
.~
i: .The development of a stable, high-extractive-efficiency
i~iviii: cripabla of essentially complete recovery in the vacuum recov-
2:y uniz 'ca yreld ueashed coal was accomplished by special treatment
sz L i~i:~::-b~iii~g coal tar distillate. The required solvent having
ascelia:-.: ccmperacure ~ t a blity i and high solvent power was attained
by rcfra-:otrLing the hifih-boiling coal tar distillate, employing
" -LL>c>e ,I. t:iarmal decomposition and fractionation to eliminate the leas
- -Li-4L-o--y , .- . -. and low-bailing constituents. Gratuitously, these are the
;CL= cffectivi ercraccion components,
2 Xicsve:y of from 88 to 95 weisht percent of the avail-
3bie ~arbsnac-s~s matter at extractor preesures in the range of 5 to 8
.i;-isJ?heiLs and ri;h solvent-to-coal ratios in the range of 2 or 311
was Ychi?ve:d using ;he iefractorized solvent with A boiling range of
600 ~a 900-F Typical extraction conditione were 750°F, 75 psig, at
a asLven;-io-co~i :de10 ot 311.
2, Extraction at residence times of 5 to 20 minutes in a
-.c-;:r3u s~i~tizer vessel orB preferably, in continurvs in-line
ssi~rroa n~~c:ng' coils which would permit a direct circuit from the
ao:vrct-csz. mixing tank through a conventional heater with a discharge
to dr~her a rotary pressure precoat filter or a suitable
tyCro:lond,% i3i Bench extractions were successfully conducted at
no1G:ng t.irnSs ;f as low as 3 minutes. There were duplicated in a
piic: f ~ ~ i i - hiater ~ e coil discharging the hot coal rolution continuously
~:hr~,gh cr, expanded section of the transfer line to the filter
charga tank,
4. Ash removal from the coal solution WAO accomplished at
i:-ir.i~ror, r.i~cs of 200 to 300 lbsfhrleq. ft, of filter surface,
?=el:cindry rates of 200 KO 250 were secured in the pilot rotary
.,;J;OL~ prcss~re filter at low pressure differentiala, Small-scale
:-zb an cocit: washing and calcining were performed to obtain closediycie
data an soibent and distillate distribution. It was anticipa~od
that the filter cake would be washed with a light oil, calcined
zni the spexit cake used as nteam fuel for the procars in A full-scale
Tlznt,
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