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P a r r I n s t r u m e n t C o m p a n y
Supercritical Fluids
Supercritical CO2
A
supercritical fluid is any substance at a
temperature and pressure above its critical
point. It can diffuse through solids like a gas and
dissolve materials like a liquid. Near the critical
point, small changes in pressure or temperature
result in large changes in density, allowing
many properties of a supercritical fluid to be
“fine-tuned”. Supercritical fluids are suitable
as a substitute for organic solvents in a range
of industrial and laboratory processes. Carbon
dioxide is one of the many commonly used
supercritical fluids. Applications that involve
supercritical fluids include extractions, nano
particle and nano structured film formation,
supercritical drying, carbon capture and storage,
as well as enhanced oil recovery studies. Parr
has provided systems at one time or another
for all the aforementioned applications.
The supercritical fluid extraction system
pictured to the right and diagramed below
incorporates a 1.2 liter vessel rated for use at
4300 psig (300 bar) at temperatures to 300 °C.
The system includes an automated inlet valve
and an air piloted back pressure regulator which
is used to facilitate a controlled pressure release
at the end of the test. The vessel is heated with
a 1500W flexible mantle heater. The feed system
(not pictured) includes a pump capable of
delivering up to 1.5 gallons per minute (5.7 lpm)
of liquid carbon dioxide at pressures up to 4000
psig (275 bar).
Supercritical CO2 System shown with automated
control features.
Vent
Vent
BPR
To Vent
air
air
CO2
Model 4871
Controller
1.2 Liter
200 Bar
300 ˚C
F
S
S
TIC
TIC
PC
PIC
PG
PT
T/C
T/C
