Pressure and Chemical Manufacture
Country: United States
Date: Fall 2009
We are talking about reactions and how increasing the pressure
usually leads to a faster chemical reaction. My student brought up a good
question...how do factories/manufacturers produce high artificial pressure?
Can you please tell me the machinery and how it works/overall mechanism?
There are many ways to increase pressure. One way is to simply push on
the fluid. The machinery that pushes fluids is known as a "pump", and
there are different kinds of pumps for different applications and
different kinds of fluids. For liquids, there are lots of styles of
pumps; one common type uses an impeller (something like a propeller)
to push liquids. For gases, you might use a pump, or also you might
use a compressor. A compressor is like a pump, except it reduces the
volume of a gas internally (creating a contained volume of gas of
higher pressure). You can also use a (compressed) gas to push a liquid
or pressurize a tank of liquid. If you search on the Internet for
"pump" or "compressor" you can find a great deal of information about
the types and inner workings of each.
I also want to address your comment about pressure and reaction rate.
That statement is fine for gaseous reactants, but it is not generally
true for liquids or solids. The rate of a reaction depends on
concentration of reactants, and since liquids are basically
incompressible, pressurizing liquid reactants would not increase their
concentrations, and therefore would not increase the reaction rate.
Hope this helps,
There are many different ways to achieve high pressure, and which one
is used depends on what is most compatible with the manufacturing
process requiring the pressure. Compressors, pumps and hydraulics are
common ways to increase pressure in a reaction vessel. Heating a gas
or liquid in a closed vessel is another. Even detonating an explosive
mixture in a contained closed vessel to produce an ultra high pressure
shock wave is sometimes used. It all depends on the process that
requires the high pressure.
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Update: June 2012