Page 27 - Compression Machinery for Oil and Gas

Equipment Overview Chapter 2 17

for vehicles. This application involves suction pressures ranging from a
slight vacuum to more than 5.2MPa, with discharge pressures exceeding
31MPa, thus requiring multistaged compressor technologies. Typical com-
pression types utilized include two-to-five stage reciprocating piston
compressors.
4. LNG (liquefied natural gas) is a growing application with increasing
demands for use in industry and domestic heating making it necessary to
use huge quantities of gas from far away production sources which create
the need to transport natural gas in its liquid form via ships and tank trucks.
Among the equipment required for this technology, centrifugal compressors
and rotary machines prove to be very versatile for use in gathering produced
gas, as well as, in later stages of pipeline transportation, liquefaction, and
regasification/expansion at the point of use by residential, commercial,
and industrial consumers.
5. Industrial gases (hydrogen/CO 2 /ammonia) hydrogen compression is
applied to reduce the volume resulting in compressed hydrogen or liquid
hydrogen. The compressor reduces the volume of hydrogen gas, to allow
the liquid hydrogen to be transported elsewhere. A proven method to com-
press hydrogen is to apply reciprocating piston compressors. Nonlubricated
compressors are preferred to avoid oil contamination of the hydrogen.
6. Ammonia compression to manufacture ammonia is a part of a complex
chemical refinery process wherein the synthesis gas needs to be compressed
to extremely high pressures, ranging from 100 to 250bars (1500–4000psi)
for ammonia synthesis. Modern plants employ centrifugal compressors
which are usually driven by steam turbines that use the steam produced from
excess process heat. Ammonia is also used as a process fluid for refrigera-
tion systems, the most common type of refrigerating system is a vapor-
compression refrigerator. This approach uses anhydrous ammonia as a
refrigerant as the means of moving heat around.
7. CO 2 compression: CO 2 is often used as an inexpensive, nonflammable pres-
surized gas and it is one of the most commonly used compressed gases for
pneumatic (pressurized gas) systems in portable pressure tools. CO 2 gas
producing process plants produce CO 2 in mainly two forms—liquid and
solid. Solid CO 2 is also known as “dry ice” and is used as a refrigerant in
food industry and for small shipments. CO 2 is widely utilized during the
storage and shipping of ice cream and other frozen foods. CO 2 is also used
as an atmosphere for welding. CO 2 is compressed to the desired usage pres-
sure using a gas compressor or is liquefied at lower pressures by using com-
pressor driven refrigeration systems and then pumped to the desired
pressure for bulk storage for CO 2 capture or large-scale industrial uses.
Large-scale CO 2 compressors are responsible for a large portion of the enor-
mous capital and operating cost penalties expected with any carbon capture
and sequestration (CCS) systems. The compressor power requirements for