March
2008
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© Copyright 2008
BDP Inc.
All Rights Reserved.
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News:
Advanced
Control Strategies enhance
propane recovery
The BDP team has
been engaged to implement
advanced process control
strategies for the Propane
Recovery Column at a CO2 recovery
facility in New Mexico.
This single column Ryan-Holmes
process design combines the
Propane Recovery Column with the
Additive Recovery Column at a
lower capital cost by eliminating
the reflux condenser, drum,
pumps, and reboiler for the
Additive Recovery Column.
Energy costs are also
reduced because the Additive
Recovery Column reflux is not
required. The Propane
Recovery Column takes feed from a
number of wells, separates
natural gas liquids (C3+) from
the feed and then returns CO2,
methane, ethane and H2S to
residue compression. The
returned gas is used for CO2
flooding for enhanced oil
recovery and is valuable for that
purpose. However, enhanced
control strategies can
significantly increase the
percent of NGL recovered which is
also valuable as propane
recovery.
The liquid heavy
bottoms stream from the Propane
Recovery Column is split into 1)
a product stream that is combined
with the side stream and 2) an
additive stream that is added
near the top of the Additive
Recovery Column. Consistent
with Ryan-Holmes technology the
heavy NGL additive stream changes
the relative volatility of the
CO2-propane mix so that the
propane recovery is substantially
increased.
Propane is removed
as a vapor side stream within
constraints for percent H2S.
Proper setting of the side
stream rate is very important for
good propane recovery with low
H2S percent. Operational
history has demonstrated the
difficulty in setting the side
stream rate appropriately, and
consequently the tower operation
suffers. Frequently the
propane side stream must be shut
in until the side stream H2S
percent is lowered to an
acceptable value. The
advanced control strategies will
focus on incorporating feed
forward material balance and
feedback control to set the side
stream correctly and maintain the
correct setting as tower
conditions change. In
addition, bottoms analysis will
be used to maintain the additive
concentration in an acceptable
range for enhanced propane
recovery.
These advanced
control strategies are one
example of BDP Inc. process
control consulting services
available to enhance the
performance of gas processing
facilities. Contact BDP Inc. for more
information on similar control
system services and process
control improvements to enhance
your plant operations today.
Partial
List of Current Projects at BDP:
<> Engineering,
configuration, system assembly,
and commissioning support for a
process automation system for a
new gas treating facility in
Texas.
<> Full-scope
design, assembly, configuration,
installation, and commissioning
of a process automation system to
upgrade a pneumatic CO2 recovery
facility in west Texas.
<> Engineering,
configuration, and commissioning
support for an integrated DCS and
SIS control system at a CO2
recovery plant in west Texas.
<> Full-scope
design, assembly, configuration,
installation, and commissioning
of a process automation system to
replace a legacy DCS at a gas
processing facility in western
Oklahoma.
<> Engineering,
configuration, system assembly,
and commissioning support for a
process automation system
expansion to automate three
industrial boilers with network
integration to a remote control
room in a gas processing facility
in Texas.
Partial
List of Systems included in
recent BDP projects:
<> Emerson Delta V control
system.
<> Matrix Total
Control from MTL Inc.
<> Honeywell
Experion
PKS system with
Allen-Bradley
ControlLogix PLC. |
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