CASE STUDY:
Chemical Company
Industry:
Manufacturing
Chemical Company Trusts
Cleaver-Brooks HRSG to Maintain
Power for Production
CHEMICAL MANUFACTURER
One of the world’s leading specialty chemical companies operates plants throughout the
world, including one in Louisiana that produces chemicals and polymers for a variety of uses
from consumer goods to agricultural applications.
PROFILE
Company executives were seeking a way to minimize the downtime caused by frequent
outages at the local electric utility. Located in the Gulf Coast region, hurricane-related
outages are commonplace. More troubling, however, are the non-weather-related outages
that occur about 10 times a year.
CHALLENGE
The company’s management team calculated the lost time due to power failures and
hurricane outages over a period of one year. The annual loss was 154 hours. Power failures
amounted to 116 hours, and production losses associated with hurricane outages amounted
to 38 hours.
LOCATION
Louisiana
The company wanted a combined
heat and power solution to improve
plant reliability, reduce electricity and
lower steam costs.
Eliminate the need to purge the
HRSG when the gas turbine is
forced into outage.
SOLUTION
Cleaver-Brooks custom designed a
Max-Fire® HRSG with auto transfer
from supplemental-firing to fresh-air
firing, and vice versa.
RESULTS
When Hurricane Isaac hit New
Orleans, the manufacturer was able
to maintain production for four days
while the grid around it was down.
In addition to the downtime, when the local utility was not providing power, the plant could
not keep raw materials such as acrylic acid cool. According to the company’s director of
engineering, that was a major concern because at high temperatures more site reactions
occur. If acrylic acid becomes too warm, it can polymerize. When the plant loses power,
there is less conversion efficiency, which substantially increases operational costs.
The company began pursuing a combined heat and power (CHP) solution to improve plant
reliability, reduce electricity and lower steam costs. The requirement was for the combustion
gas turbine to produce 4.5 MWe along with a Heat Recovery Steam Generator (HRSG) at
the plant to produce at least 80,000 lb/hr of high pressure steam.
When it came time to select the HRSG manufacturer, the company obtained proposals from
multiple manufacturers. They chose Cleaver-Brooks due to their experience, their overall
proposal and the engineering expertise of Cleaver-Brooks Engineered Boiler Systems.
“We knew that adding the ability to automatically transfer from supplemental-firing to freshair firing, or vice-versa, would be the key to this project,” recalled Greg Kaup, sales manager
for Cleaver-Brooks. “In the event the gas turbine is forced into outage, eliminating the need
to purge the HRSG would give the company increased operating flexibility by keeping the
HRSG online and contribute to the success of the project.”
Kaup added, “Since Cleaver-Brooks designs and manufactures all the major components of
our systems, including the controls, we were confident that the auto-transfer process would
be seamless, which gives customers true peace-of-mind.”
Cleaver-Brooks provided a complete scope of supply, starting with the turbine exhaust
ductwork and finishing at the main stack flue gas outlet. Equipment supplied included
a custom-designed Max-Fire® HRSG with integral water-cooled furnace capable of
handling high firing temperatures, a Cleaver-Brooks duct burner capable of operating in
supplemental or fresh-air firing modes, and an integrated control system comprised of a
PLC-based Burner Management System (BMS) and HRSG Integrated Control System
(ICS). To round out the “power island” package, a fresh-air fan with control and seal-air
dampers was provided, along with a diverter with dedicated bypass stack and a guillotine
isolation damper. Cleaver-Brooks also provided a deaerator to treat incoming feedwater.
In addition, supervisory start-up services were included.
The HRSG is capable of generating 85,000 lb/hr of 400 psig steam during both
supplemental and fresh-air firing modes with minimal back pressure on the gas turbine.
Unfired performance yields over 25,000 lb/hr.
A year after the equipment was installed, it was put to the ultimate test and passed with
flying colors.
When Hurricane Isaac hit New Orleans in 2012, the manufacturer was able to maintain
production for four days while the grid around it was down. As a result, the company
profited financially.
In addition to the hundreds of thousands of dollars the plant is adding to its bottom line
annually by consistently maintaining its production, it qualified for a 10% investment tax
credit from the Department of the Treasury for its capital investment in cogeneration.
Cleaver-Brooks helped the company perform the efficiency calculations required to
support the grant application.
Kaup said, “This project exemplified how an integrated HRSG supplier can collaborate
with an industrial client to provide a flexible combined heat and power plant.”
Cleaver-Brooks
Engineered Boiler Systems
6940 Cornhusker Hwy
Lincoln, NE 68507
Office: 402.434.2000
E-mail: [email protected]
cleaverbrooks.com
CB-8515