POWER August 2015 - 37

REINVENTION AWARD
1. Plant overview. The Golden Brewery
facilities surround the Colorado Energy
Nations power plant, shown here in the unshaded
section. The baghouse enclosure is
situated in the foreground with the Boiler 5
stack on the northwest corner of the Boiler 5
unit enclosure. Courtesy: Google Earth, Colorado
Energy Nations, GDF SUEZ Energy NA,
and Behrent Engineering
when other fuels might become feasible and
directed that Boiler 5 be specified to burn coal,
natural gas, or fuel oil as its primary fuel and
be able to accommodate supplemental fuels,
such as sludge from the process waste treatment
plant and ethanol from waste beer.
Boiler 5 was commissioned using coal
in late 1979. Bill Coors insisted that coal
be burned as cleanly as possible with available
technology, so special " felted Ryton "
baghouse filter bags were developed and
purchased from Phillips Petroleum. Total
installed cost of the new unit, including the
baghouse, was approximately $20 million.
Sludge from the process waste treatment
America with headquarters in Houston. Earlier
this year the company name changed to
ENGIE North America. Meanwhile, Coors
Brewing Co. merged U.S. operations with
Miller Brewing Co. to form MillerCoors.
Through all the corporate changes, the boilers
and generators that had been installed
in the 1970s continued to supply steam and
electricity to the Golden Brewery.
In 2012, Colorado Energy Nations (Figure
1), a subsidiary of GDF SUEZ Energy North
America, began planning a project to complete
a blended fuels plan that was originally
envisioned in the 1970s. CEN harnessed environmental,
regulatory, and commercial incentives
to replace obsolete control systems
and to enable its largest boiler (Boiler 5) to
burn blended fuels. The project was coordinated
with scheduled maintenance overhauls
and other upkeep projects. The result was a
well-managed, highly coordinated project
that was executed without a safety incident,
came in 10% under budget, and started up on
the scheduled day (February 9, 2015). Within
two weeks the boiler was smoothly running
with blended fuels (coal and gas) under automatic
control.
Designed for Fuel Flexibility
Industrial power generators are even more
directly affected by the market dynamics of
fuel supplies and costs than regulated utility
generators, which can easily pass along fuel
cost increases to customers. When fuel costs
increase, for any reason, those who supply
their own electricity see the effect on the bottom
line. To mitigate the economic impact of
fuel cost fluctuations, Coors decided several
decades ago to build in some flexibility.
In the 1970s natural gas was in short supply,
and in Colorado, gas taps for new homes
were restricted. William K. (Bill) Coors, chairman
and CEO of Coors, decided that the new
boiler should burn coal in order to save gas for
residential use. However, he foresaw a time
August 2015 | POWER
was burned until about 1998. At that time the
waste treatment process was modified, and the
sludge became a viable material for agricultural
use. Similarly, ethanol from waste beer
was burned for several years, until the benefit
of selling it as a fuel additive outweighed its
value as a boiler fuel supplement.
Boiler 5 Upgrade Rationale
Although the original plan was for Boiler 5 to
burn a variety of fuels, to defer capital costs,
natural gas fuel piping was not part of the
original installation. Fuel oil storage and supply
piping was part of the original installation,
but it was later removed. So even though the
boiler was equipped with nozzles for coal, gas,
and oil, at the start of this upgrade project, it
was only capable of burning coal.
Several factors prompted the recent upgrade
of the 1979-installed Boiler 5. Readers familiar
with utility or merchant power plants feeding
power to the grid will recognize them all.
POWER POINTS
Lessons Learned
For Plant Owners: Be proactive in recognizing environmental regulations as
opportunities to evaluate business opportunities, and create synergy whenever
possible.
For Plant Owners and Operators: Save, organize, update, and maintain your
technical documentation.
For Project Managers: Although EPC contracts are effective for shifting risk to
the contractor, they are not always the most cost-effective solution.
For Project Teams: Emphasize safe working procedures through contract
documents, training, and constant communication.
For Engineers: Work closely with plant maintenance, engineering, and operations
personnel.
For Construction Phase: Daily observation and coordination of construction
activities with plant operations is critical.
For Check-out and Shutdown Teams: Use checklists for panel check-outs,
software testing, and shutdown planning.
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37
Optimize Fuel Costs. As Bill Coors had
envisioned, today's abundant supply of natural
gas has driven down its price, making it an
economically attractive fuel source and justifying
completion of the blended fuel design
for Boiler 5.
Meet Current Regulatory Limits. As
long as other boilers at the plant were running
on natural gas, the combined emissions
from the plant met regulations. But under
certain conditions, if Boiler 5 was running
solo on coal, emissions limits could be
exceeded. By completing the blended fuels
plan for Boiler 5, even when that unit
operates alone, the plant would remain in
compliance. Both internal and external
stakeholders would benefit from sustainable
emissions reduction, which is a global
priority of the GDF SUEZ group, explained
Senior Environmental Health and Safety
Specialist Suzanne Stevens.
Flexibility to Address Future Business
Opportunities and Regulatory Compliance.
In 2010, concurrent with Colorado
developing its Regional Haze State Implementation
Plan (RH-SIP), which requires
NOx
emissions reductions through best available
retrofit technology (BART), a discussion
was initiated about changing the fuel mix of
the facility from 93% coal and 7% natural gas
to 60% coal and 40% natural gas. Additionally,
there was great uncertainty concerning
the effects of pending regulations covering
mercury and hydrogen chloride emissions
( " Industrial Boiler MACT " ), lower limits for
SO2
and NOx
under the National Ambient Air
Quality Standards, and the disposal of coal
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POWER August 2015

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