FINAL
DRAFT


Combined
Heat
and
Power



An
Energy-Efficient
Choice
for
the


Ethanol
Industry


Cmbined
heat
and
power
(CHP),
also
known
as


cogeneration,
can
be
an
excellent
solution
for


the
energy
needs
of
your
ethanol
plant.
With
CHP,


your
plant
can:


� Generate
electricity
and
steam
reliably
on
site.


� Reduce
energy
and
operating
costs.


� Reduce
greenhouse
gas
emissions
and
other



environmental
impacts.



� Optimize
the
use
of
alternative
fuels.


CHP
Now
on
Line


at
U.S.
Ethanol
Plants


Ethanol
plants
have
a
continuous
power
and
steam


demand,
which
makes
CHP
cost
effective
in
many


locations.
In
addition,
the
size
of
the
electricity


and
steam
loads
at
ethanol
plants
closely
matches


the
size
of
commonly
available
CHP
technologies.


As
a
result,
CHP
is
currently
providing
economic


and
operational
benefits
for
a
number
of
dry
mill


ethanol
facilities
in
the
United
States,
including:


� Adkins Energy, LLC. Lena,
Illinois—



5
megawatt
(MW)
gas
turbine.



� U.S. Energy Partners, LLC. Russell,
Kansas


—two
7.5
MW
gas
turbines.


� Northeast Missouri Grain, LLC. Macon,



Missouri—10
MW
gas
turbine.



� Otter Creek Ethanol. Ashton,
Iowa—7
MW


gas
turbine.


� East Kansas Agri Ethanol. Garnett,
Kansas—


1
MW
recuperative
thermal
oxidizer/steam


turbine.


By
using
CHP,
these
facilities
are
gaining
a


competitive
advantage
in
the
marketplace.


Together,
they
have
saved
millions
of
dollars
in


annual
energy
costs
and
are
reducing
greenhouse


gas
emissions
by
approximately
227,000
tons
each


year.
Additional
CHP
capacity
is
planned
for


ethanol
plants
in
Minnesota,
Missouri,
Illinois,


Nebraska,
and
Colorado
using
a
variety
of
fuels


(natural
gas,
coal,
and
biomass).


Improved
Economic
and


Business
Performance


CHP
can
provide
you
with
a
competitive


advantage
in
the
market:


� CHP
can
improve
the
economics
of
ethanol


production,
yielding
energy
savings
of
10
to


25
percent,
and
provide
a
hedge
against


future
energy
cost
volatility.


� CHP
can
ensure
that
a
plant
keeps



operating,
even
when
the
surrounding



electric
grid
is
down.



� CHP
can
offer
the
opportunity
to
partner


with
your
municipal
utility
or
rural


cooperative
to
leverage
resources.


� CHP
systems
can
be
designed
to
operate
on


any
fuel,
ensuring
that
your
plant
optimizes


the
use
of
available
energy
resources,


improving
its
overall
efficiency
and


competitive
position
in
the
marketplace.


� CHP
can
help
meet
corporate
environmental


goals
and
enhance
a
company’s
image.


Compared
to
conventional
systems,
CHP


greatly
reduces
total
energy
use
and
the


resulting
emissions
of
carbon
dioxide
(CO2),


a
contributor
to
global
climate
change.

Improved
Energy
and


Environmental
Efficiency


CHP
is
an
efficient,
clean,
and
reliable
approach


to
generating
power
and
thermal
energy
from


onsite
facilities.
It
uses
heat
that
is
otherwise


discarded
from
conventional
power
generation
to


produce
thermal
energy.
By
providing
electricity


and
steam
from
the
same
source,
CHP
significantly
reduces
the
total
fuel
used
to
supply


energy
to
your
plant,
along
with
the


corresponding
emissions
of
CO2
and
other


pollutants.


The
figure
below
compares
the
typical
efficiency


and
fuel
use
of
a
CHP
facility
(this
one,
using
a


natural
gas­fired
turbine)
to
the
typical
efficiency


and
fuel
use
of
a
conventional
system
that
provides
the
same
amount
of
energy.


In
conventional
systems,
ethanol
plants
purchase


electricity
from
the
central
grid
and
produce


steam
for
their
plant
using
an
onsite
boiler.


Together,
the
two
systems
would
typically
use


154
units
of
fuel
to
produce
30
units
of
electricity


and
45
units
of
steam
at
an
overall
efficiency
of


49
percent.
With
CHP,
one
system
could
provide


the
same
amount
of
electricity
and
steam
using


only
100
units
of
fuel.
This
system
offers
an


overall
efficiency
of
75
percent.
Because
the


CHP
system
uses
nearly
35
percent
less
fuel,
it


produces
much
lower
emissions
than
the


conventional
system.
The
CHP
system
shown


here
would
produce
about
half
the
CO2
emissions


of
conventional
separate
heat
and
power.
When


CHP
systems
replace
aging
conventional
systems,


the
emission
reductions
can
be
even
greater.

How
Is
CHP
Used
in


Ethanol
Plants?


CHP
technologies
are
flexible,
providing
many


ways
to
apply
CHP
to
the
dry
milling
ethanol


process.


1.
The
most
common
CHP
technology
used
in


ethanol
plants
today
consists
of
a
gas
turbineelectric
generator
unit,
placed
in
tandem
with
a


waste
heat
boiler.
The
turbine­driven
generator


provides
electricity
for
the
facility
and
the


turbine
exhaust
is
used
in
a
waste
heat
boiler
to


produce
process
steam.


2.
Interest
in
biomass
and
coal
CHP
is
growing.


Biomass
can
be
an
option
for
ethanol
plants


located
near
sources
of
agricultural
or
forest
waste


or
for
plants
looking
to
use
the
ethanol
process


byproducts
as
a
fuel
source.
Several
technical


approaches
are
being
implemented
for
coal
and


biomass,
including
fluidized­bed
boilers
or


gasifiers
that
integrate
volatile
organic
compound


(VOC)
destruction
directly
into
the
system
and


generate
power
through
a
steam
turbine.


3.
Ethanol
plants
with
large
thermal
oxidizer


loads
can
use
a
waste­heat
boiler
to
produce


steam
from
the
oxidizer
exhaust.
High­pressure


steam
from
the
waste­heat
boiler
is
used
in
a


steam
turbine­generator
unit
to
produce


electricity.
Low­pressure
steam
from
the
back
end


of
the
turbine
is
used
to
meet
process
heat


requirements.


4.
Other
CHP
options
are
also
being
explored
for


ethanol
plants,
including
the
integration
of
dryer


exhaust
VOC
destruction
into
gas­fired
turbinegenerator
systems.
This
approach
entails
ducting


the
dryer
exhaust
into
the
gas
turbine
waste
heat


generator
and
then
using
a
secondary


supplemental
burner
to
oxidize
the
VOCs
and


efficiently
generate
additional
steam
for
the


plant.


An Innovative Solution 

Fuel ethanol is one of the fastest growing business 

segments in the United States, with domestic ethanol 

production estimated to double between 2005 and 

2012. This expansive growth in ethanol supply, in 

conjunction with the rising demand for electricity and 

the high cost of natural gas, creates unique opportunities to utilize CHP for cost­effective “win­win” 

partnerships between ethanol plants and rural electric 

utilities. 

An example of this kind of partnership is located near 

the city of Macon, Missouri, where a CHP system was 

built in conjunction with an ethanol facility in 2003. A 

partnership was forged between the Macon Municipal 

Utilities, which purchased a natural gas­fired 10 MW 

combustion turbine, and Northeast Missouri Grain LLC, 

which built the CHP system’s housing and control 

building. 

Each organization pays for half of the cost of the 

natural gas that powers the turbine. Of benefit to the 

utility, this project supplies an additional 10 MW of electricity to the local power pool at 50 percent lower 

natural gas costs than traditional generation capacity. 

Of benefit to the ethanol plant, the project provides 

nearly 60 percent of the plant’s steam needs (51,000 

pounds per hour) for ethanol production, which reduces 

the plant’s natural gas costs by 20 percent per year. In 

addition, when the electricity grid experiences a power 

outage, the CHP system provides full backup power to 

the ethanol plant: a system that worked successfully in 

four blackouts during the first year of operation. By 

reducing fuel use and increasing reliability, this shared 

CHP system is an effective low­cost operating model for 

the ethanol plant. 

This CHP project requires approximately 25 percent 

less fuel than the typical system of onsite boilers and 

purchased electricity, and based on this comparison, 

reduces CO2 emissions by an estimated 30,200 tons 

per year. 
Is
My
Facility
a
Good


Candidate
for
CHP?


� Do
you
use
more
than
20,000
pounds
per


hour
of
steam?


� Do
you
pay
more
than
6
cents
per
kilowatthour
for
electricity?


� Is
reliable
high­quality
power
important?


� Is
it
important
to
reduce
energy
costs
and


increase
the
overall
energy
efficiency
of


your
ethanol
process?


� Are
biomass
or
alternative
fuels
readily



available
near
your
site?



� Do
you
want
to
increase
your
plant’s



environmental
performance?



If
the
answer
is
“yes”
to
two
or
more
of
these


questions,
CHP
can
benefit
your
facility.


Interested?
What’s
the


Next
Step?


EPA
staff
are
available
to
answer
your
questions


and
provide
specific
support
for
your
project.


For
information
about
how
EPA
can
support
the


evaluation
and
implementation
of
your
CHP


project
or
if
your
facility
already
uses
CHP
and


you
wish
to
apply
for
an
ENERGY
STAR
CHP


Award,
contact
EPA’s
CHP
Team
at


(202)
343­9553
or
e­mail
Neeharika Naik-Dhungel

at naik-dhungel.neeharika@epa.gov.

EPA
CHP
Partnership


The CHP Partnership is a voluntary program 

designed to foster cost-effective CHP projects. 

Through the Partnership, EPA engages energy 

users, the CHP industry, state and local 

governments, and other stakeholders in 

cooperative relationships to expand the use of CHP. Information about 

our services and program offerings is available on our Web site: 

www.epa.gov/chp. 

Last
updated
April
23,
2007