cogeneration in the forest products industry january 2008 by phil zirngibl
DESCRIPTION
Cogeneration in the Forest Products Industry January 2008 by Phil Zirngibl. What is Cogeneration?. Cogeneration is the production of electrical energy and another form of useful energy, such as heat or steam, through the sequential use of energy. - PowerPoint PPT PresentationTRANSCRIPT
1
Cogeneration in the
Forest Products Industry
January 2008
by Phil Zirngibl
2
What is Cogeneration?
• Cogeneration is the production of electrical energy and another form of useful energy, such as heat or steam, through the sequential use of energy.
• Cogeneration is also often referred to as Combined Heat and Power or
“CHP”.
Source: US DOE
3
Cogeneration – how much in the U.S.?
• CHP generation represents 9% of electricity generation capacity in the US.
• The Forest Products, Chemical and Oil Refining industries combined represent ~90% of the total CHP generation in the U.S. manufacturing sector.
• The majority of cogeneration in the Forest Products Industry is from renewable fuels (biomass).
Source: US DOE, Midwest CHP Center
4
Forest Products Industry
Represented primarily by two groups; paper and lumber Meets more than half its energy requirements through highly
efficient cogeneration processes. Since 1972:
Has increased energy self-sufficiency from 40 to 60% Utilizes nearly 85% renewable resources for onsite generation Reduced total energy usage by 30% Reduced purchased energy by 53%
Source: AF&PA
5
• STG = Steam Turbine mechanically coupled to a Generator
• GTG = Gas Turbine mechanically coupled to a Generator
• WHRB = Waste Heat Recovery Boiler
• Combined Cycle GTG = GTG with a WHRB combined with STG
• Simple Cycle GTG = Stand alone GTG
• Heat Rate = Amount of fuel (in btu’s) required to generate one Kwh of electricity. Commonly expressed in btu/kwh.
Common Cogeneration Terms
6
0 50 100 150 200 250
GTG w/heat rec
STG supplied bystm boilers
Combine CycleGTG
STG supplied byheat recovery
Paper Products Wood Products
Types of cogeneration in the Forest Product Industry
Source: MECS 1998
Number of facilities with cogeneration
Approx 75% of existing cogeneration facilities are in the Paper Products Business
7
Cogeneration from Steam Boilers in Forest Products Plants (paper)
Waste Wood Boiler
Wood-based biomass
High pressure steam
Low pressure steam
To manufacturing process
requirements
Generator
Green Power
Steam Turbine
Typical heat rate ~ 4,500 btu/kwh or 76% efficient
Recovery Boiler
Lignin
8
Typical Coal-fired utility generation
Boiler
Coal
High pressure steam
Generator
Power
Low pressure steam
Condenser
Steam Turbine
Typical heat rate ~ 10,000 btu/kwh or 34% efficient
9
Typical utility Combined Cycle GTG
Natural Gas
Power
Waste Heat
Recovery Boiler
Generator
Low pressure steam
Condenser
Generator
Steam TurbineHigh pressure
steam
Gas Turbine
Hot Gas
Typical heat rate ~ 7,000 btu/kwh or 49% efficient
10
Typical Simple Cycle GTG
Natural Gas
Power
Generator
Gas Turbine
Hot Gas
Exhaust
Typical heat rate ~ 12,000 btu/kwh or 28% efficient
11
Typical Heat Rates
0
2,000
4,000
6,000
8,000
10,000
12,000
Simple CycleGTG
Coal-Fired STG Combined CycleGTG
Ind Cogen (STG)
Typ
ical
Hea
t R
ate
(btu
/kw
h)
Utility Scale
Industrial cogeneration is significantly more efficient that other typical types of commercial electricity generation . . .
12
Cogeneration – Advantages/Issues
Advantages:• More efficient than commercial generation despite lack of scale.• Potential to increase renewable generation (esp. in Forest Products Industry)• Provides a reduction in GHG emissions. • Provides advantages of distributed generation (avoids issues w/constrained
transmission system).• Potential for advantageous tax treatments• Continued development supported by provisions of the Energy Independence
and Security Act of 2007
Issues:• Cogenerated renewable electricity from older installations not valued the same
as from newer installations.• Cogenerated renewable electricity must be sold to be eligible for Sec 45 Fed
Tax Credit.• Most recent version of Lieberman-Warner Climate Security Act of 2007 doesn’t
recognize value of cogeneration. . . in fact, penalizes facilities with cogeneration.
13
Green Power
Green(Renewable) Power = Brown Power + REC*
*REC = Renewable Energy Credit (renewable attributes of Green Power)
State RPS
15
U.S. Electricity Generation by Fuel
Coal49.0%
Hydroelectric7.0%
Other Renewables
2.4%
Petroleum1.6%
Other0.7%
Nuclear19.4%
Natgas20.0%
* Source US DOE Oct ‘07
Total = 4,065 Million MWH/yr
16
Renewable Electricity Generation by type
Coal49.0%
Nuclear19.4%
Natgas20.0%
Hydroelectric7.0%
Other Renewables
2.4%
Petroleum1.6%
Other0.7%
Woody Biomass
MSW/LFG
Geothermal
Wind
Solar
Total US Electric Generation by Fuel*
* Source US DOE Oct ‘07
17
Renewable Electricity Generation from biomass
GP generates ~ 8% of the electricity generated from woody biomass in the US . . .
Coal49.0%
Nuclear19.4%
Natgas20.0%
Hydroelectric7.0%
Other Renewables
2.4%
Petroleum1.6%
Other0.7%
Wood Waste
Blk Liquor
~ 8%
38.7 MM MWH/yr
Woody Biomass
MSW/LFG
Geothermal
Wind
Solar
U.S. generation from Woody Biomass
GP Generation from Woody Biomass
Total US Electric Generation by Fuel*
* Source US DOE