Introduction to State-of-the-Art
Commercial-Scale Wood Pellet and Wood Chip
Boiler Systems
(US and European Case Studies)
Prepared by: David Dungate, President
ACT Bioenergy, LLC
Tel: 518-956-2507
dungate@actbioenergy.com
Current Situation
•1/3 of US energy is used for heating and cooling buildings – more than
transportation or manufacturing
•1 ton of wood can replace 115 gal of heating oil and reduce CO2 by 2645 lbs.
• Current logging in the Upstate NY generates more than 1 million tons of noncommercial wood residues/yr. – Enough to heat 3-4000 school buildings.
New York Oil Economics
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7.9 million New York Households
33% heat with oil
Average oil price of $3.59/gal. over next 10
years
Consumption = 2.34 Billion gallons/yr. avg.
Cost = $8.4 Billion/yr. and $6.3 Billion/yr.
leaves US
If 10% of homes convert to wood pellet
heating over 10 years > 1000 direct jobs and
61,000 multiplier jobs in New York
(Sources: EIA, Census, Strauss - Futuremetrics 2009)
Fuel Cost Comparison in $/MMBtu
$45.00
$40.00
$35.00
$30.00
$25.00
$20.00
$15.00
$10.00
$5.00
$-
d
o
o
W
C
ps
i
h
$5
t
0/
o
W
od
ll
e
P
s
et
N
0/
0
$2
ra
u
at
t
as
lG
1
$1
C
M
/
0
.9
F
F
i
O
l
e
u
2.
$
l
/
75
l
a
g
ne
a
op
r
P
.7
2
$
ga
/
0
l
ric
t
ec
l
E
kW
/
14
.
$0
t
eo
G
CO
l
a
m
r
he
.3
3
P
Notes: Pellets = 15.6 MMBtu/ton, chips @30% moisture = 10.9 MMBtu/ton, geothermal heat pump using
electricity at $.14/kW.
Data Source: www.nyserda.org/Energy_Information/energy_prices_supplies.asp
Energy Consumed to Refine Fuel
Wood Chips
Wood Pellets
Oil/Natural Gas
Corn Ethanol
0.5-1%
2-6%
10-20%
60-100%
Note: Percent of energy in final product that was consumed during processing/refining
Source: Planning and Installing Bioenergy Systems: A guide for installers, architects and engineers. James & James. 2007
Comparative CO2 Emissions
lbs/MMBtu
Heating System CO2 Emissions (equivalent)
300
250
200
150
100
50
0
d
oo
W
C
h
s
ip
d
o
o
W
ts
ll e
Pe
N
at
a
ur
as
lG
H
tin
a
e
g
il
O
Source: Emission factors from www.nyserda.org and www.eia.doe.gov
e
n
a
p
o
Pr
ty
i
c
tri
O
C
al
rm
e
th
o
e
G
ec
l
E
.3
3
P
New Wood Boiler Technologies
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Europe’s leadership
Austria Population of 8 million
has 30 Wood Boiler Companies
(70% of European Wood Boiler
Market)
Provinces in Upper Austria
committed to 100% renewable
space heating and electricity by
2030. (Biomass/solar thermal)
Currently 30% of primary
energy is renewable almost 50%
of this is Biomass. 41% of
heating is renewable. Currently
wood boilers outsell oil boilers
for residential applications.
Austria
Commercial Boilers
Wet Fuel Type
Pellet/dry-fuel-Type
Residential Boilers
Small Commercial Pellet
Residential Log Wood Gasification
Integrated systems Biomass/Solar thermal
How to Achieve High Efficiency Combustion
Gasification and Staged Combustion
1) Residence Time - excess air at 50%
2) Combustion Temperatures 1200-1600F.
Controlled to reduce particulates and NOx.
3) Turbulence – tangential air/turbulators
4) Thermal buffering – Hot water storage tank
100gal/100,000 Btu/h output
5) PLC controls with oxygen monitoring
High efficiency wood combustion particulate is 5x
less toxic that diesel emissions (home heating oil)
Source: 15th European Biomass Conference and Exhibition, 7–11 May 2007, Berlin
N. Klippel and T. Nussbaumer. HEALTH RELEVANCE OF PARTICLES FROM WOOD COMBUSTION
IN COMPARISON TO DIESEL SOOT www.verenum.ch
Commercial Boiler Emission Comparison
Advanced (EnergyCabin)
Wood Boiler Emission Comparison
PM
N0x
CO
0.7
Comparative data source:
lbs./mmBtu
0.6
US EPA’s AP42 emission factors
for commercial boilers
0.5
0.3 lbs/MMBtu is NH
particulate standard for
conventional fuel boilers
0.4
0.3
0.2
0.1
0
E-Cabin
Typical
ACT
(Dry
Wet
Wood)
Wood
Typical Distillate No. 6
Dry
Fuel Oil Fuel Oil
Wood
Note: EPA defines dry wood as <30% moisture
Natural Propane
Gas
Gasification Type Boiler
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
Fuel bin stirrer
ACT Bioenergy™
Gear motor
Fuel auger
Fuel auger channel
Auger drive motor
Separating flap valve for the channel and intermediate
storage bin
Ultrasonic probe
Intermediate storage bin
Fuel anti-bridging device
Feeding auger
Emergency fire extinguisher
Automatic ignition
Air blower
Control panel box
Control panel
Primary combustion zone
Grating wheel
Secondary combustion zone
19.
20.
21.
22.
23.
Ash container
Exchanger flap valve
Heat exchanger with turbulators (without sheet covering)
Turbulators
Turbulator drive
Boiler Configuration
European Wood Boiler Features
User-Friendly Automation
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Electric hot air ignition
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Automatic ash cleaning from the burn plate and heat exchanger tubes. The ash
collection bin is typically emptied every 3-8 weeks depending on the fuel quality.
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Lambda probe measures oxygen levels in the exhaust and adjusts airflow and
fuel feed rates to ensure optimal combustion efficiency and lowest emissions.
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Basic operation can be remotely monitored and controlled through a PC Modem
High-Efficiency Compact Combustion Chamber and Heat Exchanger
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In the primary zone, air is supplied to gasify the fuel.
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In the secondary and tertiary combustion zones, air is tangentially delivered to
create intense turbulence and achieve complete combustion of the fuel.
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The large heat exchanger surface area with turbulators ensure optimal heat
transfer. (85-90% efficiency)
Multiple Safety Interlocks
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Automatic shut down and extinguishing if unsafe conditions are identified in the
boiler or the fuel storage chamber.
Various Fuel Storage Options
Wood chip bunker
Wood pellet fuel silo
Hotel & Spa - Indocheny, Ireland
•67 Room Hotel and Leisure Center
•Original LPG cost $140,000/yr.
(8MMBtu)
•LPG boilers completely replaced with
3 x 500,000 Btu Pellet Boiler
•Fuel savings of $62,000/yr.
•Investment $400,000 (heating system
and efficiency upgrades)
Clarkson University - Potsdam, NY
• 500,000 Btu wood pellet boiler integrated with two
300,000 Btu natural gas boilers heating the Indoor
Turf Sports Facility
• Project Coordination, emissions and performance
monitoring by University
Cayuga Nature Center – Ithaca, NY
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Containerized 0.5 MMBtu Containerized Boiler
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Cayuga Nature Center
0.5 MMBtu containerized
boiler for 15,000 ft²
facility
Fuel = Air Dried Wood
Chips
Typical Project Payback
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Boiler size 1.7 MMBtu/h
Building heat load 3680 MMBtu/yr.
Fuel Oil @$3.00/gal replaced with wood pellets
@$225/ton
Total Installed Cost $175,000
Simple ROI = 4.5 yrs. (without incentives)
15 yr savings = $832,000
370 t/yr of GHG reduction
ACT Bioenergy Summary
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Payback (2-8 yr. ROI)
Emissions comparable with oil boiler
Renewable fuel – Reduces global
warming
Fully automated controls
New government incentives possible
Thank You
David Dungate
ACT Bioenergy
Schenectady, NY
Tel: 518-956-2507
Email: dungate@actbioenergy.com