Post on 14-Jul-2020
Energy and Emissions Performance
of Commercial Wood Boilers
Wood Biomass for Heat and Power: Addressing Public Health Impacts
Massachusetts Medical Society,
Waltham, MA
November 7, 2011
Ellen Burkhard, Ph.D. Senior Project ManagerClean Energy Research and Market DevelopmentNew York State Energy Research and Development Authorityegb@nyserda.org
Conventional wood-chip technology
Wood-chip fired stoker boiler and oil-fired boiler tests
Boiler efficiency 75 to 81% at full load.
Pellet Plants in NYS 450-550 kton per year
High-efficiency wood pellet-fired boiler
Boiler efficiency 86-91%
Pellet fuel flow pathTertiary air introduction to
completely combust gases
Departure of hot gases from
combustion chamber to heat
exchanger
Completed fuel combustionSecondary air introduction and
combustion of gases
Primary air introduction and fuel
gasification
Technology Performance Evaluation
Photo credit the Wild Center
PM 2.5 emissions input basis
0.28
0.26
0.11
0.06 0.060.05
0.0080.00005
120
112
41
26 2621
3.40.021
0
23
47
70
93
117
140
0
0.05
0.1
0.15
0.2
0.25
0.3
bole chip 7 mmBtu/h
stoker
mill chip7 mmBtu/h
stoker
wood chip 0.5 mmBtu/h
2-stage
wood pellet 0.5 mmBtu/h
2-stage
wood pellet 1.7 mmBtu/h
2-stage
#6 Heating Oil1.5 mmBtu/h
#2 HHO 4.3 mmBtu/h
#2 ULSD 0.1 mmBtu/h
PM
2.5
em
issio
ns m
g/M
J
PM
2.5
em
issio
n l
b/m
mB
tu
Acknowledgements
Lisa Rector, NESCAUM
Phil Hopke, Clarkson University
Tom Butcher, BNL
Particle size distribution
Figure 2. Steady-state ultra-fine particle number size distributions for emissions
from 0.5 mmBtu pellet boiler, 0.5 mmBtu chip boiler, and 1.7 mmBtu pellet
boiler (Chandrasekaran, et al., 2011).
Particle size distribution
Figure 3. Ultra-fine particle number size distributions for start-up, steady
state, and shut-down conditions (Chandrasekaran, et al., 2011).
Electrostatic Precipitator feasibility
Aerodynamic Diameter ( m)
0.01 0.1 1 10
Par
ticl
e C
oll
ecti
on E
ffic
iency
(%
)
70
75
80
85
90
95
100
92% load
65% load
45% load
(Laing et al, 2010)
Technology Outlook
• Post-combustion emissions
controls, ESP particle reduction
of 60-90%
• European market will force ECT
commercialization
Zumikron by Ruegge
Economizers – increased efficiency by 7-10% and particle reduction of approximately 85%
Technology Outlook
Summary
Advanced wood boilers can achieve:
• the same efficiency as oil-fired boilers
• lower PM emissions of more inorganic composition
compared to conventional wood chip boilers
Post combustion controls can reduce PM emissions from
advanced units to levels of oil-fired boilers.
Thank you!
NYSERDA
2010 Stimulus funds in NYS:
Commercial wood boilers were required to be high
efficiency (>83%)
2011funding:
Demonstrations of high-efficiency pellet boilers at schools
or hospitals must include ECT.
ARRA projects may also apply for ECT demonstration
category.