Wood Pellet Workshop Vancouver Marriot Pinnacle Hotel November 17, 2014 Recent advances in wood pellet science and engineering
Dr. Shahab Sokhansanj (UBC)
Life cycle analysis for wood pellets
Dr. Warren Mabee (Queen’s University)
10:20-‐10:30
Break
4
10:30-‐11:15
Pellets to fuel heat and CO2 producWon for greenhouses
Dr. Mark Lefsrud (McGill)
5
11:15-‐ 12:00
Dr. Stefan Cenkowski (U. InnovaWve wood drying for pellet Manitoba)
6
12:00-‐1:30
7
1
9:00-‐9:40
2
9:40-‐10:20
3
Lunch trade show
WPAC
1:30-‐2:15
TorrefacWon (Steam or dry) -‐ Pre or post pelleWzaWon,
Bahman Ghiasi (UBC)
8
2:15-‐3:00
Fundamentals of operaWons resaerch applied to feedstock and pellets handling
Dr. Mahmoud Ebadian, Consultant
9
3:00-‐3:15
Break
10
3:15-‐4:00
Gas emissions and dry mass loss from stored woody biomass residues
Dr. Anthony Lau (UBC)
11
4:00-‐4:45
Sustainability and emission reducWons
Dr. Terry McIntyre (BFN)/Ms. Olga Petrov
A brief survey of research on wood pellets Shahab Sokhansanj
Presented at the Third Wood PelleWzaWon Workshop in conjuncWon with 2014 Wood Pellet AssociaWon of Canada -‐ AGM November 17, 2014 Vancouver, Canada
World Pellet produc9on and demand Demand
60
ProducWon 51
Million tonnes
50 40 22.4
30 20
15.7 17
54
35 25.5
22
10 0 2010
2012
2015
2020
2025
Wood Pellet Produc9on –North America Million tonnes 9 8 7 6 5 3 2 1
Global biomass trade routes
Research topics: • Diversity of feedstock, • logisWcs (handling, storage) • Sustainability
Approach
• Understand structural and compositional make up of biomass – concerned with quality, cost, volumes, and environment. • Develop engineering equations and data for design of unit operations. • Develop mass and energy balances for TEA and LCA • Develop logistical and integration models • Develop standards and practices for quality evaluations safety • Train and mentor highly qualified engineering (HQP) graduates in clean energy • Attend to short and long term needs of industry
Biomass & Bieoenrgy Research Group UBC Biomass Gasifier Pellet mill
Wood pellet plant
Torrefier
Hammer mill
Biomass drying is a highly integrated system The installa9on on the leL of the green drum is the biomass burner. The air and dried biomass are separated in a cyclone. The exit air from cyclone is further cleaned from par9culate maOer in a baghouse. HEAT RECOVERY
WET BIOMASS
GRINDER SIZING
HOG FUEL
EMISSION CONTROL
DRYER
BIOMASS BURNER
DRY BIOMASS
Effect of ini9al moisture content on the cost of drying 18.00
Fuel cost ($/Mg)
16.00 14.00 12.00 10.00 8.00 6.00 4.00 2.00 0.00
MC=25%
MC=50%
MC=70%
Fig. 10. Cost of hog fuel to provide heat to a dryer with the capacity to produce 10 Mg/h of biomass at 10% moisture content. The horizontal axis shows the initial moisture content of the biomass. Fuel cost is based on $44/Mg for hog fuel.
Varia9on of par9cle size affects drying rates
Moisture ra9o
1.0
Moisture ra9o vs. 9me (from 50 % MC at 100 °C) Size: Based on thickness Large (10-35 mm), Medium (3-10 mm), Small (3.5 mm). The length of pieces in each group ranged from 10 mm to 50 mm.
0.8
0.6
Large
0.4
Medium 0.2
Small
0.0 0
100
200
300
400
500
600
Time (min)
(Source: University of British Columbia)
Three Industrial Size Reduc9on Equa9ons dE = −K
Kick Bond
dL Ln
n=1.0
E = K K ln
n=1.5
E = KB (
Rifnger n=2.0
E = KR (
1 L1P/ 2
−
[1] and [2]
1 L1F/ 2
1 1 − ) LP LF
dE = power input K = constant LF = size of the feed LP = size of the ground product [1] Earle and Earle, 1983; [2] Perry et al., 1997;
LF LP )
[1] and [2]
[1] and [2]
Ques9ons: Applicability to fibrous biomass? DefiniWon of parWcle size?
Size reduc9on
Douglas-‐fir
Pine
Wheat straw
Miscanthus
Aspen
Hybrid poplar
Corn stover
Willow
14
Size reduction Specific energy required to reduce the size of biomass particles from Lf to final ⎛ 1 1 ⎞⎟ size Lp. The fit to Rittinger’s equation ⎜ E = KR −
⎜ L p ⎝
L f ⎟⎠
Refnger equaWon had a good fit to the hammer mill data
Energy input (kWh/t)
40 35 30 25 20 15 10 5 0
Rittinger's Law (with intercept) Hybrid willow Douglas-fir Canola Oat Barley straw Wheat straw Switchgrass Corn stover
200 150 100 50 0 0
1
2
1/Lp-1/Lf 3.2 mm 6.4 mm
3
4
5
6
100 80 60 40 20 0
Specific energy, kJ/ kg
Specific energy, kJ/ kg
250
y = 67.312x R² = 0.91384
Pine 0
0.5 (1/Lp)-(1/Lf)
1
1.5
Grinding stover past 6 mm screen fracWonates into a hairy material and ground parWcles 15
Energy input to make pellets 80 Forming pellets in the die
6,000
Force (N)
Energy Input (MJ/dry t)
8,000
y = 133.51e2.0087x R² = 0.8482
4,000 2,000 0 0.0
0.5 1.0 1.5 Distance ratio (Lr)
2.0
60 40 20 0
40 Energy Input (MJ/dry t)
200 160 Force (N)
Compression
120 Expulsion of pellets from die
80 40 0 0.0
5.0 10.0 Distance (mm)
15.0
30 20 10 0
FricWon
PelleWzaWon 5000
Douglas-‐fir Hybrid willow Miscanthus
Force, N
4000 3000 2000 1000 0 0
10
20 30 Displacement, mm
40
50
• Miscanthus (an agricultural biomass) used more energy to pelleWze comparing to woody biomass; • Specific energy of size reducWon is more than specific energy of pelleWzaWon;
mm screen 2 4 6
Miscanthus Pellets
17
Effect of parWcle size and shape (raw wood and pellet parWcles) on high temperature pyrolysis (0.5 mm to 5 mm parWcles)
Microscopic surface picture of the 5 mm particle (a&b top) before drying and (c&d bottom) after drying, up to temperature of 150 C.
For drying temperatures lower than 100 ˚C, mass loss decreased from 0.25 to 5 mm particles. After 100 ˚C, 5 mm particle showed different behavior which was described by some observed cracks into the structure of particle.
Pellet parWcles are denser and more regular in shape than saw dust parWcles 18
Concluding thougts • Pelle9zed fuels (biomass) is a new and exci9ng area in the bioenergy industry that is expanding rapidly. • Rapid growth oLen coincides with modifying or crea9ng new ways to increase output of exis9ng and newly developed process equipment and products to keep up with demand. • These changes in processing will raise new ques9ons about safety and cost compe99veness that will need to be researched and developed for the industry to succeed.
BBRG conducts science and engineering research on adding value to unused biomass from forestry, agriculture, and MSW – New dedicated Lab (Gas Gun) • Densifica9on (pelle9za9on, briquecng) • Drying, size reduc9on, storage • Logis9cs modeling and process designs • Life cycle analysis • Safety Short and long term R&D projects
:
Biomass and Bioenergy Research Group (BBRG) facili9es and resources UBC biomass gasificaWon CHP -‐ BRDF
Wood pellet plant
Pellet mill
Single Pellet mill Pilot scale storage
Torrefier & steam treatment Size reducWon mill
Gas Gun Bldg A DREAM PLACE
Organizing Committee and Contacts Program co-chairs: Fahimeh Yazdanpanah (
[email protected]) Hamid Rezaei,
[email protected] Communications: Jun Sian Lee,
[email protected] Executive Committee Members: Maryam Tajilrou,
[email protected] Rachel Wang,
[email protected] David Zamar,
[email protected] Members of the organizing committee except PDF Dr. Yazdanpanah are UBC graduate students
Biomass & Bioenergy Research Group
Pellet Science & Engineering an Update Shahab Sokhansanj Chemical and Biological Engineering Department The University of British Columbia
Acknowledgement • NSERC – Regional Opportunity Fund, Discovery Grant, CRD Strategic Program, • Biofuel Network (Centers of Excellence), BioFuelNet.Ca • Wood Pellet AssociaWon of Canada – Pinnacle, Premium Pellet, Viridis, Princeton Cogen, Pacific Bio (PG)
• • • • • • • • • •
BC Ministry of Forest NRCan -‐ Canmet Energy CEATI – Electric power producing consorWum -‐ OPG Cogent Industries Agriculture & Agri-‐Food Canada Nexterra Global Biocoal Inc. Ontario Ministry of Agriculture, Food and Rural Affairs Fibreco, Inc. North Vancouver BC Bioenergy Network
