san francisco urban forest wood re-use study...san francisco urban forest wood re-use study presidio...
TRANSCRIPT
San Francisco
Urban Forest Wood Re-Use Study
Presidio Graduate School Jonathan Dirrenberger
Cheryl Dorsey
Ryan Miller
Sonja O’Claire
Agenda
• Presidio Team
• Project Scope
• Methodology
• Case Studies
• Current State of Re-Use
• Stakeholders
• EOL Wood Products
• Recommendations
• Barriers to Implementation
Presidio Team
• Presidio Graduate School Sustainable Management MBA candidates
• Experiential learning project for Operations and Production course
• Study produced for SF Planning Department
Project Scope
• Current wood waste processes • Street Trees (DPW) • Park Trees (RPD)
• Case studies
• Evaluate EOL processes
• Make recommendations for a future wood re-use program
Methodology
• Stakeholder meetings
• Facility tours
• Phone interviews
• Demand forecast
• Value analysis
Case Studies
• Sacramento, CA
• Olympia, WA
• Cincinnati, OH
Current State of Re-Use
• DPW (Street Trees) • Hauls to Recology
• RPD (Park Trees) • Chips, mulch and composts
all tree waste on-site • Some logs used in parks • 100% re-use rate
• Lumber is not a current end product
• Estimated 10-20% of removed trees are of lumber quality
Stakeholders
Urban Tree EOL Wood Products • Logs
• Lumber
• Wood Chips
• Mulch
• Compost
• Hog Fuel
• Biochar
• Paper Products
• Cellulosic Ethanol
• Engineered Wood
Incre
ase
d P
rocess
ing
Tree Planting
Seed Planting & Sapling Growth
Sapling
Rough Cutting Sawmilling
Lumber Barriers,
Benches, etc. Engineered
Wood Production Pulping
Paper Products
Engineered Wood
Chipping or Grinding
Transport
Wood Chip Screening
Mixed Wood Chips
Manure or Food Waste
Sand
Overs
Composting Mulching
Hog Fuel
Landfill Waste
Wood Debris
Non-Tree Wood Waste
Cellulosic Ethanol
Fermentation
Debarking and Chipping
Storage Storage
Storage
Seed and Water
Contaminated Wood Chips†
Tree Growth
Tree Pruning
Tree Removal Immature
Tree Mature
Tree
Pruned Tree
Tree and Wood Debris
Firewood Transport
F/E
Other Applications
Storage
Other Applications
Storage
Storage
Storage
Transport
Pyrolysis
Bio-oil and Syngas
Biochar
Storage
Wood Chips Adhesives and
Binders
Storage
Fines Wood Chips
(Accepts)
Logs
Mulch Compost Storage
Other Applications Storage
Storage
Process Diagram for San Francisco Urban Tree Wood Re-Use
• Ovals indicate processes • Rectangles indicate materials • Yellow indicates relevant EOL wood products • Abbreviations:
GHG = greenhouse gas emissions P = pollution F/E = fuel and/or energy
• Dashed lines indicate processes and materials not recommended but shown for completeness
• Transport process indicates transport out of the city (transport within the city is not shown)
† Contaminated wood contains toxic chemicals (paint, waterproofing chemicals, chemicals to prevent rot, etc.) and is thus only suitable as hog fuel. This normally only occurs when non-tree wood waste is used.
Defining Value of EOL Wood
• Minimize GHG emissions and pollution
• Minimize landfill
• Keep local
• Reduce costs
• Raise awareness
• Optional: obtain revenue
Lee, C., Erickson, P., Lazarus, M., & Smith, G. (2010). Greenhouse Gas and Air Pollutant Emissions of Alternatives for Woody Biomass Residues, Final Draft Version 2.0. Stockholm Environment Institute
Lee, C., Erickson, P., Lazarus, M., & Smith, G. (2010). Greenhouse Gas and Air Pollutant Emissions of Alternatives for Woody Biomass Residues, Final Draft Version 2.0. Stockholm Environment Institute
Best Options • Priority
• Lumber & Logs
• ~10-20% of removed trees
• Secondary • Wood chips, mulch, and compost
• ~70-80% of removed trees
• Last resort • Hog fuel
• ~10% of removed trees
• Future • Biochar
• More research needed
Demand & Financial Value - 2014
Demand & Financial Value - 2034
Key Recommendations
1) DPW process and store wood chips, mulch, and compost
2) The City develop program to harvest lumber • Short term: pilot for rough sawn
program
• Long term: rough and finished lumber
3) DPW & RPD share wood processing resources
Secondary Recommendations
A. Improve data collection
B. Pre-empt possible public disapproval
Barriers to Implementation
• Funding
• Legal & policy barriers
• Public opinion
Thank you!