coppice short-rotation woody crops production systems introduction advantages of using woody crops...
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Coppice
Short-Rotation Woody Crops Production Systems Introduction
Advantages of Using Woody Crops for Bioenergy
Energy Conversion of Woody Biomass
• Provide diversity of feedstocks • Location and geographic
distributive advantages
• Adaptability of species to regional areas
• Lower ash content• Year-round availability• Stable, consistent
feedstock supply• High density products• Easy to store • Easy to handle• Mix with the other
woody feedstocks
• Protect soil, water and air quality
• Sustainable production systems
• Sequester carbon • Create wildlife habitat• Increase diversity
landscapebiologicalsoil microbial and
mesofauna• Improve productivity of
marginal farmland
• Combustion boilers• Gasification
Synthesis gas: 20% H2, 20% C0, 5% CH3
• Pyrolysis: Bio-oil & CharBio-Oil is a crude containing high
value chemicals• Biofuels• Biochemical processes requiring:
Cellulosic enzymesDistillation energy
• Thermochemical processCatalytic conversion of synthesis gasAlcohols and diesel
Table 1. Summary of practitionersurvey of potential forwoody energy crop speciesfor southeastern US.
• Southern Pines• Hardwoods• Coppice
• Southern Pines• Hardwoods• Coppice
• Elite genetic selections• Adapted to wide range
of sites• Variety of selective
herbicides• Developed operations
• Elite genetic selections• Adapted to wide range
of sites• Variety of selective
herbicides• Developed operations
• Vegetative propagation• High density planting
(6000 trees/acre)• Cut every 3 to 4 years• Replanting required after 25 years• Efficient harvesting equipment
Woody Bioenergy Crops for the Southeastern United StatesMark Coleman1 and Keith Kline2
1USDA-Forest Service, 241 Gateway Drive, Aiken, SC 29803; [email protected] Ridge National Lab, Oak Ridge, TN 37831-6038; [email protected]
Positive Response to culture treatmentsHerbicides Fertilization
Enhanced Pine Production Potential
Biomass is an important alternative energy resource that can offset greenhouse gas emissions from fossil fuels, provide crop options for marginal farmlands and improve rural economies. Forests cover nearly 60% of the southeastern US. Woody energy crops include fast growing native species that have shown large productivity gains from improved genetic resources and cultural practices. Woody feedstocks offer many advantages compared to other types of biomass and options for conversion to various types of energy (liquid fuels, electric power, and other bio-products) are possible. Here we summarize accumulated learning from southeastern practitioners’ experiences with woody cropping systems and discuss examples of many of the most promising woody energy crop species.
• Relatively low input crops • Genomic Resources• Multiple market options
Environmental Benefits
Process Benefits
Pine
• Poplar, Eucalyptus, Sycamore, Sweetgum
• Large growth potential• Forest operations
equipment• Genomic resources
• Poplar, Eucalyptus, Sycamore, Sweetgum
• Large growth potential• Forest operations
equipment• Genomic resources
Orlando, FL• 2 ½-year-old
EucalyptusGrandis
• Growth Rates of 2 to 3” diameter/year
• 7.2 dry tons/acre/yearBainbridge, GA• 4.5-year-old • survived > 150 freezing
nights• 1.7 – 2.7 diameter per year• 7 dry tons/acre/year
E. amplifolia E. viminalisE. nova-anglicaE. macarthuriiE. camphora
E. amplifolia E. viminalisE. nova-anglicaE. macarthuriiE. camphora
Hardwood
Eucalyptus
Eucalyptus
Conclusions• Several woody crops offer high growth potential in the southeastern
US under proper silviculture but costs for hardwood plantations may be prohibitive.
• Loblolly pine has the most developed infrastructure. It can be grown at lower cost and at higher rates on the largest variety of sites.
• Bottomland hardwoods such as cottonwood and sycamore are limited by site and soil requirements and disease.
• Eucalyptus out performs other species in biomass output/year but is limited by frost to Florida and a narrow band along the gulf coast.
• Coppice crops offer potential to rapidly expand production but require research to identify the best species and cultivars for a given locale and to develop appropriate cultural practices and operational equipment.
• Extensive natural hardwood and mixed forest resources in the southeast also merit further study for potential contributions to bioenergy.
Practitioners Survey
Woody Plantation Expected Production ProductionCrop (dry Mg/hectare-yr) Costs Advantages Disadvantages
Low Avg. High ($dry/Mg)
Cottonwood and 6 9 12 15-95 • Broad genetic resources • Narrow site requirements Hybrid Poplars • Disease susceptible
Sycamore 7 9 11 15-95 • Rapid early growth • Narrow site requirements • Disease susceptible
Sweetgum 4 6 8 15-65 • Broad site requirement • Relatively slow growth• Disease resistance
Eucalyptus 18 22 25 15-65 • Broad site requirement • Restricted by frost• High growth
Hybrid Aspen 9 10 12 no data • Broad site requirement • Undeveloped genetic material
Loblolly Pine 8 9 10 10-40 • Operational infrastructure • Broad genetic resources
WillowCuttingsfor plantingCuttingsfor planting
HarvesterHarvester
After cutAfter cut
• Numerous forestry practitioners were interviewed about the potential for woody energy crops in the southeastern US.
• In total, over 250 person-years of southeastern forestry research experience.
• Each was asked to name potential crop species, management requirements,expected productivity rates and factors impacting yields.
• The table summarizes results.
EucalyptusRange
Sycamore
• Experience to date has been with northern temperate culture
• Willow native to southern US,merits research
• Sycamore coppice yields twicethat of seedlings
Year 3Year 3
Late in year 2
Late in year 2
Pine & Sweetgum
trials - year 12
Pine & Sweetgum
trials - year 12
Sampling soil - sweetgum