Upload
sara-blair
View
215
Download
0
Tags:
Embed Size (px)
Citation preview
Bioenergy Energy Systems
A truly green car
In Other News . . .
The new town of Destiny (south of Yeehaw Junction, FL) will grow various biocrops to evaluate their profitability for biofuels
The Farm to Fuel program is receiving significant funding from the Florida Dep’t of Agriculture
090317
Overview: Bioenergy
Bioenergy consists of biomass (biological mass) used in the production of energy; http://www.bioproducts-bioenergy.govBiomass
Phototrophs use light to survive and propagateChemotrophs (like us) eat phototrophs
(vegetables and salads)! Salads topped with biodiesel and acetic acid!
CO2 + H2O >--solar energy and chlorophyll CH2O + O2,
or carbohydrate and oxygenWhile biomass combustion releases CO2 into the
atmosphere, new plants require CO2 to grow, balancing the process for no net CO2 over a long time
080228 Cheremisinoff and Regino, 1978
13.0 About This Presentation
13.1 Bioenergy Locations13.2 Sources and Availability13.3 Energy Extraction and Preparation
13.3.1 Dry Biomass 13.3.2 Wet Biomass13.3.3 Gaseous Biomass13.3.4 Energy Conversion
13.4 Environmental Aspects13.0 Conclusion
060306
13.1 Bioenergy Map (From Biomass)
Direct firing, cofiring, and gasification are forms of biopower
Ethanol can be made from grain or soybeans, and methanol can be made from cellulose (wood)
Liquid fuels are essential for transportation vehicles due to high energy density in the tank!
May be intentionally grown (coppicing) such as poplar trees or might use waste byproducts
Biomass satisfied 4% of energy demand in 1990
Biomass can serve as a bridge from fossil fuels, although it is an inefficient producer of energy (~1%)
060316
http://www.eia.doe.gov/cneaf/solar.renewables/page/biomass/biomass.gif
13.1 Bioenergy Use Changed with Time
The Midwest is now using less biomass while the West use is rising
060315
13.1 Bioenergy Definitions
Bagasse: Sugar cane refuse left after pressing the juice from the cane
Bioenergy: Energy derived from biomassBiomass: Mass of plant material formed from solar
energy, water, and air; any organic material that is renewable
Cofire: To burn an additional fuel with the primary fuel, such as bagasse or sawdust with coal
IWS: Industrial Waste StreamWaste wood, plastics, fiber; same kind of discard
MWS: Municipal Waste Stream, or MSW, municipal solid wasteTrash, plant trimmings, garbage (batteries,
heavy metals, poisons, chemicals?) contaminate the air
060316
13.2 Sources and Availability
Typical fuels are “sugarcane, sugar beets, sorghums, corn, wheat, forage, grasses, kenaf, eucalyptus, short rotation hardwoods, sunflowers, and comfrey.” [Blackburn, 1993]
The materials are so cheap that the cost of hauling them determines the overall economics of using themTruck haulage should not exceed ~70 miles to
avoid overall loss of energy from truck fuel consumption
Are the sources sustainable or will there be shortages?
Biomass acts as seasonal peaking, since the growth occurs in time for harvesting for winter heating
070315 Comfrey photo from biology.clc.uc.edu
13.2 Florida Biomass Resources
Biomass Resources 1,539 MW
Corn: 65,000 acres planted
2,262,000 bushels produced
Soybeans: 10,000 acres planted
261,000 bushels produced
Wheat: 10,000 acres planted
369,000 bushels produced
CRP: 83,847 acres enrolled
MSW: 24,800,000 tons generated
Forest Land: 16,285,000 acres
Poultry: 126,056,000 head
Livestock: 1,815,000 head
040315 http://www.bioproducts-bioenergy.gov/
13.2.1 Florida Energy Resources
Florida Quick Facts
•Florida’s per capita residential electricity demand is among the highest in the country, due in part to high air-conditioning use during hot summer months and the widespread use of electricity for home heating during winter months. •Geologists believe that there may be large oil and gas deposits off Florida’s western coast in the Federal Outer Continental Shelf. •Florida is a leading producer of oranges and researchers are attempting to derive ethanol from citrus peel waste. •More petroleum-fired electricity, in absolute terms, is generated in Florida than in any other State. •Hurricanes and severe storms from the Atlantic Ocean put Florida at risk for massive power outages during the storm season.
080228http://tonto.eia.doe.gov/state/state_energy_profiles.cfm?sid=FL
13.2 Biomass Pollutants
From recent Clean Air Act revisions:
Particulate (PM 10)
Annual Arithmetic Mean 50 mg/m3 Primary & Secondary24-hour Average 150 mg/m3 Primary & Secondary
Particulate (PM 2.5)
Annual Arithmetic Mean 15mg/m3 Primary & Secondary24-hour Average 65mg/m3 Primary & Secondary
Sulfur Dioxide (SO2)
Annual Arithmetic Mean 0.030 ppm (80 mg/m3) Primary24-hour Average 0.14 ppm (365 mg/m3) Primary3-hour Average 0.50 ppm (1300 mg/m3) Secondary
Nitrogen Dioxide (NO2)
Annual Arithmetic Mean 0.053 ppm 100 mg/m3) Primary & Secondary
050315 http://www.sierraclub.org
13.3 Energy Extraction and Preparation
Dry biomass may have some residual moisture but only requires physical preparation like chipping to fire it
Some research is being done to see if long trees can be directly fired on a metal conveyor belt
Wet biomass can absorb more heat energy from a furnace than it can supply; the biomass must be externally dried to burn
Small biomass pellets are made from wood scraps and sawdustThere are pellet-burning stoves with a screw
conveyor feed
070315 www.harmanstoves.com/
Dry biomass consists of tree chips, paper, various other plant matter such as corn, soybean, sorghum, sunflower, oats, barley, wheat and hay
When first cut, the sap may absorb energy, and the mass should drySpread on fields in the sunPlaced in oven heated by what would
otherwise be waste heatUsing solar thermal energy air-heaters
13.3.1 Dry Biomass
080228
13.3.1 Biofarms: Trees, Shrubs, and Grasses
Energy tree farms are grown to produce a sustainable crop suitable for chipping and combustion
Switchgrass, sugar beets, and sugar cane residual waste are likely possibilities
Counterculture groups are pushing “biohemp” for various reasons and agendas – growing hemp is illegal in the US -- Controlled Substances Act of 1971 These groups claim trace levels of THC
(tetrahydrocannibinol), active ingredient of marijuana, shouldn’t make it a controlled substanceMostly in the tips of leaves
The Drug Enforcement Agency has free food and housing for you available should you grow it anyway!
040315
13.3.1 Biofarms: Bagasse (processed cane)
The stalks of the sugar cane are squeezed to get the juice out to make sugar
The wet fibrous residue is called bagasseA bioenergy version could be developed to make
a cane maximized for energy, yet it would still yield sugar juicesThe leaves could be burned as well; now
discarded or burned off in the fields
080228
NREL
Jaggery: making from sugar cane juice
www.tide-india.org/ images/big-images/conservi...
13.3.1 Examples of Existing Systems
Forest waste or mill waste byproducts
Agricultural wasteA boiler receives the
combustion heat and produces steamThe boiler supplies steam to
a condensing steam turbine-generator unit generating about 25 to 60 MW
Coal plants can cofire biomass or convert completely to burn only biomass
060306 http://www.energysystems.com.au/pages/biomass_cogeneration.htm
13.3.1.1 Example: Forest Waste
Prairie Woods Cogeneration Plant at Prairie Woods Oregon burns sawmill waste called “hog fuel”
Operates under PURPA to produce 450 psi steam Fuel units are 200 cubic feet, and 200 units per
day is the typical rateGenerator is 2-pole, 13,800V GE 7500kW
upgraded to 9375kVA, and often runs at 7.5 MWHigh line electrical transmission is at 69kVThe plant is considered distributed generationPlant meets DEQ PM10, NOx, CO, SO2, and VOC
and is less polluting than wildfiresA Warm Springs tribe forester says, “This
material is going to burn. We get to choose how.”060316 http://www.solwest.org/news/page1.htm#feature2
13.3.1.2 Municipal Solid Wastes (MSW)
Municipal waste streams may have anything in it that people want to throw away -- it’s a mix
Air blast and magnetic separation can select different streams to go in various piles Permanent magnets first extract the steel and
iron Alternating current electromagnets use the
eddy current effect to remove nonferrous metals (Al, Cu)
Light paper and plastic will stratify in an air column to remove them from heavier substances (metal and bottles)
Hand sorting can pick out some of what’s leftWithout this process, pollutants aren’t removed
050315
13.3.1.3 Industrial Waste Streams (IWS)
Industrial wastes differ from municipal wastes in that they are often separated or categorized as outputs from specific processesIt’s relatively easy to have “pure” waste
streams all of one material, like wood strips, pallets, trim scrap
Paper products are a possibility, but dioxin content can cause air pollution
Any wet waste stream will require drying before burning Could require more energy to dry than can be
extracted from it
070315
Wet biomass tends to be in water or to stay moistExamples are water plants, animal wastes, and
biodiesel oilFlorida has lots of weeds that came from
dumped aquariums (also fish that shouldn’t be here, like piranha and snakehead – will they burn?)
Treated with hydrogasification at high pressure and low temperatures to produce a gas or biofuel oil
13.3.2 Wet Biomass
080228 www.bridgewater.edu
13.3.2.1.1 “Hydrofarms”: Water Hyacinth, etc.
Impoundments containing water plants can clean effluent water by extracting nutrients that should be kept out of lakes and streams
Harvesting by boats uses wide conveyor belts that lift the weed onto the boat
The wet weeds are heavy and hard to pack densely
This is uneconomic in most areasDrying is by dumping in fields for sun drying
060316
www.water-hyacinth.com
www.water-hyacinth.com
13.3.2.1.2 “Hydrofarms”: Orlando Wetlands Park
040315 http://boonie-maps.home.att.net/Orlando_Wetlands/doq_map.jpg
13.3.2.1.3 “Hydrofarms”: Orlando Utilities Water Park
This tertiary cleaning process extracts nutrients and flows the water through long channel lakes and ponds
030317
Average manure production for fully bred cows and pigs is 40 kg and 2.3 kg wet weight per day [Sorensen, 2000](a thing I never wanted to know)
Manure lagoons at Consolidated Animal Feeding Operations (CAFO) pose a stored pollution problemLagoon dam breaches have poisoned nearby
streams and killed thousands of fish in NCAnaerobic digestion allows methane gas recovery
13.3.2.2 Animal Wastes
050317
The same processes for farm animal wastes can be used at city sewer plants
40 billion Btus of methane per 100,000 people per year
Florida methane could yield 20 trillion Btus per year
Cost would be $6 to $8 per million BtuAt present, filtered sewage sludge is often bulk
dumped (sprayed) on agricultural pasturesThe methane gas from a sewage lagoon can be
recovered by a bioenergy process, reducing the sludge before disposal
A cruise ship is like a small city -- where does the sewage go?
13.3.2.2.1 Municipal Sewer Plants
060306
Biodiesel is liquid fuel oil that can be burned in diesel engines
See http://www.homepower.com/files/HP93_32.pdf for an excellent discussion on how to make it
A $20 million biodiesel plant is being built for Utah’s Smithfield Foods, Inc. to convert swine waste into biodieselIf fryer oil smells like french fries, does this
stuff smell like pork chops?A local company, Brevard Biodiesel, is
experimenting with developing a local market for biodiesel
SynFuel (Grant) is working to make syngas from glycerol, a biodiesel byproduct
13.3.2.3 Biodiesel Fuel
080228
Used, strained canola oil from a supermarket deli
Methanol and crystal lye are used in processing some 48 gallon batches
5 parts oil to 1 part methanol plus titration of the mixture with 0.1% lye to reach a ~8.5 pH
Mixture separates after several hours
13.3.2.3.1 Biodiesel Fuel Process
050315 http://www.homepower.com/files/HP93_32.pdf
See Home Power magazine [the ultimate renewable energy magazine; ed. comment] #93 for the full story
The top layer is biodiesel oilThe middle sometimes appears
and is soapThe bottom part is glycerin, and
can be used to make soap [do you smell like French fries after a bath?]
13.3.2.3.2 Biodiesel Fuel Results
050315 http://www.homepower.com/files/HP93_32.pdf
http://www.veggievan.org
Methane is the primary biogasAside from sewage, there’s termites, livestock
flatulence, swamps, etc.Landfill gas is primarily methane but contains
CO2 and other gases from plastics, etc.
80% of odors humans find offensive are the result of nitrogen- or sulfur-bearing compounds. The nitrogen and sulfur atoms are rearranged into smaller molecules that give off odor when they're volatilized as gases into the air, as little as one part per billion - needs to be present for sensitive noses to notice. --- Doug Mason of Continuum Chemical Corporation in Houston, TX
13.3.3 Gaseous Biomass
050315 http://www.forester.net/mw_0303_controlling.html
Methane, CH4, is a likely future hydrogen gas source
The four H atoms allow more hydrogen to be produced per molecule of methane
Cracking or pyrolysis changes the molecules to yield hydrogen and CO, which is also combustible
The combination of methane and COx is known as biogas and can be made from acetic acid, produced from glucose by microorganisms
Methane hydrates exist in cold, deep water in the ocean, but are difficult to extract without methane release
13.3.3.1 Methane
080228
13.3.3.2 Landfill Gases
Landfills, often dubbed “Mount Trashmore”, emit methane and other gases due to decomposition of organic materials
The methane leaks to the atmosphere and is a GHG that is “twenty times more potent than its combustion product of CO2 and water”; some say 23 times
Collecting and burning the methane is clearly better than letting it escape to the air
Landfill gas cleanup is necessary because of the many other VOCs that should be kept out of the air
080228
Conversion from biomass to heat requires some extraction if the fuel stream is contaminated with polluting substances
Typical processes are the following:Direct combustionAnaerobic DigestionFermentationPyrolysisOther less-used techniques
13.3.4 Energy Conversion
030318
Refuse Derived Fuel (RDF) can be fired (burned) directly or in combination with conventional fuels
Some processing, such as cleaning, chopping, etc. may be needed for handling or air pollution avoidance
Fluidized grate furnaces blow air in beneath the grate, and this keeps the burning mass in seething flotation as it burns
13.3.4.1 Conversion: Direct Combustion
040315
Bacteria produce acetic acid (found in vinegar)Methane gas 50% to 80%, $2.50/kft3 (1976)Microgy Cogeneration Systems, Inc. is building a 25 MW
digestion plantEssex Junction Wastewater Treatment facility in Essex
Junction, Vermont treats 1.7 million gallons of waste water per day and will produce 400 MW electricity per year to reduce plant costsPrice of electricity is estimated at $0.02 per kWh
13.3.4.2 Conversion: Anaerobic Digestion
030317
Enzymes can change cellulose into sugars, which can then be fermented into alcohol
Cane sugar, C6H12O6 2C2H5OH + 2CO2
Fermentation of corn or other biomass will produce ethanolThe use of food stocks in this way might be
seen as a poor use of foodBrewery spillage or waste and outdated soda
can be filtered, cleaned, and reprocessed to produce fuelIt is denatured with 15% gasoline to
discourage drinking and avoid Federal liquor law taxes
Fermentation of “stillage” refuse can also produce methane
13.3.4.3 Conversion: Fermentation
070315
Fast pyrolysis is heating biomass without oxygen to decompose it into vapors, aerosols and char
The liquid has ~one-half the heating value of fuel oil
The process is tuned to produce liquid rather than charcoal
Low-quality “producer” gas can be cleaned to remove CO2 and N2, then this “synthesis” gas reacted as 2H2 + CO CH3OH to yield methanol
13.3.4.4 Conversion: Pyrolysis
030318
HydrogasificationLow temperature and high pressure produces
ethane & methane plus CO2
A catalyst aids the processHydrogenation
Waste + Steam and CO forms low-sulfur oil having 16000 Btu/pound heating value
Used to make peanut butter and margarine
13.3.4.5 Conversion: Other
050315
13.4 Issues and Trends
Environmental considerationsBiomass conversion plants are often fought by
some as a source of pollutantsLess polluting than a coal plantMSW may contain heavy metals and should
not be burnedPaper colored inks often contain heavy
metalsTrash production can be decreased by careful
purchases, conservation, reusing, and recyclingIf these waste reduction practices are
followed, there is less available for bioenergy
050315
13.4.1 Some Environmental Biomass Views
Policies or viewpoints of the Sierra Club (a large environmental organization) may be found at http://www.beyondgrass.org/greenpower/archives/Florida%20Sierra%20Biomass%20or at http://sierraclub.org/policy/conservation/biomass.asp
The reuse or recycling of wastes is necessary prior to land filling or biomass combustion to avoid more toxics introduced into the air and waterIn many cases, separation of undesirable materials is
so difficult that combustion should be avoided Municipal waste streams have heavy metals,
toxins, pesticides, etc.; whatever someone wanted to get rid of
080228
Renewables are a very small contributor to present Florida energy sources
Biomass energy is the predominate renewable energy source in Florida; little wind or sun, surprisingly
Unfortunately, most of present production is from municipal solid waste (MSW) that should be avoided or phased out due to heavy metal contaminants
13 Conclusion: Biomass
050315
http://www.eia.doe.gov/cneaf/electricity/st_profiles/florida/fl.html#t1
Olin Engineering Complex 4.7 kW Solar PV Roof Array
080116
Questions?
References: Books/Periodicals
Blackburn, John O. Solar Florida: A Sustainable Energy Future. Winter Park: Florida Conservation Foundation, 1993. ISBN 0-913297-07-1.
Cheremisinoff, Paul N., and Thomas C. Regino. Principles and Applications of Solar Energy. Ann Arbor: Ann Arbor Science, 1978. ISBN 0-250-40247-5.
Brower, Michael. Cool Energy. Cambridge MA: The MIT Press, 1992. 0-262-02349-0, TJ807.9.U6B76, 333.79’4’0973.
Boyle, Godfrey. Renewable Energy, Second Edition. Oxford: Oxford University Press, 2004, ISBN 0-19-26178-4. (my preferred text)
Duffie, John and William A. Beckman. Solar Engineering of Thermal Processes. NY: John Wiley & Sons, Inc., 920 pp., 1991
Sørensen, Bent. Renewable Energy, Second Edition. San Diego: Academic Press, 2000, 911 pp. ISBN 0-12-656152-4.
Durkee, Scott. Getting off the Petroleum Grid with Biodiesel. Home Power, No.93, pp. 32-39, 2003.
Tickell, Joshua. From the Fryer to the Fuel Tank. Ashland OH: BookMasters, 2001? www.veggievan.org
http://www.wnbiodiesel.com/ Willie Nelson
090317
References: Websites, etc.
http://mmf.ruc.dk/energy/Amsterdam2002.PDF Sorensen’s paper on Bioenergyhttp://www.biomass.org/http://boonie-maps.home.att.net/Orlando_Wetlands/doq_map.jpg Florida trail map of Orlando Utilities Wetlands Park
http://www.solwest.org/news/page1.htm#feature2 story by Jennifer Barker on a biomass planthttp://gis.joensuu.fi/termit/termeng/frame.htm Bioenergy glossaryhttp://www.bioproducts-bioenergy.gov/ US Govt. Bioenergy Officehttp://www.bioproducts-bioenergy.gov/about/glossary.asp Bioenergy definitionshttp://florida.sierraclub.org/issues/energy.html Florida Chapter on Energyhttp://florida.sierraclub.org/issues/energylinks.html links to sustainability and renewable organizationshttp://www.energycentral.com/sections/search/site_search.cfm enter “biomass”http://www.homepower.com/files/HP93_32.pdf on biodiesel fuelhttp://www.biomass.org/ Lobbying grouphttp://www.forester.net/msw.html More than you ever wanted to know about trashhttp://www.forester.net/mw_0303_controlling.html Smelly trash and suppressionhttp://www.pnl.gov/biobased/bcf.stm Hydrogenationhttp://www.coppicing.com/ on cutting plants to the ground and letting them regrowhttp://www.veggievan.org Biodiesel productionhttp://www.brevardbiodiesel.orghttp://journeytoforever.orghttp://biodiesel.orghttp://changingworld.tech.com__________________________________________________________________________________-www.dieoff.org. Site devoted to the decline of energy and effects upon populationwww.ferc.gov/ Federal Energy Regulatory Commissionwww.google.com/search?q=%22renewable+energy+course%22solstice.crest.org/dataweb.usbr.gov/html/powerplant_selection.htmlhttp://www.eere.energy.gov/state_energy/tech_biomass.cfm?state=FL
050315
Notes bioenergy
P. 827, 725 in SorensonBiomass fuel costs twice fossil fuel
www.seco.cpa.state.tx.us/.../ re_renew_maps_bio_poten.htm