Presentation on theme: "Biomass Composition of Municipal Solid Waste Energy Retrieval from Recycling Incineration and Incinerator Ash Secure Landfills Efficiency of Conversion."— Presentation transcript:
Biomass Composition of Municipal Solid Waste Energy Retrieval from Recycling Incineration and Incinerator Ash Secure Landfills Efficiency of Conversion of Sunlight into Biomass Methane Digesters Alternative Biomass Fuels for Vehicles Wood Combustion Energy Plantations
Energy in the News
Composition of Urban Garbage William Rathje Garbologist When did Arizona Residents throw out the most meat?
Composition of Solid Waste: 23 Cities
Waste Generation Rates over Time
Changes in Disposal Methods
Energetics of Recycling and Substitution
Biodegradability Biodegradability in garbage dumps: an non-issue. Rapid biodegradation: requires oxygen and/or water. Rathje:perfectly preserved years old meat and vegetables!
Waste to Energy Plant Locked into long term contract: may discourage recycling Fly ash: Bottom ash: Where collected and transported?
Metal in Incinerator Ash Additional concerns: dioxin from burning of chlorine containing compounds (plastics,etc.). Dioxin: carcinogen, endocrine disrupter Fly ash: from electrostatic precipitators. Bottom ash: bottom of boiler Which is most dangerous??
Recycling Trivia Americans consume 2.5 million plastic bottles every hour If you drink 2 cans ofsoft drink per day in aluminum cans and cans are not recycled,you waste more energy than is used daily by one human in the lesser developed countries Recycling one aluminum can saves enough energy to run a TV for 3 hours Recycling of all paper used in the Sunday edition of the New York Times would save 75,000 trees per year
Fly Ash Dump in Korba India (from power plant) No vegetation.
Fly Ash Dump in Badarpur, India Reclaimed using mycorrihizal fungi (bioremediation) Also small amounts of compost. Reduces air pollution from fly ash dump.
Secure Landfill Black layers on top and bottom: liner Liner thickness: about 1/3 inch Circles on bottom: leachate pipes Note: Gas vent, low permeability soil, filter layer, barrier layer, drainage layer
Percent Trash Disposal in Landfills
Biomass Production vs Energy Use Uses of biomass Aside from energy?
Methods of Biomass to Energy Conversion Direct combustion Pyrolysis: thermal decomposition into gas or liquid Involves high temperatures (500-900°C), low oxygen Biochemical processes: Anaerobic digestion by methanogens Controlled fermentation produces alcohols: Ethanol (grain alcohol) Methanol (wood alcohol)
Anaerobic Digester Converts animal or plant waste Into methane Typical wastes: Manure (feed lots,pig farms, poultry) Olive oil mill waste Potato processing waste Big deal: Agricultural Science Depts
Optimum Operating Temperature 35°C, maximum liters of methane per day, best retention time?
Cellulose High Solids Fermenter Adjusting agitator shaft of high solids fermenter. Produces methane gas, high quality compost from sewage sludge, use 1/20th the water Compared to conventional digesters. Downside: agitator needed.
Energy Used to Grow vs Food Energy Ethanol from corn: 1.74 per gallon to produce vs 95 cents per gallon Of gasoline. 70% more energy to make ethanol from US corn than energy in ethanol Good use of ethanol: oxidizer to replace MTBE in gasoline 10% ethanol boosts octane rating of gasoline, replaces lead.
Energy Contributions to Bread Loaf Grain production, Baking, Transport, Milling, Shops, Packaging
Energy in Biomass Only a small amount energy in sunlight converted into biomass by plants. Conversion efficiency varies: Sugar cane: 2% Corn: 1% Typical forest: 0.8% Most food plants: <0.8% Maximum theoretical efficiency: 10%
Sugar Cane Sugar cane: very high productivity per acre. Use bagasse (sugar cane waste) to run boilers to boil sap for sugar. Bagasse to energy plants: 7% of Hawaiian energy (Mauritius)
Bagasse to Methane Plant: Hilo, HI
Hemp Plants Advantages: 4 times as much pulp per acre as wood, no pesticides needed Can make cloth,rope paper. Does need nitrogen fertilizer. Not good to smoke. 1763-1767-Virginia farmers jailed if no hemp grown.
Four Year Old Eucalyptus: Hawaii Eucalyptus: produce high amounts Of biomass under drier conditions Than hemp. Very hardy species.
Plants as Sources of Petroleum Like Substances Gopher plant: grows wild in California: 25 barrels of crude oil per hectare Copaifera multijuga: found in Brazil: produces almost pure diesel fuel Bladderpod: can be used to make plastic Jojoba: 50% oil by weigh: resembles sperm oil: doesnt go rancid
Plastics Made from Pyrolysis Oil (Wood Chip Waste)
Low Cost, Efficient Woodstoves A India, B. Nepal C. Guatemala, Most of the world cooks with wood. Typical wood stove: Only 10% efficient. Time to collect wood: 2 to 5 hours per day. 80% of fuel use in developing world; wood for cooking. Major cause of deforestation, soil erosion.
Comparable Efficiency Values Efficiency: multiply by 100.
Rocket Stove vs Three Stone Fire Rocket Stove: insulated fire box, short chimney, cooks on top of Chimney, skirt surrounds pot. Built in Guatemala.
Addition of Haybox Haybox: insulated box. Food placed in box and left once water heated to boiling point. Food continues to cook without fire. (Why?)
Air Tight Stove Stove has lower chamber With burning wood, Upper chamber with Secondary combustion Long path for exhaust gas = more complete burning Note high surface area of Stove. About 50% efficient