Transcript Bio-energy
Monday - Day1 Bioenergy & Biofuels Renewable Energy Resources Objectives: • What are the different forms and sources of energy • What sources of energy are renewable or nonrenewable energy? • What is Bioenergy? What is Biomass? Biofuels? • Making Biodiesel • Collecting Biogas Classifying Energy Forms Potential • Gravitational Potential – energy due to the position of an object. • Chemical Potential – energy present within the chemical bonds of a substance. • Elastic potential – energy of a stretched or compressed object. • Nuclear potential – energy of particles inside an atomic nucleus. Kinetic • Radiant solar energy – the motion of EMR • Sound energy – the motion of sound waves • Electrical energy – the motion of flowing electrons • Thermal energy – the motion of particles Sources of Energy: How do we Produce Energy for our Needs? Originate From Solar Energy • • • • • Direct solar (e.g. photovoltaic panels) Biomass (e.g. wood, manure, ethanol) Hydro Wind Fossil fuels (coal, natural gas, petroleum) Do NOT Originate from Solar Energy • • • Tidal and wave Geother mal Nuclear fission Renewable vs. Non-Renewable Energy & Energy Transformations • What are the differences? – Non-renewable energy sources: • are extracted from the Earth as resources that are finite and may last, at most, for a few hundred years – Renewable energy sources: • are continuously replenished or renewed by energy from the Sun • are considered renewable because they will last indefinitely Bioenergy & Biofuels New English Words • • • • • • • • • Bioenergy Biomass Biofuels Cellulose Organic Photosynthesis Flammable Anaerobic Bacteria What is Bioenergy? • Bioenergy is renewable energy made available from materials derived from biological sources. • In other words - Bioenergy is energy stored in materials made with the help of living things. Biomass • Plants use photosynthesis to convert the Sun’s energy into a form of chemical energy called cellulose (a type of sugar). • When plant matter or agricultural waste is used as a fuel it is called biomass. • The most common form is burning wood Biomass to Biofuels •Biomass can be converted into forms that are easier to use for transportation fuel needs, called biofuels. Energy Transformations How do we turn biomass into electricity? • • • • • chemical potential energy (biomass cellulose) thermal energy (burning biomass) kinetic energy (steam) kinetic energy (spinning turbine) electrical energy Canadian and Norwegian Bioenergy • Bioenergy currently accounts for approximately 15% of the World’s total energy consumption. • Bioenergy currently accounts for approximately 6% of Canada’s total energy supply. • Bioenergy also accounts for approximately 6% of Norway’s total energy consumption Ethanol • Ethanol is produced by feeding biomass into large heated tanks called digesters. Inside the tanks, yeast converts the biomass into alcohol. • the ethanol can then either be blended with gasoline, or burned directly – conventional engines can run on up to 10% ethanol – special models can run on up to 85% ethanol • http://dsc.discovery.com/tv-shows/othershows/videos/how-stuff-works-ethanol.htm Biogas • Most mammals, humans included, produce a flammable gas called “biogas” as they digest their food. Bacteria living in their digestive systems produce methane as they break down cellulose present in the food. • Biogas is also produced in bogs and wetlands where large amounts of rotting vegetation may accumulate. This methane is the same as the “natural gas”, commonly burned in our home’s furnaces and barbecues. Biogas can be used instead of natural gas for heating and cooking. • Where else might biogas be “naturally” produced around human communities? Biogas • collected during the decomposition of organic waste. • the main gas produced during decomposition is methane •the Cloverbar Landfill in northeast Edmonton collects enough biogas to produce electricity for 4600 homes Biomethane Production http://www.wired.com/autopia/2009/01/oslos-buses-to/ Biogas Generators • Humans have learned to duplicate the biogas production process in large tanks called biogas generators. • To start the process, shredded plant materials and animal wastes are mixed with water in the biogas generator. Many kinds of naturally occurring bacteria arrive with the shredded plant material. The tank is then sealed so no air can get in. We say the conditions are anaerobic. • Within days, a special kind of bacteria in the tank will begin to produce biogas. These bacteria are known as “methanogenic”, because they produce methane, the main ingredient in biogas. The biogas forms bubbles in the mixture, and collects at the top of the tank. It is piped to a large balloon-like bag where it is stored until needed. Lets Design a Biogas Generator for Your Backyard Let’s Build a Biogas Generator Evaluating Biomass • An advantage of biomass is that some of the CO2 produced from combustion is absorbed by the next generation of plants •Sometimes called a carbon-neutral energy source Biomass PROS • fuels are readily available • no complex technology is required • can be converted into biofuels • biofuels burn cleaner than gasoline • Less net CO2 produced CONS • not very energy efficient • Increases pesticide use • Ethanol is toxic and highly flammable • In colder climates, biodiesel tends to lose viscosity. • requires large areas of land and irrigation to make enough plant matter (food vs. fuel) Biodiesel • Biodiesel is a non-toxic and biodegradable fuel that is made from vegetable oils, waste cooking oil, or animal fats. • Biodiesel is produced through a process which reacts the oil with an alcohol (usually methanol, although ethanol can also be used) and a catalyst (such as sodium hydroxide). • The resulting chemical reaction produces glycerine and biodiesel. Let’s Make Biodiesel!