Presentation on theme: "Biomass, biofuel, chemical energy, carbon neutral."— Presentation transcript:
1 Biomass, biofuel, chemical energy, carbon neutral. 16 April, 2017BiomassObjectivesBe able to understand what biomass is, how it can be used to produce electricity, and be able to evaluate its advantages and disadvantages.HSW: AF2: Make balanced judgments about scientific developments by evaluating the economic, moral, social or cultural implications.Used before in:Will use again in:PLTS: Independent enquirers: support conclusions, using reasoned arguments and evidence.KeywordsBiomass, biofuel, chemical energy, carbon neutral.
2 All students should be able to: Give examples of biofuels. OutcomesAll students should be able to:Give examples of biofuels.Most students should be able to:Explain the process by which electricity is produced and why biomass power stations are carbon neutral.Some students should be able to:Evaluate the advantages and disadvantages of using biomass fuels.
3 What is biomass? Examples… Boardworks GCSE Science: PhysicsRenewable Energy: Solar and ThermalBiomass, also known as biofuels or bioenergy, is material from living sources. The simplest biomass energy sources are plants, which can be burned to produce steam to turn a turbine.Traditionally, wood is burned to give heat but trees grow slowly and require a lot of land. Other materials, such as poultry farm waste, can also be burned.The carbon dioxide released during burning biomass is absorbed bythe replacement plants. Biomass is said to be ‘carbon neutral’ and does not add to global warming.Biomass fuels are renewable as more plants can be grown, producing yet more biomass.
4 How can waste create biofuel? Boardworks GCSE Science: PhysicsRenewable Energy: Solar and ThermalMethane is a biogas, which can be used a replacement for natural gas. This biofuel can be produced by making use of the natural decomposition of organic waste material.Methane can be produced from concentrations of rotting sewage or manure stored in containers called anaerobic digesters. These can be readily used in remote places, such as this digester on a pig farm.Photo credit: California Polytechnic State University/NRELConcrete anaerobic digester and biogas storage on a pig farm in The Philippines.Another source of methane is the rotting organic waste buried underground in landfill sites. The gas can be drawn up through pipes to generate electricity or provide heat.
5 How else can biofuel be made? Boardworks GCSE Science: PhysicsRenewable Energy: Solar and ThermalSome sources of biomass energy can be processed to produce biofuels that are even more useful.Certain plants can be fermented to form ethanol,a biofuel, which can be used instead of petrol or even aviation fuel, as in this plane!Sugar cane and beet are the most efficient sources of this ‘bioethanol’ but potatoes, corn, wheat and barley can also be used.Photo credit: Laurent Simon - Aviation & Pilot/NRELAircraft (Pitts S2-B Special Aircraft) fuelled with ethanol at the Paris Air Show in France. The Renewable Aviation Fuel Development Center (RAFDC) at Baylor University is making great strides in establishing ethanol as an aviation fuel. Research at RAFDC revealed that ethanol is less expensive, performs better, and has less harmful effects on the environment than conventional aviation fuel.Another biofuel is ‘biodiesel’ which can be made from vegetable oils, animal fats or recycled cooking oils.
6 Using non-renewable fuels in power stations 1) A fuel is burned in the boiler2) Water turns to steam and the steam drives a turbine3) The turbine turns a generator4) The output of the generator is connected to a transformer5) The steam is cooled down in a cooling tower and reused
7 Energy ChainSunUse the energy chain to explain how electricity is produced by biofuels.Plantsfuelburntsteamturbinegenerator
8 What are the pros and cons of biofuels? Boardworks GCSE Science: PhysicsRenewable Energy: Solar and ThermalSome advantages of using biofuels are:Biofuels are made from plant materials which makes them completely renewable.They are biodegradable, so do not cause as much pollution if spilled.They produce less pollution, when burnt, than fossil fuels.Some disadvantages of using biofuels are:Vehicles need to be adapted to run on pure biofuel.Large areas of land are needed to grow crops, which could lead to loss of habitats.Biomass is ‘carbon neutral’ but the environmental impact of using fertilizers to grow sources of bioenergy and theenergy used in transportation must also be considered.
9 Using biofuels – true or false? Boardworks GCSE Science: PhysicsRenewable Energy: Solar and ThermalTeacher notesThis true-or-false activity could be used as a plenary or revision exercise on biofuels, or at the start of the lesson to gauge students’ existing knowledge of this subject matter. Coloured traffic light cards (red = false, yellow = don’t know, green = true) could be used to make this a whole class exercise.
10 TASKScenarioYou work for an electricity company, “El Power”, who uses Fossil Fuels to produce most of your power. You want to become greener and are planning to produce 10% of your power using Biofuels to become greener and attract new customers.TaskWrite a speech to the board of directors of your company outlining (ALL) what biofuels are, (MOST) how they make electricity and are carbon neutral and (SOME) explain their advantages and disadvantages.
11 Students deliver their speeches. Video. Peer assess: PlenaryStudents deliver their speeches.Video.Peer assess:Tell them what went well and even better ifDid they:ALL: Give examples of biofuels?MOST: Explain the process by which electricity is produced and why biomass power stations are carbon neutral?SOME: Evaluate the advantages and disadvantages of using biomass fuels?CBA