6.6 Flashcards
Biomass
Organic matter used as fuel, especially in power stations for generating electricity
Biofuels
General name for fuels produced from organic matter (biomass)
Primary Biofuels
any organic material used in an unprocessed form, primarily used for heating, cooking and electricity generation
fuelwood, wood chips
Secondary Biofuels
Derived from processing biomass. Used by vehicles
Liquid biofuels such as ethanol and biodiesel
Strength of Biofuels
- Renewable energy source
- Lower emission than fossil fuels. Brazil, since 2003, reduced CO2 emissions more than 350 mill tons
- Bio-degradable
- Easily grown and does not need specialist machinery
Weakness of Biofuels
- Clearing forest to grow crops mean loss of carbon sink and increase CO2 emissions from deforestation
- Needs pesticides and fertilisers, which use fossil fuels in their production, not carbon neutral
Threat of Biofuels
Takes investment from food production
Food shortages occur, higher food prices
Opportunities of Biofuels
Provides rural inward investment and local development projects
Problem with some biofuels
Coal is needed to ‘fire up’ the biomass
Some biomass fuels produce 150-400% more CO2 than Coal
What is CCS
Capturing CO2 released by burned fossil fuels and burying it deep underground
Promises greatest saving in emissions where coal is being used to generate electricity
Challenges of CCS
Obvious
Expensive. Complex tech involved. By 2014 only 22 countries do CCS
Leakage contaminating soil and water
Hydrogen Fuel Cells
H2 is usually combined with other elements. Separated, provides alternative to oil.
Fuel cells convert chemical energy in H2 to electricity, pure water as by-products
H2 cells more energy efficient than petrol engines in vehicles
Problem with Hydrogen Fuel Cells
Process separating H2 requires large amounts of energy and may emit large quantities of greenhouse gases
Cars on bio-ethanol
emit 80% less CO2 then petrol-driven car
World leader in bio-fuels
Brazil
