Fuels - 1B Flashcards
biofuels
fuels sourced from organic matter
Biogas
gaseous fuel produced by the anaerobic breakdown of organic matter
Bioethanol
fuel produced by the anaerobic fermentation of glucose(a sugar) in organic matter (biomass) by microorganisms (yeast)
it is then distilled to remove the water and make pure bioethanol
Biodiesel
fuel produced by the transesterification of fats and oils in organic matter
biogas contains
most methane then co2.
small amounts of hydrogen, nitrogen and others
what does biodiesel contain
mixture of fatty acid methyl esters and glycerol
transesterification reactions
triglycerides (animal fat or plant oil) + alcohol (methanol) + catalyst (potassium hydroxide) -> biodiesel
What makes a fuel renewable, and why are biodiesel and biogas classified as renewable energy sources?
A fuel is renewable if it can be replenished by natural processes within a short time. Biodiesel is renewable because it is derived from crops and animal fats, replenished in less than a year. Biogas is renewable because it is produced directly from organic matter.
E10
a blend of 10% bioethanol and 90% petrol,
Why is bioethanol considered relatively carbon neutral but not completely?
CO₂ released during combustion is offset by CO₂ absorbed by plants during photosynthesis.
- not completely carbon neutral due to energy used in transportation, harvesting, and production processes.
What is the “food vs fuel” issue in biofuel production?
Biofuel production should not reduce food availability for the global population. Feedstock must come from food crop waste or non-edible plant materials, such as sugarcane pulp
Why is energy input vs energy output important for biofuels?
the energy needed to grow, collect, and process feedstock should be a small percentage of the total energy produced by biofuels to ensure sustainability.
How much land would Australia need to meet biofuel production goals in the next 30–40 years?
Researchers estimate around 100 million hectares of land (the size of China) would be required.
