biofuels Flashcards
what are biofuels
fuels that come from plant or animal products
what are 4 advantages of biofuels
- less harmful to plants and animals if spilled
- renewable, unlike crude oil
- low carbon footprint
- burn cleanly, little sulfur dioxide
what are 3 disadvantages of biofuels
- use large areas or farmland meant for crops
- can cause famine
- forests cleared to make land which could endanger species
what are 2 ways to produce ethanol
hydration
fermentation
explain hydration talk about energy costs pressure and purity
ethanol is mixed with steam to produce ethanol
high cost high pressure more pure product
explain fermentation talk about energy costs and purity
it converts glucose into ethanol and carbon dioxide at 30 degrees in anaerobic condition
low energy costs and low pure product
how is cracking carried out
hydrocarbons are heated into vapour and passed over steam or a hot catalyst, they are heated till thermal decomposition occurs
what is polymerisation
when many small monomers join together to form polymers
what do the properties of polymers depend on
monomer used
conditions it was made in
what are thermosetting and thermosoftening polymers
thermosetting- polymers that don’t melt, strong covalent bonds between polymer chains
thermosoftening- soften easily when heated and reset when cooled down