sustainability Flashcards
define sustainability
the use of resources in such as way that there
will be resources left for future generations
the ability to exist and develop without depleting natural resources for the future.
where is most of our energy derived from
fossil fuels like coal oil natural gas
what is one exajoule of energy equivalent to?
23.88 million tonnes of oil or
34.12 million tonnes of coal
why in 2022, did renewable energy supply from solar, wind, hydro, geothermal and ocean rose by close to 8%
higher fossil fuel prices, energy security
concerns and growing concern for the environment
what is biomass or biofuel
additional form of alternative energy
which was not previously covered.
what does biofuel production involve
involves making use of ‘waste’ biomass to
provide energy. In the form of solid, liquid or gaseous fuels
list some types of biofuel
Biogas (methane), ethanol and biodiesel
how is biogas methane made
Cattle dung digested by anaerobic bacteria in underground vessels
(biodigester), producing a roughly 60:40 mix of methane and carbon
dioxide.
The CO2 is removed, leaving the methane gas which is a clean and
efficient fuel that can be used for both heat and power
why is biogas good for the environment
zero emission of
greenhouse gases into the atmosphere
define ethanol
Fermentation of carbohydrate rich crops, such as sugar cane, is used
to produce ethanol
why is ethanol good for the environment
can be used as a petroleum substitute in cars, reducing pollution
what is one challenge for ethanol
the need to pre-treat the cellulose found in the biomass before it can be fermented
what is biodiesel
renewable, biodegradable fuel manufactured from vegetable
oils, animal fats or recycled restaurant grease.
biomass-based diesel
manufactured from oil from canola seed or rapeseed
how is biodiesel formed
300kg of oil can be extracted from 1 tonne of rapeseed and then converted into
rape methyl ester (RME).
what is biodiesel used for
fuel filters, heating oils, oil spill cleanups
and biodiesel electricity generators
used in conventional diesel engines, substituting for traditional petroleum diesel, reducing pollution