Energy Efficiency and Sustainability Flashcards
1
Q
Sustainability issues with Lithium Ion Batteries
A
- Sourcing the lithium: Difficult to keep expanding production
- Sourcing of scarce metals contained in Lithium batteries. e.g. Cobalt and Nickel
- Difficulty of recycling batteries
- The safety of the batteries
- Disposal of used batteries
2
Q
Advantages of using hydrogen gas as a fuel
A
- High energy density
- Is abundant on Earth - in water and most carbon compounds
- Sole product of combustion is water
3
Q
Disadvantages of using hydrogen gas as a fuel
A
- Is not found as an element, so energy is required to produce it
- Very low boiling point, therefore requires a lot of energy to make it liquid
- High pressures needed to store as gas
- Is explosive
- If difficult to transport safely as a gas or liquid
4
Q
Brown Hydrogen comes from…
A
…fossil fuels
5
Q
Grey Hydrogen comes from…
A
… Industrial processes
6
Q
Blue Hydrogen comes from…
A
…Fossil fuels with carbon capture
7
Q
Green Hydrogen comes from…
A
… Renewable energy
8
Q
What is steam reforming?
A
- A method of producing hydrogen and carbon dioxide gas from hydrocarbons/alcohols/etc with steam (H2O gas)
9
Q
What does PEM electrolyser stand for?
A
- Polymer Electrolyte Membrane Electrolyser
10
Q
What is unique about PEM electrolysers?
A
- They use a solid electrolyte, as opposed to a solution
11
Q
Advantages of PEM electrolyser
A
- Rate of Hydrogen production is high
12
Q
Disadvantages of PEM electrolyser
A
- Inclusion of other metals can make them expensive
13
Q
How do Photoelectrochemical cells work?
A
- Makeshift photosynthesis/like a solar panel
Steps:
- Sunlight lands on the anode
- Energy from sunlight excites the metals in the electrode
- Energy in metals is used to oxidise water to oxygen gas
- Hydrogen ions migrate to cathode
- Reduction at cathode causes H2 to be formed
