6.11: Hydrogen Fuel Cell

Question 1

Inputs

Answer 1

Hydrogen gas and oxygen gas are used to generate electricity with water as a waste product

Question 2

Electricity Generation

Answer 2

1. Hydrogen gas enters the fuel cell and is split into protons and electrons by an electrolyte membrane which only lets the protons through
2. Electrons flow through the circuit around the membrane which generates an electrical current
3. Oxygen gas molecules enter the fuel cell and break into individual oxygen atoms which combine with the hydrogen protons to form water as a byproduct

Question 3

Creating Hydrogen Gas

Answer 3

Steam reforming and electrolysis

Question 4

Steam reforming

Answer 4

Burning natural gas and using steam to separate the hydrogen gas from the methane

Question 5

Electrolysis

Answer 5

An electrical current is applied to water which breaks it into oxygen and hydrogen

Question 6

Benefits of hydrogen fuel cell

Answer 6

1. It can be stored in pressurized tanks and saved for later
2. It can be used as a fuel for vehicles and emits no air pollutants only water vapor
3. These fuel cells are approximately 80% efficient in converting chemical energy to electricity

Question 7

Cons of hydrogen fuel cell

Answer 7

1. Production of hydrogen gas via steam reforming requires methane burning which is a green house gas
2. Hydrogen fuel cells are non-renewable
3. If electrolysis is used to produce hydrogen gas, it’s only as sustainable as the electricity source