L8 (Hydrogen)

Question 1

Hydrogen fundamentals

Answer 1

• Clean energy, no GHG emitted from combustion
• H2 + O2 = H2O
• Good LHV
• Bad density

Question 2

Uses for hydrogen

Answer 2

• Ammonia production
• Transportation
• Oil refineries
• Methanol production

Question 3

Sources for hydrogen

Answer 3

Biomass

• gasification
• bio-hydrogen

Natural gas

• reforming
• partial oxidation

Coal
- Gasification

Nuclear

• Electrolysis
• Thermo-catalytic

Solar and Wind
- Electrolysis

Question 4

Increasing H2 content and CO2 capture in DFB gasification by application of catalytic bed materials

Answer 4

Mechanisms

1. ) Removal of CO2 from producer gas will increases concentrations of remaining gases
2. ) Removal of CO2 promotes WGS reaction and methane reforming reaction towards H2 generation direction

Question 5

Metal hydride tanks fundamentals

Answer 5

• Metal hydrides = combinations of metallic alloys that act to ‘soak up’ hydrogen
• Absorb hydrogen and release it water, either at room temperature or through heating the tank
• Hydrogen absorbed generally 1-2 total weight of tank

Question 6

Advantages/disadvantages of metal hydride tanks

Answer 6

Advantages

• Safely deliver hydrogen at a constant pressure
• Also absorbs impurities. Released hydrogen is extremely pure

Disadvantages
- Impurities left behind will decrease tank’s lifetime and ability to store hydrogen

Question 7

Compressed hydrogen

Answer 7

• Compression into high pressure tanks
• Requires energy to accomplish
• Expensive

Question 8

Liquid hydrogen

Answer 8

• Liquid hydrogen can only exist at low temperatures
• Energy is required to maintain this low temperature and compress the hydrogen
• net loss of about 30% the energy that liquid hydrogen is storing

Question 9

Chemically stored hydrogen

Answer 9

• Chemical compounds can be used as a hydrogen storage method
• Hydrogen is combined in a reaction that creates a stable compound containing hydrogen. A second reaction will release the hydrogen.