F5 Hydrogen Flashcards
How to make renewable H2 (schematic)
How renewable hydrogen can be used in the steel industry
Renewable electricity is produced (ex windpower)
→ the green electricity is used fot electrolysis of water
→ water molecules are split into hydrogen and oxygen
→ H2 is pumped into iron oven
→ The oxygen in the iron oxide pellets reacts with the H2
→ Iron in solid form is created and the restproduct is H2O
Hydrogen sources
Crude oil
Coal
Coke/residues
Natural gas, shale gas (skiffergas)/Biogas (from wastewater treatment)
Biomass
Rapeseed oil, palm oil, soybean oil
Solar cells, photosynthesis
Hydropower, wind, tidal, geothermal
Nuclear
Why do we need more hydrogen?
The population in the world increases → need more food → need ammonia (NH3) to grow more food and we need fuel to drive that production
Use of hydrogen
Ammonia and fertilisers
Refining and desulfurization (hydrotreatment, esp. hydrodesulurization)
Synthesis of methanol, ethanol, DME (dimetyleter gasform)
Chemical plants, food preperation
Alternative fuels, ex Fischer Tropsch
Gas-to-liquid technology
Rocket fuel
Hydrogenation of hazardous waste
*hydrotreatment = reaction with high pressure H2 to remove oxygen (with other heteroatoms as nitrogen, sulfur etc.)
What is hydrogen?
Odourless, colourless gas
The lightest element
Highly flammable
Diffuses very quickly
Combustion product = H2O
Highest energy content per unit mass of all fuels
Both safe and unsafe - due to the easily diffusion and high flammability
What is the main trouble with H2?
Storing H2 is the main problem. The volumetric density and the gravimetric density (available energy per unit mass) is low.
Ways of storing and distributing H2?
(Physical and chemical)
Physical methods:
Compressed H2 gas; 350-700 bar; room temp (280K)
Cryo-compressed H2 gas (CcH2); 250-500 bar; cool it and pressurise it (60K)
Liquid H2 (LH2); 1 bar; 20K
Chem based methods:
Adsorbents (MOFs)
Hydrides LiCe(BH4)3
Chemical NH3, CH4
Liquid organic H2 carriers
The world has a high hydrogen demand - what for?
Ammonia (for fertilisers)
Refining (use H2 for desulphurisation for ex - hydrotreatment)
Synthesis of methanol, methanol and DME (dimetyleter - fuel in gas form)
Chemical plants & food preperation
Alternative fuels (ex Fischer Tropsch)
Gas-to-liquid technology
Rocket Fuel
Hydrogenation of hazardous waste
Fuel processing of solid, gaseous and liquid fuels for hydrogen production (schematic)
Different Feedstock and Process alternatives for hydrogen production
Fuel options for different feedstock
- Rapeseed and sunflower oil
- Wheat, sugar-beet and straw
- waste wood and farm wood
- Organic waste, sewage and manure (gödsel)
Biomass to hydrogen pathways
Steam reforming of methane (schematic process)
Schematic overview of multi-stage integrated biohydrogen system
Conversion of Lignocellulose to fuel (main routes)
Gasification of biomass (reaction)
How does LOHC (liquid organic hydrogen carriers) work?
Advantages of LOHC
Advantages of using Methanol CH3OH as fuel
Advantages of using dimethyl ether DME as fuel (CH3OCH3)
