This document discusses hydrogen as an alternative fuel source. It describes three types of hydrogen - grey, blue, and green - based on their production method. It also outlines four key methods for producing hydrogen: natural gas reforming, electrolysis, gasification, and fermentation. The document then explains how hydrogen fuel cells work as an energy conversion device before concluding with some drawbacks to hydrogen as a fuel, such as lack of infrastructure and safety concerns due to its combustible nature.

1. Alternative Fuels
XI’AN JIAOTONG UNIVERSITY
SCHOOL OF ENERGY AND POWER ENGINEERING
Hydrogen as an Alternative Fuel

2. Hydrogen as an Alternative Fuel

3. Contents
• Abstract
• Introduction
• Types of Hydrogen
• Methods of Producing Hydrogen
• Hydrogen fuel cells
• Hydrogen | Fuel of the fuel
• Drawbacks

4. Abstract
• This study looks at an alternative source of fuels.
• The goal is to produce energy using hydrogen fuel cells.
• It is also an abundant chemical species that could be used to
produce more efficient and environmentally friendly energy.
• Hydrogen fuel cells can be used as an alternative to produce
electric cars, boats, electric motors, and possibly for home
applications in the future.

5. Introduction
• Increase dependency on non-renewable energy resources
• Clean energy
• Abundance of Hydrogen
• Highly flammable
• Either forms, which are liquid and gaseous
• One kilogram of hydrogen is able to produce energy
equivalent to gallon of gasoline
• Reduce carbon dioxide emissions

6. Types of Hydrogen
1. Grey Hydrogen
Extracted from Hydrocarbons
By products are 𝐶𝑂2
2. Blue Hydrogen
Sourced from fossil fuels
By products CO and 𝐶𝑂2 are captured and stored
3. Green Hydrogen
Generated from renewable energy (solar, wind)
Electricity splits water into hydrogen and oxygen
By products are water and water vapours.

7. Methods of producing Hydrogen
• Natural gas reforming
• Electrolysis
• Gasification
• Fermentation

8. Methods of producing Hydrogen
• 1. Natural gas reforming
• Cheapest
• Most efficient
• Hydrocarbon source
• 𝐶𝐻4 + 𝐻2O + Heat ⇌ CO + 3𝐻2

9. Methods of producing Hydrogen
• Partial oxidation method
• Hydrocarbons react with a small amount of oxygen in the
process.
• Faster than reforming process
• Yields smaller amount of hydrogen
• 2𝐶𝐻4 + 𝐻2O ⇌ CO + 2𝐻2 + 𝐻𝑒𝑎𝑡

10. Methods of producing Hydrogen
• 2. Electrolysis Method
• Splitting or the decomposition of a water molecule into two
hydrogen and one oxygen atom using an electric current.
• Other methods:
• High temperature electrolysis
• High pressure electrolysis.
• Preferable
• More efficient
• Cheaper

11. Methods of producing Hydrogen
Electrolysis method is shown in picture

12. Methods of producing Hydrogen
• 3. Gasification
• Gasification is the process in which coal or biomass is reacted
with high temperature steam and oxygen in a pressurized
reactor called a gasifier and converted into gaseous
components.
• The resulting synthesis gas contains hydrogen and carbon
monoxide, which can be reacted with steam to produce more
hydrogen.

13. Methods of producing Hydrogen
• 3. Gasification
• Flexible use
• It can use the waster from coals.
• Low waste emission
• Best use in motor vehicles
• Power turbine

14. Methods of producing Hydrogen
• 4. Fermentation
• Biomass is converted into sugar-rich feedstock that can
be fermented to produce hydrogen.
• In other word, bacteria is used for the production of
hydrogen.
• Since some strains of bacteria can thrive without light, it
can be used to produce hydrogen all day and all night.
• An example of this is by using Rhodobacter spaeroides
S𝐻2𝐶 to convert molecular fatty acids into hydrogen.

15. Hydrogen fuel cells
• Energy conversion device
• Types of fuel cells:
1. Stationary
2. Portable

16. Hydrogen fuel cells
• Phosphoric Acid fuel cells (PAFC) use phosphoric acid as the
electrolyte.
• Efficiency ranges from 40 to 80 percent, and operating
temperature is between 150 to 200 degrees C (about 300 to 400
degrees F).
• Existing phosphoric acid cells have outputs up to 200 kW, and
11 MW units have been tested. PAFCs tolerate a carbon
monoxide concentration of about 1.5 percent, which broadens
the choice of fuels they can use.
• If gasoline is used, the sulfur must be removed. Platinum
electrode-catalysts are needed, and internal parts must be able
to withstand the corrosive acid

17. Hydrogen | Fuel of the Future
• Net zero carbon footprints
• Provides longer driving range
• Decarbonizing industrial sectors
• Stored in tanks but integrated into the vehicles (unlike CNG)
• Lighter than heavy lithium-ion batteries
• Easy to store and easy to use
• Refuel in five minutes
• Successful use in Space travel.

18. Drawbacks
• Small Scale
• Lack of infrastructure
• Less than 500 hydrogen stations globally
• Less Safety, explosion risk and highly combustible

19. Thank You