Hydrogen as a fuel is one of the best alternatives to other types of fuel like fossils. It is a clean fuel that produces only water. There are different hydrogen types based on their source of production. Hydrogen has a high energy efficiency per unit of weight and can help to reduce greenhouse gas emissions from multiple industries.

For decades, hydrogen has been considered as a potential fuel for the future. However, only recently it has gained traction from all factions of society. Funding has been pouring in from governments to find economical ways to utilize different types of hydrogen fuel to fulfill energy needs.

This blog presents a brief guide on every detail you need to know about hydrogen technology and how hydrogen as a future fuel can be a game changer.

Basics of Hydrogen

Hydrogen is the first element on the periodic table and is denoted by the symbol H. It is the most abundant element in the universe. In standard temperature and pressure, pure hydrogen is a diatomic non-toxic gas that has no color, taste, or odor. However, gaseous hydrogen is also highly combustible and flammable.

Hydrogen is one of the basic elements along with carbon that supports life forms on Earth. Most forms of hydrogen found on the earth exist in complex molecular forms like water and other organic compounds.

Its molecular form H2 types are used in fuel cell vehicles and other hydrogen-based technologies. Similarly, the atomic hydrogen type is highly reactive and it is used in industrial processes like surface cleaning and wielding. 

Production of Hydrogen

Hydrogen energy is produced using the following methods:

Thermal Process: - The thermal process for producing hydrogen involves steam methane reforming, a high-temperature process in which steam reacts with a hydrocarbon fuel to produce hydrogen. Hydrocarbon fuels such as natural gas, diesel, renewable liquid fuels, and gasified coal, among others, can be reformed to produce hydrogen.

Electrolytic Process: - The electrolytic process is an extremely eco-friendly way of producing hydrogen. In this process, water is separated into oxygen and hydrogen. The electrolytic process takes place in an electrolyzer.

Solar-driven Processes: - Solar-driven processes use light to produce hydrogen. Some solar-driven processes include photobiological, photoelectrochemical, and solar thermochemical. Photobiological processes make use of the photosynthetic activity of bacteria and green algae to produce hydrogen. Photoelectrochemical processes use special semiconductors to separate water into oxygen and hydrogen. The solar thermochemical process uses solar energy to produce hydrogen.

Biological Processes: The biological process uses microbes such as bacteria and microalgae, which produce hydrogen through biological reactions. These microbes make use of organic matter like biomass or wastewater to produce hydrogen.

Different types of hydrogen

The various hydrogen types that are currently in use are as follows:

Green Hydrogen

Green hydrogen is the most eco-friendly way of producing hydrogen. It is produced by splitting water by electrolysis, using electricity obtained from renewable sources. This produces only hydrogen and oxygen, out of which the hydrogen is used, and oxygen is vented. This method involves almost zero carbon emissions.

Also Read: World's Top 10 Green Hydrogen Producing Companies

Blue hydrogen

Blue hydrogen is produced when natural gas is split into hydrogen and CO2 either by the process of steam reforming or auto-thermal reforming. In this process, the greenhouse gasses released are trapped so as to reduce their negative impacts on the environment.

Grey hydrogen

Also known as Gray Hydrogen, this is the most common form of hydrogen. When the excess CO2 is not captured and is released into the atmosphere, it is known as grey hydrogen. This method of hydrogen production emits about 9.2kg of CO2 for 1 kg of hydrogen produced.

Brown hydrogen

This is the oldest way of producing hydrogen. Brown hydrogen is created through coal gasification. Organic or fossil-based materials are converted into carbon dioxide, carbon monoxide, and hydrogen at a very high temperature. This process is exceedingly harmful to the environment as carbon dioxide and carbon monoxide cannot be reused and thus are released into the atmosphere.

White hydrogen

White hydrogen is the hydrogen that is naturally occurring and is found in nature. It is mostly found in the gaseous form and rarely in underground deposits.

Pink hydrogen

Pink hydrogen is hydrogen obtained from the electrolysis of water using renewable energy. It is considered as a form of green hydrogen. However, the name comes from the pink-colored power grid in France where it was conceptualized first.

Turquoise Hydrogen

A new way of extracting hydrogen from natural gas is currently being experimented with. This type of hydrogen has solid carbon as a by-product.

Hydrogen Energy: Advantages and Disadvantages

Advantages

• Low carbon emissions: Hydrogen reduces carbon footprints as hydrogen-powered technologies do not release any toxic by-products or greenhouse gases; the only by-product is water. 
• Abundance: Hydrogen is readily available. It can be produced domestically from various resources such as gas, coal, wind, solar energy, biomass, etc.
• Conserve non-renewable resources: Hydrogen fuel cells, when used in automobiles, help conserve petroleum, a non-renewable resource.
• Fast charging: Hydrogen fuel cells charge extremely fast compared to automobiles powered by Lithium-Ion batteries. Li-Ion batteries used in electric cars take between 30 minutes to a couple of hours to charge. However, hydrogen fuel cells can be recharged within a few minutes.
• NO noise pollution: Hydrogen cells do not produce any noise whatsoever and thus reduce noise pollution. Like electric automobiles, hydrogen-powered automobiles are much quieter than conventional internal combustion engines, and unlike other sources of renewable energy like wind energy, hydrogen does not produce noise.

Disadvantages

• High cost of production: Platinum, a precious metal used in the production of hydrogen is very expensive. The initial high cost of making hydrogen fuel cells deters people from investing in this technology.
• Complexity in transportation and storage: Unlike fossil fuels, the transportation and storage of hydrogen are extremely complex. It cannot be transported through pipelines or loaded into trucks. That means alternative systems have to be developed which increases the costs further.
• Extremely flammable: Hydrogen is a tremendously flammable fuel source that jeopardizes the safety of everyone involved. Hydrogen gas burns in the air at concentrations ranging from 4 to 75%.
• A big carbon contributor: Currently, the majority of hydrogen is supplied using natural gas and coal. This method of production releases more CO2 than Indonesia and the United Kingdom combined because producing green hydrogen from renewable energy sources is extremely costly at the moment.
• Challenge to set up new supporting infrastructure: The mass and economical use of hydrogen needs new refueling infrastructure. The development of this infrastructure is slow and is holding back widespread adoption.

Applications of hydrogen fuel cell system

Hydrogen Fuel Cells are devices that can transform the chemical energy of hydrogen into electrical energy without any carbon by-product. A Hydrogen Fuel Cell is more energy-efficient compared to an internal combustion engine. Therefore, it has a wide range of applications.

HVAC

When combined with oxygen in a fuel cell, hydrogen produces energy in the form of electricity which can be used for heating purposes. The heat produced as a by-product of combined heat and power is used to cover part of the building's heat demand. The advantage that fuel cells have over thermal power processes is the direct electrochemical conversion during electricity and heat generation. 

Power Supply

Stationary hydrogen fuel cells can be used for power supply in off-grid areas. Fuel cells have much higher electrical efficiency compared to conventional thermal power plants. Fuel cells produce high-value electricity and little heat; they also have low maintenance costs due to the lack of moving parts and have a long service life, and operate quietly. Hydrogen energy conversion systems are expected to become the choice of future energy systems.

Hydrogen Fuel Cell Vehicle

A hydrogen fuel cell vehicle uses hydrogen as a fuel and converts its chemical energy into electricity through a chemical reaction in a fuel cell. This electricity powers an electric motor that drives the vehicle. The only byproduct of this process is water, which is emitted from the vehicle as steam.

Check out - Global Fuel Cell Electric Vehicle (FCEV) Market Report

Hydrogen Internal Combustion Engine Vehicle (HICEV)

A hydrogen internal combustion engine vehicle (HICEV) is a modified version of traditional vehicle engines. Unlike gasoline where a fossil-based fuel is used, HICEV uses hydrogen as the fuel to power the engine. Since hydrogen is free from carbon, no greenhouse gas is produced, thereby reducing carbon-based pollutant emissions into the atmosphere.

Conclusion

Hydrogen, being a clean, green, and highly energy-efficient fuel, can be a game changer in the global efforts to transition into carbon-free fuel sources. Its abundance is a huge advantage that can be put to use with the right technology. The advancement in global hydrogen technology is surely in the right direction but it needs to pick up pace to make hydrogen one of the potential alternative fuels for the future.