Hydrogen, the fuel of the future

The energy potential of hydrogen.


Hydrogen is a chemical element represented by the symbol H and has an atomic number of 1. Under normal conditions of pressure and temperature, it is a colorless, odorless, tasteless, non-metallic, and highly flammable diatomic gas (H2). With an atomic mass of 1.00794(7) u, hydrogen is the lightest chemical element and also the most abundant, constituting approximately 75% of the visible matter in the universe.


Hydrogen is frequently found with other components, such as water (H2O) and other organic elements. Hydrogen stands out for its enormous energy potential per unit of mass for being the lightest chemical element. In its gaseous state, compressed at 350 bars of pressure, it offers no less than 39,300 Wh/kg, and in its liquid state, 39,000.


Due to its composition and behavior, hydrogen has clear environmental advantages apart from its energy potential.


Clean, economical, and efficient transformation technology


• Does not pollute: Hydrogen does not pollute or consume natural resources. It is taken up from water, oxidized, and returned to the water.


• Toxicity: Hydrogen could be much safer as energy than any other fuel type. If released and dissipated, it does not contaminate people or the environment.


• High efficiency: Hydrogen converted into energy can achieve excellent efficiency, even more significantly than other energies.


• Silent: Converted into energy and used as fuel, hydrogen is a practically silent element.


• Long life and power: Hydrogen as energy can provide long life to the elements on which it is applied. In addition, its power could be regulated, and the energy of the systems modulated according to the growth in energy demand, drastically reducing costs. Initials.


Ways to obtain Hydrogen


There are several technologies for hydrogen production which can be used depending on specific requirements and available resources.


Here are some standard methods:


Steam reforming of natural gas:

It is the technology most currently used for hydrogen production. In this process, natural gas, composed mainly of methane, is heated with water vapor in the presence of a catalyst. Figuratively speaking, the steam reforming process can be considered the “decomposition” of natural gas.


In this process, methane from natural gas reacts with water vapor and produces hydrogen (H2) and carbon monoxide (CO). The hydrogen obtained is purified and can be used as fuel in vehicles, to generate electricity in fuel cells, or in various industrial applications. This process is economical, but it also has disadvantages. Carbon dioxide is released as a byproduct, which impacts the environment.


Water electrolysis:

In electrolysis, water is split into hydrogen and oxygen with the help of an electric current. To do this, equipment or devices called electrolyzers are used to carry out the electrolysis process.



Hydrogen production with solar energy:

This method uses solar energy instead of electrical energy to carry out the electrolysis process. To do this, direct sunlight or solar radiation can be concentrated with the help of mirrors or solar collectors. This new technology could be used in countries where sufficient sunlight is available, which would allow hydrogen to be produced particularly cost-effectively.

 

Thermochemical hydrogen production (biological hydrogen production):

Some microorganisms, such as certain bacteria or algae, can produce hydrogen through fermentation or photosynthesis. This method is still in the development phase but can become a sustainable and environmentally friendly source of hydrogen. However, the disadvantage of this type of production is finite resources.


The most promising method for obtaining Hydrogen.


Electrolysis is the most promising process. It allows hydrogen to be produced in an environmentally friendly way, especially if the electricity used for this comes from renewable energy sources. These technologies enable clean hydrogen to become a sustainable energy source for various applications.


Below, we analyze in detail the different technologies and the advantages and disadvantages of each of them.


PEM electrolysis:

  • PEM electrolysis, also known as proton exchange membrane electrolysis, splits water into hydrogen and oxygen using a polymer membrane and electrical current.


  • Advantages:

  • Quick start-up and adaptation with variable loads.

  • High efficiency in operation with partial loads.

  • Low operating temperature (50-80°C), reducing the use of expensive materials.

  • Compact size and easy integration into existing systems.

  • High level of technological maturity (TRL 7-8).


  • Disadvantages:

  • Sensitivity to impurities in water, requiring prior water treatment.

  • Limited PEM fuel cell life (approx. 10,000 operating hours).

  • Higher costs compared to alkaline electrolysis.


Alkaline electrolysis:

  • In alkaline electrolysis, water is split into its hydrogen and oxygen components using an alkaline electrolyte, typically an aqueous potassium hydroxide solution.


  • Advantages:

  • Lower costs compared to PEM electrolysis.

  • Resistance against water contaminants.

  • Long electrolytic cell life (approx. 40,000-80,000 hours of operation).

  • Maximum level of technological maturity (TRL 8-9).


  • Disadvantages:

  • Slower reaction rate compared to PEM electrolysis.

  • Higher operating temperatures (70-100°C) lead to higher power consumption.

  • More difficult integration into existing systems due to different operating parameters.


SOEC (Solid Oxide Electrolysis Cell):

  • SOEC stands for solid oxide electrolysis cell and refers to a high-temperature electrolytic cell that converts water into hydrogen and oxygen at high temperatures and with solid oxides as electrolytes.


  • Advantages:

  • High efficiency and heat recovery thanks to high operating temperatures (800-1000 °C).

  • Flexibility in the use of different fuels (e.g. steam, CO2).


  • Disadvantages:

  • High operating temperatures require the use of expensive materials and special thermal insulation.

  • Slow start-up and adaptation with variable loads.

  • Larger dimensions and complex integration into systems.

  • Little large-scale operational experience.


AEM (anion exchange membrane) electrolysis:

  • AEM stands for anion exchange membrane and refers to an electrolyzer technology that uses a special membrane that allows the permeability of negatively charged ions and splits water into hydrogen and oxygen using an electrical current.


  • Advantages:

  • Lower costs compared to PEM electrolysis.

  • Resistance against water contaminants.

  • Operation at lower temperatures (approx. 60-80 °C).


  • Disadvantages:

  • Limited development and commercialization compared to PEM electrolysis and alkaline electrolysis.

  • Possible challenges to ensure long-term membrane stability.

  • No large scale facilities available. Low level of technological maturity.


Transformation cycle into usable energy


Once the hydrogen is obtained, it is used in gas-powered electric generators to produce useful electrical power for any area or industry.


Positive effects on the environment


From the combustion of hydrogen gas, the resulting waste is water vapor, which could be delivered to the environment, reinforcing the hydrological cycle and not causing damage to the environment.