Hydrogen FAQ

This hydrogen FAQ is aimed at providing you some answers to the most common questions you may have on hydrogen technologies before you purchase a hydrogen system.

What is hydrogen?

Hydrogen is a chemical element with symbol H and atomic number 1.

It is the simplest, most abundant and lightest element in the whole universe.

Hydrogen constitutes about 75% of the universe mass (while some argue that hydrogen constitutes 90% of the visible universe).

At earth temperature and pressure (say when found in our living environment temperature and pressure), hydrogen is most commonly identified as a colourless, tasteless, non-toxic, highly flammable and odourless diatomic gas (H2).

Hydrogen gas is rarely found alone in nature because it is usually bonded with other elements.

For instance, hydrogen can be found in water (H2O).

Hydrogen was first recognised as an element by Henry Cavendish in 1766.

However, it was discovered long before and documented by Robert Boyle in 1671.

Robert Boyle produced hydrogen during his experimentation with iron and acids.

Hydrogen is mostly known to the human being as a raw fuel.

Most stars in the sky as we know them burn hydrogen to produce energy.

Therefore move in a given direction.

One of the planets that uses hydrogen abundantly is the Sun.

And when the hydrogen available on the sun will run out, then the sun as we know it today, will simply switch off.

Fortunately for us human being, hydrogen will supply the sun for another 5 billion years, enough for us to hopefully find a solution.

Hydrogen is used widely at a global level.

It is a commercially important element as large quantities of hydrogen are combined with other elements to form useful compositions.

For instance, hydrogen is mixed with nitrogen to produce ammonia (NH3) through the Haber process.

Hydrogen is also added to many other compounds such as fats and oils, e.g., peanut oil.

The process of adding hydrogen to fats or oil is called hydrogenation.

Further to this, hydrogen can also be liquefied.

In its liquid state, it is used in the study of superconductors.

At times liquid hydrogen is combined with liquid oxygen to make rocket fuel, such as space rockets.

In summary, hydrogen combines with many other elements to form different types of compounds such as water (H2O), ammonia (NH3), hydrogen peroxide (H2O2) and hydrochloric acid (HCl), table sugar (C12H22O11), methane (CH4).

Is hydrogen safe to store & handle?

Hydrogen, in gaseous form, is widely stored in Hydrogen high-pressure storage cylinders, tubes or tube trailers.

In liquid form, hydrogen is mainly stored at the consumer site in cryogenic liquid tank or cylinders.

These liquid hydrogen tanks are highly insulated and specifically designed to reduce evaporation of the Hydrogen gas.

Liquid hydrogen is dangerous and therefore only trained individuals must handle it with care.

The handling of Hydrogen liquid gas is risky and therefore all precautions must be taken to avoid any accidents.

The hydrogen concentration in air detection unit is highly advisable.

As a rule of thumb, any hydrogen system (H2 compressor, hydrogen generator, H2 steam reformation system, etc.) should be located in a highly ventilated area.

It is also best practice to use a hydrogen monitoring system.

The H2 monitoring system will monitor the hydrogen in air concentration and if the set up threshold is reached, then the system is shut down and hydrogen vented in the air to make it inert.

To dispose of hydrogen gas from a pressurised hydrogen vessel, one should vent the hydrogen slowly to a well-ventilated outdoor location remote from personal work areas and building air intakes.

Usually, a hydrogen pipe is used to direct Hydrogen to a safe venting place.

As for liquid Hydrogen, first, allow the H2 to evaporate.

Liquid Hydrogen boils quickly, so there should not be an issue to get it to transform to its gaseous form.

How can we produce hydrogen?

Hydrogen can be produced in many different ways.

However, the vast majority of Hydrogen currently produced worldwide uses steam reformation of natural gas and electrolysis of water.

Everyone can produce hydrogen in their own home using water electrolysis (home electrolysis is not recommended if you are not properly trained on hydrogen safety – get trained on hydrogen safety here).

Water electrolysis is simply a means to split up water into its two gas constituents that is hydrogen and oxygen.

To split water, we use a device called electrolyzer.

An electrolyzer splits hydrogen from oxygen by sending an electrical current between two electrodes (metallic bars).

The electrodes are put into the water without touching each other.

When the current flows between the two electrodes, hydrogen and oxygen split up.

Hydrogen will be generated onto one electrode while oxygen will be generated onto the other electrode bar.

Below is an example of an electrolyzer picture where water is fed to the electrolyzer and you get hydrogen produced on one side and oxygen on the other side.

Hydrogen Electrolyzer Schematic Diagram Pure Energy Centre Electrolyser

One has to remember that each hydrogen electrolyzer may need a hydrogen compressor.

The role of the hydrogen compressor is to compress the hydrogen gas into a hydrogen storage system at a given pressure such as 200 bar, 350 bar, 400 bar, 700 bar, and other pressures.

Many electrolyzers also produce hydrogen at high pressure such as 10 bar, 12 bar, 30 bar and 75 bar.

Can hydrogen be produced using an environmentally friendly method?

Yes – and the process has over 150 years.

When hydrogen is produced using renewable energy and electrolysis process, then it is produced in an environmental manner.

For instance, if you take the power generated from a wind turbine.

And if you supply an electrolyzer with this green power, then you will be producing green hydrogen.

Can hydrogen be used as a fuel?

Yes, hydrogen gas is nowadays being used aggressively as a fuel for passenger vehicles and other transport systems.

It can be used in fuel cells to power electric motors and combined with battery constitute a hybrid fuel cell battery electric vehicle.

It can also be burned in Internal Combustion Engines (ICEs) such as the one used in our vehicles.

Hydrogen is seen as a green or pure fuel because H2 is an environmentally friendly fuel with no associated CO2 emission. And it can also be produced without any emissions too.

As such hydrogen has the potential to dramatically reduce our dependence on imported oil as well as reduce the dangers associated with emissions.

What is electrolysis?

This has been described above, but electrolysis is simply the process of dissociating water (H2O) into hydrogen and oxygen using a device called electrolyzer (see above about electrolyzers).

Do we need the energy to create hydrogen from water?

Yes – The extraction of any fuel takes energy.

In the case of hydrogen production from water electrolysis, you need electricity from any source of power.

The power can be from a fossil fuel generator such as a genset, from a nuclear power station, or from renewable a source.

Does it take more energy to produce hydrogen than to take oil out of wells?

This is a difficult question that must be answered by a Yes and No.

You need to look at the bigger picture here.

It took several million years to produce the oil and gas as we know it today. So, oil and gas is not something that we can produce easily.

Now, Oil and Gas are resources that are becoming more difficult to extract from the production fields.

So, the difficulties to extract the hydrocarbon from the underground requires substantial energy, which is not really documented at the moment.

Hydrogen, on the other hand, can be produced from any renewable source right away and you require about 55kWh to produce 1kg of hydrogen.

Now, for hydrogen, it is clear that we know how much energy we need to produce 1kg of the gas.

But to date, there is no real detail to compare this value to the energy cost for producing the oil or gas equivalent.

So why do I need to consider hydrogen at all?

Because hydrogen can be produced and used with no harmful emissions.

Also, hydrogen can be used everywhere we use energy (transport, cooling, heating, cooking, electricity generation, etc).

In addition, hydrogen can be used in a fuel cell (see our fuel cell tab) which is more efficient than any conventional energy devices.

The electrical efficiency of a fuel cell can reach 50%. So the overall cycle from the production of hydrogen to its usage in a fuel cell is quite high (it can reach up to 40% if we use the waste heat of the fuel cell).

Do we have enough water to produce hydrogen for all our needs?

Yes. In fact, the full cycle is water neutral as per the below description:

  1. Water is split into hydrogen and oxygen.
  2. Hydrogen is stored.
  3. When hydrogen fuel is used in a fuel cell, then water is the by-product.
  4. This provide a fully water neutral cycle.

Why not use renewable electricity to satisfy our needs instead of converting it to hydrogen?

We can use electricity from renewables directly to satisfy our immediate needs in electricity and heat.

However, there are many times when there is wind/solar/hydro electrical power being generated, but there is no demand.

In other words, we are not needed to use this green electricity at the time of it being produced.

So, what do we do?

We just shut down the wind turbines, solar PV and hydropower systems.

Or we better find a use for these?

Obviously, it is best to use the power and in our case, we store it as hydrogen.

So hydrogen production system using electrolysis processes can be used when we have surplus renewable energy.

And the hydrogen can be used for cooking, heating, cooling, electrical power generation, as a fuel for transport, for chemical process, etc.

So producing hydrogen could help in providing us with continuous power and fuel?

Yes. Wind and solar systems, on their own, do not address our need for continuous power and fuel.

Green hydrogen energy systems as a whole can do that. And this is energy storage technologies.

In the case of hydrogen, this is called hydrogen energy storage technologies.

If you need an around the clock clean energy solution, then call us on +44 (0) 1957 711 410.

We can provide complete solutions including transport.

Is hydrogen safe?

Yes, it is safe as long as you know what you are doing.

Hydrogen is like any flammable fuel such as natural gas and petrol.

It requires care and safe handling.

Many scientists agree that the properties of hydrogen make it safer than other conventional fuels in many cases.

To learn more about the safety aspects of hydrogen and fuel cells, please attend our training course.

How do we store hydrogen?

The most common way is to store hydrogen in a pressurised cylinders similar to the butane bottles we find installed outside a home and used for cooking purposes.

There are other means to store hydrogen such as liquid and in metal hydride canisters.

If you want to know more, please attend our training course.

How do you transport hydrogen?

The two main methods for transporting hydrogen are in compressed tankers and in gas pipelines.

But there are new techniques such as in liquid form in Ammonia.

Can hydrogen be used in my petrol car?

Yes – Hydrogen can be used in a petrol car.

Modification of your fuel supply system in the car is required.

Then your vehicle will run on two fuels, petrol, and hydrogen.

Can we compare H2 with other fuels?

Yes. Here are some pointers:

  • Hydrogen can be produced anywhere in the world from any energy sources. 
  • H2 can be totally non-polluting with water being the exhaust from fuel cells. 
  • Hydrogen can help prevent the depletion of fossil fuel reserves by only using fossil fuels where we really cannot do without them and not burning them in transport applications 
  • H2 can be as safe as if not safer in some cases than diesel/petrol, or natural gas

How much water do I need to produce the equivalent of 1 litre of petrol?

Between three to four litres of water is needed to produce the equivalent of 1 litre of petrol.

Can I install a hydrogen system myself?

This is not advisable.

You will need to get a company with expertise in hydrogen installations so that you reduce your installation risk.

Do not forget, you are dealing with flammable gas, and if you do not know how to handle this gas, then it is preferable that you allow experts in this field to support you in your project.

Can I sell my hydrogen as fuel?

Yes. You just need to find someone who wants to buy it such as a hydrogen bus, fuel cell manufacturer or users and others.

How much money will I make selling hydrogen?

It is hard to say as there is a very closed market for hydrogen.

You really need to find an end user first and then you can sell the hydrogen as you wish.

Does a hydrogen system require maintenance?

Yes. Like any other system, you need to do some maintenance work on a hydrogen system.

We provide all our systems with standard maintenance contracts. Contact us for more information.

How much does a hydrogen system cost?

This all depends on size and site specifics. Please contact us to find out more.

What do I do if I want to do to buy a hydrogen system?

Call us on +44 (0) 1957 711 410 or fill up our contact form on our contact page.

What are the benefits of hydrogen?

As discussed above, hydrogen can be produced locally using a green source of energy such as a wind turbine or a solar photovoltaic system.

As such it can increase a country’s energy security and reduce its dependence on hydrocarbon imports.

When burned or consumed hydrogen do not emit pollutants or greenhouse gases.

However, like diesel or petrol engines, it does produce some nitrogen oxides (NOx) when burned in Hydrogen Internal Combustion Engines (ICE).

But in a hydrogen ICE, NOx can be reduced to a minimum using special techniques.

Have more question before purchasing a hydrogen system?

Please do not hesitate to contact the Pure Energy Centre to discuss your requirements on +44 (0) 1957 711 410 or click here and fill up the form for your hydrogen system (compressor, electrolyzer, fuel cell, hydrogen refueller, storage, sensors, piping, etc).

We truly hope that you have enjoyed our Hydrogen FAQ.

If you feel we need to add more questions and answers to our Hydrogen FAQ, please do not hesitate to contact us here.