How is hydrogen distributed?

The most common way of producing hydrogen today is in centralised, large scale production facilities, where after it is distributed to the user. Another option is to produce it locally on a smaller scale, which has the advantage of decreasing vulnerability and dependency on other energy suppliers. Alternatively, the supply of hydrogen can be based on distribution systems belonging to other carriers of energy, such as methane, ethane, electricity, natural gas or biogas, where after it can be converted into hydrogen once it reaches the user. Such carriers of hydrogen have higher energy density, enabling lower transport volumes which are easier to handle.

Hydrogen occurs in a gaseous state at standard temperature and pressure. It can be stored in comprised form in gas bottles. In industries hydrogen is normally compressed to 200 bar and stored in bottles made of stainless steel. When used as vehicle fuel, hydrogen is compressed to 350 or 700 bar. The compressing leads to an energy loss of 5-10 percent. In addition, today’s tanks are both bulky and expensive, since they are made of carbon fibre materials using complicated production techniques.

Another method of transporting hydrogen is to decrease its temperature until it liquidises at
-253˚C and store it in cryogenic tanks. Storing it as a liquid requires less space than storing it as a gas does. However, the cooling of the hydrogen until it becomes a liquid results in an energy loss of approximately 30 percent, and over time it evaporates causing additional losses of energy.

Pressurized hydrogen is transported in regular trucks, whereas liquid hydrogen requires tank trucks. Train transport is another option, although not frequently used as of yet. Hydrogen can also be distributed through pipelines, with the advantage that hydrogen can be stored in the pipelines when supply exceeds demand. However, this alternative has the disadvantage of requiring an extensive system of lines able to hold hydrogen. There is no such system at present and the cost of investment would be relatively high. It may be possible to distribute hydrogen through existing natural gas lines, but this needs to be investigated further. If there is an increase in the demand for hydrogen then a pipeline system could be profitable in the long run.

A further way of storing hydrogen is in so called metal hydrides. There are hundreds of different kinds of such alloys. The advantages of this method are that it is safer and requires considerably less storage space. However, metal hydrides are often heavy and extracting the hydrogen may take time.

Did you know that…?

• In Europe there are approximately 1600 kilometres of hydrogen pipelines today.
• When hydrogen is used as a raw material in industries it is usually produced in the same place as it is being used, thus creating no need for transportation.
• Scandinavia is aspiring to become one of the first regions in the world where hydrogen is used to fuel vehicles.