Industrial gases are an everyday part of our lives as they are used to produce the vast majority of the items we use. Industrial gases are not only an essential part of manufacturing processes in industry, but are also indispensable in healthcare, food, electrical engineering, research and many other applications. Their use therefore affects not only everyone's life but also the environment in which we live. This module focuses on hydrogen and related technologies. In this part of the text we will look at other technical gases besides hydrogen. You will also find basic information on the production of industrial gases, their transport and distribution. Technical gas filling plants supply technical gases to customers, fill empty technical gas tanks and transport them.

The production and distribution of industrial gases is a process that is carried out by international companies with a global presence. The products of their activities are not only industrial gases, but also chemicals used in various industries, processing waste products of chemical production. The largest producers and distributors of hydrogen in the world are Linde, Air Products, Messer, Air Liquide International, Cummins and others.

In industrial gas filling plants, hydrogen is stored in above-ground or underground steel tanks. From these tanks, the hydrogen is further filled into transport or pressurised cylinders. The pressurised storage tanks can be replaced by large capacity underground tanks at suitable locations. These are usually underground spaces created by mining. The hydrogen storage pressure is approximately 110 bar; higher pressures are not used because of possible leakage of natural gas through the rock mass. Underground storage tanks have the advantage of a large capacity and do not take up space on the surface. The disadvantage of this type of storage is the selection of a suitable location due to the geological conditions. The expansion of hydrogen vehicles is conditional on a sufficiently dense network of filling stations, which must be easily accessible to users. For this reason it is necessary to build filling stations in towns and around roads where there are no suitable sources of hydrogen. It is therefore necessary to import hydrogen to filling stations in a similar way to fossil fuel or LPG/CNG filling stations. At the point of production, the hydrogen is filled into suitable containers for transport and then transported to the final distribution point.

Due to the specific characteristics of hydrogen, a number of problems arise in its storage, transport and distribution, the most important being:

- Extremely low bulk density (3.2 times lower than natural gas and 2700 times lower than gasoline).

- Compressed hydrogen can be explosive – risk of explosion

- Hydrogen storage regulations are inconsistent around the world

- Difficult to mix hydrogen with natural gas when transporting it in existing pipelines

- Hydrogen can increase the brittleness of the materials from which transport and storage equipment is made [18]