*3.3. Cyclohexane*

In order to store and transport hydrogen, it is necessary to consider the technology of hydrogenation of aromatic hydrocarbons, such as benzene-toluene-xylene, which can be obtained at the field with the release of C1–C2 gas and hydrogen.

So, in the process of hydrogenation, benzene-toluene-xylene will be converted into cyclohexane by the reaction, for example, of benzene:

$$\text{C}\_6\text{H}\_6 + 3\text{H}\_2 \overset{\text{l.Pl}}{\leftrightarrow} \text{C}\_6\text{H}\_{12} \text{ } \Delta\text{H} = -239.13 \text{ kJ/mol.} \tag{3}$$

This reaction occurs at a pressure of 5 MPa and a temperature above 300 ◦C, after cooling to 25 ◦C (standard conditions), cyclohexane becomes a liquid, and in the liquid state, 1 L of cyclohexane will contain 673 L of hydrogen.

The processes of catalytic conversion of unsaturated and saturated light hydrocarbons C2–C5 into benzene, toluene and xylene have recently attracted the attention of many researchers [16,23,26,27,55–57].
