Dehydrogenation

Dehydrogenation refers to the removal of hydrogen from a chemical compound. Is the reverse reaction for the hydrogenation. Dehydrogenation take place both in biochemical processes as well as in chemical engineering processes.

Types of dehydrogenation

The elimination of hydrogen can take place under release of molecular hydrogen, the hydrogen is often, however, be transferred to other chemical compounds ( transfer hydrogenation ), or by oxidizing bound acceptors. Find a dehydrogenation in the presence of enzymes or metallic or oxidic catalysts instead of a hydrogen molecule is split off in an elimination reaction, respectively. Oxygen radicals, quinones, sulfur or selenium lead, however, to the elimination of individual hydrogen atoms ( univalent dehydration ).

Enzymatic dehydrogenation

The enzymes which enable dehydrogenation in biochemistry, hot dehydrogenases. An important coenzyme NAD is such dehydrogenases, which acts as a hydrogen acceptor and is reduced thereby to NADH.

Technical dehydrogenations

The dehydrogenation is an important reaction in the chemical process engineering. In most cases, molecular hydrogen is split off from the respective substrates. To steer this actually endothermic process in the desired direction, the dehydrogenation is often carried out in the presence of oxygen, which reacts with the hydrogen to split water; thereby the total exothermic reaction.

Examples of technically guided dehydrogenations:

• Primary alcohols aldehydes →
• Secondary alcohols ketones →
• Alkanes, alkenes →
• Cycloalkanes → aromatics

The latter reaction takes place on a large scale as part of the reaction catalytic reforming in petroleum refineries instead.