In what type of reaction is an alcohol converted to an alkene?

The reaction of dehydration converts an alcohol to an alkene.

Explanation:

In order to converto an alcohol to an alkene, we need heat and a strong acid.

Primary alcohols require higher temperatures than secundary and terciary alcohols. If the temperature is lower than it is needed, the product will be an ether instead of an alkene.

The mechanism usually involves the formation of an an alkyloxonium ion, water will be produced during the reaction. The reaction  goes through an E2 mechanism.

One symplified mechanism is represented in the figure attached.