Lower olefins alkenes and acetylene ethyne

The paraffinic hydrocarbons in natural resources show very low reactivity under moderate conditions. Early petrochemical processes drew upon the greater reactivity of olefins, and when refinery supplies failed to meet demand means of converting alkanes to alkenes were developed. During the later period, low prices of naphtha (in Europe and Japan) and natural gas (in the U.S.A., and more recently Europe) also promoted petrochemical routes to acetylene. 

The resulting processes all require high temperatures and are, therefore, both energy- and capital-intensive, so that very large scales of operation are desirable for efficiency and economic viability. 

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