Review

Due to the growing restrictions on the content of aromatic compounds by the European legislation in motor fuels and at the same time the need for higher quality fuels (minimizing the presence of contaminants and hazardous products to health), it has become necessary to increase processes that can maximize the number of octane in gasoline. This manuscript is aimed to provide current trends and processes related to isomerization, alkylation and etherification processes to improve gasolines as final product. Examples provided include the isomerization of light n-alkanes into iso-alkanes or the alkylation, in which the preferred olefin is the methylbutilene and i-butane to produce a high octane number gasoline. Currently, there are two main commercial processes for alkylation processes (hydrofluoric and sulfuric acid technologies). Other incoming suitable process is the etherification of iso-olefins to bio-ethers (the European Union have as a minimum target of biofuel content in fuels of 10% in 2020). The refiners are recently investing in the production of bio-ETBE (ethyl tertiary butyl ether) and other products as additives using bio-ethanol and olefins. Commercial and new potential catalysts for all these processes are currently being used and under investigation.