ABSTRACT
Fuel ethers are high octane number oxygenates used as blendstock for motor-gasoline as an alternative to alcohols when inclusion of oxygenates is mandated. Methanol is preferred as alcohol for etherification, because its etherification equilibrium is more favorable than that of ethanol. Etherification is a process that converts alcohols on their own or alcohols in combination with olefins into ethers. Only the reaction of alcohols with olefins found widespread use in petroleum refining. Interest in etherification was spurred by the phase out of tetraethyl lead as additive to increase the octane number of motor gasoline. The alcohol used for the etherification reaction is either methanol, or ethanol. Various commercial technologies for etherification are described in the literature. The process technology is illustrated using the process flow diagram of one of the etherification technologies. Any acid catalyst with sufficient acid strength can in principle catalyze etherification reactions.
