Effect of third-phase properties on benzyl-n-butyl ether synthesis in phase transfer catalytic system

The production of benzyl-n-butyl ether from benzyl chloride and n-butanol is studied in phase transfer catalytic system. A third phase is formed when polyethylene glycol (PEG) and dodecane are used as the phase transfer catalyst (PTC) and an organic solvent, respectively. The production rate at the three-phase system is higher by seven times than that at the two-phase system. The ether production rate and its selectivity are dependent on the initial concentration of n-butanol. These are affected by the properties of the third phase, especially the concentrations of n-butanol and water in the third phase.

n-Butanol reacts with benzyl chloride and potassium hydroxide simultaneously. The reaction between n-butanol and potassium hydroxide occurs in the aqueous phase. Then, the selectivity of ether on a basis of initial n-butanol is below 0.6 in a stirred tank batch reactor. The selectivity is much improved at 0.9 by using a static triphase batch reactor in which the organic and aqueous phases are separated by the third phase. The interphase mass transfer can be accelerated by ultrasonic device.