Increasing yield in alkylene oxide prodn. from corresp. chlorohydrin - by alkaline hydrolysis in presence of ferric ions, opt. with addn. of di:chloroalkane

摘要

Increasing the yield in the prodn. of alkylene oxide (I) is by alkaline hydrolysis of dil. or conc. aq. HCl solns. of alkylene chlorhydrin (II), as obtd. by the aq.-phase reaction of chlorine and olefin. Fe(III) ions, 2-500 ppm, is added to the soln. of (II), opt. with addn. of dichloroalkane (III). Pref., soln. (II) is treated with 2-200 ppm Fe(III) ions, or 5-500 ppm Fe(III) ions and 0.15-0.30% (III). Pref., Fe(III) is added as FeCl3 or via an ion exchange resin, and (III) is a dichloroalkane corresp. to (II), e.g. dichloropropane in the case of propylene chlorhydrin (IIA); hydrolysis is carried out with NaOH or Ca(OH)2 soln. USE/ADVANTAGE - Enables increased yields of (I) in the above process, with reduced formation of sec. prods. and without special appts. or technology. In an example, a system of 5 hydrolysers in parallel was supplied with an aq. HCl soln. of 6.5% (IIA) at 250 m3/hr. and 18% milk of lime at 120 m3/hr., with addn. of 5.5 t steam/t (I) produced; the temp. was 373 K at the bottom of the hydrolysers and 368 K at the top; the mixt. of (I) and water obtd. was condensed, collected and distilled to give 6.875 t/hr. (I) (70% yield). If 20% FeCl3 soln. was added to the soln. of (IIA) at the rate of 50 l/hr. before hydrolysius, the yield of (I) was increased to 78.5%. Yields of up to 99% were obtd. in a laboratory appts., using 45% aq. (IIA), with addn. of 75 ppm Fe-III ions and 0.22% dichloropropane