摘要 |
In an integrated epoxidation process (1) comprising: (a) reacting a 3-4C secondary alcohol (I) and molecular oxygen in liq. phase to form an oxidant mixt. of (I), the corresp. 3-4C aliphatic ketone (II) and hydrogen peroxide; (b) sepg. substantially all the (II) from the mixt. to provide a conc. stream contg. hydrogen peroxide, (I) and 1% of (II); (c) reacting the conc. stream with a 2-4C olefin (III) in the presence of a Ti silicalite catalyst (IV) and a diluent (V) to form an epoxidation reaction mixt. comprising a 2-4C epoxide (VI) corresp. to (III), water and (I); and (d) sepg. substantially all of (VI) from the epoxidation mixt. to form a crude alcohol stream contg. water, (I) and 1 wt.% of (VI); (e) at least a portion of the crude alcohol stream is recycled for use as (V). Also claimed is a more specific embodiment of the process, process (2), comprising: (a) reacting IPA and O2 in liq. phase at 50-200[deg]C to form an oxidant mixt. of IPA, acetone and hydrogen peroxide; (b) distilling the mixt., vaporising acetone which is removed as overhead to provide a conc. stream of IPA, 10-30 wt.% hydrogen peroxide and 1 wt.% acetone; (c) reacting the conc. stream with propylene at 25-120[deg]C in the presence of (IV) and (V) to form an epoxidation mixt. of water, propylene oxide and IPA; (d) sepg. substantially all propylene oxide from the mixt. by distn. to form bottoms streams of water, IPA and 1 wt.% of propylene oxide; (e) recycling at least some of the bottoms stream for use as (V) in (c); (f) hydrogenating the acetone from (b) to IPA; and (g) recycling at least some IPA from (f) for use in (a). |