The invention relates to a process for the epoxidation of an olefin comprising (a) reacting the olefin with hydrogen peroxide in the presence of methanol as solvent in at least two reaction stages to obtain a mixture (M-a) comprising olefin oxide, unreacted olefin, methanol and water, wherein between at least two reaction stages, olefin oxide is separated by distillation; (b) separating unreacted olefin from the mixture (M-a) by distillation to obtain a mixture (M-bi) comprising at least 80 wt.-% of olefin and a mixture (M-bii) comprising methanol, water and at least 7 wt.-% of olefin oxide; (c) separating olefin oxide from the mixture (M-bii) in at least one distillation stage to obtain a mixture (M-ci) comprising at least 99 wt.-% of oletin oxide and a mixture (M-cii) comprising water and at least 55 wt.-% of methanol; (d) separating methanol from the mixture (M-cii) in at least one distillation stage to obtain a mixture (M-di) comprising at least 85 wt.-% of methanol and up to 10 wt.-% of water, and a mixture (M-dii) comprising at least 90 wt.-% of water; wherein a vapor top stream (Td) obtained from at least one distillation column used in (d), said vapor top stream (Td) comprising at least 85 wt.-% methanol, is used to operate at least partially at least one vaporizer used in at least one distillation column used in at least one of stages (a), (b) and (c).
该发明涉及一种烯烃环氧化的工艺,包括(a) 在至少两个反应阶段中,在
甲醇作为溶剂的存在下,将烯烃与
过氧化氢反应,以获得包含烯烃氧化物、未反应的烯烃、
甲醇和
水的混合物(M-a),在至少两个反应阶段之间,通过蒸馏分离烯烃氧化物;(b) 通过蒸馏将未反应的烯烃从混合物(M-a)中分离,以获得含有至少80重量%烯烃的混合物(M-bi)和含有
甲醇、
水和至少7重量%烯烃氧化物的混合物(M-bii);(c) 在至少一个蒸馏阶段中,将烯烃氧化物从混合物(M-bii)中分离,以获得含有至少99重量%烯烃氧化物的混合物(M-ci)和含有
水和至少55重量%
甲醇的混合物(M-cii);(d) 在至少一个蒸馏阶段中,将
甲醇从混合物(M-cii)中分离,以获得含有至少85重量%
甲醇和最多10重量%
水的混合物(M-di),以及含有至少90重量%
水的混合物(M-dii);其中从(d)中使用的至少一个蒸馏柱获得的蒸汽顶流(Td),该蒸汽顶流(Td)含有至少85重量%
甲醇,用于至少部分操作用于至少一个反应阶段(a)、(b)和(c)中的至少一个蒸馏柱的至少一个蒸发器。