TH68630B - A process for olefin epoxidation with an improved energy balance. - Google Patents

Abstract

DC60 (28/02/14) Process invention for olefin epoxidation consisting of (a) hydrogenation of olefins. Peroxide in methanol-containing state The reaction solvent in at least two stages to obtain a mixture (Ma) consisting of olefin oxide, unreactive olefin, methanol and water, between at least two different stages of reaction. , Eilefin oxide is separated by distillation; (b) the separation of unreactive olefins from the mix (Ma) by distillation to obtain a mixture (M-bi) comprising at least 80% by weight of olefins and mixtures. (M-bii) containing methanol, water and at least 7% by weight of olefin oxide; (c) olefin separation Oxides from mixtures (M-bii) are distilled for at least one stage to produce a mixture (M-ci) containing at least 99% by weight of olefin oxide and mixtures (M-cii). A) that is composed of water and at least 55% by weight of methanol; (d) separation of methanol from mixtures (M-cii) in at least one distillation to obtain at least 85% M-di compound by weight of methanol; and Up to 10% by weight of water, and mixtures (M-dii) comprising at least 90% by weight of water; Where the tower top vapor stream (Td) produced from at least one distillation column used in (d), such top vapor stream (Td) comprising at least 85% by weight of methanol, It is used to operate one or more of the evaporators used in one or more distillation columns. Used in at least one phase of (a), (b) and (c) process fabrication for olefin epoxidation consisting of (a) olefin reactivity. With hydrogen Peroxide in methanol-containing state The solvent in at least two stages of the reaction to obtain a mixture (M-a) containing olefin oxide, inert olefin, methanol and water, during which the reaction At least two phases, the elefin oxide is separated by distillation; (b) the separation of unreactive olefins from the mix (Ma) by distillation to obtain a mixture (M-bi) comprising at least 80% by weight of olefins and mixtures. (M-bii) containing methanol, water and at least 7% by weight of olefin oxide; (c) olefin separation Oxides from mixtures (M-bii) in at least one distillation to obtain at least 99% by weight of the mixture (M-ci) of olefin oxide and mixtures (M- cii) the compound contains at least 55% water and by weight of methanol; (d) separation of methanol from mixtures (M-cii) in at least one distillation to obtain at least 85% M-di compound by weight of methanol; and Up to 10% by weight of water, and mixtures (M-dii) comprising at least 90% by weight of water; Where the tower vapor (Td) current obtained from at least one distillation column used in (d), the above (Td) vapor stream comprising at least 85% by weight of methanol, It is used to operate one or more of the evaporators used in one or more distillation columns. Used in at least one term of (a), (b) and (c)

Claims (22)

Updated 07/03/2018. No claims made. 1. Procedures for the epoxidation of composite olefins include: (a) reaction of olefins with hydrogen peroxide in the presence of methanol as a solvent in at least two reaction phases to obtain a mixture (M-a) consisting of olefin oxides, non-reactive olefins, methanol, and water, during at least two reaction phases, olefin oxides are separated by distillation; (b) separation of non-reactive olefins from the mixture (M-a) by distillation to obtain a mixture (M-bi) consisting of at least 80% by weight of olefins and a mixture (M-bii) consisting of methanol, water, and at least 7% by weight of olefin oxides; (c) separation of olefins. (d) The separation of methanol from the mixture (M-cii) in at least one distillation stage to obtain the mixture (M-di) containing at least 99% by weight of olefin oxides and the mixture (M-cii) containing water and at least 55% by weight of methanol; (d) The separation of methanol from the mixture (M-cii) in at least one distillation stage to obtain the mixture (M-di) containing at least 85% by weight of methanol and up to 10% by weight of water, and the mixture (M-dii) containing at least 90% by weight of water; whereby the top steam stream (Td) obtained from at least one distillation column used in (d), such top steam stream (Td) containing at least 85% by weight of methanol, is used to operate at least one evaporator in at least part of the distillation column used in at least one stage of (a), (b) and (c). 2. The procedures under claim 1, from 5 to 60% by weight of (Td) are used to operate at least some of the evaporators used in (a), from 1 to 20% by weight of (Td) are used to operate at least some of the evaporators used in (b), and from 1 to 50% by weight of (Td) are used to operate at least some of the evaporators used in (c). 3. Processes under the rights claimed in claim 1 or 2, whereby the olefin is propene and the olefin oxide is propylene oxide. 4. The procedures provided for in claim 3, in which (a) the mixture (M-a) also contains propane, in which (b) the non-reactive propane is separated from the mixture (M-a) by distillation to obtain the mixture (M-bi) containing propane and non-reactive propane, in which such procedures also include (x) the separation of propane from the mixture (M-bi) by distillation to obtain the mixture (M-x) containing at least 90% by weight of propane, and in which the top steam stream (Td) is used to operate at least one evaporator, at least one partial evaporator in the distillation column, and at least one distillation column operating at least one of the stages of (a), (b), (c), and (x). 5. The procedures under claim 4, from 5 to 60% by weight of (Td) are used to operate at least some of the evaporators used in (a), from 1 to 20% by weight of (Td) are used to operate at least some of the evaporators used in (b), from 1 to 50% by weight of (Td) are used to operate at least some of the evaporators used in (c), and from 1 to 20% by weight of (Td) are used to operate at least some of the evaporators used in (x). 6. Any of the procedures under claims 3 through 5, in which (c), the mixture (M-cii) contains at least one compound with a boiling point lower than methanol and lower than water at a given pressure, in which such procedure includes (y) the separation of at least one compound with a boiling point lower than methanol and lower than water from the mixture (M-cii) by distillation to obtain the mixture (M-y) containing 40 to 80% by weight of methanol and 10 to 55% by weight of water; (d) the separation of methanol from the mixture (M-y) in at least one stage of distillation to obtain the mixture (M-di) containing at least 85% by weight of methanol and up to 10% by weight of water, and the mixture (M-dii) containing at least 90% by weight of water, and in which the top steam stream (Td) is used to operate at least one evaporator. Some of the components used in at least one distillation column are used in at least one stage of (a), (b), (c), and (y). 7. The procedures under claim 6, from 5 to 60% by weight of (Td) are used to operate at least some of the evaporators used in (a), from 1 to 20% by weight of (Td) are used to operate at least some of the evaporators used in (b), from 1 to 50% by weight of (Td) are used to operate at least some of the evaporators used in (c), and from 1 to 20% by weight of (Td) are used to operate at least some of the evaporators used in (y). 8. Any of the procedures provided under claims 3 through 5, in which (c) the mixture (M-cii) contains at least one compound with a boiling point lower than methanol and lower than water at a given pressure, in which such procedure is included; (d) the separation of methanol from the mixture (M-cii) by at least one distillation to obtain the mixture (M-di) containing at least 85% by weight of methanol and up to 10% by weight of water, and at least one compound with a boiling point lower than methanol and lower than water, and the mixture (M-dii) containing at least 90% by weight of water; (z) the separation of compounds with boiling points lower than methanol and lower than water from the mixture (M-di) by distillation to obtain the mixture (M-z) containing 85 to 99.5% by weight of methanol and 0.5 to 10% by weight of water; and in which the top steam flow (Td) is used to operate at least one evaporator, at least some of which is used in the distillation column, at least one of which is used in at least one stage of (a), (b), (c), and (z). 9. The procedures under claim 8, from 5 to 60% by weight of (Td) are used to operate at least some of the evaporators used in (a), from 1 to 20% by weight of (Td) are used to operate at least some of the evaporators used in (b), from 1 to 50% by weight of (Td) are used to operate at least some of the evaporators used in (c), and from 1 to 20% by weight of (Td) are used to operate at least some of the evaporators used in (z). 10. Any of the procedures provided under claims 1 through 9, in (c), olefin oxides are separated in two sets of distillation columns, and in which 0 to 20% by weight of (Td) is used to operate the evaporator of the first set of distillation columns at least partially yielding a mixture consisting of at least 98% by weight of olefins, by which such mixture is fed into the second set of distillation columns, and in which 1 to 30% by weight of (Td) is used to operate the evaporator of the second set of distillation columns at least partially yielding a stream of olefin oxides consisting of at least 99.8% by weight of olefin oxides. 11. The procedure under any of the claims in claims 1 through 10, which also includes (e) evaporation of the mixture (M-dii). 12. The procedures under claim 11, from 5 to 60% by weight of (Td) are used to operate at least some of the evaporators used in (a), from 1 to 20% by weight of (Td) are used to operate at least some of the evaporators used in (b), from 1 to 50% by weight of (Td) are used to operate at least some of the evaporators used in (c), and from 1 to 20% by weight of (Td) are used to operate at least some of the evaporators used in (e). 13. Any of the processes under Rights 1 through 12, in which 1 to 50% by weight of (Td) is used to operate at least one heat-controlled heat exchanger used in the process. 14. Any of the processes under claims 1 through 13, in which the feed of at least one distillation column used in stages (a), (b), (c), and (d) is heated by the bottom stream of this distillation column. 15. Any of the processes under claims 1 through 14, in which the column top flow obtained from at least one distillation column used in stages (a), (b), and (c) is condensed in two stages, in which in the first stage the condenser is cooled with water with an inlet temperature of 5 to 40 °C and in the second stage the condenser is cooled with water with an inlet temperature of 5 to 20 °C, in which the inlet temperature of the water used in the second stage is lower than the inlet temperature of the water used in the first stage. 16. The procedure provided for in Claim 15, in (c), olefin oxides are separated in two distillation columns, and in which 0 to 20% by weight of (Td) is used to operate the evaporator of the first distillation column at least partially, yielding a mixture consisting of at least 98% by weight of olefin oxides, by which such mixture is added to the second distillation column, and in which 1 to 30% by weight of (Td) is used to operate the evaporator of the second distillation column at least partially, yielding a stream of olefin oxides consisting of at least 99.8% by weight of olefin oxides, by which such stream of olefin oxides consisting of at least 99.8% by weight of olefin oxides is condensed in two stages, in which in the first stage, the condenser is cooled with water with an inlet temperature of 15 to 40 °C and in the second stage, the condenser is cooled with water. With inlet temperatures ranging from 5 to 20°C, where the inlet temperature of the water used in the second stage is lower than the inlet temperature of the water used in the first stage. 17. Any of the procedures under claims 1 through 16, in which (d), methanol is separated from the mixture (M-cii) in a double-pressure distillation procedure, in which, in the first distillation column, the distillation is carried out at an upper pressure different from the upper pressure of the second distillation column, and in which the condenser used to make the top stream of the first or second distillation column condense is used simultaneously as the evaporator of the second or first distillation column. 18. The process as claimed in claim 17, whereby the upper pressure of the first distillation column is from 2 to 8 bar and the upper pressure of the second distillation column is from 8 to 15 bar. 19. Any of the procedures under claims 1 to 18, in which (d), (i) the mixture (M-cii) is introduced into the first distillation column (K1) from which the top stream (Td) is obtained, by which distillation in (K1) is carried out at an overpressure of 2.5 to 6 bar; and (ii) the bottom stream obtained from (K1) is introduced into the second distillation column (K2), by which distillation in (K2) is carried out at an overpressure of 9 to 13 bar, in which, prior to introduction into (K2), the bottom stream obtained from (K1) is heated to a temperature of 110 to 180 °C with the bottom stream obtained from (K2), and in which the condenser used to condense the top stream obtained from (K2) is used simultaneously as the evaporator of (K1). 20. Procedures as provided for in claim 19, where (K2) is a wall dividing column. 21. The procedure under any of the claims 1 through 20, in which the olefin separated in (b) is re-entered into (a). 22. The process under any of the claims 1 through 21, in which the methanol separated in (d) is reintroduced into (a).