EP-4412993-B1 - SYSTEMS AND METHODS FOR REMOVING OR REDUCING WATER IN MIXTURES THAT INCLUDE T-BUTYL HYDROPEROXIDE

Inventors

• NGUYEN, Ha, H.
• YANG, Xueyong

Dates

Publication Date

20260506

Application Date

20221003

Claims (13)

1. A method for producing epoxide, the method comprising: providing a first mixture comprising t -butyl hydroperoxide, t -butyl alcohol, and a first amount of water; contacting at least a portion of the first mixture with a membrane one or more times to produce a second mixture comprising t -butyl hydroperoxide, t -butyl alcohol, and a second amount of water, wherein the second amount of water is at least 30 % less than the first amount of water; and reacting the second mixture with propylene to produce a third mixture comprising propylene oxide and t-butyl alcohol; wherein the membrane is a pervaporation membrane.
2. The method of claim 1, wherein the first amount of water is present in the first mixture at an amount of at least 2 %, by weight, based on the weight of the first mixture.
3. The method of claim 1, wherein the second amount of water is present in the second mixture at an amount of about 0.01 % to about 0.5 %, by weight, based on the weight of the second mixture.
4. The method of claim 1, wherein the second amount of water is present in the second mixture at an amount of about 0.08 % to about 0.15 %, by weight, based on the weight of the second mixture.
5. The method of claim 1, wherein the second amount of water is at least 75 % less than the first amount of water.
6. The method of claim 1, wherein a temperature of the first mixture prior to the contacting of at least a portion of the first mixture with the membrane is about 80 °C to about 100 °C.
7. The method of claim 1, wherein the contacting of the second mixture with propylene occurs in the presence of a catalyst.
8. A system for producing an epoxide, the system comprising: a feed mixture comprising t -butyl hydroperoxide, t -butyl alcohol, and a first amount of water; a membrane module comprising a membrane, the membrane module receiving the feed mixture and contacting the feed mixture with the membrane one or more times to produce a first mixture stream and a second mixture stream, wherein the first mixture stream comprises t -butyl hydroperoxide, t -butyl alcohol, and a second amount of water, the second amount of water being at least 30% less by weight than the first amount of water; and an epoxidation reactor receiving the first mixture stream and reacting the first mixture stream with propylene in the presence of a catalyst to produce a product stream comprising propylene oxide; wherein the membrane module comprises a pervaporation membrane.
9. The system of claim 8 additionally comprising a depropanizer, wherein the depropanizer receives the product stream from the epoxidation reactor, the product stream additionally comprises unreacted propylene, and the depropanizer separates at least a portion of the unreacted propylene from the product stream.
10. The system of claim 9 wherein the unreacted propylene separated from the product stream is recycled to the epoxidation reactor.
11. The system of claim 9 additionally comprising a separation apparatus, wherein the product stream additionally comprises t-butyl alcohol, and the separation apparatus separates at least a portion of the t-butyl alcohol from the product stream.
12. The system of claim 8 additionally comprising: an oxidation reactor wherein oxygen gas and isobutane are reacted to produce an oxidation mixture comprising t-butyl hydroperoxide, t-butyl alcohol, unreacted isobutane, and water; and a debutanizer which receives the oxidation mixture, separates at least a portion of the unreacted isobutane from the oxidation mixture thereby producing the feed mixture.
13. The system of claim 12 wherein the unreacted isobutane separated from the oxidation mixture is recycled to the oxidation reactor.

Description

Cross-Reference to Related Application This application filed under the Patent Cooperation Treaty, which claims the benefit of priority to U.S. Provisional Patent Application No. 63/251,909, filed on October 4, 2021. Background In typical processes that use t-butyl hydroperoxide to produce propylene oxide, a first step may include reacting isobutane with oxygen to form a mixture of t-butyl hydroperoxide and t-butyl alcohol. This mixture usually is purified, and the resulting purified mixture is reacted with propylene to produce propylene oxide. When the mixture or purified mixture of t-butyl hydroperoxide and t-butyl alcohol includes a relatively high water concentration (e.g., > 2 wt.%), propylene oxide selectivity can be reduced significantly, due at least in part to the fact that propylene oxide can react with water to form one or more undesirable byproducts, such as mono propylene glycol. There remains a need for effective and/or economical processes for reducing the amount of water in a mixture or purified mixture that includes t-butyl hydroperoxide. Brief Summary Provided herein are methods and systems for removing or reducing an amount of water in mixtures that include t-butyl hydroperoxide, including mixtures that can be used in propylene epoxidation to produce propylene oxide. In some embodiments, the methods and systems herein can reduce an amount of water in a mixture including t-butyl hydroperoxide to 0.1 %, by weight, or less, based on the weight of the mixture. In one aspect, methods are provided for removing or reducing an amount of water in mixtures that include t-butyl hydroperoxide, including mixtures that can be used in propylene epoxidation to produce propylene oxide. In some embodiments, the methods include providing a first mixture including t-butyl hydroperoxide, t-butyl alcohol, and a first amount of water; contacting at least a portion of the first mixture with a pervaporation membrane one or more times to produce a second mixture including t-butyl hydroperoxide, t-butyl alcohol, and a second amount of water, wherein the second amount of water is at least 50% less than the first amount of water; and contacting the second mixture with propylene to produce a third mixture including propylene oxide and t-butyl alcohol. In another aspect, systems are provided for producing an epoxide following the removal or reduction of water in mixtures that include t-butyl hydroperoxide. In some embodiments, the systems include a feed mixture comprising t-butyl hydroperoxide, t-butyl alcohol, and a first amount of water; a membrane module comprising a pervaporation membrane, the membrane module receiving the feed mixture and contacting the feed mixture with the membrane one or more times to produce a first mixture stream and a second mixture stream, wherein the first mixture stream comprises t-butyl hydroperoxide, t-butyl alcohol, and a second amount of water, the second amount of water being at least 30% less by weight than the first amount of water; and an epoxidation reactor receiving the first mixture stream and reacting the first mixture stream with propylene in the presence of a catalyst to produce a product stream comprising propylene oxide. Additional aspects will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the aspects described herein. The advantages described herein will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive. Brief Description of the Drawings FIG. 1 depicts a schematic of an embodiment of a method described herein.FIG. 2 depicts a schematic of an embodiment of a method described herein.FIG. 3 depicts a schematic of an embodiment of a system described herein. Detailed Description Provided herein are methods and systems for removing or reducing an amount of water in mixtures that include t-butyl hydroperoxide, including mixtures that can be used in propylene epoxidation to produce propylene oxide. Methods for Removing/Reducing Water An embodiment of a method described herein is depicted schematically at FIG. 1. The method 100 of FIG. 1 includes providing a first mixture 110. The first mixture 110 may include t-butyl hydroperoxide, t-butyl alcohol, and a first amount of water. At least a portion of the first mixture 110 is contacted with a pervaporation membrane 120 to produce a second mixture 130 and a third mixture 121. The second mixture 130 includes t-butyl hydroperoxide, t-butyl alcohol, and a second amount of water. The second amount of water is at least 50% less, by weight, than the first amount of water. The second mixture 130 is contacted in a reservoir 140 with propylene 150 to produce a third mixture 160 that includes propylene oxide and t-butyl alcohol. Th