Two-step process for production of RON-enhanced mixed butanols and diisobutenes

Patent metadata

Field	Value
Publication number	US-10041016-B2
Application number	US-201615170515-A
Country	US
Kind code	B2
Filing date	Jun 1, 2016
Priority date	Dec 11, 2013
Publication date	Aug 7, 2018
Grant date	Aug 7, 2018

Abstract

A two-step process for the oligomerization and hydration of a mixed butenes feed is provided and is implemented in a two-stage system. The two-step process yields a product consisting of diisobutenes (DIBs) and mixed butanols. The DIBs are produced via the selective oligomerization of isobutene in a first stage and the mixed butanols are produced via the hydration, in a second stage, of mixed butenes that remain unreacted in the first stage.

First claim

What is claimed is:

1. A method for preparing a gasoline composition, the method comprising the steps of:
providing a fuel grade gasoline;
providing an octane enhancing composition comprising an oligomerized and hydrated hydrocarbon product stream formed by a process that includes the steps of:
introducing a hydrocarbon feed that comprises mixed butenes including isobutene and n-butenes into a first reactor vessel under reaction conditions that are operable to oligomerize isobutene into diisobutenes;
contacting the hydrocarbon feed with an oligomerization catalyst within the first reactor vessel, the oligomerization catalyst being of a type that selectively oligomerizes the isobutene into diisobutenes;
separating the diisobutenes from unreacted butenes to form a diisobutene stream;
introducing the unreacted butenes into a second reactor vessel in the presence of water and under reaction conditions that operable to hydrate the unreacted butenes including the unreacted n-butenes and any unreacted isobutene;
contacting the unreacted butenes with a hydration catalyst within the second reactor vessel to hydrate the unreacted butenes to form a mixed butanols stream; and
combining the diisobutene stream and mixed butanols stream to form the product stream; and

combining the fuel grade gasoline and octane enhancing composition to form the gasoline composition.

2. The method of claim 1 , wherein the octane enhancing composition is combined with the fuel-grade gasoline after preparation without further purification.

3. The method of claim 2 , wherein the octane enhancing composition is present in an amount of between about 5 and 30% by weight of the gasoline composition.

4. The method of claim 1 , wherein the n-butenes comprise 1-butene, 2-trans-butene, and 2-cis-butene.

5. The method of claim 1 , wherein the hydrocarbon feed is introduced into the first reactor vessel in the absence of water.

6. The method of claim 1 , wherein prior to introducing the hydrocarbon feed into the first reactor vessel, the hydrocarbon feed passes through: (a) a first compressor which compresses the hydrocarbon feed to a first predetermined pressure; and (b) a first heat exchanger that adjusts a temperature of the hydrocarbon feed to a first predetermined temperature.

7. The method of claim 6 , wherein the first predetermined pressure is between about 5 bar and 100 bar and the first predetermined temperature is between about 30° C. and about 250° C.

8. The method of claim 1 , wherein the step of contacting the unreacted butenes with a hydration catalyst within the second reactor vessel results in the n-butenes being hydrated to 2-butanol and any isobutene being hydrated to tert-butanol.

9. The method of claim 1 , further including the steps of: (a) passing the mixed butanols stream from the second reaction vessel through a high pressure separator which is configured to separate an organic phase containing unreacted mixed butenes along with extracted mixed butanols from an aqueous phase that is saturated with mixed butanols; (b) passing the separated organic phase through a debutenizer column in which the organic phase is separated and unreacted mixed butenes are removed; and (c) passing the separated aqueous phase to an azeotropic distillation column in which alcohol-water azeotrope is distilled out of the aqueous phase.

10. The method of claim 9 , wherein the unreacted mixed butenes removed from the debutenizer are recycled and combined with the hydrocarbon feed upstream of the first reactor vessel and the alcohol-water azeotrope is recycled back to the high pressure separator for further recover alcohols while water is recycled back to a location upstream of the second reactor vessel.

11. The method of claim 1 , wherein the oligomerization conditions can be varied independent from the hydration conditions to maximize diisobutene formation in the first reactor vessel from 5 mol % to a maximum of up to 100 mol % of isobutene in the hydrocarbon feed.

12. The method of claim 1 , wherein a conversion rate of converting isobutene to diisobutene in the first reactor vessel is between about 5 mol % and about 100 mol %.

13. The method of claim 1 , wherein the hydrocarbon feed consists essentially of butenes.

14. The method of claim 1 , further comprising the step of combining the product stream with a gasoline stream to produce a gasoline product having increased research octane number (RON) and reduced Reid vapor pressure (RVP) as compared to a second gasoline product having an absence of the product stream.

15. The method of claim 1 , wherein each of the oligomerization catalyst and the hydration catalyst comprises at least one of an acidic catalyst and substituted/non-substituted heteropoly acids.

16. The method of claim 15 , wherein the acidic catalyst comprises an ionic exchange resin.

17. The method of claim 1 , wherein the oligomerization catalyst and hydration catalyst are the same.

18. The method of claim 1 , wherein the conversion rate of converting isobutene to diisobutene in the first reactor vessel is greater than 90%.

19. A method for preparing a gasoline composition, the method comprising the steps of:
providing a fuel grade gasoline;
providing an octane enhancing composition comprising an oligomerized and hydrated hydrocarbon product stream formed by a process that includes the steps of:
introducing a hydrocarbon feed that comprises mixed butenes including isobutene and n-butenes into a first reactor vessel under reaction conditions that are operable to oligomerize the butenes;
contacting the hydrocarbon feed with an oligomerization catalyst within the first reactor vessel, the oligomerization catalyst being of a type that selectively oligomerizes isobutene into diisobutenes;

separating the diisobutenes from unreacted butenes to form a diisobutene stream, wherein the step of separating the diisobutenes from the unreacted butenes comprises the step of:
introducing the diisobutenes and the unreacted butenes from the first reactor vessel into a low pressure separator that is configured to separate the diisobutenes from the unreacted butenes including unreacted n-butenes and any unreacted isobutene;
introducing the unreacted butenes into a second reactor vessel in the presence of water and under reaction conditions that operable to hydrate the unreacted butenes including the unreacted n-butenes and any unreacted isobutene;
contacting the unreacted butenes with a hydration catalyst within the second reactor vessel to hydrate the unreacted butenes to form a mixed butanols stream; and
combining the diisobutene stream and mixed butanols stream to form a product stream; and
combining the fuel grade gasoline and octane enhancing composition to form the gasoline composition.

20. The method of claim 19 , wherein prior to introducing the unreacted butenes into the second reactor vessel, water is added to the unreacted butenes, including the unreacted n-butenes, to form an aqueous mixture that passes through: (a) a compressor which compresses the aqueous mixture to a predetermined pressure; and (b) a heat exchanger that adjusts a temperature of the aqueous mixture to a predetermined temperature.

21. The method of claim 20 , wherein the predetermined pressure is between about 10 bar and 100 bar and the predetermined temperature is between about 80° C. and about 250° C.

Assignees

• Saudi Arabian Oil Co

Inventors

• Shaik Kareemuddin M
• Xu Wei
• Mohammed Thamer
• Babiker Hassan
• Kalghatgi Gautam Tavanappa

Classifications

• C07C29/82

  by azeotropic distillation · CPC title

• C07C2531/10

  sulfonated · CPC title

• C10L2290/10

  Recycling of a stream within the process or apparatus to reuse elsewhere therein · CPC title

• C10G50/00 Primary

  Production of liquid hydrocarbon mixtures from lower carbon number hydrocarbons, e.g. by oligomerisation · CPC title

• C10L2290/24

  Mixing, stirring of fuel components · CPC title