JPS5827249B2 - Futsuka Isoalkyl Kahou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for producing alkylation reaction products from isobutane and C3-C5 olefins using a hydrofluoride alkylation catalyst, This invention relates to an improvement in the alkylation method to give.

Hydrogen fluoride is used as a catalyst to convert isoparaffinic hydrocarbons such as isobutane, impentane, etc., to olefinic hydrocarbons such as propylene, butylene, amylene, or C.
As is well known, alkylation with compounds that act like olefins, such as 3-C5 alkylno-lides,
It is of commercial importance as a method of producing hydrocarbons in the gasoline boiling range.

The C3-CIO hydrocarbons commonly produced in isoparaffin-olefin alkylation reactions are called "alkylates."

Alkylates have high motor and research octane ratings, making them particularly useful as motor fuel formulation feedstocks, and their use improves the overall octane rating of the gasoline pool to meet the demands of modern vehicle motors. can do.

High octane alkylate fuel components are also important components in achieving desired octane values in motor fuels without the use of alkyl lead compounds.

Alkylation technology has always excelled in making hydrogen fluoride-catalyzed alkylation processes more economically viable than conventional alkylation processes, and the octane ratings of the Motor and Research methods are Both methods aim to obtain higher alkylate products than those obtained by the above method.

Generally, commercial isopanfin-olefin alkylation processes use isobutane as the inparaffinic reactant and propylene, butylene, or
Acrylene or mixtures thereof are respectively used.

Isobutane and olefin are typically mixed in an alkylation reactor in contact with a hydrogen fluoride catalyst to form an emulsion, or alkylation reaction mixture.

After the alkylation reaction between isobutane and olefin is substantially complete, the reaction mixture of hydrocarbon and catalyst is removed from the reactor and allowed to stand to separate the immiscible hydrocarbon and catalyst phases. be done.

The hydrogen fluoride catalyst phase thus separated is recycled to the reactor for reuse.

The hydrocarbon phase obtained in the static operation is usually further subjected to a fractional distillation operation to recover the alkylate product, and the unconsumed isobutane separated is removed from the alkyl distillation step for reuse. is recycled to the reaction reactor.

It is known that reactor temperature, relative amounts of catalyst and feed hydrocarbon, catalyst strength, and other process conditions need to be kept within narrow ranges in order to achieve high quality alkylate products.

Setting the molar ratio of isobutane to oleinin in the hydrocarbon fed to the alkylation reactor to about 10=1 or more means that
This is an essential condition for producing alkylates with high octane numbers using an alkylation method using hydrogen fluoride as a catalyst.

The molar ratio of inbutane to olefins in the hydrocarbons fed to the alkyl reactor is commonly referred to as the "external" isobutane/olefin molar ratio.

This external isobutane/olefin molar ratio is to be distinguished from the isobutane to olefin molar ratio in the reaction mixture formed in the alkylation reactor, which is typically the "internal" isobutane/olefin molar ratio. called molar ratio.

In alkylation processes using hydrogen fluoride catalysts, increasing the external isobutane/olefin molar ratio substantially improves the quality of the alkylate product;
Even with increasing internal isobutane/olefin molar ratio,
Quality is not improved.

That is, only the isobutane to olefin molar ratio of the hydrocarbons fed to the alkylation reactor is important in the hydrofluoride alkylation process to obtain high octane alkylates, and the isobuta/concentration is not critical.

The opposite is true for sulfuric acid alkylation processes, where increasing the internal isobutane/olefin molar ratio, in other words, increasing the isobutane concentration in the reaction mixture in the reactor, improves the quality of the alkylate product. do.

Therefore, in a hydrogen fluoride-catalyzed alkylation process, the inbutane/olefin molar ratio in the hydrocarbon fed to the reactor should be as high as economically possible in order to improve the quality of the alkylate product. is desirable.

In particular, these effects have been demonstrated by increasing the octane number of the alkylate product with increasing external inbutane/olefin molar ratios.

For this reason, in normal operation it is necessary to pass a very large amount of unreacted isobutane through the mill reactor, and therefore the hydrocarbon phase obtained in the settler must be fractionated and then recycled to the reactor. No.

Fractional distillation of the settled hydrocarbon phase is carried out to separate excess unreacted isobutane from the high boiling alkylate product.

Therefore, in conventional hydrogen fluoride alkylation processes, a large amount of isobutane must be passed unreacted through the air alkylation reactor and settler, and the isobutane must be separated from the alkylate product by fractional distillation. .

This fractionation, in turn, requires the use of high-capacity, energy-consuming fractionation equipment to vaporize the isobutane and separate it from the heavier alkylates.

As a means of alleviating the problems resulting from the need for large quantities of isobutane, the prior art has proposed, for example, that an emulsion (alkylation reaction mixture) of a hydrogen fluoride catalyst, isobutane, and the reaction product be continuously fed into an alkylation reactor. The method teaches how to ensure the necessary amount of excess isobutane by circulating isobutane into the reaction mixture.

This method is effective in alkylation using a sulfuric acid catalyst.

This is because, in this case, increasing the isobutane concentration of the reaction mixture in the alkylation reactor will improve the quality of the alkylate product.

However, in modern hydrofluoride alkylation processes, the emulsion is removed from the alkylation reactor and is returned to the reactor again along with fresh olefin, fresh isoparaffin and recycled inparaffin.

An improved method of emulsion circulation is to send the emulsion of the reaction mixture consisting of hydrogen fluoride catalyst, isoparaffin, and reaction products from the first alkylation reaction zone to the second alkylation reaction zone, where the emulsion is freshly recycled. There are methods in which further alkylation occurs by contacting with an olefinic feed.

However, all of the conventional attempts as described above increase the internal paraffin/olefin molar ratio in the alkylation reactor, similar to the treatment method of the sulfuric acid alkylation method, so hydrogen fluoride is used as a catalyst. These alkylation methods are unable to improve the quality of the alkylate product, and therefore these attempts are typically not carried out commercially.

In summary, the improvement of the alkylate product in the hydrogen fluoride-catalyzed alkylation process is only achieved when the external isobutane/olefin molar ratio is increased, whereas the internal isobutane/olefin molar ratio is increased. , it does not improve the quality of the product.

That is, the conditions necessary to satisfactorily perform a hydrogen fluoride-catalyzed alkylation process are not similar to those for a sulfuric acid-catalyzed alkylation process.

Therefore, in commercial hydrofluoride alkylation processes, external isobutane/
Regarding maintaining the olefin molar ratio at a predetermined value,
Great expense and difficulty are still required.

In order to achieve a high external inbutane/olefin molar ratio in normal operation, excess inbutane must be separated and recycled within the operating system.

This problem is substantially alleviated by the present invention.

The prior art has attempted to use multiple reactors for various reasons, such as the present invention proposes, to increase the inparaffin/olefin molar ratio in the feed to the alkylation reactor. It is completely impossible.

For example, US Pat. No. 2,256,880 discloses the use of several alkylation reactors and settlers in a process for alkylating isoparaffins with olefins using sulfuric acid as a catalyst.

In this process, the apparatus hydrocarbon phase consisting of each reactor-settler system is subjected to seven flash distillations between subsequent stages, and isopacifine vapor is separated from the high boiling alkylation reaction product which remains as a flash separation liquid.

The evaporated isoparaffins are then condensed and recycled.

A portion of the liquid alkylation reaction product is fed to the next stage, while at least a portion of the liquid remaining after interstage flash distillation is sent to a fractionation column for product recovery.

The above-mentioned US patents also teach about avoiding the accumulation of reaction products in the reactor and significantly lowering the inparaffin/olefin molar ratio in the reaction zone, but they do not use hydrogen fluoride catalysts. This is completely different from the measures taken by the present invention.

U.S. Pat. No. 2,820,073 also teaches the use of a multi-Ml alkylation reactor and settler in the isoparaffin-olefin alkylation process.

However, in order to separate unreacted impala twine from alkylation reaction products in the stationary hydrocarbon phase,
A fractionating column is used between each stage.

The impala twin separated here is recovered as steam, condensed, and then supplied to the next stage.

U.S. Pat. No. 3,007,983 teaches the use of two reactors and a settler for isoparaffin-olefin alkylation.

In this process, the static hydrocarbon phase recovered from each stage is subjected to flash distillation to separate the isoparaffins as vapor from the high-boiling alkylation reaction products that remain in liquid form.

The isoparaffin vapor is then condensed and supplied to the next stage, and the reaction product is recovered as a liquid.

The teachings of this US patent are primarily directed to automated rectification in sulfuric acid alkylation processes.

U.S. Pat. No. 3,236,912 alkylates inbutane with propylene and butylene in a single reactor-settler system to produce a single alkylated reaction product;
A method is taught for alkylating ethylene with butane in a second reactor-settler system to produce a second alkylated reaction product.

According to this method, the ethylene reactant is sent in a mixture with propylene, butylene and inbutane to a first reactor-settler system, where it does not react.

If it is desired to obtain the first and second alkylation reaction products as a mixture, the stationary hydrocarbon phase containing unreacted ethylene can be withdrawn from the first reactor-settler system and transferred directly to the second reaction product. is fed to a vessel-settler system where ethylene in the stationary hydrocarbon phase reacts with isobutane.

ethylene first without alkylating it.
This is possible because the ethylene does not react with the isoparaffins to form alkylation reaction products.

Therefore, if ethylene is reacted under normal propylene or butylene alkylation conditions to form an alkylate, the ethylene will react in the first reactor settler system.

When ethylene is contacted with a hydrogen fluoride catalyst under glopyrene-butylene alkylation reaction conditions, ethylene forms stable ethyl fluoride, which is inert to the alkylation reaction.

The purpose of the present invention is to convert isobutane to C using a hydrogen fluoride catalyst.
An object of the present invention is to provide a method for alkylating with 3-C5 olefins.

Another object of the present invention is to provide a hydrogen fluoride catalyzed alkylation process that produces alkylate products of superior utility and quality as motor fuel formulations.

Yet another object of the present invention is to provide a method for economically increasing the external isoparaffin/olein molar ratio in a hydrogen fluoride catalyzed isoparaffin-olein alkylation process.

Yet another object of the present invention is to simplify the fractional distillation process in separating the alkylate product from unreacted isoparaffins to be recycled to the alkylation reactor. The aim is to provide a method for converting

Accordingly, one aspect of the present invention provides a method for producing an alkylated reaction product from a monoolefin selected from propylene, butylene, and allene, and an isoparaffin, including mixing a first portion of the monoolefin and an isoparaffin. contacting the first hydrocarbon mixture in a first reaction zone with a first hydrogen fluoride alkylation catalyst phase under hydrogen fluoride alkylation conditions to form a first alkylation reaction mixture; removing a first reaction mixture from the zone, allowing the first reaction mixture to stand to provide a first stationary hydrocarbon phase and a first hydrogen fluoride catalyst phase; and transferring the first catalyst phase to the first alkylation reaction zone. circulating a second portion of the monoolefin with at least a portion of the first stationary hydrocarbon, and introducing the second hydrocarbon mixture into a second reaction zone with substantially the same fluorine as the first reaction zone. contacting a second hydrofluoride alkylation catalyst phase under hydrofluoride alkylation conditions to form a second alkylation reaction mixture;
A second reaction mixture is removed from the reaction zone, the second reaction mixture is allowed to stand to obtain a second standing hydrocarbon phase and a second hydrogen fluoride catalyst phase, and the second catalyst phase is subjected to a second alkylation reaction. fractionating the second standing hydrocarbon phase to obtain a high-boiling alkylate product stream and a low-boiling isoparaffin stream and recycling the isoparaffin stream to the first alkylation reaction zone;
The present invention relates to a method comprising recovering an alkylation reaction product from a product stream.

One of the important advantages of the process of the present invention is that it substantially reduces the overall amount of excess paraffin required for the olefin reactant compared to conventional alkylation processes.

That is, in the process of the present invention, in order to maintain the external molar ratio of isobutane to the amount of olefin used at an appropriate value, all of the isobutane and a portion of the olefin are mixed together in the first alkylation reactor. By supplying
This substantially reduces the amount of isobutane required for the first alkylation reaction with hydrogen fluoride.

The unit hydrocarbon phase, comprised of a first settler, is mixed with a second portion of olefin to provide a second reactor feed, which is fed to a second alkylation reactor to provide a second hydrogen fluoride catalyst. It is brought into contact with the phase.

This method therefore allows the hydrocarbon feed fed to each reactor to maintain the desired external molar ratio of isobutane in both the first reactor and the second reactor.

The system hydrocarbon phase consisting of the second settler is fractionated, the separated unreacted inbutane being recycled to the first reactor and the desired alkylation reaction product being recovered.

In this case, the amount of isobutane that must be separated by fractional distillation and recycled is compared with that of conventional isobutane with a hydrogen fluoride catalyst at the same external isobutane/olefin molar ratio.
Substantially less compared to olefin alkylation methods.

In other words, if the amount of isobutane in the hydrocarbon fed to the first reactor is the same as before, an alkylate product with a higher octane number than before is obtained.

With the method of the invention! I, any unreacted isobutane in the stationary hydrocarbon phase recovered from the first reactor-settler system is mixed with the second portion of the olefinic feed;
The external isobutane/olefin molar ratio in the hydrocarbons fed to the second alkylation reactor can be increased.

This second hydrocarbon feed contacts a second fluoride catalyst phase in a second reactor.

The external inbutane/olefin molar ratio is substantially increased when the second portion of the olefinic feed and the first standing hydrocarbon phase are mixed externally to the second reactor and fed to the second reactor. Therefore, a high-grade alkylate product can be obtained from the second reactor.

In contrast, in the conventional method, isobutane is mixed with a hydrogen fluoride catalyst and fed to multiple alkylation zones.
The external inbutane/olefin molar ratio in the reactor feed cannot be increased by isobutane, thus reducing the quality of the alkylate product.

Other objects, aspects, advantages, etc. of the present invention will be understood from the detailed description below.

The accompanying drawing diagrammatically shows a preferred embodiment of the method according to the invention.

In this example, the alkylatable hydrocarbon is isobutane and the olefinic feed is a mixture of propylene and butylene.

The present invention is not limited to the examples presented herein; other suitable reactants and examples will be apparent to those skilled in the art from the discussion below.

Referring now to the drawings, tube 1 continuously supplies a conventional alkylating olefin feedstock at a rate of about 300 mov/hr of propylene and about 300 mov/hr of butylene.

In this case, along with the olefins mentioned above, 12
0 mol/h of isobutane, 85 mol/h of n-butane and 70 mol/h of propane are fed into tube 1, but these are not the hydrocarbons necessary for the process of the invention.

The olefinic feed continuously fed to tube 1 is divided into two streams of equal volume and sent to tubes 2 and 3, respectively.

150 mol/h propylene, 150 mol/h butylene, 60 mol/h inbutane, 17.5 mol/h n-butane and 35 mol/h propane are therefore flowing in tubes 2 and 3, respectively. There is.

In a conventional manner, externally prepared make-up butane is fed into the system through line 4 and led to line 2 where it is mixed with a portion of the olefin feedstock.

This make-up isobutane stream supplies isobutane to tube 4 at a rate of 500 mol/h, with an associated
Non-reactive hydrocarbons are also fed into tube 4, including mol/h of n-butane and about 10 mol/h of propane.

The make-up isobutane and a portion of the olefin feed are mixed and flow through tube 2.

Recycled isobutane from line 24 is also combined into line 2 for mixing.

This circulating isobutane is, in addition to 3550 mol/h of isobutane, 52
It contains 5 mol/h of n-butane and 225 mol/h of propane.

The total hydrocarbon feed fed to reactor 5 is therefore 15
0 mol/h propylene, 150 mol/h butylene, 4110 mol/h isobutane, as well as 270 mol/h propane as non-reactive hydrocarbons, 557.
Contains 5 mol/h of n-butane.

The external isobutane/olefin molar ratio of the feed to reactor 5 is therefore 13.7.

This mixed feed is passed through tube 2 to reactor 5 and contacted with a conventional hydrogen fluoride alkylation catalyst to form a reaction mixture.

Hydrogen fluoride catalyst is fed to reactor 5 via tube 10.

The catalyst contains about 85 wt% acid, 1 wt% residual water, and the balance is conventional organic diluent.

The temperature in the reactor 5 is about 90 to 100'P, and the pressure is maintained at a pressure that can maintain the hydrocarbon and catalyst in a liquid phase.

The catalyst/hydrocarbon volume ratio is from about 1=1 to about 2:1.

The heat generated during the alkylation reaction is removed using an indirect heat exchanger within the reactor 5.

Cooling water enters reactor 5 through tube 6 and indirectly exchanges heat with the reaction mixture.

The used cooling water is taken out from the pipe 7.

After a contact time of about 0.1 to about 5 minutes, the reaction mixture in reactor 5 is removed and passed through tube 8 to settler 9.

When the reaction mixture is left unstirred in the settler 9, the hydrogen fluoride catalyst forms a heavy phase, and the hydrocarbon components in the reaction mixture form a light hydrocarbon phase.

The catalyst phase is removed from the bottom of the settler 9 and fed via tube 10 to the reactor 5 for reuse.

Regeneration of the catalyst used in reactor 5 can be accomplished by sending a portion of the catalyst stream from tube 10 to a conventional regenerator.

The first stationary hydrocarbon phase formed in settler 9 is removed from the top of the settler into tube 11 and merged into tube 3 where it is mixed with the remaining C portion of the olefin feed.

The first stationary hydrocarbon phase flowing through tube 11 contains r3800 mol/h of isobutane, 557.5 mol/h of n-butane, 280 mol/h of propane and 300 mol/h of alkylate. , substantially olefin-free.

The mixed hydrocarbon feed from tube 3 to reactor 12 is therefore:
Approximately 3860 moles/hour of inbutane and 150-eh/F
f @ propylene, 150 mol/h butylene, 5
It contains 75 mol/h of n-butane, 315 mol/h of propane and 300 mol/h of alkylate.

Thus, the external isobutane/olefin molar ratio in the hydrocarbon feed to reactor 12 is approximately 13=1.

The reaction conditions for reactor 12 are the same as those for reactor 5, with a temperature of about 90 to 100'F, an acid/hydrocarbon volume ratio of about 1:1 to about 2:1, and a pressure of about 1:1 to about 2:1 for the reaction mixture components. This is the pressure that can maintain the liquid phase.

A hydrogen fluoride catalyst containing about 85 wt% acid and about 1 wt% residual water, with the remainder being an organic diluent, is fed into reactor 12 through line 19 and intimately mixed with the hydrocarbon mixture from line 3. are mixed to form a second reaction mixture.

Cooling water is supplied through pipe 18 and indirectly exchanges heat with the reaction mixture in reactor 12.

The used cooling water is removed from pipe 14.

After a contact time of about 0.1 to about 5 minutes, the reaction mixture is removed from reactor 12 into tube 15 and sent to reaction noker 16.

The reaction mixture of catalyst, reactants, and reaction products is maintained in reaction soaker 16 for about 10 minutes at substantially the same temperature and pressure as reactor 12.

The reaction mixture is then removed into tube 11 and settler 18
sent to.

In the settler 18, when the reaction mixture is allowed to stand without being stirred, the catalyst and hydrocarbon are separated into two phases.

The heavy catalyst phase is removed from the bottom of settler 18 in tube 19 and recycled to reactor 12 for reuse as described above.

A portion of the catalyst in tube 19 can be fed to a conventional regenerator if desired.

The second stationary hydrocarbon phase is removed from settler 18 in line 20 and fed to an inbutane stripper 21 containing about 825 moles/hour of propane and 3550 moles/hour of propane.
of isobutane, 575 mol/h of D-butane, 6
00 mol/h of alkylene) (C5+ hydrocarbon).

In isobutane stripper 21, the second standing hydrocarbon phase is fractionated and separated into a lighter recycled isobutane stream and a heavier product alkylate stream.

Although not shown, well-known equipment such as a tray, a reboiler device, and a reflux device are used for the normal fractionation operation carried out in the stripper 21.

The alkylate product is passed to the stripper 21 as a bottom product.
from the pipe 22 at a rate of 600 moles/hour for use as motor fuel or other desired use.

In this example, normal butane is a by-product from pipe 23 to 5.
It is removed at a rate of 0 mol/hour.

Normal circulating isobutane is removed from a tray above the stripper 21 as a side cut into a tube 24.

This circulating inbutane stream consists of 3320 mol/h of isobutane, 500 mol/h of n-butane and 225 mol/h of propane.

This circulating isobutane stream in tube 24 is combined into tube 2 as described above.

The overhead stream removed from the stripper 21 is fed through a line 25 to a conventional depropaniser 26;
It contains 00 mol/h of propane, 230 mol/h of isobutane and 25 mol/h of n-butane.

In depropaniser 26, the feed from line 25 is separated to separate propane from isobutane and n-butane.

Isobutane and n-butane are taken off as bottom products at rates of 230 mol/h and 25 mol/h, respectively, and are sent via line 27 to line 24 for use as a recycled inbutane stream.

Propane is removed at a rate of 100 mol/hour together with a small amount of hydrogen fluoride as an overhead component in pipe 28, and in pipe 29,
It is mixed with hydrogen fluoride from tube 36.

The mixture of propane and hydrogen fluoride in tube 29 is fed to the contemplator and the propane and acid are condensed and liquefied.

The liquefied propane and acid then pass from pipe 31 to settler 32.
sent to.

Most of the hydrogen fluoride sent to the settler forms a relatively pure heavy phase by standing still and is removed from the pipe 33.

This relatively concentrated acid can be returned to the circulating catalyst stream in tubes 10 and 19 by conventional means (not shown).

The liquefied propane phase in settler 32 is removed in line 34 and fed to a hydrogen fluoride stripper 35 where the propane is separated from residual acid by fractional distillation.

The acid obtained here is removed as an overhead component in line 36 and returned to line 29 where it is processed as described above.

Propane is removed as a by-product from the bottom of the hydrogen fluoride stripper 35 into a line 37 at a rate of 100 mol/hour.

The usual equipment necessary to operate the embodiments described herein, such as pumps, valves, reboilers, etc., are not shown or described, but their use will be obvious to those skilled in the art.

The example given above shows that isoparaffin-
The advantages of the present invention over the olefin alkyl process are demonstrated.

For example, the hydrocarbons fed to reactors 5 and 12 have an external isobutane/olefin molar ratio of approximately 18=1, maintaining the high molar ratio necessary to obtain alkylate of sufficient grade. .

The degree of fractional distillation in isobutane stripper 21 is sufficient to separate isobutane such that the overall isobutane/olefin molar ratio is less than 7:1.

The quality of the alkylate produced is comparable to that of the alkylate produced by a conventional alkylation method using an external inbutane/olefin molar ratio of 12:1, and the degree of fractional distillation is also substantially lower. reduced, saving capital and utility costs.

In contrast, the alkylates produced by conventional hydrofluoric alkylation processes with an overall isobutane/olefin molar ratio of 7=1 are of lower grade and are therefore used to increase the octane number of low-grade gasoline pool components to the desired value. It lacks usefulness as a compounding agent.

The hydrogen fluoride catalyzed alkylation process according to the invention is applicable to the alkylation of isobutane, impentane or similar isoparaffins.

Preferred isoparaffins are isobutane and impentane, with isobutane being particularly preferred.

Mixtures of two or more isoparaffins can also be used if desired.

Conventional isobutane alkylation feedstocks are suitable for use in the present invention.

Such conventional make-up isobutane feedstocks contain some non-reactive hydrocarbons such as normal paraffins.

For example, typical commercial inbutane alkylation feedstocks typically contain 95 wt% isobutane plus 4 wt% n
- Contains butane and 1 wt% propane.

Olefins suitable for use in the process of the invention include C3-
Included are C5 olefins.

Mixtures of two or more olefins can also be used with good results in the present invention.

For example, common olefin feedstocks used in commercial olefin alkylation operations include mixtures of propylene and butylene, mixtures of butylene and alene, or mixtures of propylene, butylene, amylene, and the like.

The advantages of the present invention can be obtained with these feedstocks as well as with a single olefin.

Particularly preferred conventional C3-C5 for use in the method of the invention
Feedstocks for olefin alkylation are derived from petroleum refining processes such as catalytic cracking and therefore contain substantial amounts of saturated hydrocarbons, light olefins, heavy olefins, etc.

Hydrogen fluoride catalysts used in the process of the invention are well known in the art.

Generally, the hydrogen fluoride alkylation catalyst contains about 75 wt% or more titratable acid, about 5 wt% or less water, and the balance is an organic diluent.

Such alkylation catalysts are suitable for use in both the first and second alkylation steps of the invention.

A particularly preferred catalyst for use in both alkylation steps is about 85
The catalyst contains wt% acid and 1wt% water, with the remainder being an organic diluent.

Numerous alkylation reaction zones suitable for use in the process of the invention are known in the art.

For example, US Patent Nos. 3,456,033 and 3,46994.
Although alkylation reactors of the type taught in No. 9 and No. 3,501,536 are suitable for use in both alkylation steps of the present invention, the reactors of the present invention are of course limited thereto. It's not a thing.

The alkylation conditions typical of the alkylation reactors described in the above-mentioned US patents and other suitable alkylation reactors may be employed in combination with the conditions set forth in the embodiments of the present invention.

Suitable hydrogen fluoride alkylation conditions for use in embodiments of the present invention include temperatures from about 0 to about 200"F and sufficient pressure to maintain the reactants and hydrogen fluoride in the liquid phase. , about 0.1~
A contact time (between hydrocarbon and catalyst) of approximately 30 minutes is included.

In a preferred embodiment using a hydrogen fluoride alkylation catalyst containing about 85 wt% acid, the catalyst/
The volume ratio of hydrocarbons is about 1:1 to 5:1, and the temperature is about 5:1.
Preferably, it is below 0 to about 150.

In particularly preferred embodiments, the reaction mixture consisting of hydrogen fluoride catalyst, reactants, and reactant acid formed in the alkylation reactor is fed to a reaction soaker.

In the description of the preferred embodiments presented herein, both the alkylation reactor and the reaction sorter are meant to be encompassed by the phrase "alkylation reaction zone" if one is used. There is.

Suitable reaction soakers are well known in the art, such as those disclosed in US Pat. No. 3,560,587 and US Pat. No. 3,607,970 are suitable for use in the present invention.

Such reaction soakers are conventional vessels equipped with perforated plates, balanol compartments, etc. so as to maintain the alkylation reaction mixture as a homogeneous mixture, ie, as an emulsion, for a predetermined period of time.

The alkylation reaction mixture of catalyst and hydrocarbon is maintained in the reaction soaker for a period of time depending on its composition.

The residence time in the reaction soaker is preferably about 1 to about 30 minutes.

The temperature and pressure in the reaction noker are maintained at the same temperature and pressure as the alkylation reactor to which it is attached.

Settling devices for separating the reaction mixture exiting the alkylation reaction zone into a static hydrocarbon phase and a catalyst phase are well known in the art.

Generally, the reaction mixture recovered from the alkylation reactor or soaker is a mixture containing unreacted inparaffins, alkylation reaction products, hydrogen fluoride catalyst, and catalyst-soluble organic materials, as well as small amounts of light hydrocarbons. .

When this alkylation reaction mixture is left unstirred, ie, allowed to stand, the alkylation reaction products, isoparaffins, and light hydrocarbons form a light stationary hydrocarbon phase.

On the other hand, the hydrogen fluoride catalyst and the catalyst-soluble hydrocarbon form separate phases.

The stationary hydrocarbon phase is separated from the catalyst phase by simple mechanical manipulation.

The temperatures and pressures in the above-described centring operation are substantially the same as those of the hydrogen fluoride alkylation conditions employed in the reactor.

During the centration operation, the hydrocarbons and catalyst are kept in the liquid phase.

Equipment for removing heat from the alkylation zone is necessary for optimal operation of the present invention.

Various heat removal devices are known.

For example - in embodiments, the heat produced in the alkylation reaction is removed directly from the alkylation reactor by indirect heat exchange between cooling water and the reaction mixture within the reactor.

The system hydrocarbon phase comprised from the first settling operation is mixed with a second portion of the olefin feed to provide a hydrocarbon feed to the second alkylation reactor.

That is, the first stationary hydrocarbon phase is utilized to increase the external inbutane/olefin molar ratio of the feed to the second alkylation reactor.

A hydrocarbon feed consisting of a first stationary hydrocarbon phase and a second portion of olefinic reactant is sent to a second alkylation reactor where it is contacted with a second alkyl hydrofluoride catalyst.

In summary, the present invention provides a first alkylation reaction zone with a sufficient amount of isobutane to provide a sufficient amount of isobutane to the feed to the second alkylation reaction zone, i.e., a mixture of olefinic feedstock and first stationary hydrocarbon phase. There is no need to add any inbutane from outside.

The reaction conditions for the second alkylation step are generally the same as those for the first alkylation step.

Although reaction soakers can be attached to both the first and second alkylation reactors, in a preferred embodiment,
Only the second alkylation reactor is equipped with a reaction soaker.

The temperature and pressure of this reaction noker are the same as those of the reactor to which it is attached.

After all of the olefins fed to the second alkylation reaction zone have reacted, the resulting reaction mixture is allowed to settle by any suitable conventional method, thereby providing a second stationary hydrocarbon phase and a second alkyl The second hydrogen fluoride catalyst phase that is recycled to the reaction zone is recovered.

The second stationary hydrocarbon phase recovered in this second settling operation is sent to a conventional inbutane stripping fractionation schedule where the heavy alkylate product is separated from the lower boiling unreacted isobutane and the second stationary hydrocarbon phase. It is separated from hydrogen fluoride in the hydrocarbon phase.

In this case, any method conventionally used in fractionating the system hydrocarbon phase comprised of a settler can be employed to separate the high boiling alkylate product from the low boiling isobutane recycle stream.

In a preferred embodiment of the process of the invention, the alkylation reaction of isobutane with an olefin in the first and second alkylation reaction zones provides an alkylation reaction product consisting generally of C7-C0 saturated hydrocarbons. .

The main components of this product are, for example, dimethylpentane and trimethylpentane.

It is known that more branched hydrocarbons generally have superior properties as motor fuels.

One of the aims of the present invention is to obtain alkylates for motor fuels containing extra hydrocarbons with higher branching dust, such as trimethylpentane, and with less hydrocarbons, with lower branching dust, such as dimethylhexane. be.

Such benefits can be achieved by increasing the external isobutane/olefin molar ratio in both alkylation reaction zones, which could not be achieved in the prior art for economic or operational reasons.
Accordingly, the present invention provides an alkylation method that is more economical and simpler than conventional hydrogen fluoride alkylation methods, and that also produces high quality motor fuel alkylates. It can be said that it provides a method for manufacturing things.

Generally, the advantages of the process of the invention are obtained when using at least two hydrogen fluoride catalysts and at least two portions of the olefin reaction feed in at least two different alkylation reaction zones.

A suitable alternative to the process of the invention is to provide a plurality of olefin feeds,
In other words, it is a method of dividing into three or more parts.

In this case, the entire inbutane feed and a first portion of the olenyne feed are mixed and contacted with a first hydrogen fluoride catalyst in a first alkylation reaction zone.

The catalyst and hydrocarbon are separated statically, and the first static hydrocarbon phase and a second portion of the olefin feed are mixed and contacted with a second hydrogen fluoride catalyst in a second alkylation zone.

The second, which is recovered by allowing the resulting mixture to stand still,
The stationary hydrocarbon phase is mixed with a third portion of the olefin feed, and this mixture is contacted with a third hydrogen fluoride catalyst in a third alkylation zone.

This way no further isobutane is added between any zones.

The system hydrocarbon phase, consisting of the last alkylation zone in the series, is fractionated to recover the alkylation reaction product and unreacted inbutane is separated for recycling to the first alkylation zone.

Such alternatives are, of course, encompassed by the present invention.

If, as in the preferred embodiment, two alkylation zones are used and it is desired to divide the olefin feed into two portions, then both portions of the olefin feed will each contain at least about 10 vol% of the total amount of olefins used. It is preferable that it contains.

For example, in a continuous operation, the fourth portion of olefin may be added to 10 moles/olefin with an amount of isobutane sufficient to maintain the desired isobutane/olefin molar ratio in the first reaction zone under hydrofluoric alkylation conditions. to the first alkylation zone.

The second portion of olefin is preferably mixed with the first stationary hydrocarbon phase at least about 1 mole/hour and at about 10
It is fed to the second alkylation reaction zone at a rate of 0 mol/hour or less.

Preferably, the two portions of the olefin feed do not differ in relative amounts of olefin, but the volume ratio of both portions is about 1:
It can be from less than 5 to about 5:1.

When two reactors are used, as in the preferred embodiment described above, best results are obtained when the two portions of olefin feed contain a minor amount of olefin feed.

In this way, the amount of isobutane required to achieve a high external isobutane/olefin molar ratio of the hydrocarbon feed fed to each alkylation reactor can be minimized, yet both the first and second The highest quality alkylate product can be obtained from the reactor.

EXAMPLE In order to concretely demonstrate the features of the present invention in comparison with a conventional alkylation method, two experiments were conducted: one using the method of the present invention and the other using a conventional conventional alkylation method. Ta.

The olefin feed used in both experiments was 48 wt% propylene, 10.4 wt% butene-1, and 26 wt%
Butesase 2 and 15.6 wt% isobutylene.

Isobutane was used as the imparaffin feed.

Experiment 1 was conducted by the method of the present invention employing two-stage alkylation, and Experiment 2 was conducted by a conventional single-stage alkylation method.

Both experiments used the same temperature, pressure, and catalyst.

The hydrogen fluoride catalyst used was 89 wt% hydrogen fluoride and 10 wt% hydrogen fluoride.
It contained 1 wt% organic diluent and 1 wt% water.

The temperature employed for the alkylation reaction was approximately 90''F and the pressure employed was such that the reactants and catalyst were maintained as liquids.

In each experiment, the hydrocarbon feed and catalyst were fed continuously to a conventional bench scale alkylation reactor at a catalyst/hydrocarbon weight ratio of approximately 1.5:1 and Residence time was kept at 10 minutes for both experiments.

In experiment 1 according to the method of the invention, the olefin feed was divided into two parts.

Total isoparaffin feed and first olefin feed
The portions are mixed and the mixture is fed to a conventional alkylation reactor where it is contacted with a hydrogen fluoride catalyst under the conditions described above to form a first reaction mixture.

After a predetermined residence time, the first reaction mixture is removed and allowed to stand in the conventional manner to separate the first standing hydrocarbon phase from the standing catalyst phase.

This first static hydrocarbon phase and a second portion of the olefinic feed are continuously fed to a conventional alkylation reactor where they are contacted with a hydrogen fluoride catalyst under the conditions described above to form a second reaction mixture. form.

No additional isobutane is added to the second reaction mixture, and the first stationary hydrocarbon phase is the only source of isobutane to the second reaction mixture.

After a predetermined residence time, the second reaction mixture is removed and allowed to settle in the conventional manner to separate the second stationary hydrocarbon phase from the stationary catalyst phase.

This second stationary hydrocarbon phase is recovered and fractionated to separate the C5 and heavier hydrocarbons, and the C6 hydrocarbons are recovered as the alkylate product of Run 1.

The analysis results of the alkylate product of Experiment 1 are shown in the following table.

In Run 2, a conventional single-stage alkylation process, the entire olefin feed is continuously subjected to a conventional alkylation reaction in a proportion equal to the total feed rate of the first and second fractions of the olefin feed in Run 1. supplied to the vessel.

In Run 2, the total inbutane feed is continuously fed to the alkylation reactor at the same rate as in Run 1.

That is, the olefin feed and the isobutane feed are mixed and the mixture is fed to an alkylation reactor where it is contacted with a hydrogen fluoride catalyst under alkylation conditions as described above to form a reaction mixture.

After a residence time of 10 minutes, the reaction mixture is removed from the reactor and allowed to settle in the conventional manner to separate the stationary catalyst phase from the stationary hydrocarbon phase.

After recovery, the stationary hydrocarbon phase is fractionated to separate the C3 and heavier hydrocarbons, and the C5+ hydrocarbons are recovered as the alkylate product of Run 2.

The analysis results of the alkylate product of Experiment 2 are shown in the following table.

Table: Analysis results of alkylate products As shown in the table, it is clear that the method of the present invention (Experiment 1) provides alkylate products of superior quality compared to the conventional alkylation method (Experiment 2). It is.

No additional inbutane was used in Run 1, and the fractional distillation required to separate the C5+ alkylate hydrocarbons was the same as in Run 1.2.

The numbers shown in the table indicate that the process of the present invention produces high octane alkylate products and that the undesirable heavy components (C
9+ hydrocarbons).

Embodiments of the present invention will now be described.

1. The method according to the claims, wherein the imparaffin is isobutane.

2. The method as claimed in the claims, wherein the monoolefin is selected from 1-butene, 2-butene and inbutylene.

3. The first portion of the monoolefin is about 10% of the second portion.
1000 mole %.

[Brief explanation of the drawing]

The drawing is a flow sheet diagrammatically illustrating an embodiment of the method of the invention. DESCRIPTION OF SYMBOLS 1... Olefin supply pipe, 2... Make-up isobutane supply pipe, 5... First alkylation reactor, 9... First settler 12.・・・
... Alkylation reactor, 16 ... Reaction soaker, 18 ... Second settler, 21 ...
Inbutane stripper, 22...Alkylate drain pipe, 23...N-butane drain pipe, 26...
...Propane removal ff, 30 ... Condenser, 32 ... Settler 33 ... Hydrogen fluoride discharge pipe, 35 ... Hydrogen fluoride stripper 31
・・・・・・Propane exhaust pipe.

Claims (1)

[Scope of Claims] 1. A method for producing an alkylated reaction product from a monoolefin selected from propylene, butylene and amylene and isoparaffin, comprising: (a) mixing a first portion of the monoolefin and the isoparaffin; contacting the first hydrocarbon mixture with a first hydrofluoride alkylation catalyst phase under hydrofluoride alkylation conditions in a first alkylation reaction zone to form a first alkylation reaction mixture; (b) removing a first alkylation reaction mixture from said first alkylation reaction zone and allowing it to stand to obtain a first stationary hydrocarbon phase and said first hydrogen fluoride alkylation catalyst phase; (C) recycling this first catalyst phase to said first alkylation reaction zone; and (C) a second portion of said monoolefin and said first
and subjecting the second hydrocarbon mixture to substantially the same hydrogen fluoride alkylation conditions in a second alkylation reaction zone as in the first alkylation reaction zone. contacting a second hydrofluoride alkylation catalyst phase to form a second alkylation reaction mixture; (d) removing the second alkylation reaction mixture from the second alkylation reaction zone and allowing it to stand; (e) obtaining a second undisturbed hydrocarbon phase and said second hydrofluoride alkylation catalyst phase, and circulating said second catalyst phase to said second alkylation reaction zone; fractionating the hydrocarbon phase to obtain a high boiling product stream and a low boiling inparaffin stream and recycling the isoparaffin stream to the first alkylation reaction zone;
A method for producing an alkylation reaction product from isoparaffins and monoolefins comprising recovering the alkylation reaction product from said product stream.