CA1154964A - Methanol extraction with glycol in the preparation of gasoline containing tertiaryamyl methyl ether - Google Patents
Methanol extraction with glycol in the preparation of gasoline containing tertiaryamyl methyl etherInfo
- Publication number
- CA1154964A CA1154964A CA000374239A CA374239A CA1154964A CA 1154964 A CA1154964 A CA 1154964A CA 000374239 A CA000374239 A CA 000374239A CA 374239 A CA374239 A CA 374239A CA 1154964 A CA1154964 A CA 1154964A
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- Prior art keywords
- methanol
- glycol
- methyl ether
- phase
- hydrocarbons
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- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
- C10L1/00—Liquid carbonaceous fuels
- C10L1/02—Liquid carbonaceous fuels essentially based on components consisting of carbon, hydrogen, and oxygen only
- C10L1/023—Liquid carbonaceous fuels essentially based on components consisting of carbon, hydrogen, and oxygen only for spark ignition
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P30/00—Technologies relating to oil refining and petrochemical industry
- Y02P30/20—Technologies relating to oil refining and petrochemical industry using bio-feedstock
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- Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Liquid Carbonaceous Fuels (AREA)
Abstract
METHANOL EXTRACTION WITH GLYCOL IN THE PREPARATION OF
GASOLINE CONTAINING TERTIARYAMYL METHYL ETHER
Abstract Tertiaryamyl methyl ether to be blended into gasoline for octane improvement of the blend usually contains methanol which may be undesirable for some blends. This invention provides for extraction of methanol from admixture with the ether, using glycol, before the ether is blended into gasoline product.
GASOLINE CONTAINING TERTIARYAMYL METHYL ETHER
Abstract Tertiaryamyl methyl ether to be blended into gasoline for octane improvement of the blend usually contains methanol which may be undesirable for some blends. This invention provides for extraction of methanol from admixture with the ether, using glycol, before the ether is blended into gasoline product.
Description
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This invention relates to a process for preparing gasoline containing tertiaryamyl methyl ether to improve the octane rating thereof, and more particularly to the exclusion from the gasoline of methanol residues which generally accompany such ether when it is prepared for blending into gasoline.
It is well known in the art of preparing gasolines for internal combustion engines that tert1aryamy1 methyl ether, among a few other dialkyl ethers, can be used to improve the octane ratings of the gasolines. Several authors have described various processes for preparing gasolines containing this ether, most recently John D Chase et al in USP 49l93,770. The processes generally involve etherification of 2-methyl butenes with methanol and blending the resulting mixture containing tertiaryamyl methyl ether product into a gasoline pool. The reaction of 2 methyl butenes with methanol is a typical organic reac~ion9 achieving an equilibrium which leaves a significant proportion Qf the reactant methanol in admixture with the product etherO Because methanol also has an octane improving effect in most ; gasoline pools, its presence is not objectionable with regard to octane qualityg but there are objections on the grounds of the increased ~20 water miscibility which methanol imparts to the gasoline. The present invention is intended to reduce the proportion of methanol which generally accompanies tertiaryamyl methyl ether prepared from 2-methyl bùtenes by etherification for blending into gasoline.
The invention thus consists in a process for the preparation of gasoline containing tertiaryamyl methyl ether comprising:
(1) etherifying a hydrocarbon fraction of essentially five carbon atom hydrocarbons containing 2-methyl butenes with methanol under etherifying conditions to form a mixture containing tertiaryamyl ~3 methyl ether admixed with unreacted me-thanol and unreacted hydrocarbons 3
This invention relates to a process for preparing gasoline containing tertiaryamyl methyl ether to improve the octane rating thereof, and more particularly to the exclusion from the gasoline of methanol residues which generally accompany such ether when it is prepared for blending into gasoline.
It is well known in the art of preparing gasolines for internal combustion engines that tert1aryamy1 methyl ether, among a few other dialkyl ethers, can be used to improve the octane ratings of the gasolines. Several authors have described various processes for preparing gasolines containing this ether, most recently John D Chase et al in USP 49l93,770. The processes generally involve etherification of 2-methyl butenes with methanol and blending the resulting mixture containing tertiaryamyl methyl ether product into a gasoline pool. The reaction of 2 methyl butenes with methanol is a typical organic reac~ion9 achieving an equilibrium which leaves a significant proportion Qf the reactant methanol in admixture with the product etherO Because methanol also has an octane improving effect in most ; gasoline pools, its presence is not objectionable with regard to octane qualityg but there are objections on the grounds of the increased ~20 water miscibility which methanol imparts to the gasoline. The present invention is intended to reduce the proportion of methanol which generally accompanies tertiaryamyl methyl ether prepared from 2-methyl bùtenes by etherification for blending into gasoline.
The invention thus consists in a process for the preparation of gasoline containing tertiaryamyl methyl ether comprising:
(1) etherifying a hydrocarbon fraction of essentially five carbon atom hydrocarbons containing 2-methyl butenes with methanol under etherifying conditions to form a mixture containing tertiaryamyl ~3 methyl ether admixed with unreacted me-thanol and unreacted hydrocarbons 3
(2) contacting at least part of said mixture containing tertiaryamyl methyl ether admixed with unreaeted methanol and hydrocarbons in liquid phase with a proportion of a hydrocarbon 1mmiscible liquid glycol phase to extract methanol therefrom and form a raffinate phase of tertiaryamyl methyl ether and hydrocarbons, and
(3) blending said ether containing raffinate into a gasoline product.
In a modified embodiment of the invention, in which part of said mixture containing tertiaryamyl methyl ether admixed with unreacted methanol and hydrocarbons is distilled to separate a distillate of the more volatile hydrocarbons and at least some of the ~ methanol for recycling to the ether1fying step, from a residue of tertiaryamyl methyl ether9 the less volatile hydrocarbons, and residual methanolS the said residue also is contacted in liquid phase with a proportion of an immis~ible liquid glycol phase to extract methanol therefrom and form a raffinate phase of tertiaryamyl methyl ether and ~: ~ : hydrocarbons, uhich raffinate phase is blended into a gasoline product.
~20 In a preferred form of this modified embodiment of the invention, the residue from thc distillation is combined with the part o~ the mixture ~: from the etherifying step which is directly contacted with the glycol phase, whereby the distillat10n residue and etherification mixture part : in combination contact the glycol phase for extraction of methanol.
25 : Throughout this specification and accompanying claims, all : proportions and percentages are expressed on a weight basis unless otherwise specifically indicatedO
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: .
~.~54964 The invention may be more readily understood From the following description of particular embodiments which can be illustrated by reference to the accompanying drawing. The drawing is a flow sheet showing the preparation of product streams containing tertiaryamyl methyl ether from methanol and the 2-methyl butenes content of a light olefinic hydrocarbon stream with removal of methanol from any tertiaryamyl methyl ether containing stream that is to be blended into gasoline.
It is known in the art of preparing tertiaryamyl methyl ether for blending into gasoline, particularly the aforementioned USP
In a modified embodiment of the invention, in which part of said mixture containing tertiaryamyl methyl ether admixed with unreacted methanol and hydrocarbons is distilled to separate a distillate of the more volatile hydrocarbons and at least some of the ~ methanol for recycling to the ether1fying step, from a residue of tertiaryamyl methyl ether9 the less volatile hydrocarbons, and residual methanolS the said residue also is contacted in liquid phase with a proportion of an immis~ible liquid glycol phase to extract methanol therefrom and form a raffinate phase of tertiaryamyl methyl ether and ~: ~ : hydrocarbons, uhich raffinate phase is blended into a gasoline product.
~20 In a preferred form of this modified embodiment of the invention, the residue from thc distillation is combined with the part o~ the mixture ~: from the etherifying step which is directly contacted with the glycol phase, whereby the distillat10n residue and etherification mixture part : in combination contact the glycol phase for extraction of methanol.
25 : Throughout this specification and accompanying claims, all : proportions and percentages are expressed on a weight basis unless otherwise specifically indicatedO
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: .
~.~54964 The invention may be more readily understood From the following description of particular embodiments which can be illustrated by reference to the accompanying drawing. The drawing is a flow sheet showing the preparation of product streams containing tertiaryamyl methyl ether from methanol and the 2-methyl butenes content of a light olefinic hydrocarbon stream with removal of methanol from any tertiaryamyl methyl ether containing stream that is to be blended into gasoline.
It is known in the art of preparing tertiaryamyl methyl ether for blending into gasoline, particularly the aforementioned USP
4,193,770, that the light catalytically cracked gasoline (LCCG) fraction from gas oil cracking operations and the partially hydrogenated pyrolysis gasoline fraction (HPGB or "dripolene") from steam cracking of naphtha or heavier distillate fractions are the major sources of 2 methyl bu~enes for preparation of tertiaryamyl methyl ether. The 2-methyl butenes are separated from either of thes~ sources in a distillate stream of mixed hydrocarbons predominantly of essentially five carbon atoms each, and this hydrocarbon fraction of essentially five carbon atom hydrocarbons is mixed with methanol under etherifying conditions to form the desired tertiaryamyl methyl ether.
In the drawing, 1 is a hydrocarbon feed stream containing 2-methyl butenes, for example the aforementioned LCC~ or HPGB fraction.
A fractional distillation column 2 separates, as distillate, a smaller fraction of essentially five carbon atom hydrocarbons containing the 2-methyl butenes, the smaller fraction passes via line 3 to an etherifying reactor 4 containing conventional etherifying catalysty where it mixes and reacts with methanol introduced via lines 5 and 6.
The effluent discharging from the reactor via line 7 is a mixture of 3 _ ~lSq~
tertiaramyl methyl ether, unreacted methanol, and hydrocarbons, including some unreacted 2 methyl butenes whose concentration is unlikely to have been reduced to the equilibrium concentration in the etherification reaction. For that reason, and more particularly because even the equilibrium concentration does not require high conversion of 2-methyl butenes, as is pointed out in the aforementloned USP 4,1939770, it is usually desirable to fractionally distill part, but not all, of the reactor effluent in order to separate from a residue containing the tertiaryamyl methyl ether, a distillate containing the unreacted 2-methyl butenes for recycle to reactor 4.
Although it is not necessary to the performance of the present invention, in preferred embodiments of the present invention such recycle operation is included~ Hence the e~ffluent flowing through line 7 is directed entirely into line 8 if it is not desired to increase conversion of 2-methyl butenes by recycling as described in USP 4,193,7709 or the effluent through line 7 is divided and part is diverted through line 9~ for recycling as described in USP 4,193,770, : with the remalnder of the effluent being directed into line 8. Effluent in line 8 flows into the bottom of a liquid liquid extraction column lO, wherein it is contacted9 preferrably in counter-current flow, with a stream of a hydrocarbon immiscible glycol extractant phase which : : enters the column9 for example through line 11. In the column, the stream of glycol extracts from the effluent substantially all of the methanol and effluent discharges from the column as a raffinate phase via line 12 with substantially no residual methanol content. The effluent thus contains the tertiaryamyl methyl ether product of the etherification reaction in a mixed hydrocarbon stream which is suitable for blending into a gasoline product. When part of the reactor 9~i4 effluent is diverted through line 9 for recycle of the unreacted 2-methyl butenes9 this part of the effluent is fractionally distilled, as is disclosed in USP 4,193,770, to separate the 2-methyl butenes with other volatile hydrocarbons in the distillate from the tertiaryamyl methyl ether and less volatile hydrocarbons in the residue. Some of the methanol in this part of the effluent distills into the distillate with the 2-methyl butenes, and the rest remains in the residue. As shown in the drawing, the residue withdrawn from the bottom of this fractional distillation is removed via line 13. When the fractional distillation is highly efficient, only a small and perhaps insignificant proportion of the methanol in the effluent is retained in the residue, by far the largest proportion of it distilling into the distillate, with one or more hydrocarbon components of which It forms mlnimum boiling azeotropes. When ~here is only an insignificant amount ~15 of methanol in the distillation residue of tertiaryamyl methyl ether and hydrocarbon removed in line 13, this residue can be blended directly in~o a gasoline product. When there is an undesirable proportion of methanol in the distillation residue removed in line 13, the residue i5 diverted through lîne 14 to join the flow in line 8 to exkraction column 10~ Because the Feature of directing this distillation residue to the extraction column is optional, depending on ~here being both reactor effluent recycled via line 9 and significant methanol being retained in the distillation residue rather than distilling~with recycled distillate, the line I4 is shown as a broken ~25~ line. The extractant glycol liquid phase with extracted methanolleaves the extraction column 10 via line 15 and ls passed to fractionating column 16 in which methanol 1S distilled from the glycol;
the glycol then recycles via line 11 to extraction column 10~ Methanol
In the drawing, 1 is a hydrocarbon feed stream containing 2-methyl butenes, for example the aforementioned LCC~ or HPGB fraction.
A fractional distillation column 2 separates, as distillate, a smaller fraction of essentially five carbon atom hydrocarbons containing the 2-methyl butenes, the smaller fraction passes via line 3 to an etherifying reactor 4 containing conventional etherifying catalysty where it mixes and reacts with methanol introduced via lines 5 and 6.
The effluent discharging from the reactor via line 7 is a mixture of 3 _ ~lSq~
tertiaramyl methyl ether, unreacted methanol, and hydrocarbons, including some unreacted 2 methyl butenes whose concentration is unlikely to have been reduced to the equilibrium concentration in the etherification reaction. For that reason, and more particularly because even the equilibrium concentration does not require high conversion of 2-methyl butenes, as is pointed out in the aforementloned USP 4,1939770, it is usually desirable to fractionally distill part, but not all, of the reactor effluent in order to separate from a residue containing the tertiaryamyl methyl ether, a distillate containing the unreacted 2-methyl butenes for recycle to reactor 4.
Although it is not necessary to the performance of the present invention, in preferred embodiments of the present invention such recycle operation is included~ Hence the e~ffluent flowing through line 7 is directed entirely into line 8 if it is not desired to increase conversion of 2-methyl butenes by recycling as described in USP 4,193,7709 or the effluent through line 7 is divided and part is diverted through line 9~ for recycling as described in USP 4,193,770, : with the remalnder of the effluent being directed into line 8. Effluent in line 8 flows into the bottom of a liquid liquid extraction column lO, wherein it is contacted9 preferrably in counter-current flow, with a stream of a hydrocarbon immiscible glycol extractant phase which : : enters the column9 for example through line 11. In the column, the stream of glycol extracts from the effluent substantially all of the methanol and effluent discharges from the column as a raffinate phase via line 12 with substantially no residual methanol content. The effluent thus contains the tertiaryamyl methyl ether product of the etherification reaction in a mixed hydrocarbon stream which is suitable for blending into a gasoline product. When part of the reactor 9~i4 effluent is diverted through line 9 for recycle of the unreacted 2-methyl butenes9 this part of the effluent is fractionally distilled, as is disclosed in USP 4,193,770, to separate the 2-methyl butenes with other volatile hydrocarbons in the distillate from the tertiaryamyl methyl ether and less volatile hydrocarbons in the residue. Some of the methanol in this part of the effluent distills into the distillate with the 2-methyl butenes, and the rest remains in the residue. As shown in the drawing, the residue withdrawn from the bottom of this fractional distillation is removed via line 13. When the fractional distillation is highly efficient, only a small and perhaps insignificant proportion of the methanol in the effluent is retained in the residue, by far the largest proportion of it distilling into the distillate, with one or more hydrocarbon components of which It forms mlnimum boiling azeotropes. When ~here is only an insignificant amount ~15 of methanol in the distillation residue of tertiaryamyl methyl ether and hydrocarbon removed in line 13, this residue can be blended directly in~o a gasoline product. When there is an undesirable proportion of methanol in the distillation residue removed in line 13, the residue i5 diverted through lîne 14 to join the flow in line 8 to exkraction column 10~ Because the Feature of directing this distillation residue to the extraction column is optional, depending on ~here being both reactor effluent recycled via line 9 and significant methanol being retained in the distillation residue rather than distilling~with recycled distillate, the line I4 is shown as a broken ~25~ line. The extractant glycol liquid phase with extracted methanolleaves the extraction column 10 via line 15 and ls passed to fractionating column 16 in which methanol 1S distilled from the glycol;
the glycol then recycles via line 11 to extraction column 10~ Methanol
- 5 -~54964 dist;lled from the glycol in column 16 is removed via line 17 and returned to etherification reactor 4 via line 6.
The hydrocarbon immiscible liquid glycol which is required for the process of this invention must have the ability, as a separate liquid phasey to extract substantially all of the methanol from an etherification reactor effluent containing some tertiaryamyl methyl ether but comprising principally hydrocarbons~ without at the same t1me extracting any significant proportion of the said ether from the hydrocarbon phase. Some of the ether will, of course, initially be extracted by the glycol, but this will not be a continuous drain on ~he yield of ether going to gasoline product providing that the glycol is recycled to further extraction of methanol after previously extracted methanol is stripped therefrom without stripping out initially extracted ether~ Recycling of the glycol soon saturates it with the ether and no further extraction of ether from the raffinate occurs. Suitable glycols include, -For example, (mono) ethylene glycol9 ; diethylene glycol9 triethylene 91yCol9 propylene glycol~ and mixtures of any of these.
The range of relative proportions of glycol extractant and .
: 20 extractor feed (on a methanol free basis) is wide, with a minimum ratio set by the need to limit the number of extracting stages or limit the height of an extracting column to a practicable figure, and a maximum rctio set by the need to limit the amount of glycol being used to a reasonable, economic quantity. Preferred ratios lie in the range from 0.074 to 6.5 on a weight basis and most preferred ratios lie in the range from 0.11 to 0.33.
The operating conditions in the critical step of the present invention, namely the contacting of glycol phase with a hydrocarbon
The hydrocarbon immiscible liquid glycol which is required for the process of this invention must have the ability, as a separate liquid phasey to extract substantially all of the methanol from an etherification reactor effluent containing some tertiaryamyl methyl ether but comprising principally hydrocarbons~ without at the same t1me extracting any significant proportion of the said ether from the hydrocarbon phase. Some of the ether will, of course, initially be extracted by the glycol, but this will not be a continuous drain on ~he yield of ether going to gasoline product providing that the glycol is recycled to further extraction of methanol after previously extracted methanol is stripped therefrom without stripping out initially extracted ether~ Recycling of the glycol soon saturates it with the ether and no further extraction of ether from the raffinate occurs. Suitable glycols include, -For example, (mono) ethylene glycol9 ; diethylene glycol9 triethylene 91yCol9 propylene glycol~ and mixtures of any of these.
The range of relative proportions of glycol extractant and .
: 20 extractor feed (on a methanol free basis) is wide, with a minimum ratio set by the need to limit the number of extracting stages or limit the height of an extracting column to a practicable figure, and a maximum rctio set by the need to limit the amount of glycol being used to a reasonable, economic quantity. Preferred ratios lie in the range from 0.074 to 6.5 on a weight basis and most preferred ratios lie in the range from 0.11 to 0.33.
The operating conditions in the critical step of the present invention, namely the contacting of glycol phase with a hydrocarbon
- 6 -, phase containing methanol and tertiaryamyl methyl ether, are not severe and do not require any unconventional equlpment. The pressure condition prevailing during the contacting must be sufficiently high to maintain all the ~aterials in the liquid phase at the temperature prevailing during the extraction, but need not be significantly higher;
because of the volatility of some of the components, pressure usually will be at least slightly above atmospheric. Suitable temperature during extraction does not require that there be any heating of the components; ambient room temperatures are eminently suitable, and temperatures above these, for example the ambient temperature of the effluent from the etherification reactor9 are likewise suitab1e providing they do not create vapor pressures of the components to exceed the pressure limits of the equipment being used.
It will be apparent to those skilled in the art that t~lo ; 15 functions are performed by fractional distillation column 2, in the invention embodiments shown in the accompanying drawing~ viz: (1) separation of a hydrocarbon fraction ~for example LCCG or HPGB) into a distillate of five carbon atom hydrocarbons and a residue of higher ~: boiling hydrocarbons of more than five carbon atoms, and (2) separation of an etherification reactor effluent into a residue of tertiaryamyl methyl ether in admixture with less volatile hydrocarbons and a : distillate o~ more volatile hydrocarbons of essentially five carbon atoms. It should also be apparent to such persons, from the disclosure of USP 4,193,770, that two separate fractional distillation columns could be~utîlized to perform the two functions9 rather than the one column, and performance of the process of the invention with either arrangement of apparatus is fully contemplated within the scope of the ; appended claimsO
:
1~LS~L~6~
It will also be apparent to those skilled in the art that if all of an etherification reactor effluent as contemplated in this invention is distilled to separate a fraction o~ the most volatile hydrocarbons as distillate for recycle to the etherification reactor, the most volatile component would accumulate in such cycle, to preclude such accumulation, it would be necessary to bleed off part of such distillate (which contains methanol) for blending into gasoline product, and before such blending to extract this portion of the distillate as well as extracting methanol from the distillation residue. Because this method of operation involves recomb1ning fractions that have just been separated by distillation, it is most inefficient from an energy consumption standpoint and is not recommended. For all practicable operations it is recommended that at . least part of the effluent From an etherification reaction as contemplated for this invention should be diverted directly to the llquid liquid extraction step disclosed herein, thereby providing a bleed-off for the most volatile component of the reaction system even ., .
: when a high proportion of the eFfluent is recycled to achieve higher conversion of 2-methyl butenes to tertiaryamyl methyl ether.
The following examples are is given to illustrate, but not to limit the scope of the invention.
Exame~e l ~ Principal parts o~ the equipment for carrying out this :~25 example are arranged as shown in the accompanying drawing. From alight catalytically cracked gasoline fraction, a smaller fraction of : : fiv~:carbon atom hydrocarbons is distilled in a fractional distillation : column and fed to an etherification reactor containing acid form, ~ .
~ 8 -~L54~64 sulfonated, cross~linked, polystyrene ion-exchange resin etherification catalyst. Simult~neously a stream of methanol is fed to the reactor, in a proportion of about one mol per mol of 2-methyl butenes in the hydrocarbon feed, thereby forming a proportion of tertiaryamyl methyl ether in the reactor. Effluent withdrawn from the reactor is divided into two streams, with one of the streams (80% of the effluent) being recycled to the distillation column and the other (20% of the effluent) being fed to the bottom of a liquid-liquid extraction tower ~3.9 cm internal diameter) packed (to a height of 183 cm) with 0~61 cm "Pro Pak"(trademark) protruded sta;nless steel packing having a sur~ace/volume factor (a) of 1223 m2/m3. The stream of reactor effluent recycled to the distillation column is fractionated therein, along with the light cracked gasoline fraction9 whereby five carbon atom hydrocarbons are separated as d;st;llate and sent to the etherification reactor while higher boiling hydrocarbons and tertiar~yamyl methyl ether are withdrawn as residue from the bottom of the distillation column. Methanol in the distillation column, coming from the reactor effluent, largely distills with the five carbon atom hydrocarbons and returns therewith to the etherification reactor for additional etheriflcation reaction. Methanol in the distillation column~which~does not distill overhead is withdrawn in the residue with the tertiaryamyl methyl ether and residue hydrocarbons~ This entire residue, comprising mostly hydrocarbons, is fed into the bottom of the liquid-liquid extraction tower referred to above~ where it combines ~25 with the stream of effluent flowing directly from the etherification reactor, giving a combined flow of 3.3 kg per hour, and together they are contacted with a counter-current flow of (mono)ethylene glycol.
The concentrations of methanol and tertiaryamyl methyl ether in the g _ ~iS496~
hydrocarbon phase entering the bottom of the extraction tower are 4.5%
and 12% by weight respectively, and the weight ratio of the rate oF
glycol feed at the top of the tower to 1;he rate of feed of hydrocarbon phase at the bottom of the tower, on a methanol free basis, is 0.038.
Temperature in the tower is maintained at substantially 23C average, and the associated pressure is slightly above atmospheric. The pressure drop in the Flow of the hydrocarbon phase across the extraction tower is 7.47 kilopascals (kPa). The raffinate effluent of ! tertiaryamyl methyl ether and hydrocarbons flowing from the top of the tower is found to contain only OolO weight percent methanol, and is eminently suitable for blending into gasoline. Ethylene glycol containing approximately 30 weight percent extracted methanol is withdrawn from the bottom of the extraction tower and passed to a stripping~column wherein methanol is distilled from the glycol; the methanol is recycled to the etherification reactor and the glycol, containing ~30 parts per million of methanol9 is recycled to the top of the extraction towerG
':
This example utilizes the same general arrangement of equipment as the previous example, but with a shorter liquid-liquid extraction tower and a modified recycle flow. As in the previous example, a stream of five carbon atom hydrocarbons from a light catalytically cracked gasoline fraction is reacted with methanol in an ZS etherification reactor, forming a reactor effluent stream containing tertiaryamyl methyl ether. Again the eFfluent is divided into two streams; this time only 30% of the efFluent is recycled for ~ distillation and 70% of the efFluent passes directly to the bottom of a ; ~ ' :
: ~ : ~ 10 -' ' ' '' ' ~l1549~4 liquid-liquid extraction tower 3O9 cm Int:ernal diameter packed to a height of 152 cm~ again using 0.61 cm "Pro-Pak" packing as previously used. Methanol concentration in the disl:illation residue is so low as not to require removal, and only etheriflcation reactor effluent~ at a rate of 3.3 kg/hour, is fed to the extraction tower for methanol extraction Methanol concentration ih this effluent is 6.36% by weight, with 12.2% tertiaryamy1 methyl etherl balance hydrocarbons~
and feed rates of glycol to the top of the extraction tower and effluent to the bottom of the tower are in the ratio of 0.159 by weight. Temperature in the tower is maintained at substantially 23C
and pressure is slightly above atmospheric. The pressure drop in the flow of the hydrocarbon phase across the extraction tower is 6.22 kPa.
Raffinate from the top of the tower contains only 0.04% methanol by weight, and is eminently suitable for blending into gasoline. Glycol containing extracted methanol is readily stripped of methanol and recycled to the extraction tower.
Numerous modifications may be made in the various expedients and embodiments of the invention described herein without departing from the scope of the invention which is defined in the following claims.
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~ 25
because of the volatility of some of the components, pressure usually will be at least slightly above atmospheric. Suitable temperature during extraction does not require that there be any heating of the components; ambient room temperatures are eminently suitable, and temperatures above these, for example the ambient temperature of the effluent from the etherification reactor9 are likewise suitab1e providing they do not create vapor pressures of the components to exceed the pressure limits of the equipment being used.
It will be apparent to those skilled in the art that t~lo ; 15 functions are performed by fractional distillation column 2, in the invention embodiments shown in the accompanying drawing~ viz: (1) separation of a hydrocarbon fraction ~for example LCCG or HPGB) into a distillate of five carbon atom hydrocarbons and a residue of higher ~: boiling hydrocarbons of more than five carbon atoms, and (2) separation of an etherification reactor effluent into a residue of tertiaryamyl methyl ether in admixture with less volatile hydrocarbons and a : distillate o~ more volatile hydrocarbons of essentially five carbon atoms. It should also be apparent to such persons, from the disclosure of USP 4,193,770, that two separate fractional distillation columns could be~utîlized to perform the two functions9 rather than the one column, and performance of the process of the invention with either arrangement of apparatus is fully contemplated within the scope of the ; appended claimsO
:
1~LS~L~6~
It will also be apparent to those skilled in the art that if all of an etherification reactor effluent as contemplated in this invention is distilled to separate a fraction o~ the most volatile hydrocarbons as distillate for recycle to the etherification reactor, the most volatile component would accumulate in such cycle, to preclude such accumulation, it would be necessary to bleed off part of such distillate (which contains methanol) for blending into gasoline product, and before such blending to extract this portion of the distillate as well as extracting methanol from the distillation residue. Because this method of operation involves recomb1ning fractions that have just been separated by distillation, it is most inefficient from an energy consumption standpoint and is not recommended. For all practicable operations it is recommended that at . least part of the effluent From an etherification reaction as contemplated for this invention should be diverted directly to the llquid liquid extraction step disclosed herein, thereby providing a bleed-off for the most volatile component of the reaction system even ., .
: when a high proportion of the eFfluent is recycled to achieve higher conversion of 2-methyl butenes to tertiaryamyl methyl ether.
The following examples are is given to illustrate, but not to limit the scope of the invention.
Exame~e l ~ Principal parts o~ the equipment for carrying out this :~25 example are arranged as shown in the accompanying drawing. From alight catalytically cracked gasoline fraction, a smaller fraction of : : fiv~:carbon atom hydrocarbons is distilled in a fractional distillation : column and fed to an etherification reactor containing acid form, ~ .
~ 8 -~L54~64 sulfonated, cross~linked, polystyrene ion-exchange resin etherification catalyst. Simult~neously a stream of methanol is fed to the reactor, in a proportion of about one mol per mol of 2-methyl butenes in the hydrocarbon feed, thereby forming a proportion of tertiaryamyl methyl ether in the reactor. Effluent withdrawn from the reactor is divided into two streams, with one of the streams (80% of the effluent) being recycled to the distillation column and the other (20% of the effluent) being fed to the bottom of a liquid-liquid extraction tower ~3.9 cm internal diameter) packed (to a height of 183 cm) with 0~61 cm "Pro Pak"(trademark) protruded sta;nless steel packing having a sur~ace/volume factor (a) of 1223 m2/m3. The stream of reactor effluent recycled to the distillation column is fractionated therein, along with the light cracked gasoline fraction9 whereby five carbon atom hydrocarbons are separated as d;st;llate and sent to the etherification reactor while higher boiling hydrocarbons and tertiar~yamyl methyl ether are withdrawn as residue from the bottom of the distillation column. Methanol in the distillation column, coming from the reactor effluent, largely distills with the five carbon atom hydrocarbons and returns therewith to the etherification reactor for additional etheriflcation reaction. Methanol in the distillation column~which~does not distill overhead is withdrawn in the residue with the tertiaryamyl methyl ether and residue hydrocarbons~ This entire residue, comprising mostly hydrocarbons, is fed into the bottom of the liquid-liquid extraction tower referred to above~ where it combines ~25 with the stream of effluent flowing directly from the etherification reactor, giving a combined flow of 3.3 kg per hour, and together they are contacted with a counter-current flow of (mono)ethylene glycol.
The concentrations of methanol and tertiaryamyl methyl ether in the g _ ~iS496~
hydrocarbon phase entering the bottom of the extraction tower are 4.5%
and 12% by weight respectively, and the weight ratio of the rate oF
glycol feed at the top of the tower to 1;he rate of feed of hydrocarbon phase at the bottom of the tower, on a methanol free basis, is 0.038.
Temperature in the tower is maintained at substantially 23C average, and the associated pressure is slightly above atmospheric. The pressure drop in the Flow of the hydrocarbon phase across the extraction tower is 7.47 kilopascals (kPa). The raffinate effluent of ! tertiaryamyl methyl ether and hydrocarbons flowing from the top of the tower is found to contain only OolO weight percent methanol, and is eminently suitable for blending into gasoline. Ethylene glycol containing approximately 30 weight percent extracted methanol is withdrawn from the bottom of the extraction tower and passed to a stripping~column wherein methanol is distilled from the glycol; the methanol is recycled to the etherification reactor and the glycol, containing ~30 parts per million of methanol9 is recycled to the top of the extraction towerG
':
This example utilizes the same general arrangement of equipment as the previous example, but with a shorter liquid-liquid extraction tower and a modified recycle flow. As in the previous example, a stream of five carbon atom hydrocarbons from a light catalytically cracked gasoline fraction is reacted with methanol in an ZS etherification reactor, forming a reactor effluent stream containing tertiaryamyl methyl ether. Again the eFfluent is divided into two streams; this time only 30% of the efFluent is recycled for ~ distillation and 70% of the efFluent passes directly to the bottom of a ; ~ ' :
: ~ : ~ 10 -' ' ' '' ' ~l1549~4 liquid-liquid extraction tower 3O9 cm Int:ernal diameter packed to a height of 152 cm~ again using 0.61 cm "Pro-Pak" packing as previously used. Methanol concentration in the disl:illation residue is so low as not to require removal, and only etheriflcation reactor effluent~ at a rate of 3.3 kg/hour, is fed to the extraction tower for methanol extraction Methanol concentration ih this effluent is 6.36% by weight, with 12.2% tertiaryamy1 methyl etherl balance hydrocarbons~
and feed rates of glycol to the top of the extraction tower and effluent to the bottom of the tower are in the ratio of 0.159 by weight. Temperature in the tower is maintained at substantially 23C
and pressure is slightly above atmospheric. The pressure drop in the flow of the hydrocarbon phase across the extraction tower is 6.22 kPa.
Raffinate from the top of the tower contains only 0.04% methanol by weight, and is eminently suitable for blending into gasoline. Glycol containing extracted methanol is readily stripped of methanol and recycled to the extraction tower.
Numerous modifications may be made in the various expedients and embodiments of the invention described herein without departing from the scope of the invention which is defined in the following claims.
.
~ 25
Claims (9)
1. A process for the preparation of gasoline containing tertiaryamyl methyl ether comprising:
(1) etherifying a hydrocarbon fraction of essentially five carbon atom hydrocarbons containing 2-methyl butenes with methanol under etherifying conditions to form a mixture containing tertiaryamyl methyl ether admixed with unreacted methanol and unreacted hydrocarbons, (2) contacting at least part of said mixture containing tertiaryamyl methyl ether admixed with unreacted methanol and hydrocarbons in liquid phase with a proportion of a hydrocarbon immiscible liquid glycol phase to extract methanol therefrom and form a raffinate phase of tertiaryamyl methyl ether and hydrocarbons, and (3) blending said ether containing raffinate into a gasoline product.
(1) etherifying a hydrocarbon fraction of essentially five carbon atom hydrocarbons containing 2-methyl butenes with methanol under etherifying conditions to form a mixture containing tertiaryamyl methyl ether admixed with unreacted methanol and unreacted hydrocarbons, (2) contacting at least part of said mixture containing tertiaryamyl methyl ether admixed with unreacted methanol and hydrocarbons in liquid phase with a proportion of a hydrocarbon immiscible liquid glycol phase to extract methanol therefrom and form a raffinate phase of tertiaryamyl methyl ether and hydrocarbons, and (3) blending said ether containing raffinate into a gasoline product.
2. A process as claimed in Claim 1 in which the entire mixture flowing from the etherifying reaction is contacted with the glycol phase to extract methanol.
3. A process as claimed in Claim 1 in which part of the mixture flowing from the etherifying reaction is fractionally distilled to separate, as distillate, a fraction of the more volatile hydrocarbons and part of the methanol from a residue of the less volatile hydrocarbon, tertiaryamyl methyl ether and methanol, said residue is contacted with a proportion of a hydrocarbon immiscible liquid glycol phase to extract methanol therefrom, and said extracted residue is blended into a gasoline product.
4. A process as claimed in Claim 3 in which the said residue is admixed with the part of the mixture from the etherifying step for contact with said liquid glycol phase.
5. A process as claimed in Claim 1 in which the relative weight proportions of glycol extractant and extractor feed (on a methanol free basis) contacting said glycol are in the range from 0.074:1 to 6.5:10
6. A process as claimed in any of Claims 2, 3, and 4, in which the relative weight proportions of glycol extractant and extractor feed (on a methanol free basis) contacting said glycol are in the range from 0.11:1 to 0.33:1.
7. A process as claimed in Claim 5 in which the contacting with glycol phase is carried out at ambient room temperature.
8. A process as claimed in Claim 5 in which the contacting with glycol is carried out at the ambient temperature of the mixture coming from the etherifying step.
9. In a process for the preparation of gasoline containing tertiaryamyl methyl ether comprising (1) etherifying a hydrocarbon fraction of essentially five carbon atom hydrocarbons containing 2-methyl butenes with methanol under etherifying conditions to form a mixture containing tertiaryamyl methyl ether admixed with unreacted methanol and unreacted hydrocarbons, and (2) blending at least part of said ether containing mixture into a gasoline product, the improvement which comprises contacting that part of the mixture to be blended into a gasoline product in liquid phase, before said blending, with a proportion of a hydrocarbon immiscible liquid glycol phase in a liquid-liquid extraction operation to extract methanol therefrom and form a raffinate phase of reduced methanol content.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000374239A CA1154964A (en) | 1981-03-24 | 1981-03-24 | Methanol extraction with glycol in the preparation of gasoline containing tertiaryamyl methyl ether |
| DE19823210067 DE3210067A1 (en) | 1981-03-24 | 1982-03-19 | Process for producing gasoline containing tertiary-amyl methyl ether |
| FR8204990A FR2502638A1 (en) | 1981-03-24 | 1982-03-24 | PROCESS FOR THE PREPARATION OF PETROL OIL CONTAINING T-AMYL-METHYL ETHER |
| NL8201228A NL8201228A (en) | 1981-03-24 | 1982-03-24 | Gasoline prodn. contg. 1-amyl methyl:ether - by blending after extraction of methanol from the ether |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000374239A CA1154964A (en) | 1981-03-24 | 1981-03-24 | Methanol extraction with glycol in the preparation of gasoline containing tertiaryamyl methyl ether |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1154964A true CA1154964A (en) | 1983-10-11 |
Family
ID=4119586
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000374239A Expired CA1154964A (en) | 1981-03-24 | 1981-03-24 | Methanol extraction with glycol in the preparation of gasoline containing tertiaryamyl methyl ether |
Country Status (3)
| Country | Link |
|---|---|
| CA (1) | CA1154964A (en) |
| DE (1) | DE3210067A1 (en) |
| FR (1) | FR2502638A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012068633A1 (en) * | 2010-11-25 | 2012-05-31 | Gane Energy & Resources Pty Ltd | Fuel and process for powering a compression ignition engine |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR3010998B1 (en) * | 2013-09-23 | 2016-11-25 | Arkema France | LIQUID EXTRACTION - LIQUID PROCESS FOR THE PRODUCTION OF ACRYLIC ESTERS |
-
1981
- 1981-03-24 CA CA000374239A patent/CA1154964A/en not_active Expired
-
1982
- 1982-03-19 DE DE19823210067 patent/DE3210067A1/en not_active Withdrawn
- 1982-03-24 FR FR8204990A patent/FR2502638A1/en active Granted
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012068633A1 (en) * | 2010-11-25 | 2012-05-31 | Gane Energy & Resources Pty Ltd | Fuel and process for powering a compression ignition engine |
| US9447724B2 (en) | 2010-11-25 | 2016-09-20 | Gane Energy & Resources Pty Ltd. | Fuel and process for powering a compression ignition engine |
| US10023818B2 (en) | 2010-11-25 | 2018-07-17 | Gane Energy & Resources Pty Ltd. | Process for powering a compression ignition engine and fuel therefor |
| US10815441B2 (en) | 2010-11-25 | 2020-10-27 | Gane Energy & Resources Pty Ltd. | Fuel and process for powering a compression ignition engine |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2502638A1 (en) | 1982-10-01 |
| FR2502638B3 (en) | 1984-12-21 |
| DE3210067A1 (en) | 1982-11-11 |
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