Note: Descriptions are shown in the official language in which they were submitted.
wo 95/16763 2 1 7 8 9 5 5 PCT/USg4/14234
USE OF l~;KllARY-HEXYL METHYL ~;NI~;K AS A MOTOR GASOLINE
ADDITIVE
This invention relates to the use of one isomer of tertiary-hexyl methyl
ether, which is 2-methoYy-2,3-dimethylbutane, as an octane booster in motor
g~coline
Generally, any component that has a research octane number over
105 and a motor octane number over 95 is considered to be an octane
booster for use in motor gasoline. It is well known in the art that ethers
0 made from C4 and Cs oleffns are eYcelle.nt octane boosters. Methyl tertiary-
butyl ether (MTBE) made from isobutene, a C4 olefin, has a research octane
number (RON) of 118 and a motor octane number (MON) of 100; and
tertiary-amyl methyl ether (TAME) pro~ ce~ from Cs olefins has a RON of
111 and a MON of 98 accordi.lg to Un7elm~n, Oil & Gas Journal, Volume
44, April 15, 1991.
It is also well known that these ethers have a higher octane booster
number than their counterpart olefins. "Physical 1~O~ of Hydrocarbon
and Non-Hydrocarbon Co~ ounds" ASTM data series publiG~tion DS 4B,
1991 states that the octane numbers for one of the parent olefins of TAME,
2-methyl-2-butene, is 97 for the RON and 82 for the MON. Ftherific~tion of
this Cs olefin increases the octane numbers to 111 for the RON and 98 for
the MON. While the art te~hes that ethers produced from C4 and Cs
olefins are excellent octane boosters, it te~clles away from the use of ethers
produced from C6 and heavier olefins.
For example, in Pescarollo et al.'s article, "Etherify light g7~colines"~
Hydrocarbon Proceccing, February 1993, pp 53-60, he states that " . . . ethers
derived from C6 and heavier olefins do not cignifiç~ntly enh~n~ e octane over
the parent olefins".
Also, US-A-4,193,770, and its equivalent, DE-A-2,854,250 (1979)
3 o te~hes that the octane numbers of the C6 ethers are no higher than those of
the parent olefins mixed with the same amount of methanol. The blending
octane numbers for tertiary-hexyl methyl ether which is pro~ ce~l from a C6
olefin are reported as being 100 for the RON and 90 for the MON, but no
mention is made of any specific isomers, inrhlding 2-methoxy-2,3-
dimethylbutane (MDMB). Hence, there is no recognition or te~ing that
MD~IB is effective as an octane booster. The reported numbers serve to
WO 95/16763 PCT/US94/14234
-2- ~ 17,'69~
teach away from investig~ting the performance of ether produced from C6 or
C7 olefins.
This reference te~heS the importance of etherifying C4 and Cs
olefins separately from each other bea~-se of the di~erelll re~ction kinetics.
5 Also stressed is the ~ol l~ce of keeping each of these fractions separate
from the C6 olefin fraction, which forms tertiary hexyl methyl ether, ber~llse
there is no prove~l.ent in octane rating as co...l ~red to the ethers from the
C4 and Cs olefinc. The reference goes as far as saying that any reported
increases in octane rating for ethers from C6 and q olefins, are "illusory".
See cohlmn 3, lines 5 to 13 and 26 to 37.
This reference sets up a major prejudice ~e~inct using C6 ethers as
motor gasoline octane boosters. And there is absolutely no m~ntion of
MDMB.
MICROLOG-88-03391 from Energy Res. Abstr., 13(22), Abstr. No.
5031, 1988, also te~hes against the use of ethers prod~lced from C6 olefins in
that "pre~lictiQnC for C6 ethers were not carried out bec~l~ce there was
virtually no .. l,love"lent in octane number when co...p~red with its
precursors".
EP-A-0 036 260, tlicrloses the use of ethers prod-lced from a ~i~.lule
20 of C4 through q olefins as components in a motor ~colin~ blend from a
refinery catalytic cracker unit, with 7% being C6 olefinc, but lei"rorces the
belief that the octane booster effect is due to the ethers prod~lced from C4
and Cs olefins rather than those ethers produced from C6 or q olefinc.
It would be desirable if ethers pro~ced from C6 olefins could be used
2 5 as motor octane boosters. Current market predictions indicate that there will
be a glut of propylene, which could be used to make C6 olefins, in the market
place within the next ten years. Currently, propylene is sent to the motor
g~coline pool from refinery catalytic crackers, but the propylene does not
boost the octane. It would be very profitable if one could determine a way to
3 0 coll~el l propylene into an octane booster.
SUMMARY OF THE INVENTION
This invention relates to using an octane boosting amount of a
35 tertiary hexyl methyl ether co",~onent col~ g 2-m~thc-Yy-2,3-dimethyl
butane (MDMB) which enables providing a blend CO~ iSi~g
WO 95/16763 2 1 7 8 9 5 5 PCT/US94/14234
(a) motor gasoline or motor gasoline feedstock; and
(b) an octane boosting amount of a tertiary hexyl methyl ether
component colllplish~g 2-methoxy-2,3-dimethyl butane
(MDMB) in an ~mount of at least 10% by weight based on the
total weight of tertiary hexyl methyl ether,
wherein composition (b) has a Research Octane Number (RON) and/or a
Motor Octane Number (MON) greater than those of co~ osilion (a).
One emboAim~-nt includes providing a blend wherein the tertiary
hexyl methyl ether component of composition (b) colll~ lises in various
0 amounts and ranges, inrlllding, greater than 10%, preferably from 20 to
100~, more preferably greater than 50%, even more yrcferably from 60~o to
100%, and most prefe~bly greater than 80% by weight of MDMB.
Another embodiment inrllldes providing a blend wherein coLu~osilion
(b) co.~ greater than 50%, preferably from 60% to 100%, and more
15 l,refe~ably greater than 80%, by weight of the tertiary hexyl methyl ether.
Yet another emboAiment inçl~ldes providing a method of increasing
the octane number in motor g~coline collll,lishlg blending MDMB with the
motor gasoline or with a motor g~coline feedstock to boost the octane
number of the motor g~coline or motor g~colin~. feedstock which co~ a
2 o sufficient ~mollnt of composition (b) to boost the octane number of
co..l~ullent (a) by at least 1, l,lcfeldbly by at least 2, and more prefelably by
at least 3 units.
Still another emboAim~nt inrllldes the use of a tertiary hexyl methyl
ether co-llpûllcnt co...l-t;~ing MDMB and having a blending RON greater
than 100 and a ble-nAin~ MON greater than 90, as an octane booster for
motor ~coline
The tertiary hexyl methyl ether component co~ lisillg MDMB may
be ~rcpared by dimerizing propylenes and ~d(lition~l emboAim~o.ntc of the
present invention in~ de a blend wherein composition (b) is made by a
process cOlll~lisillg:
(i) dimerizing propylene to form dimethylbutenes; and
(ii) etherifying the dimethyl butenes with meth~nol, to form the
desired col~o~ilion and/or a blend.
~AAition~lly, another embo~liment inÇllldec the funher tre?~tment
wherein step (ii) comprises panial etherifiç~tion and is followed by (iii)
WO 95/16763 PCT/US94/14234
~ 17 '76q55
-4 -
hydrogen~ti-n of unetherified dimethylbutenes to form a tertiary hexyl
methyl ether composition COlll~liSillg MDMB and dimethyl butanes.
DETAILED DESCRIPIION OF THE INVENTION
Not all of the isomers of tertiary-hexyl methyl ether produced from C6
olefins are suitable for use as octane boosters. The four isomers of tertiary-
hexyl methyl ether (C6 H13-OCH3) are as follows:
1) 2-Methoxy-2,3-dimethylbutane(MDMB)
CH3 CH3
CH3 -- CH- C--OCH3
CH3
2) 2-Methoxy-2-methylpent~ne (2MMP)
CH3
I
CH3 -CH2 -CH2--C--OCH3
I
2 5 CH3
3) 3-Methoxy-3-methylpentane (3MMP)
OCH3
I
CH3--CH2 -C--CH2 - CH3
I
CH3
2 1 78~55
WO 9S/16763 PCT/US94/14234
-5 -
4) l-Methoxy-l-methylcyclopentane (MMCP)
CH2 CH2
I
CH2 /cH2
C
CH3 OCH3
l-Metboxy-l-methylcyclopentane (MMCP) is conci~lered an isomer of
tertiary-hexyl-methyl ether even though it has two fewer hydrogen atoms.
One isomer of tertiary-hexyl methyl ether has been found to be a very
useful high octane booster for use in motor g~coline~ That particular isomer
15 is 2-methoxy-2,3-dimethylbutane (MDMB).
MDMB may be ~epared from propylene and methanol by first
llim~ri7ing the propylene to dimethylbutenes (2,3-dimethyl)-(1 and/or 2)-
butene), and then by ethe~ i-lg the dimethylbutenes with meth~nol, as
shown in the following reaction equationc Both 2,3-dimethyl-1-butene and
20 2,3-dimethyl-2-butene react with methanol to form the desired product ether.
CH3 CH3
2 CH3CH = CH2 ~ CH3--CH- C = CH2
propylene 2,3-dimethyl-1-butene
CH3 CH3 CH3 CH3
CH3--CH - C = CH2 + CH30H ~ CH3--CH - C--OCH3
3 o 2,3-dimethyl-1-butene methanol
(DMB) CH3
2-methoxy-2,3-
dimethylbutane
3 5 (MDMB)
WO 95/16763 PCTIUS94/14234
,~17~q~5
Olefin dimerization and codimerization processes are known in the
art. The propylene may be dimerized to dimethylbutenes (DMB) using a
tnng~ten catalyst, such as that tli~rlose~ in U.S. Patent 5,059,739. The
dimethylbutenes (DMB) may also be produced using nickel with specific
organo-phosphine lig~n~l~
In the event, the tun~cte~ catalyst is used, the ratio of olefin to
tungsten should be such that a catalytic amount of the tnn~tçn complex is
used. The reaction may be run in either a batch or a co,-l;.,llous manner.
The re~çtion ~res~ule is normally the p'es~ulc generated by the olefin at the
reaction tempeldlule, ~lth~lgh the ple~ulc may be increased with an inert
gas. The re~ction temperature may range, for eY~mple, from about 40 to
100~C, with 50 to 80~C being preferred. The reaction or resi~len~e time may
be, for example, from S min~ltes to about 3 hours, with 0.5 to 2.0 hours being
preferred. The preferred embodiment uses a catalyst which is prepared by
taking a tungsten salt and an aniline to form a complex of the t~mgstçn salt
and ~niline S~1bst~nti~lly all of the hydrogen chloride pro~l~lce~l in this
re~ction is removed from the sol~ltion during the course of the re~ction
After form~tion of the tlmgstçn and aniline complex, an alkyl ~ ",;n~",
halide is added to the sohltion to form the active catalyst system of the
invention. The l,refelled feedstock is refinery grade propylene, after
sufficient removal of water and other catalyst poisons.
The etherific~tion of the dimethylbutenes with meth~nol to prcpare
MDMB may take place in a m~nner similar to the ~lepalalion of methyl
tertiaIg-butyl ether (MTBE) from isobutylene or the preparation of tertiary-
amyl methyl ether (TAME) from isoamylenes. The re~ o~ takes place over
the acid form of an ion eY-~h~nge resin.
The present invention involves the feeding of a llli,LIure conl~ g
DMB and methanol into the feed zone of a reactor (i.e., a fixed-bed guard
reactor), and cont~cting the reslllt~ns ll~ lure of DMB and methanol with a
fixed bed acidic cation exchange resin (e.g., Amberlys~) 15) in the reaction
zone, thereby catalytically re~cting the DMB with the methanol under
conditions which favor forming the res~llt~nt 2-methoxy-2,3-dimethylbutane
(MDMB).
Where the etherification step of the present invention is practiced in a
catalytic ~ till~tion process, the catalytic material may be in any form which
WO 95/16763 2 ~ 7 8 9 5 5 PCT/USg4/1423~
pcllllils its incorporation into a tlictill~tion tower, such as a fixed bed, butmay also be in a form which serves as a di~till~tion p~ing, for example,
rings, s~ lles, balls, irregular pieces, sheets, tubes, spirals, packed in bags,plated on grills or screens, and reticlll~ted polymer foams.
Catalysts which have been found to be suitable for use in the
etherification step of the present invention are resin catalysts such as cation
h~e resin catalysts, acidic resin catalysts, macroreticular s~llfonic acid
cation eYrh~nge resin catalysts, and solid acid catalysts. Still others have used
a zeolite as an etherific~fion catalyst. Preferred catalysts for purposes of thepresent invention, however, are acid catalysts, such as acidic resin catalysts.
A more ~refelled catalyst for purposes of the present invention is a
macroreticular sulfonic acid cation eYrh~n~e resin such as a slllfon~te~
copolymer of poly~lylelle-divinyl-ben7ene. Such catalysts inrlude Amberlyst
t!~) 15 and 15C (m~rkçted by Rohm and Haas), Lewatit SPC 118 and SPC 118
BG (marketed by Miles/Bayer), and Dowex M-31 and M-32 (marketed by
the Dow Chemical Co.). A special version of this type of catalyst, i.e., Dowex
DR-2040 (marketed by the Dow Ch~mic~l Co.), is used specifi~lly for
reactive dict~ tinn
It has been found that eqllilibrinm co--vel~ion to ether is only 50-60%,
so it is expected that catalytic tlictill~tion will be advantageous in the
etherific~fion step. Catalytic dictill~tion is commercially pr~ ticed in the
prodllction of MTBE and this process has been extensively explored with
TAME. Therefore, there is every reason to expect that catalytic ~icfill~tion
would be advaIltageous when applied to the process for producing ethers
from C6 olefinc.
When the ether is pro~l~lce~ from a C6 olefin which has been formed
by ~im~ri~in~ propylene, the co---~osilion of the reslllting ~-~lu e of isomers
may be as pure as 98 wt% MDMB, 2 wt% 2MMP, with n~ligihle amounts of
3MMP and MMCP. When the C6 olefin is pro~ ed in a refineIy catalytic
cracker, the isomer ll~ ule is di~ere--l, with more than 50% being 2MMP
and ~plo~;...~tely 7% being MDMB.
It is well known in the art that ethers are used as motor E~coline
additives to enh~nce the quality of the motor gasoline due to el-viro.. ent~l
regulations, both eYictin~ and pending in the USA. By using an oxygenate
35 rather than its counter part olefin in motor gasoline, less carbon monoYide
pollution is produced upon combustion of the motor g~coline Also, the rules
WO 95/16763 PCT/US94/14234
~17 ~q5~
re~ ting reformnl~ted ~coline which is a particular type of motor ~coline,
require that a lower olefin content be present in the g~coline due to the fact
that olefins contribute to ozone formation more than their counter part
ethers. An ~d~liti~n~l advantage of using the ether rather than the olefin in
5 motor g~coline is that the ether has a lower Reid vapor pl~s~ulc, which
reduces evaporative emiccionc which contribute to pollution.
The ~d~lition of the MDMB to the motor e~colinP, or motor ~colinP,
feedstock to boost the octane may be ~ccomplished in several ways. One
method includes the preparation of a blend C(illlpliSillg the ll~lure of two
0 compositions, (a) and (b), wherein composition (a) cO.~;cl~ of the motor
~colinP, or motor &~coline feedstock which is blended with colllposilion (b)
which colll~lises an octane boosting amount of a tertiary hexyl methyl ether
collll,ollent comprising 2-mPthoYy-2,3-dimethyl butane (MDMB) in an
~mollnt of at least 10% by weight based on the total weight of tertiary hexyl
15 methyl ether, wherein the colll~osilion (b) has a Research Octane Number
(RON) and/or a Motor Octane Number (MON) greater than those of
colll~osilion (a).
In ~d~lition to the tertiary hexyl methyl ethers and the MDMB,
co,l.posilion (b) may inrhlde other colll~ ne~b. These ~ ition~
20 colll~ollents may be any other hydroc~l.ol~s typically found in motor g~colin~
or motor g~colin~ fee~lctocl~c~ inrlu~ling, but not limited to, aro...s~;rc, olefinc,
and saturates.
These ~d(lition~l hydrocarbons may or may not be cqncidered useful
as octane boosters. In the case where the other hydroc~l,olls are useful as
octane boosters, composition (b) may inclucle either MTBE or TAME, or
n~i~lures thereof.
Co~ osilion (b) may have a RON greater than 95, preferably greater
than 100, and/or a MON greater than 85, ~refel~bly greater than 90.
Optionally composition (b) has a blen~ling RON greater than 100,
~le~lably greater than 105 and/or a blen~lin~ MON greater than 90,
prefelably greater than 9S.
The tertiary hexyl methyl ether colll~onent of col,l~osilion (b) may
col~lise greater than 10%, prefelably from 20 to 100%, by weight of
MDMB. Optionally, this tertiary hexyl methyl ether collll~onent of
co~ osilion (b) may co~ lise from 50 to 100%, l,lerel~bly greater than
80%, by weight of MDMB.
W095/16763 2 1 18 9 S 5 PCT/US94/14234
The tertiary hexyl methyl ether component may have a RON greater
than 100 and/or a MON greater than 90. Optionally, this tertiary hexyl
methyl ether component may have a blending RON greater than 100 and/or
a blen~ling MON greater than 90.
The MDMB component of co"",osilion (b) may have a RON greater
than 105 and/or a MON greater than 95. Optionally, the MDMB component
may have a blen~ling RON greater than 105 and/or a blen-ling MON greater
than 9S.
The resultin~ blend may have a RON greater than 90, l"~felably
0 greater than 93, and/or a MON greater than 80, preferably greater than 83.
A sufficient amount of composition (b) must be blended with
co".~osilion (a) such that the octane number of component (a) is boosted by
at least 1, preferably by at least 2, and more prefelably by at least 3 units.
The resnlting blend may which comprise greater than 1%, preferably greater
than 2%, and most preferably greater than 5%, by volume of MDMB.
In addition to its use as an octane booster, MDMB has the added
benefit of not significantly increasing the RVP of the motor g~coline blend as
is typical with other octane boosters, such as MTBE or TAME.
For example, MTBE has a blçn~ling RVP of 57.9 kPa (8.4 psi) and
TAME has a blending RVP of 27.6 kPa (4.0 psi), both of which are higher
than that of MDMB being 6.9 kPa (1 psi).
When the starting motor g~coline fee~lctQck has a high RVP level, one
could be limited on how much MTBE or TAME ~d~lition is possible to
achieve the required octane requirçm~-ntc, while at the same time, not
~Y~eetling the RVP limit.
Therefore, an additional embo~imçnt of the present invention
inl~hldes the use of more than one octane booster to achieve the ",~xi,
octane boosting effect and without the co"esponding undesirable increase in
RVP.
For example, one could make a blend COl"~,iSi"g the ~ddition of
MTBE and/or TAME up to the m~x;...,.... RVP limit of the motor g~colin~
product as set by an el,viro.~..ent~l st~nd~rd. Then, MDMP, either alone or
in llli~ure with the tertiary hexyl methyl ether, could be blended into the
motor ~coline to achieve on even higher octane number without incurring
35 any increase in the RVP of the final blend of motor ~coline.
WO 95/16763 PCT/US94/14234
~ 1 7 ~ ~5~
- 10-
One embo~lim~nt of the invention inr~ es a blend which cont~inc a
sufficient amount of composition (b) to boost the octane number of
co~ ,onent (a) by at least 1, while at the same time increasing the Reid vapor
plcs~urc of component (a) by less than 13.8 kPa (2 psi), preferably by less
than 6.9 kPa (1 psi), and more preferably by less than 3.4 kPa (0.5 psi).
The MDMB may be preparcd using a process colllplising (i)
~limeri7ing propylene to form dimethylbutenes and (ii) etherifying the
dimethyl butenes with methanol. Optionally, wherein step (ii) colll~lises
partial etherification, the process may further col~ lise the ~ ion~l step of
0 (iii) hydrogen~tion of the unetherified dimethylbutenes to form a tertiary
hexyl methyl ether composition COlll~liSillg MDMB and dimethyl butanes.
Co~ .osilion (b) may co..l;l;.. dimethylbutenes and may also cont~in
less than 1% meth~nol and/or less than 5% olefinc Composition (b) may
co~ greater than 50%, ~rcferably from 60% to 100%, and more
15 l,refelably greater than 80%, by weight of the tertiary hexyl methyl ether.
By ble-n~ling the pre~ared MDMB, with a motor g~coline or motor
g~coline feedstock, the octane number of the blended ~coline may be
increased by 1 or more units, prcfe~ably 2 or more units, and most preferably
3 or more units, over the original octane number of the motor gasoline or
20 motor g~coline feedstock.
The foregoing invention will now be illustrated by, ~lthollgh not
limited to, the following examples.
EXAMPLES
EXAMPLE I
2-MMP Col-lpa~alivc Example
This co..~p~ativc example illustrates that not all ethers prodllce-l from
3 C6 olefins are useful as octane boosters.
An ion eY~ h~nge resin in the acid form (Amberlyst R15, washed with
methanol) was added to a 5000 mL round-bottom _ask along with 1000 g of
2-methyl-1-pentene and 416 g methanol. The slurry of resin catalyst was
stirred magnetically and reflmre~ at ~tmospheric pressure for 16 hours. In
35 the relll-x;--g process, the material boils at ~tmospheric prcssule and
conde-ncec the vapors back into the boiling material. The resin catalyst was
WO 95/16763 2 ~ 7 8 9 5 5 PCT/USg4/14234
11
filtered from the product lllL~Iure, and then uncollvelled methanol and
methyl pente-nes were distilled away from the product ether (2MMP). The
uncollvelled materials were placed back in the re~ction flask with the resin
catalyst and refluxed again for another 16 hours. This procedure of reaction
s followed by removal of product ether was repe~te~l three times. This was
desirable in order to achieve good collvel~ion of the starting material since
the etherific~tion re~ction is equilibrium limite~l The product ether was
distilled again (boiling point 112~C) to yield product purity of 99.4% by GC
analysis.
0 The octane numbers and Reid vapor ~les~ure results were mç~cllred
using the st~n~l~rd test methods well known in the art. The Research Octane
Number (RON) was 88.3 and the Motor Octane Number (MON) was
a~rc.-;...~tçly 90. The precise MON could not be ~p~cl~ed as the fuel/air
ratio was set at the hiehest setting available on the test eneine~ In the
st~n(l~rd test procedure, the fuel/air ratio is co~ lly increased until
m~x;.",),- knock is obtained. The Reid vapor plcs~ure was 1.25 psi.
These results are concictent with the reported octane numbers for
ethers of C6 olefinc, and support the industry view (for example, as e,-~fessed
in US-A~,193,770) that such ethers are not useful as octane boosters for
2 o motor ~colinç~
EXAMPLE II
MDMB - the Invention
This example of the invention illustrates that one of the ethers
pro~h~ce~ from C6 olçfinc, spe~fic~lly MDMB, is useful as an octane booster.
2-Methoxy-2,3-dimethyl butane (MDMB) was ~ ed from 2,3-
dimethyl-2-butene (2112 g) and methanol (879 g) in a similar m~nnçr as
described for prepa~ation of 2MMP in Example I. The product had a boiling
point of 115C and a product purity of 98.2% 2-methoxy-2,3-dimethylbutane
with the balance being 2-methoxy-2-methyl pentane from 2-methylpentene
h~ulil~ in the starting material. The Research Octane Number mç~cllred
for this MDMB rich product was 108.1 and the Motor Octane Number was
96.8. The Reid vapor ~res~ule was 7.3 kPa (1.06 psi).
WO 95/16763 PCT/US94/14234
- 12- ~ q 5
Analysis of Examples I and II
The octane numbers from Examples I and II along with those of C4
and Cs olefins are reproduced below in a table format for easy co,.,r ~ on
Parent Olefin Ether RON MON
C4 MTBE 118 100
C~ TAME 111 98
C6 MDMB 108.1 96.8
2MMP 88.3 less than 90
One can see that unexpectedly, and con~ to the prejudice arising
from the prior art investig~tion of C6 olefin ether, MDMB has RON and
MON values which _ake it sul~ gly good as an octane booster for motor
g?~colin
EX~MPLE III
In ~d~lition to the coJl,l)o"ent RON, MON, and Reid vapor l,le~uie
(RVP) numbers being determined, a set of col,esponding blen~ling values for
5 MDMB was also ascertained. As it is well known to one of ordi"a,~ skill in
the art, the "blen~ling" RON, MON, and RVP values vary based upon the
base g~coline composition- Typically, the "Blending Values" (BV) are higher
for RON and MON and are slightly lower for RVP.
Blends of appro-;",~tely 14, 19, and 25% volume MDMB/volume
20 g~colinet as synthe-ci7e~l in Example II, were plepared using two diL~ere,
g~colin.os, A and B, as described below.
Gasoline AG~coline B
RON 93 97
MON 83 87
RVP, kPa 50.3 (7.3 psi)53.8 (7.8 psi)
The res~llting RON, MON, and Reid vapor pres~ure numbers were
25 me~c~lred for each of the blends with the following results.
WO 95/16763 2 1 7 8 9 5 5 PCTIUS94/14234
Gasoline MDMB RON MON RVP RVP
Vol %Blend Blend Blend, Blend,
kPa psi
A 13.895.6 85.2 45.5 6.6
A 18.796.3 85.8 43.4 6.3
A 24.397.3 87.0 37.9 5.5
Average A ~ 96.4 86.0 42.1 6.1
B 14.298.8 88.2 42.7 6.2
B 19.299.4 88.8 46.2 6.7
B 24.999.9 89.6 40.7 5.9
AverageB --- 99.4 88.7 43.4 6.3
The values of the blend were then used in the following m~nner to
c~ te the l,lopellies of the finiche~ blend. RVP is used as an example.
VOL ga~ e VOL MDMB
RVP bknd ' RVP ~olinc + BV RVP MDMB
VOL gasolinc ~ VOL MDMB VOL g~ c I VOL MDMB
Even though this equation is not 100% accurate for cal~ ting octane
0 numbers, as the RON and MON do not blend linearly, it can be used to
predict octane withinil number for the n~low range of blends investig~te~l
This example illustrates that the blçn-ling values for the properties of
MDMB for the RON and MON are somewhat higher with an average of 110
and 97 respectively, and the RVP is somewhat lower at 6.9 kPa (1 psi), which
iS typical, as co~ 3ared to the colll~ollent values for the RON, MON, and
RVP of the MDMB component, which were 108, 97, and 7.3 kPa (1.06 psi)
respectively. Also shown for reference are the typical blen~ling values for
15% MTBE, 10% ethanol and 12% TAME.
WO 95/16763 PCT/US94/14234
~ 1~ '6 9 s~
- 14-
COMPONENT RON BV MON BV RVP BV
MDMB with 112 98
Gasoline A
MDMB with 109 96
G~coline B
MTBE 117 98 8.4
ETHANOL llS 96 22
TAME 106 94 224
One can see that the blen~ling RON and MON values of MDMB are
co...~ able to those of MTBE, ethanol, and TA~E, which makes MDMB
5 attractive as an octane booster for motor ~coline. MDMB's low blen~ling
RVP value makes it espec~ y attractive as an octane booster in co...p~ o--
to MTBE, cth~nol and TAME, as it does not carIy a high RVP debit ac is
typically associated with the other octane boosters.
