Apparatus for producing alkylene glycols, alkyene glycols having higher primary hydroxyl content, method of producing glycols having higher primary hydroxyl content, method of producing acrylate esters

Disclosed is an apparatus and process for producing a tripropylene glycol in which alkylene oxide, water, an acid catalyst and a dipropylene glycol are contacted together under conditions suitable to form the tripropylene glycol. Water is present in the reaction mixture in the range of about 1 to about 50 weight percent of the reaction mixture. The ratio of water to alkylene oxide is less than about 9. The tripropylene glycol thus produced exhibits a higher primary hydroxyl group content generally exceeding 36 percent. Such tripropylene glycols find utility in the production of acrylics. Also disclosed is a process for making esters from such glycols.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to alcohols, to apparatus for producing 
alcohols, to a method of producing alcohols, and to a method of producing 
esters from alcohols. In another aspect, the present invention relates to 
alkylene glycols, to apparatus for producing such glycols, to a method of 
producing such glycols, and to a method of producing esters from such 
glycols. In yet another aspect, the present invention relates to alkylene 
glycols having an increased primary hydroxyl content, to apparatus for 
producing such glycols which include one or more continuous stirred tank 
reactors in series feeding a plug flow reactor, to a method of producing 
such glycols from a reaction mixture of water, lower order alkylene 
glycols, alkylene oxide and acid, and to a method of producing acrylate 
esters from such glycols. 
2. Description of the Related Art 
Monoalkylene glycols are generally produced by the hydrolysis of the 
alkylene oxide at large excess of water, generally on the order of 15 to 
40 moles water to mole of alkylene oxide, with water generally comprising 
85 weight percent of the reaction mixture. See, Kirk-Othmer Encyclopedia 
of Chemical Technology, 3rd. ed. (hereinafter "Kirk-Othmer"), Vol. 19 at 
246-274 and 250. 
Higher order alkylene glycols are generally produced either as by-products 
in the hydrolysis of monoalkylene oxides or as by-products in the 
production of lower order alkylene glycols, or are produced directly 
through one or more additions of an alkylene oxide with a lower order 
alkylene glycol. 
For example, in the production of monopropylene glycol through the 
hydrolysis of propylene oxide at a large excess of water of 15 moles 
water/mole propylene oxide, the product mix is generally 85 percent 
propylene glycol, 13 percent dipropylene glycol, and 1.5 percent 
tripropylene glycol and higher adducts. See, Kirk-Othmer, vol. 11 at 
933-956 and 952. 
Tripropylene glycol can also be obtained directly by the addition of 
propylene oxide to dipropylene glycol, generally in a catalyzed process. 
Since water is a competitor with the dipropylene glycol for the propylene 
oxide, its presence in the reaction mixture is to be avoided. 
In the production of tripropylene glycol both primary and secondary 
hydroxyl groups are obtained. It is understood that the produced glycols 
will have either two primary hydroxyl groups, two secondary hydroxyl 
groups or one of each. As used herein the primary hydroxyl content is a 
percentage of the hydroxyl groups that are primary. 
The primary hydroxyl group content obtained in the prior art propylene 
glycol processes is generally in the range of about 15 to about 36 
percent. However, there is a need in the art for alkylene glycols having a 
higher primary hydroxyl group content. 
There is also a need in the ark for a process useful in providing alcohols, 
especially higher order alkylene glycols, having higher primary hydroxyl 
group content. 
There is also a need in the art for an apparatus useful in providing 
alcohols, especially higher order alkylene glycols, having higher primary 
hydroxyl group content. 
There is also a need in the art for a process useful in providing esters 
from alcohols and organic acids, the process having increased alcohol 
conversion and/or an increased reaction rate. 
SUMMARY OF THE INVENTION 
It is therefore one object of the present invention to provide for alkylene 
glycols having a higher primary hydroxyl group content. 
It is therefore another object of the present invention to provide a 
process useful in producing alcohols, especially higher order alkylene 
glycols, having higher primary hydroxyl group content. 
It is yet another object of the present invention to provide an apparatus 
useful in producing alcohols, especially higher order alkylene glycols, 
having higher primary hydroxyl group content. 
It is even another object of the present invention to provide a process 
useful in producing esters from alcohols and organic acids, the process 
having increased alcohol conversion and/or an increased reaction rate. 
Other objects of the present invention will become evident to those of 
skill in the art upon review of the foregoing disclosure of the invention. 
As discussed above, it is known in the prior art that dipropylene glycol 
and propylene oxide react to form tripropylene glycol. It is also known in 
the prior art that water and alkylene oxide react to form monopropylene 
glycol, with the water present at 15 plus mole excess and comprising 85 
percent of the reaction mixture. 
From these reactions, the prior art teaches that when forming tripropylene 
glycol by the reaction of a dipropylene glycol and propylene oxide, any 
water present in the reaction mixture would compete with the dipropylene 
glycol for the propylene oxide resulting in a reduced tripropylene glycol 
production rate. 
Surprisingly, the presence of water in the reaction mixture, at low water 
to alkylene oxide ratios and/or at a low concentration, actually enhances 
the production rate of the desired tripropylene glycol, and enhances the 
primary hydroxyl content of the final end product. 
Equally unexpectedly, was the novel reactor design, which included one 
continuous stirred tank reactor ("CSTR"), or several in series, which 
allowed for the production of higher order alkylene glycols having a 
higher primary hydroxyl content, under increased reaction rates. Also 
unexpected was the improved results achieved with the combination of 
utilizing a plug flow reactor in combination with one or more CSTRs. 
Also surprising, was an alternate semi-batch reactor design in which 
alkylene oxide and the acid were over time slowly added to the reaction 
mixture of water, and the other order alkylene glycols. 
According to one embodiment of the present invention there is provided a 
process for producing an Nth order alkylene glycol. The method generally 
includes the step of contacting together in a reaction mixture alkylene 
oxide, water, an acid catalyst and one or more lower order alkylene 
glycols under conditions suitable to form the Nth order alkylene glycol. 
As compared to prior art methods, water is present in small amounts and 
comprises in the range of about 1 to about 60 weight percent of the 
reaction mixture. The mole ratio of water to alkylene oxide is less than 
about 9. 
As a specific example of this embodiment, there is provided a process for 
producing a tripropylene glycol in which alkylene oxide, water, an acid 
catalyst and dipropylene glycol are contacted together under conditions 
suitable to form the tripropylene glycol. 
According to another embodiment of the present invention there are provided 
2nd and higher order alkylene glycols having an increased primary hydroxyl 
group content as compared to such glycols achieved by prior art methods. 
In a specific example of this embodiment, there is provided a tripropylene 
glycol composition having a higher primary hydroxyl group content than the 
prior art content of about 15 to about 36 percent. The inventive 
tripropylene glycol composition of the present invention generally has a 
primary hydroxyl content greater than 36 percent. 
According to yet another embodiment of the present invention there is 
provided an apparatus for producing higher order alkylene glycols. The 
apparatus generally includes one or more continuous stirred tank reactors 
("CSTR") in series feeding a plug flow reactor. The CSTR will receive a 
mixture of water, alkylene oxide, and lower order alkylene glycols, 
generally in a combined stream. Acid is slowly added to the reactor, 
through a heat exchange loop. The reactor contents are maintained in a 
stirred state by return of material from the heat exchange loop which is 
injected into the reactor at high velocity through nozzles. As the 
reaction mixture exits the CSTR with about 90 to 99 percent of the 
alkylene oxide converted, the plug flow reactor allows for substantially 
complete conversion of the alkylene oxide. 
According to still yet another embodiment of the present invention there is 
provided a process for producing higher order alkylene glycols in which 
water, alkylene oxide, and lower order alkylene glycols are continuously 
introduced into a reactor. Inside the reactor, the reaction mixture is 
subjected to continuous heating and vigorous stirring. Simultaneously, 
product is withdrawn from the reactor and fed to a second reactor to 
undergo plug flow through the reactor. 
According to even yet another embodiment of the present there is provided a 
semi-batch process for producing higher order alkylene glycols in which 
water, and lower order alkylene glycols are first batched into a reactor 
to form a reaction mixture. Subsequently, alkylene oxide and acid are 
added to the reaction mixture over the course of the process. 
According to even still yet another embodiment of the present invention 
there is provided a process for producing esters. This method generally 
includes as a first step contacting together in a reaction mixture 
alkylene oxide, water, an acid catalyst and an (N-1)th order alkylene 
glycol under conditions suitable to form a Nth order alkylene glycol, 
under conditions as described above. The second step of this method 
includes contacting the Nth order alkylene glycol of the first step with a 
carboxylic acid in the presence of an acid catalyst to form an ester. 
While the present invention is illustrated herein specifically for the 
reaction of an alkylene oxide with glycol, it is understood that the 
teachings of the present invention are believed to be equally applicable 
to reactions of alkylene oxide with alcohols in general, including mono-, 
di-, tri- and polyhydric alcohols. Therefore, such reactions are within 
the scope of the disclosure of the present invention.

DETAILED DESCRIPTION OF THE INVENTION 
In the practice of the present invention a higher order alkylene glycol 
adduct is generally produced from a reaction mixture that includes a small 
amount of water, alkylene oxide, an acid catalyst, and a lower order 
alkylene glycol adduct. Surprisingly, the presence of the small amount of 
water in the reaction mixture increases the production rage of the higher 
order alkylene glycol. Additionally, in the practice of the present 
invention higher primary hydroxyl content is Obtained in the higher order 
alkylene oxide product. 
As used herein, the "order" of an alkylene glycol adduct refers to the 
number of alkylene units in the alkylene glycol addition product. For 
example, a monoalkylene glycol is first order, dialkylene glycol is second 
order, trialkylene glycol is third order, tetraalkylene glycol is fourth 
order, etc. 
It is most unexpected that the presence of water in the reaction mixture, 
at low water to alkylene oxide ratios and/or at a low concentration, would 
actually enhance the production rate of the desired tripropylene glycol. 
Additionally, in the practice of the present invention, higher primary 
hydroxyl group content is obtained in the final end product as compared to 
prior art methods. 
At the very least, water is generally present in the reaction mixture in an 
amount suitable to promote increased rate of formation of the desired 
higher order alkylene glycol adduct. The concentration or mole ratio of 
water utilized in the present invention must be less than that which would 
unduly inhibit the production of the desired higher order alkylene glycol 
adduct. 
Generally, water is present in the reaction mixture in a concentration in 
the range of about 1 to about 60 weight percent based on the total weight 
of the reaction mixture. Preferably, the concentration of water in the 
reaction mixture is in the range of about 10 to about 50 weight percent, 
and more preferably in the range of about 10 to about 35 weight percent. 
Even more preferably, the concentration of water in the reaction mixture 
is in the range of about 15 to about 30 weight percent. 
In the present invention, the mole ratio of water to alkylene oxide is 
generally less than about 14:1. Preferably, the mole ratio of water to 
alkylene oxide in the reaction mixture is in the range of about 12:1 to 
about 1:1, more preferably in the range of about 10:1 to about 2:1, and 
most preferably in the range of about 8:1 to about 2:1. 
The alkylene oxide utilized in the present invention is generally selected 
to provide the desired higher order alkylene glycol adduct. For example, 
where the desired higher order alkylene glycol adduct is tripropylene 
glycol, propylene oxide is utilized. Where the desired higher order 
alkylene glycol adduct is tributylene glycol, butylene oxide is utilized. 
The alkylene oxide of the present invention is generally of the empirical 
formula: 
##STR1## 
wherein R.sub.1 is a C1 or higher order alkyl or substituted alkyl. 
Preferably, R.sub.1 is a C1 to C3 alkyl or substituted alkyl-. More 
preferably, R.sub.1 is a C1 to C2 alkyl or substituted alkyl, and most 
preferably, R1 is a C1 alkyl or substituted alkyl. 
Exemplary examples of the alkylene oxide utilized in the present invention 
include propylene oxide and butylene oxide. 
Most preferably, the alkylene oxide of the present invention is generally 
of the empirical formula: 
##STR2## 
wherein y is at least one, preferably y is 1 to 3, and most preferably y is 
1 or 2. 
In the practice of the present invention the concentration of free alkylene 
oxide in the reaction mixture must generally be minimized to avoid a 
runaway reaction, and/or to avoid deactivation of the catalyst. Generally, 
the concentration of the alkylene oxide in the reaction mixture is in the 
range of about 0.01 to about 20 weight percent. Preferably, the 
concentration of the alkylene oxide in the reaction mixture is in the 
range of about 0.1 to about 8 weight percent, and most preferably in the 
range of about 0.1 to about 6 weight percent. 
The acid catalyst utilized in the present invention is generally selected 
to catalyze the reaction mixture reactants in the formation of the desired 
higher order alkylene glycol. Acids suitable for use in the present 
invention are any non-oxidizing strong acid, having a counter ion that is 
a good leaving group and/or a poor nucleophile. 
Classes of acids suitable for use in the present invention include those 
having sulfuric or phosphoric functional groups. Examples of such acids 
include: sulfuric acid; substituted or unsubstituted alkyl-, aryl- or 
alkyl/aryl- sulfonic acids; phosphoric acid; substituted or unsubstituted 
alkyl-, aryl- or alkyl/aryl-phosphoric acids and sulfonic ion exchange 
resins. Preferably, the acid utilized in the present invention is selected 
from the group consisting of sulfuric acid, phosphoric acid, 
trifluoromethane sulfonic acid and paratoluene sulfonic acid. 
The desired higher order alkylene glycol adduct produced by the process of 
the present invention is generally of the empirical formula: 
EQU HO(CH.sub.2 CHR2O--).sub.(N-1) (CH(R1)CH.sub.2)OH 
wherein N is the order of the alkylene glycol and is at least 2, R1 is as 
described above, and each R2 is hydrogen or is the same as R1 or each R2 
is independently selected from among alkyls or substituted alkyls with 1 
or more carbon atoms. Preferably, each R2 is independently selected from 
among alkyls or substituted alkyls having 1 to 3 carbon atoms. Most 
preferably, N is 2 or 3 and each R2 is independently selected from among 
alkyls or substituted alkyls having 1 to 2 carbon atoms, Even more 
preferably, N is 3 and each R2 is independently selected from among methyl 
or substituted methyl. Still even more preferably, N is three and each R2 
is methyl. 
Preferable desired higher order alkylene glycol adducts produced by the 
process of the present invention are of the empirical formula: 
EQU HO(C.sub.x H.sub.2x O--).sub.(N-1) (CH(C.sub.y H.sub.(2y+1))CH.sub.2)OH 
wherein N is the order of the alkylene glycol and is at least 2, and x is 
greater than 3 and y is at least 1. Preferably, N is 2 to 4, y is 1 or 2, 
and x is 3 or 4. Most preferably, N is 3, y is 1, and x is 3. 
Examples of higher order alkylene glycols which may be produced in the 
present invention include dipropylene glycol, tripropylene glycol, 
tetrapropylene glycol, dibutylene glycol, tributylene glycol and 
tetrabutylene glycol. 
It is to be understood that in the production of an Nth order alkylene 
glycol adduct, the reaction mixture may include any one of or combination 
of 1st to (N-1)th order alkylene glycols. These lower order alkylene 
glycols may be added to the reaction mixture or they may be made in-situ. 
The lower order alkylene glycol adduct utilized in the present invention is 
generally selected to allow production of the desired higher order 
alkylene glycol adduct. Thus, the lower order alkylene glycol adduct 
utilized in the reaction mixture will generally have the empirical 
formula: 
HO(R.sub.2 O--).sub.M E 
wherein M may range from 1 to N-I, where N is at least 2 and N is the order 
of the desired higher order alkylene glycol, and wherein R.sub.2 is as 
described above. 
Preferable lower order alkylene glycol adducts present in the reaction 
mixture are of the empirical formula: 
EQU HO(C.sub.x H.sub.2x O--).sub.M H 
wherein M and x are as described above. 
For example, where the higher order alkylene glycol to be produced is 
tripropylene glycol, the lower order alkylene glycols which may be present 
in the reaction mixture include monopropylene glycol and dipropylene 
glycol. 
The process of the present invention my be carried out in any suitable 
reactor that will allow production of the desired higher order alkylene 
glycol adduct from a reaction mixture that includes a lower order alkylene 
glycol adduct, alkylene oxide, water and an acid catalyst. 
An example of a suitable reactor system includes a semi-batch reactor 
process in which the water, lower order alkylene glycol, and some of the 
acid catalyst is first charged to the reactor, followed by slow addition 
of the alkylene oxide and periodic charging of the remainder of the acid 
catalyst. It is generally necessary to maintain a low level of alkylene 
oxide in the reaction mixture. At the Very least, acid catalyst is added 
at a rate necessary to avoid accumulation of alkylene oxide. Higher acid 
levels tend to cause quicker catalyst deactivation, and may pose 
corrosivity problems in the reactor and attendant equipment. Thus, at the 
upper limit, acid catalyst is added at a low enough rate to avoid rapid 
catalyst deactivation and to avoid corrosivity problems. 
The reaction mixture in the semi-batch reactor is generally subjected to 
mixing suitable to maintain the alkylene oxide in intimate contact with 
the other reactants. Any of the mixing techniques known to those of skill 
in the art may be utilized, such as with an internal impeller, or by 
recirculating the reaction mixture and reinjecting it back into the 
reactor through nozzles. The alkylene oxide will generally be in gaseous 
form, with the remainder of the reactants in liquid form. Thus, to improve 
the contacting of the alkylene oxide with the other reactants, the reactor 
is generally operated at or near liquid full to minimize the vapor space. 
Additionally, the alkylene oxide may be sparged into the bottom of the 
reactor. 
The semi-batch reactor is generally operated for a reaction time suitable 
to obtain the desired product and desired reactant conversion. Generally, 
such semi-batch reaction times are on the order of about 5 minutes to 
about 100 hours. Preferably, semi-batch reaction times are in the range of 
about 15 minutes to about 50 hours, more preferably in the range of about 
30 minutes to about 30 hours, and most preferably in the range of about 5 
hours to about 30 hours. 
Another reactor system suitable for use in the present invention includes a 
continuous stirred tank reactor ("CSTR") in which the alkylene oxide, 
water, lower order alkylene glycol and acid are continuously fed to the 
reactor. The reactants may be introduced into the CSTR either premixed or 
through separate conduits. Where there is a concern that the reaction will 
be catalyzed in the feed stream, the acid is introduced to the CSTR 
separately from the other reactants to avoid a runaway reaction in the 
feed stream. 
In the design of the CSTR system, it is also preferable to utilize some of 
the heat produced in the CSTR to preheat the incoming alkylene oxide, 
glycol and water feed mixture to increase the alkylene oxide conversion. 
In a CSTR system, the steady state concentration of the alkene oxide will 
generally be less than that in utilized in a batch process. In general, 
the steady state concentration of the alkylene oxide in the CSTR is 
generally maintained at a very low level on the order of about 0.1 to 
about 6 weight percent based on the weight of the reactor mixture. A 
product stream is continuously removed from the reactor. As the conversion 
of the alkylene oxide is generally in the range of about 90 to about 99 
percent, further conversion in a subsequent reactor is optionally 
undertaken as desired. If subsequent conversion is desired, one suitable 
option is to feed the product stream from the CSTR to a plug flow reactor 
where the remainder of the alkylene oxide will be converted. Examples of 
suitable plug flow reactors useful in the present invention include a 
tubular reactor or a tank having plug flow enhancing elements such as 
baffles, structural packing or random packing. 
The reaction mixture in the CSTR is generally subjected to mixing adequate 
to maintain the alkylene oxide in intimate contact with the other 
reactants. Any of the mixing techniques known to those of skill in the art 
may be utilized, such as with an internal impeller, or by recirculating 
the reaction mixture and reinjecting it back into the CSTR through 
nozzles. As with the semi-batch reactor described above, it is preferable 
to operate the CSTR at or near liquid full. 
Residence times in the CSTR are generally suitable to obtain the desired 
higher order alkylene glycol product and obtain the desired reactant 
conversion. Generally, CSTR residence times are in the range of about 1 
second to about 12 hours. Preferable CSTR residence times are in the range 
of about 1 minute to about 6 hours, and most preferably in the range of 
about 10 minutes to about 2 hours. 
Referring now to FIG. 1 there is illustrated in schematic form one 
embodiment of the CSTR system of the present invention, showing feed 
streams 10, CSTR 30, heating and cooling loop 40, acid addition system 60 
and plug flow reactor 70. 
Water feed stream 11, alkylene oxide feed stream 13 (propylene oxide in the 
embodiment shown) and dialkylene glycol feed stream 14 (dipropylene glycol 
in the embodiment shown) form reactant feed stream 17 which is pumped via 
pump 21 and motor 23 via stream 18 to CSTR reactor 30. Acid is provided 
from acid addition tank 61 from acid circulation loop 67 via acid slip 
stream 68 and reinjection stream 59. Acid circulation is maintained by 
acid circulation pump 63 powered by motor 65. 
Heating and cooling of the reaction mixture is provided by heating and 
cooling loop 40 which includes cooler 46, heater 48 and heating and 
cooling loop pump 25 with motor 27. In the embodiment shown, cooler 46 is 
an air cooler, and heater 48 is a steam heater with steam inlet line 51 
and condensate return line 53. Stream 41 circulates the reaction mixture 
to pump 25. Pump outlet stream 28 is split at valve 42 to cooler 46 via 
steam 43 or to heater 48 via stream 45. Cooler return line 57 joins with 
heater return line 55 to form stream 58 which is joined by acid slip 
stream 68 to form reinjection stream 59. Stream 59 is reinjected into CSTR 
30 via nozzles 33 which provide adequate mixing of the reaction mixture. 
Reaction mixture is continuously removed from CSTR 30 and fed to plug flow 
reactor 70 via line 72. Product leaves plug flow reactor 70 via line 75. 
As a non-limiting example of the reactor design a tank with straight 
vertical sides, a cylinder, and rounded top and bottom may be utilized. 
The reactor has height:diameter ratio on the order of 1. The feed will 
enter the reactor just below the straight side to head weld and the 
desired product will flow out of the top of the CSTR to the plug flow 
reactor. A recycle loop going to the heat exchanger will exit from the 
center bottom of the reactor and return through one or more jets located 
on the head just below the straight side to head weld at an angle of about 
40.degree. from the vertical. At startup the CSTR is filled and feed is 
heated in a heat exchange loop, with the same loop used for cooling when 
necessary. Acid addition will also take place in the heat exchange loop. 
Some of the product stream from the CSTR will be routed to the plug flow 
reactor for completion of the alkylene oxide conversion. Entry into the 
plug flow reactor will generally not be at the beginning of the plug flow 
reactor, but will be at a suitable point generally half way through the 
plug flow reactor. The ratio of feed to the CSTR to feed to the plug flow 
reactor is generally less than about 1/2, e.g. 1/3. 
The reaction temperature and reaction pressure of the present invention are 
generally suitable to allow production of the desired higher order 
alkylene glycol adduct from a reaction mixture that includes a lower order 
alkylene glycol adduct, alkylene oxide, water and an acid catalyst. In the 
present invention, the reaction temperature and reaction pressure are very 
much a function of the water concentration and the type of catalyst 
utilized. 
In the present invention, the reaction rate generally increases with 
increasing temperature. Therefore, it is generally desirable to practice 
the present invention at the maximum convenient temperature below the 
temperature at which significant decomposition of the reaction mixture 
components or product takes place. It is also desirable that the reaction 
temperature be selected to maintain the water and alkylene glycol in the 
liquid phase. Thus, generally the reaction temperature is greater than the 
water/glycol mixture freezing point at the reaction pressure and less than 
the water/glycol mixture boiling point at the reaction pressure. 
Generally, depending upon the catalyst Utilized, suitable reaction 
temperatures are in the range of about -60.degree. C. to about 300.degree. 
C. More commonly, the reaction temperature is in the range of about 
20.degree. C. to about 180.degree. C. It is understood that preferred 
reaction temperatures will depend upon the specific type of catalyst 
utilized, as reaction temperature is also generally selected to provide an 
environment in which the acid catalyst will not be subject to undue 
degradation. 
For example, with perfluorosulfuric acid polymers, the preferred reaction 
temperature is in the range of about 20.degree. C. to about 90.degree. C. 
With phosphoric acid, the preferred reaction temperature is in the range 
of about 100.degree. C. to about 200.degree. C. 
The reaction pressure for the present invention should be selected so that 
the water and glycol in the reaction mixture will generally be in liquid 
form even when higher reaction temperatures are utilized. Suitable 
pressures will be in the range of about 1 to about 100 atmospheres, 
preferably in the range of about 1 to about 20 atmospheres. 
The higher order alkylene glycol product obtained with the process of the 
present invention comprises glycols having primary hydroxyl group, 
secondary hydroxyl groups or both. One advantage of the present invention 
is that second order and higher alkylene glycols can be obtained which 
have higher primary hydroxyl content than that obtained with the prior art 
processes. 
The primary hydroxyl group content of the higher order alkylene glycol 
produced in the present invention generally exceeds 36 percent. 
Preferably, the primary hydroxyl group content of the higher order 
alkylene glycol exceeds 40 percent, more preferably exceeds 44 percent and 
most preferably exceeds 48 percent. 
Once the higher order alkylene glycol product is recovered, the various 
components of the reaction mixture are separated by techniques well known 
to those of skill in the art. Generally, distillation is used to separate 
the various components of the reaction mixture. 
The higher order alkylene glycol products of the present invention having a 
higher primary hydroxyl content find utility in a wide range of 
applications, including the production of esters. 
In contacting the desired higher alkylene glycol of the present invention 
with an acid to made an ester, the inventors believe that the higher 
primary hydroxyl content will result in less unreacted glycols in the 
product mixture which is economically desirable, and also technically 
desirable as the unreacted glycols are difficult to separate from the 
ester product. Additionally the inventors believe that the higher primary 
hydroxyl content will speed the reaction rate and will thus avoid many of 
the problems associated with long reaction times, i.e., detrimental heat 
history, coloring and an increased viscosity. 
In the production of esters, the higher order alkylene glycol is contacted 
with 10 to 20 mole percent excess of a carboxylic acid in the presence of 
an acid catalyst to form the ester. Suitable acid catalysts generally 
include Lewis or Bronsted acids such as paratoluene sulfonic acid or 
dibutyl tin oxide. It is generally necessary to remove water from the 
reaction mixture to drive the reaction, in many instances with the aid of 
an azeotroping agent, such as xylene or toluene. 
The higher order alkylene glycol products of the present invention having a 
higher primary hydroxyl content are especially useful in the production of 
acrylate esters in which acrylic acid and the glycol are generally reacted 
as described above. 
EXAMPLES 
Example 1 
This example is for comparative purposes showing the reaction of propylene 
oxide and dipropylene glycol in the absence of water without catalyst 
(batch). 
Recipe: 
41.51 grams of propylene oxide ("PO") 
0.0 grams of water 
1860.0 grams of dipropylene glycol ("DPG") 
Conditions: 
125.degree. 
250 rpm 
85 psig 
1 sample per hour 
The reactor was charged liquid full with DPG and allowed to reach 
124.degree. C., and an additional 44 mls of reaction mixture was removed 
from the reactor vessel to insure a complete PO charge. The PO charge was 
rapidly injected into the highly agitated reaction mixture. Sample #0 was 
removed after 1 minute of elapsed reaction time, the agitator speed was 
lowered to 250 rpm, and the sample analyzed. Thereafter samples of the 
reaction mixture were removed and analyzed every hour for six hours. 
PO conversion was determined and found to be 11.2%. PO conversion, even in 
the liquid filled vessel, was much lower than expected. The data were used 
to determine the kinetic parameters for the reactions in the absence of 
water, since the available literature data for the parameters of the 
uncatalyzed reactions of PO, PG, and DPG, were obtained in solutions 
containing a large excess of water. 
Example 2 
This example shows the effect of a small amount of water on the reaction of 
propylene oxide and dipropylene glycol without catalyst (batch). 
Recipe: 
40.34 grams of PO 
18.47 grams of water 
1828.5 grams of DPG 
Conditions: 
125.degree. C. 
250 rpm 
100 psig 
1 sample per hour 
The reactor was filled with the recipe mixture of water (1%) and DPG and 
heated to 125.degree. C. The PO charge was injected into the reactor, the 
reaction mixture agitated for 2 minutes, and sample #0 was removed and 
analyzed. Additional samples were removed, and analyzed every hour for 3.5 
hours. The data from the samples indicated a PO conversion of 10.3%, 
compared to 8.3% PO conversion at 3.5 hours in Example 1. The rate of 
reaction increased by about 25% using a low concentration of water versus 
no addition of water. 
Example 3 
This example shows the effect of using a higher water concentration, to 
better define the effect of water in the hydrolysis and coupling 
reactions. 
Recipe: 
40.4 grams of PO 
96.55 grams of water 
1834.5 grams of DPG 
Conditions: 
125.degree. C. 
250 rpm 
100 psig 
variable sample frequency 
The recipe quantities of water (5%) and DPG were mixed, poured into the 
reactor, and heated to reaction temperature. When the temperature 
stabilized 125.degree. C., and the agitator stabilized at 750 rpm, the PO 
charge was injected into the reaction mixture. Sample #0 was removed after 
two minutes of reaction after which time the agitator speed reduced to 250 
rpm. Subsequent samples of the reaction mixture, were obtained at 
approximately 30 minute intervals for 1.3 hours and then every hour for an 
additional 3 hours, and analyzed. PO conversion was determined to be 15.1% 
after 4.3 hours reaction time. When compared with a PO conversion of 10.2% 
for Example 1, after the same elapsed reaction time, the data shows that 
the conversion rate increased by about 50%. Another noticeable effect of 
the increased water content was the increased quantity of propylene glycol 
(PG) in the reaction product. The PG increased from 0.02%, in Example 1, 
to 0.2% in this example. 
As this experiment shows, the effect of water on the rate of reaction, at 
5% water, is not very great. 
Example 4 
This example was performed in an autoclave reactor using a base catalyst as 
is well known in the prior art. 
Recipe: 
44.74 grams of PO 
18.57 9rams of water 
1837.9 grams of DPG 
1.6 grams of 50% NaOH solution 
Conditions: 
125.degree. C. 
250 rpm 
100 psig 
variable sample frequency 
The precatalyzed reaction mixture containing the caustic was heated to 
125.degree. C. and the PO charge was injected into the highly agitated 
reaction solution. Sample #0 was obtained from the reactor through the 
sample cooling coil at the bottom of the reactor. A single drop of 25% 
sodium dihydrogen phosphate (75% water) solution was added and the sample 
was vigorously shaken to neutralize any NaOH in the sample. The samples, 
obtained every 10 minutes, were neutralized, filtered, and analyzed. 
The data showed that the caustic catalyzed reaction had produced a final PO 
conversion of 86.5%. The reaction solution contained 0.08% PG, 7.3% TPG, 
and 0.1% TEPG. The yield to TPG versus PO conversion was exceptional when 
compared to the previous reactions, but the data on the final product 
sample indicated that a large fraction of the mass of the TPG product was 
the undesirable secondary hydroxyl isomers. 
Reactions using phosphoric acid as the reaction catalyst were studied as 
the first choice to develop a homogeneous acid catalyzed process to 
produce TPG commercially. 
Example 5 
This example illustrates the use of phosphoric acid as the reaction 
catalyst. 
Recipe: 
42.29 grams of PO 
100.0 grams of water 
1850.0 grams of DPG 
0.96 grams of 85% H3PO4 acid (426 ppm) 
Conditions: 
125.degree. C. 
250 rpm 
100 psig 
6 samples per hour 
The water content of the reaction mixture was increased to 5% water, as 
other experiments indicated that at 1% water the catalyst was deactivating 
in about 30 minutes. The catalyst concentration was also increased to 426 
ppm to aid in achieving a higher PO conversion and faster reaction rate. 
The reaction mixture was sampled eight times in 1 hour and 45 minutes of 
reaction time. The analysis of the samples showed a higher PO conversion 
had been achieved, and more TPG was produced. PO conversion was 67.7%, and 
the product mixture contained 3.5% TPG. The mixture also contained 0.7% 
propylene glycol (PG). 
The catalyst still lost activity after 30 minutes. The catalyst extinction 
time remained essentially the same, even with the addition of more water 
to and an additional quantity of catalyst. 
Example 6 
This experiment shows the effect of adding portions of the acid catalyst 
during the reaction. 
Recipe: 
47.70 grams of PO 
100.0 grams of water 
1801.0 grams of DPG 
0.48 grams of 85% H3PO4 acid (200 ppm)+four 
200 ppm additions (con-adds) 
Staged-addition recipe: 
8 mls DPG 
2 mls water 
0.47 grams of 85% H3PO4 in the con-add mixture 
Conditions: 
125.degree. C. 
250 rpm 
250 psig 
sample frequency was variable 
The reaction mixture was heated to 125.degree. C., agitation increased to 
750 rpm, sample #0 was removed, and the PO charge injected into the 
vigorously agitated solution. After two minutes, reactor agitation was 
reduced to 250 rpm, and sample #1 obtained; at ten minutes, sample #2 was 
obtained; at 15 minutes staged-addition #1 was injected into the reaction 
mixture. This was accomplished by the pressurized injection of the 
staged-addition mixture, using the PO injection cylinder. Two minutes 
after the staged-addition, sample #3 was obtained; 7 minutes later sample 
#4 was obtained; at twenty five minutes of elapsed reaction time, 
staged-addition #2 was injected, and the sampling cycle repeated. The 
cycle was repeated until a total concentration of 1000 ppm H3PO4 catalyst 
was achieved in the reactor solution. Eleven reaction samples and an 
original feed mixture sample were obtained, analyzed. 
The data showed the PO conversion was 96.5%, and the final reactor mixture 
composition was 1.0% PG, 5.3% TPG, 0.2% TEPG, 0.09% of residual unreacted 
PO, with the balance comprising DPG and water. The reaction was 
accomplished in 1.33 hours. The slope of the PO conversion line was smooth 
until the PO concentration in the reaction mix was less than 0.5%. The 
slope of the conversion curve flattened out as the PO concentration 
decreased. The curve for the appearance of TPG matched the rate of 
disappearance of PO. 
A comparison of the data from Example 5 and this Example 6, showed that the 
rate at which TPG appeared in the two reactions to be essentially the 
same, even though Example 5 utilized 426 ppm of H3PO4 versus the 200 ppm, 
staged-addition of the H3PO4 catalyst utilized in Example 6. One major 
difference noted is that the final composition from Example 6 contained 
1.9% more TPG than the composition from Example 5. The pulsed con-adds 
kept an active quantity of catalyst in the reaction mix at all times, thus 
achieving a higher PO conversion and a higher yield to TPG. 
Example 7 
This example compares how a total of 400 ppm, in 40 ppm staged-additions of 
H3PO4, perform versus the single catalyst addition to the reaction of 
Example. 5. 
Recipe: 
45.25 grams of PO 
100.0 grams of water 
1814.0 grams of DPG 
0.08 grams of 85% H3PO4 acid solution (40 ppm) 
Staged-addition recipe: 
18 mls DPG 
2 mls water 
0.08 grams of 85% H3PO4 in the staged-addition mixture. 
Conditions: 
125.degree. C. 
250 rpm 
250 psig 
sample frequency was variable 
The reaction mix was heated to 125.degree. C. and the PO charge injected 
into the reaction solution. The reaction mixture was sampled on 3 minute 
intervals, and injections of the 40 ppm H3PO4 staged-addition mixture were 
made on ten minute intervals. This sample and staged-addition cycle was 
maintained for 1 hour and fifteen minutes reaction time. The reaction was 
continued for an additional hour after the final 40 ppm H3PO4 
staged-addition, and samples obtained on 30 minute intervals. 
A small exotherm, about 1.degree. C., was observed after each 
staged-addition of catalyst to the reaction mixture. 
The data shows a smooth, continuous PO conversion profile throughout the 
reaction, and the expected loss of catalytic activity after the final 
H3PO4 staged-addition. 
PO conversion was 79.8%, and the final reaction mix sample contained 3.6% 
TPG, o.8% PG, 0.1% TEPG with the balance comprising DPG and water. The 
data for this Example 7 shows that the staged-addition PO increases the 
conversion rate of propylene oxide as compared to the single PO addition 
of Example 5. The slope of the PO conversion curve was much steeper in 
Example 5, due to the initially higher concentration of H3PO4 catalyst, 
even though the two reactions achieved approximately the same final 
concentration of TPG; 3.4% for Example 5 and 3.6% for Example 7. 
Example 8 
This example studies the effect of using a perfluorosulfonic acid polymer 
on a solid support of sintered 1/8" alumina spheres. 
Recipe: 
45.25 grams of PO 
100.0 grams of water 
1814.0 grams of DPG 
100.0 grams of supported perfluorosulfonic 
acid polymer 
Conditions: 
125.degree. C. 
300 rpm 
250 psig 
sample frequency was variable 
The PO charge was injected into the hot, agitated, reaction mixture. The 
reaction temperature increased from 125.degree. C. to 133.degree. C. in 
about 5 seconds. Total reaction time was 2.6 hours. 
The data showed the PO conversion to be 93.8% in the first 2 minutes of the 
reaction, and full PO conversion was achieved at 5 minutes of elapsed 
reaction. The reaction produced 5.9% TPG, 0.4% PG, and 0.5% of 
tetrapropylene glycol ("TEPG") and pentapropylene glycol ("PEPG") with the 
balance comprising water and DPG. 
The exotherm noted during the early portion of the reaction indicates that 
a significant reduction in the reactor temperature can be made with this 
catalyst and the reaction would still proceed to completion in a 
reasonable time. 
The primary hydroxyl group content of the TPG produced was 29.78 percent. 
Example 9 
Recipe: 
43.3 grams of PO 
20.0 grams of water 
1838.0 grams of DPG 
100.0 grams of supported perfluorosulfonic 
acid polymer 
Conditions: 
65.degree. C. 
300 rpm 
250 psig 
sample frequency was variable 
This Example No. 9 was performed using the same catalyst used in Example 
No. 8. The catalyst was water washed to remove any residual organics, left 
over from Example No. 8. The reactor was charged with the same recipe 
mixture as in Example No. 8, and the PO charge injected. A 1.degree. C. 
exotherm was observed for 2 about minutes. 
PO conversion was 50% after about 10 minutes of reaction. The final sample 
of the reaction mixture showed that PO conversion was 94.6%. The reaction 
product also contained 5.2% of TPG, 0.2% MPG, 0.5% TEPG, and 0.5% PEPG 
with DPG and water comprising the balance. The supported perfluorosulfonic 
acid catalyst was very active compared to the previously studied acid 
catalysts. 
The primary hydroxyl group content of the TPG produced was 31.28 percent. 
Example 10 
This example, using a supported perfluorosulfonic acid polymer catalyst, 
was performed in an attempt to reduce the formation of undesirable 
byproducts, by reducing the reaction temperature. 
Recipe: 
46.67 grams of PO 
94.4 grams of water 
1798.0 grams of DPG 
100.0 grams of supported perfluorosulfonic acid polymer 
Conditions: 
50.degree. C. 
300 rpm 
250 psig 
sample frequency was variable 
The PO charge was injected into the reaction mixture, and a small exotherm, 
of 2.degree. C., was observed for about 5 minutes. The reaction was 
continued for a total of 2 hours and 5 minutes of reaction time. 
The data showed the PO conversion was 50% at 15 minutes into the 
experiment, and a final PO conversion of 90.9%. The reaction produced a 
final product having 4.3% TPG , 0.9% MPG, 0.4% TEPG, and 0.2% PEPG with 
the balance comprising DPG, water and byproducts. Undesirable byproducts 
concentration was determined to be in the range of 1.4% to 2.2%. The 
reduction in reaction temperature did reduce the production of dioxanes by 
approximately 50%. 
The primary hydroxyl group content of the TPG produced was 29.90 percent. 
Examples 11-17 
These examples were performed using a 2 liter continuous stirred tank 
reactor system ("CSTR") with a mechanical agitator and a jacketed 
heating/cooling system. The reaction was uncatalyzed in a water 
environment up to about 19.9 moles water to mole of PO at water 
concentrations up to about 60 percent. In these experiments, the reactor 
was operated until steady state was reached. The results from Examples 
11-17 were then utilized to study the kinetics of the reaction. 
Example 11 
Recipe: 
333.4 grams of PO 
1500.0 grams of water 
1500.0 grams of DPG 
Conditions: 
150.degree. C. 
390 psig 
sample frequency=variable 
pump feed flowrate=32-34 mls/min 
The CSTR reactor was operated at 150.degree. C., and the recipe mixture 
pumped through the reactor at 32.8 mls/min. The reactor effluent contained 
2.6% PO, 9.1% PG, 3.1% TPG, 0.2% TEPG, 0.07% PEPG, 0.007% byproducts with 
the balance being water and DPG. The PO yield to products was 91.4%, and 
the calculated PO molar mass balance was 102.9%, based on the analytical 
data. 
Example 12 
This example studies the effects of reduced water in the feed mixture. 
Recipe: 
300.0 grams of PO 
750.0 grams of water 
1950.0 grams of DPG 
Conditions: 
155.degree. C. 
390 psig 
sample frequency=variable 
pump feed flowrate=32-34 mls/min 
At steady state, the reactor effluent contained 4.6% PO, 5.4% PG, 3.9% TPG, 
0.2% TEPG, 0.05% PEPG, 0.0023% byproducts, with no balance of DPG and 
water. 
As compared to Example 11, the TPG concentration in the reactor effluent 
increased by only 0.8%, from 3.1% to only 3.9% , even though there was a 
rather large change in the water concentration in the feed mix. The 
effects of excess water in the feed are nominal on the production of TPG, 
but affects the production of PG and DPG very significantly. 
PO conversion was only 45.9% and PO yield was 83.5%. 
Example 13 
This is an example of the CSTR operated at a higher reaction temperature. 
Recipe: 
300.0 grams of PO 
750.0 grams of water 
1950.0 grams of DPG 
Conditions: 
180.degree. C. 
390 psig 
sample frequency=variable 
pump feed flowrate=15-16 mls/min 
At steady state the reactor effluent contained 1.3% PO, 8.8% PG, 6.7% TPG, 
0.6% TEPG, 0.09% PEPG., 0.02% byproducts with a balance of DPG and water. 
Compared to Example 12, the TPG yield increased from 3.9% to 6.7% in 
response to the increase in reaction temperature and subsequently 
increased conversion of PO. 
Example 14 
This example was performed to more completely determine the effects of 
water on the reaction product distribution and the rate of conversion of 
PO, using a recipe with very high water concentration. 
Recipe: 
304.2 grams of PO 
1800.4 grams of water 
900.0 grams of DPG 
Conditions: 
155.degree. C. 
390 psig 
sample frequency=variable 
pump feed flowrate=15-16 mls/min 
agitator speed=500 rpm 
At steady state the reactor effluent contained 0.6% PO, 11.5% PG, 2.7% TPG, 
0.2% TEPG, 0.05% PEPG, 0.079% byproducts and a balance of water and DPG. 
The PO conversion was 94.1%, and the calculated PO molar mass balance was 
108.3%. 
The data showed that a larger concentration of water dramatically reduces 
the production of TPG in favor of PG production. 
The primary hydroxyl group content of the TPG produced was 28.2 percent. 
Example 15 
Recipe: 
300.0 grams of PO 
540.0 grams of water 
2160.0 grams of DPG 
Conditions: 
155.degree. C. 
390 psig 
sample frequency=variable 
pump feed flowrate=15-16 mls/min 
agitator speed=500 rpm 
The reactor was operated in the same manner as in Example 14. 
At steady state the data showed that the PO conversion was 58.5%, the PO 
yield was 69.7%, and the PO molar mass balance was 100.97%. The reactor 
effluent contained 4.2% PO, 6.1% PG, 4.7% TPG, 0.28% TEPG, 0.006% PEPG, 
0.009% byproducts with a balance of water and DPG. 
The reaction showed that low water concentration in the feed mixture 
improved the production of TPG , but the PO conversion decreased 
correspondingly. 
The primary hydroxyl group content of the TPG produced was 25.33 percent. 
Example 16 
The reactor of Examples 11-15 was modified to accommodate the acid 
catalyzed process previously discussed, by addition of a separate metered 
feed system for the acid catalyst. 
The modified reactor assembly further included a cross exchanger on the 
inlet of the reactor to preheat the incoming PO-water-DPG feed mix. 
A pump, capable of 0.2 mls/min. to 10 mls/min. of flow, was used to pump 
the catalyst feed mixture to a mixing tee in front of the first 
preheater-cross exchanger, where the two feed components were partially 
mixed before heating. The first exchanger was a 2 feet length of 1/8" 
stainless steel tube inside a 1/4" tube, with the hot reactor effluent 
flowing on the shell side. The second exchanger was constructed the same 
way, except that the length was 2.5 feet, the total length of cross 
exchanger needed to raise the feed mix temperature to 100.degree. C. 
The flow velocity through the preheater exchanger tubes provided some 
mixing of the reactants and catalyst solution prior to entry into the 
agitated reactor vessel. 
Recipe: 
801.5 grams of PO 
921.5 grams of water 
57.0 grams of DPG 
Catalyst feed pump recipe: 
3.78 grams of H3PO4 (85%) in 956.24 grams of water 
catalyst pump feed flowrate=2.0-2.1 mls/min 
Conditions: 
155.degree. C. 
390 psig 
sample frequency=variable 
organic pump feed flowrate=30-32 mls/min 
agitator speed=500 rpm 
100 mls of water containing 0.47 grams of H3PO4 pumped into the reactor to 
achieve a starting concentration of 200 ppm of H3PO4 catalyst prior to 
pumping the PO-water-DPG feed mixture into the reactor vessel. The two 
pump flows were calibrated and matched such that the catalyst feed pump 
would feed enough H3PO4 and water into the reactor to achieve the correct 
recipe composition and maintain 200 ppm of H3PO4 catalyst in the reactor 
at all times. The PO-water-DPG feed mix and the H3PO4-water catalyst mix 
were pumped to the reactor at 16 mls/min, total flow, to establish the 
ability of the cooling bath to handle the expected reaction exotherm. 
After two reactor volumes the feed flows to the reactor were slowly 
increased to 30.8 mls/min., including 2.0 mls/min. of catalyst feed mix. 
At steady state a typical reactor effluent had the following composition; 
0.35% P.O., 36.9% PG, 17.5% DPG, 5.9% TPG, 1.9% TEPG, 0.7% PEPG, 0.1% 
hexapropylene glycol ("HEXPG"), 0.03% byproducts with a balance of water. 
The reactor residence time was 62 minutes, PO conversion was 98%, and the 
yield was 71.7%., The PO yield calculation formula does not include the 
DPG produced by the reaction. 
The reaction product contained large concentrations of PG and DPG due to 
the presence of the water in the feed mixture. 
The primary hydroxyl group content of the TPG produced was 42.9 percent. 
Example 17 
This example at higher reactants feed throughput, and lower reaction 
temperature, was performed to determine the limits of the modified reactor 
described in Example 16. 
Recipe: 
801.5 grams Of PO 
921.5 grams of water 
57.0 grams of DPG 
Catalyst feed pump recipe: 
3.78 grams of H3PO4 (85%) in 956.2 grams of water 
catalyst pump feed flowrate=3.3-3.5 mls/min. 
Conditions: 
125.degree. C. 
390 psig 
sample frequency=variable 
organic pump feed flowrate=40-45 mls/min 
agitator speed=500 rpm 
The reaction was performed in the same manner as in Example 16. 
At steady state the analytical results were as follows: 2.03% PO, 36.2% PG, 
16.5% DPG, 5.4% TPG, 1.7% TEPG, 0.52% PEPG, 0.015% byproducts and the 
balance of water. 
The primary hydroxyl group content of the TPG produced was 42.3 percent. 
ANALYSIS OF EXAMPLES 11-17 
Generally propylene glycol (PG) dipropylene glycol (DPG) and tripropylene 
glycol (TPG) are formed by reacting water and PO under neutral conditions 
as: 
1. PO+H.sub.2 O.fwdarw.PG 
2. PO+PG.fwdarw.DPG 
3. PO+DPG.fwdarw.TPG 
4. PO+TPG.fwdarw.TET 
5. PO+TET.fwdarw.PENT 
6. PO+PENT.fwdarw.HEX 
Table 2 presents the portion of the data Examples 11-17 used to evaluate 
water effect. 
TABLE 2 
__________________________________________________________________________ 
EXPERIMENTAL DATA FOR CSTR* PROPYLENE GLYCOL REACTIONS 
Res 
Temp 
Time 
Feed Comp, wt % 
Product Comp, (normalized), wt % 
EXAMPLE # 
deg C. 
min. 
Water 
PO DPG 
PO PG DPG 
TPG 
TET+ 
__________________________________________________________________________ 
11 153.5 
58 45 10 45 2.47 
8.58 
42.78 
2.94 
0.19 
12 155.0 
58 25 65 10 4.93 
6.06 
60.91 
4.17 
0.23 
13 179.5 
118 25 65 10 1.18 
7.99 
61.04 
6.10 
0.59 
14 155.0 
126.5 
60 10 30 0.55 
10.12 
29.13 
2.48 
0.20 
15 155.0 
117.3 
18 10 72 4.10 
5.99 
68.36 
4.65 
0.27 
16 155.0 
61.7 
48.5 
48.5 
3 0.35 
36.73 
17.37 
5.81 
1.94 
17 125.0 
49 48.5 
48.5 
3 2.04 
36.38 
16.56 
s.39 
1.70 
__________________________________________________________________________ 
*Continuous Stirred Tank Reactor (or backmix reactor) 
As stated above, Examples 11-17 were conducted in a 2000 ml CSTR. 
Temperature was controlled at the value shown. Samples were collected and 
analyzed until the reactor reached steady state. Data were normalized 
based on the effective PO content of the feed. The normalized product 
concentrations are shown in Table 2. 
Adjustment factors, F1 and F2, were added to the reaction kinetics to 
account for the presence of the water as shown below: 
1. rate 1=k.sub.1 PO! WATER!*F1 
2. rate 2=k.sub.2 PO! PG!*F1 
3. rate 3=k.sub.3 PO! DPG!*F2 
4. rate 4=k.sub.4 PO! TPG!*F2 
5. rate 5=k.sub.5 PO! TET!*F2 
6. rate 6=k.sub.6 PO! PENT!*F2 
The rate equations shown correspond to the reactions described earlier. The 
factors were split so that reactions 1 and 2 had a different correction 
factor than did reactions 3-6. Both F1 and F2 are functions only of the 
water concentration. F1 is applied to reacting hydroxyl species whose 
pK.sub.A is .about.14, while F2 is applied to the weaker hydroxyls with a 
pK.sub.A .about.16. 
Using a simulator and the example results, F1 and F2 were varied to 
determine the best fit for each of the runs shown in Table 1. Appropriate 
values were selected based on how well the predicted TPG production 
matched lab data. Comparisons with PG and DPG production were also noted. 
There are multiple combinations of F1 and F2 which will properly adjust the 
model to match an experimentally determined component concentration for a 
given water concentration. The (F1,F2) pairs were chosen to provide a 
smooth relationship between water concentration and the respective 
adjustment factor. 
The values chosen for Examples 11 through 15 are presented in Table 3. The 
respective regression lines are shown in FIGS. 1 and 2. 
TABLE 3 
______________________________________ 
EXPERIMENTALLY DETERMINED F1 AND F2 VALUES 
Example # 
Water, wt % F1 F2 
______________________________________ 
15 18 0.26 0.062 
12 25 0.37 0.12 
11 45 0.78 0.28 
14 60 0.96 0.47 
______________________________________ 
The factors F1 and F2 were fit to a generalized sigmoid function of the 
form: 
EQU y=C+A/B+exp(-ax+b)! 
End points used in the regression were: 
______________________________________ 
Water, wt % F1 F2 
______________________________________ 
0.01 0.01 0.01 
99 1. 1. 
______________________________________ 
Results of the regression are shown in Table 4. 
TABLE 4 
______________________________________ 
REGRESSED CONSTANTS FOR F1 AND F2 EQUATIONS 
A B C a b 
______________________________________ 
F1 0.287 0.262 -0.079 0.0818 
1.020 
F2 0.027 -0.959 -0.281 0.00096 
0.525 
______________________________________ 
The data from Table 4 is shown plotted in FIGS. 2 and 3 which are plots of 
the water regression factors F1 and F2, respectively, plotted as a 
function of percent water in feed. Surprisingly, as the data shows, the 
addition of water to the system increases the reaction rates of all of the 
reactions. 
Example 18 
BUTYLENE OXIDE TO BUTYLENE GLYCOLS REACTION 
(H3PO4 catalyzed) 
A semi-batch reaction was performed in a 2 liter reactor vessel which 
contained 350 grams of water, 600 grams of monobutylene glycol and 2.35 
grams of 85% phosphoric acid. The reactor and the mixture were heated to 
155.degree. C., with vigorous agitation. To this mixture, butylene oxide 
was added at the rate of 5 milliliters per minute. Fresh 85% phosphoric 
acid catalyst was injected into the reaction mixture at 45 minute 
intervals during 4.5 hours of butylene oxide addition. The reaction 
mixture was analyzed for residual butylene oxide at 1 hour intervals. The 
final reaction product contained no detectable butylene oxide. The product 
mixture contained 58% monobutylene glycol, 32% dibutylene glycol, 8% 
tributylene glycol and higher oligomers. The tributylene glycol primary 
hydroxyl content is 50%. 
While the present invention is illustrated herein specifically for the 
reaction of an alkylene oxide with glycol, it is understood that the 
teachings of the present invention are believed to be equally applicable 
to reactions of alkylene oxide with alcohols in general, including mono-, 
di-, tri- and polyhydric alcohols, especially where it is desired to have 
a faster reaction rate and/or higher primary hydroxyl group content. 
Therefore, such reactions are intended to be within the scope of the 
disclosure of the present invention. 
The description given herein is intended to illustrate the preferred 
embodiments of the present invention. It is possible for one of ordinary 
skill in the art to make various changes to the details of the present 
invention, without departing from the spirit of this invention. Therefore, 
it is intended that all such variations be included within the scope of 
the present invention as claimed.