Title: Separation process
Abstract: Bisphenol-A-bis(neopentylglycolphosphate) products of enhanced properties and processes for preparing them are described. One of the processes includes (a) mixing and reacting neopentyl glycol and bisphenol-A-bis(dichlorophosphate) in an inert polar organic solvent which (1) if mixed by itself with an equal volume of water at 25° C., will form a separate phase, (2) the solvent by itself will dissolve at least about 10 wt % of bisphenol-A-bis(neopentylglycolphosphate) at a temperature in the range of 25 to 50° C., and optionally but preferably (3) the solvent by itself can be completely vaporized at a temperature below about 180° C.; (b) washing bisphenol-A-bis(neopentylglycolphosphate) product formed in a) while dissolved in inert organic solvent having such characteristics at least once with an aqueous alkaline washing solution; and (c) optionally but preferably, recovering bisphenol-A-bis(neopentylglycolphosphate) product from organic solvent having such characteristics. The reaction of (a) can be conducted in an inert non-polar solvent if that solvent is replaced by an inert polar organic solvent satisfying (1) and (2), and preferably (3). A solvent satisfying (1), (2), and (3) is used when (c) is conducted by distilling or vaporizing off the solvent to recover the bisphenol-A-bis(neopentylglycolphosphate) product as such. The product has a low acid number or a high thermal stability, and usually both.
Patent Number: 6,964,728 Issued on 11/15/2005 to McKinnie, et al.
| Inventors:
|
McKinnie; Bonnie G. (261 Columbia Rd. 10 W., Magnolia, AR 71753);
Williams; Robert E. (235 Columbia Rd. 525, Magnolia, AR 71753);
Sharp; Gary L. (238 Palmetto Dr., Magnolia, AR 71753);
Dadgar; Alireza M. (1500 E. University St., Magnolia, AR 71753)
|
| Appl. No.:
|
147621 |
| Filed:
|
May 16, 2002 |
| Current U.S. Class: |
203/6; 203/19; 203/38; 203/41; 203/47; 203/57; 203/100; 203/DIG.13; 568/749; 568/890; 568/913 |
| Intern'l Class: |
B01D 003/34; C07C 027/28; C07C 029/80 |
| Field of Search: |
203/29,6,100,50
568/779,726,913,641
159/DIG.20
|
References Cited [Referenced By]
U.S. Patent Documents
| 2165378 | Jul., 1939 | Hickman.
| |
| 3182088 | May., 1965 | Hennis.
| |
| 3234289 | Feb., 1966 | Hennis.
| |
| 3347937 | Oct., 1967 | Carr et al.
| |
| 4302614 | Nov., 1981 | Dannenberg et al.
| |
| 4701568 | Oct., 1987 | McKinnie et al.
| |
| 5395994 | Mar., 1995 | Williams et al.
| |
| 5527971 | Jun., 1996 | McKinnie.
| |
| 5723690 | Mar., 1998 | McKinnie.
| |
| 5847232 | Dec., 1998 | McKinnie.
| |
| 6002050 | Dec., 1999 | McKinnie.
| |
| 6084136 | Jul., 2000 | Holub et al.
| |
| 6084137 | Jul., 2000 | McKinnie et al.
| |
| 6300527 | Oct., 2001 | Manimaran et al.
| |
| Foreign Patent Documents |
| 1049071 | Nov., 1966 | GB.
| |
| 2049452 | Dec., 1980 | GB.
| |
| 9837046 | Aug., 1998 | WO.
| |
Primary Examiner: Manoharan; Virginia
Attorney, Agent or Firm: Kliebert; Jeremy J.
Claims
1. A process which comprises distilling in a column a distillable liquid from
a liquid mixture, said liquid mixture comprising (i) said distillable liquid, (ii)
one or more liquid component(s) other than said distillable liquid, and (iii) dissolved
solid component(s), comprised of 2,2-propylenebis[4,4'-(2,6-dibromophenol)], wherein
said distilling is conducted at a temperature at which said distillable liquid
is being distilled from said liquid mixture, wherein said dissolved solid component(s)
tend(s) to precipitate from the distillate and thereby cause pluggage in the distillation
column, and wherein there is added to said liquid mixture an amount of tribromophenol
which forms with said dissolved solid component(s) a composition that melts below
the temperature at which said distillable liquid distills, the amount of tribromophenol
added to said liquid mixture being an amount which forms with substantially all
of said dissolved solid component(s) a composition that melts below the temperature
at which said distillable liquid is being distilled, so that said pluggage is minimized
or avoided.
2. The process according to claim 1 wherein said dissolved solid component(s)
further comprise(s) tribromophenol in an amount that is not high enough to form
with substantially all of said dissolved solid component(s) a composition that
melts below the temperature at which said distillable liquid is being distilled.
3. The process according to claim 1 wherein said adjuvant is formed in situ.
4. A process which comprises distilling in a column a distillable liquid from
a liquid mixture, said liquid mixture being a mother liquor remaining after physically
removing a solid product formed in that liquid mixture, said liquid mixture comprising
(i) said distillable liquid, (ii) one or more liquid components(s) other than said
distillable liquid, and (iii) dissolved solid component(s), wherein said distilling
is conducted at a temperature at which said distillable liquid is being distilled
from said liquid mixture, wherein said dissolved solid component(s) tend(s) to
precipitate from the distillate and thereby cause pluggage in the distillation
column, and wherein there is added to said liquid mixture an amount of an adjuvant
which forms with said dissolved solid components(s) a composition that melts below
the temperature at which said distillable liquid distills, the amount of adjuvant
added to said liquid mixture being an amount which forms with substantially all
of said dissolved solid component(s) a composition that melts below the temperature
at which said distillable liquid is being distilled, so that said pluggage is minimized
or avoided.
5. The process according to claim 4 wherein said distillable liquid is an organic
solvent that is at least partially dissolved in water.
6. The process according to claim 1,
3,
4 or wherein said distilled
liquid is ethyl alcohol.
7. A process which comprises distilling in a column a water-soluble distillable
liquid that boils below the boiling temperature of water from a liquid mixture
comprised of (i) said water-soluble distillable liquid, (ii) water, and (iii) dissolved
solid component(s) comprised of 2,2—propylenebis[4,4'—(2,6—dibromophenol)],
wherein said distilling is conducted at a temperature at which water-soluble distillable
liquid is being distilled from the liquid mixture, wherein said dissolved solid
component(s) tend(s) to precipitate from distillate of water-soluble distillable
liquid and thereby cause pluggage in the distillation column, and wherein there
is added to said liquid mixture an amount of tribromophenol that is soluble in
said liquid mixture and which forms with said dissolved solid component(s) a composition
that melts below the temperature at which said water-soluble distillable liquid
is being distilled, the amount of tribromophenol added to said liquid mixture being
an amount which forms with substantially all of said dissolved solid component(s)
a composition that melts at a temperature below the temperature at which said water-soluble
distillable liquid is being distilled, so that said pluggage is minimized or avoided.
8. The process according to claim 7 wherein said solid component is 2,4,6-tribromophenol,
and wherein said water-soluble distillable liquid is ethanol.
9. The process according to claim 8 wherein the temperature at which the ethanol
is being distilled is about 110° C.
10. A process which comprises distilling in a column a distillable liquid from
a liquid mixture, said liquid mixture comprising (i) said distillable liquid, (ii)
one or more liquid component(s) other than said distillable liquid, and (iii) dissolved
solid component(s) comprised of 2,2-propylenebis[4,4'-(2,6-dibromophenol)] and
a small amount of tribromophenol, wherein said distilling is conducted at a temperature
at which said distillable liquid is being distilled from said liquid mixture, wherein
said dissolved solid component(s) tend(s) to precipitate from the distillate and
thereby cause pluggage in the distillation column, and wherein there is formed
in situ in said liquid mixture an amount of tribromophenol which, together
with said small amount of tribromophenol, forms with substantially all of said
dissolved solid component(s) a composition that melts below the temperature at
which said distillable liquid is being distilled, so that said pluggage is minimized
or avoided, said small amount of tribromophenol not being high enough to form with
substantially all of said dissolved solid component(s) a composition that melts
below the temperature at which said distillable liquid is being distilled.
11. A process which comprises distilling in a column a distillable liquid from
a liquid mixture, said liquid mixture comprising (i) said distillable liquid, (ii)
bromine, (iii) one or more liquid component(s) other than said distillable liquid
and bromine, and (iv) dissolved solid component(s) comprised of 2,2-propylenebis[4,4'-(2,6-dibromophenol)],
wherein said distilling is conducted at a temperature at which said distillable
liquid is being distilled from said liquid mixture, wherein said dissolved solid
component(s) tend(s) to precipitate from the distillate and thereby cause pluggage
in the distillation column, and wherein there is added to said liquid mixture molten
phenol which is brominated
in situ to form tribromophenol which forms with
said dissolved solid component(s) a composition that melts below the temperature
at which said distillable liquid is being distilled, the amount of tribromophenol
formed in said liquid mixture being an amount which results in substantially all
of said dissolved solid component(s) being converted into a composition that melts
at a temperature below the temperature at which said distillable liquid is being
distilled, so that said pluggage is minimized or avoided.
12. The process according to claim 11 wherein said dissolved solid component(s)
further comprise(s) tribromophenol in an amount that is not high enough to form
with substantially all of said dissolved solid component(s) a composition that
melts below the temperature at which said distillable liquid is being distilled.
Description
BACKGROUND
Distillation is a commonly used method for separating and recovering
one distillable liquid from another. There are however instances where a mixture
of different liquids contains a dissolved substance tending to precipitate from
the distillate and thereby cause pluggage of distillation equipment, such as distillation columns.
SUMMARY OF THE INVENTION
This invention is based in part on the discovery that the above pluggage problem
can arise when the melting temperature of the dissolved solid component is above
the distillation temperature being used to separate one distillable liquid component
from one or more residual, non-distilling liquids. Pursuant to this invention,
it has been further found that this problem can be avoided by providing to the
mixture to be distilled, an adjuvant which forms with the dissolved component a
composition that, if isolated, melts at a lower temperature than the distillation
temperature to be used for recovering at least one of the distillable liquids from
the mixture. The lower melting composition may be a eutectic mixture. However,
the proportions of the components in the lower melting composition, whether or
not a eutectic mixture, need not be the proportions that form the mixture thereof
having the lowest melting temperature—all that is required is that the adjuvant
and the higher melting dissolved solid component be proportioned in the solution
to form a composition, if isolated, having a melting temperature below that of
the distillation temperature to be used for recovering one of the distillable liquids
from the mixture.
In a preferred embodiment the adjuvant corresponds to at least one dissolved
solid
component already present in the solution, such as a by-product or other impurity.
This avoids introducing into the solution a component that is not already present,
albeit at a smaller concentration. Note that if the component were already present
in high enough concentration to form the lower melting composition with the dissolved
higher melting solid component, the problem would not arise, and there would be
no need to provide an additional amount of such component already present in the
solution to be distilled.
Other features and advantages of this invention will be still further apparent
from the ensuing description, accompanying drawing, and appended claims.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 schematically depicts a distillation system embodying the features of
this invention.
FURTHER DETAILED DESCRIPTION
For ease of reference, the following terms are sometimes used hereinafter:
- "distillable mixture" is the mixture to be subjected to distillation;
- "distillable liquid" is a liquid component of the distillable mixture,
which component is to be distilled from the distillable mixture;
- "dissolved higher melting solid" is a component of (i.e., a solute in)
the distillable mixture, such component, if isolated, having a melting temperature
above the distillation temperature of the distillable liquid; and
- "lower melting soluble mixture" is a dissolved solute that, if isolated,
melts below the distillation temperature of the distillable mixture.
The prime requirements of the distillable mixture are:
- a) the distillable mixture contains at least two different liquid components
at least one of which is a distillable liquid;
- b) the distillable mixture also contains a dissolved higher melting
solid; and
- c) the dissolved higher melting solid is capable of forming and thus
will form with the adjuvant to be used, a soluble mixture or solute, which, if
isolated, will constitute a lower melting soluble mixture.
Often the dissolved higher melting solid will be residual amounts of one or
more chemical products from a synthesis reaction conducted in the liquid phase
of the distillable mixture.
The prime requirements of the adjuvant to be used pursuant to this invention are:
- a) the adjuvant can and will form with the dissolved higher melting
solid, a solute mixture which, if isolated, will constitute a lower melting soluble
mixture; and
- b) the adjuvant has sufficient solubility in the distillable mixture
to be added in an amount needed to form, if isolated, a lower melting soluble mixture
with all or substantially all of the amount of dissolved higher melting solid present
in the distillable mixture. By "substantially all" is meant that if an amount of
dissolved higher melting solid remains in excess, that amount is small enough as
to cause no statistically significant increase in column pluggage during usage
as compared to an identical column operated under identical conditions for the
same period of time with the same liquid mixture except being devoid of any dissolved
higher melting solid.
Distillations at atmospheric pressure are preferred in any situation
permitting use of distillation. However, in conducting the distillation, reduced
pressures, or pressures greater than atmospheric, can be employed whenever deemed
necessary or desirable.
Various mixtures of distillable liquid components can make up the liquid
phase of the distillable mixtures utilized in the practice of this invention, provided
at least one of such liquid components is a distillable liquid. More than one such
component can be distillable, and in such case the boiling temperature(s) of each
distillable component to be removed by distillation from the distillable mixture
should be above the temperature at which the lower melting soluble mixture would
solidify, if isolated from the distillable mixture. The distillable mixtures can
also contain one or more liquid components which are not distillable or which,
if distillable, are not intended or planned to be distilled from the original distillable
mixture, all provided that no such component will interfere with the formation
of the solute mixture that, if isolated, would constitute a lower melting soluble
mixture or otherwise interfere with the distillation. Thus the liquid components
of the distillable mixture can comprise water and one or more liquid hydrocarbons,
ethers, esters, nitrites, amines, amides, ketones, sulfones, sulfoxides, or other
organic substances which are liquid at ordinary ambient room temperatures, or a
mixture of two or more organic components at least one of which is to be distilled
from the other(s). Various reference publications are available to anyone seeking
information about such materials. For example, one may refer to
CRC Handbook
of Chemistry and Physics, 63rd Edition, CRC Press, Inc., Boca Raton, Fla.,
copyright 1982, for information about physical states, boiling temperatures and
solubilities of numerous chemical substances. Other suitable reference works, of
course, also exist.
This invention is especially useful in recovering a distillable organic solvent
that is dissolved in water where the mixture is a mother liquor remaining after
physically removing a solid product formed in that solvent mixture. Non-limiting
examples of such water-soluble distillable solvents are alcohols such as ethyl
alcohol, propyl alcohol, isopropyl alcohol, and tert-butyl alcohol; ethers such
as tetrahydrofuran, 1-ethoxypropane, 2-ethoxypropane, p-dioxane, and m-dioxane;
ketones such as acetone and 2-butanone; amides such as N,N-dimethylformamide and
N,N-diethylformamide; esters such as methyl formate, methyl glycolate, and methyl
acetoacetate; amines such as cyclohexylamine and N-methylcyclohexylamine; and nitrites
such as acetonitrile and propionitrile. In mixtures involving water and a distillable
organic solvent, it is preferable that the distillable organic solvent boil at
a temperature below the boiling temperature of water. But where the water is the
distillable liquid, the organic solvent can subsequently be distilled and recovered,
leaving a residue of the lower melting soluble mixture.
Numerous compounds exist that can be formed in and remain dissolved in the
two or more liquid components referred to above. Thus the dissolved higher melting
solid can be any compound that is soluble enough to be dissolved in liquid components
of the distillable mixture, that is stable at least up to the distillation temperature
to be used (and preferably above that temperature), and that can form a lower melting
soluble mixture with the adjuvant.
The adjuvant used will of course depend upon the dissolved higher melting solid
present in the distillable mixture. Other than being a solid at ordinary ambient
room temperatures, the adjuvant used must have the capability of forming with the
dissolved higher melting solid, a dissolved composition having a melting temperature,
if isolated, that is below both the melting temperature of the dissolved higher
melting solid and the distillation temperature to be used in the distillation to
be conducted.
The practice and advantages of this invention will now be illustrated with reference
to FIG.
1. It will be seen that the apparatus depicted includes a distillation
column
20 into which flows via line
15 a liquid mixture from which
a distillable liquid component is to be separated and recovered. Column
20
can be of any conventional type and configuration suitable for effecting the particular
separation to be carried out. The vaporized distillate exits from column
20
and is transferred via line
25 to condenser
30. Condenser
30
is cooled by some appropriate cooling medium circulated in line
32. The
condensed distillate is transmitted via line
35 to receiver
40 for
storage or reuse by means of line
42. Line
10 serves as the feed
line for an adjuvant of this invention. Line
22 can be used to remove the
lower melting soluble mixture form column
20. Flows in the lines of the
system can be effectuated by pumps (not shown).
The liquid mixture in line
15 upstream from the junction of lines
15
and
10, which mixture can originate from any source, contains at least two
different liquid components, at least one of which is to be separated and recovered
in purified form. For purposes of this illustration, the liquid mixture is a mixture
of ethyl alcohol and water, and among the dissolved components is 2,2-propylenebis[4,4′-(2,6-dibromophenol)],
the higher melting solid, with a melting temperature of about 180° C., and
also smaller amounts of tribromophenols and still smaller amounts of dibromophenols.
The dissolved mononuclear tribromophenol has a melting temperature of about 94°
C. Column
20 is operated at a temperature of about 110° C. To prevent
pluggage of column
20, an adjuvant of this invention, viz., additional tribromophenol
dissolved or slurried in ethyl alcohol, is fed via line
10 and thence with
the above liquid mixture into column
20 via line
15. The amount of
tribromophenol fed into the column is sufficient to produce a mixture with the
2,2-propylenebis[4,4′-(2,6-dibromophenol)] and the mononuclear bromophenols
initially present which mixture, if isolated from solution, is in the molten state
at less than 110° C. Hence column pluggage, which would occur in the absence
of the adjuvant feed, is avoided.
In another embodiment of the invention, described with reference to FIG. 1, the
system schematically depicted and described above is again used in the same manner
with the following adjustments. First, the liquid mixture in line
15 upstream
from the intersection of lines
15 and
10 additionally contains dissolved
elemental bromine. Secondly, instead of feeding a solution or slurry of tribromophenol
adjuvant in ethyl alcohol, the feed in line
10 is molten phenol. The phenol
is brominated in situ to form tribromophenol adjuvant so that a lower melting composition
involving the 2,2-propylenebis[4,4′-(2,6-dibromophenol)] is formed. Small
amounts of tribromophenol can already be present in the initial mixture, and when
they are initially present, a further impurity is not introduced or formed in this system.
Compounds referred to by chemical name or formula anywhere in this document,
whether referred to in the singular or plural, are identified as they exist prior
to coming into contact with another substance referred to by chemical name or chemical
type (e.g., another component, a solvent, or etc.). It matters not what preliminary
chemical changes, if any, take place in the resulting mixture or solution, as such
changes are the natural result of bringing the specified substances together under
the conditions called for pursuant to this disclosure. Also, even though the claims
may refer to substances in the present tense (e.g., "comprises", "is", etc.), the
reference is to the substance as it exists at the time just before it is first
contacted, blended or mixed with one or more other substances in accordance with
the present disclosure.
All documents referred to herein are incorporated herein in toto as if fully
set forth in this document.
This invention is susceptible to considerable variation within the spirit and
scope of the appended claims. Therefore the foregoing description is not intended
to limit, and should not be construed as limiting, the invention to the particular
exemplifications presented hereinabove. Rather, what is intended to be covered
is as set forth in the ensuing claims and the equivalents thereof permitted as
a matter of law.
*
