NZ617588B2 - Process for the production of chlorinated and/or fluorinated propenes - Google Patents
Process for the production of chlorinated and/or fluorinated propenes Download PDFInfo
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- NZ617588B2 NZ617588B2 NZ617588A NZ61758812A NZ617588B2 NZ 617588 B2 NZ617588 B2 NZ 617588B2 NZ 617588 A NZ617588 A NZ 617588A NZ 61758812 A NZ61758812 A NZ 61758812A NZ 617588 B2 NZ617588 B2 NZ 617588B2
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07B—GENERAL METHODS OF ORGANIC CHEMISTRY; APPARATUS THEREFOR
- C07B2200/00—Indexing scheme relating to specific properties of organic compounds
- C07B2200/09—Geometrical isomers
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C17/00—Preparation of halogenated hydrocarbons
- C07C17/26—Preparation of halogenated hydrocarbons by reactions involving an increase in the number of carbon atoms in the skeleton
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C17/00—Preparation of halogenated hydrocarbons
- C07C17/26—Preparation of halogenated hydrocarbons by reactions involving an increase in the number of carbon atoms in the skeleton
- C07C17/263—Preparation of halogenated hydrocarbons by reactions involving an increase in the number of carbon atoms in the skeleton by condensation reactions
- C07C17/269—Preparation of halogenated hydrocarbons by reactions involving an increase in the number of carbon atoms in the skeleton by condensation reactions of only halogenated hydrocarbons
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C17/00—Preparation of halogenated hydrocarbons
- C07C17/26—Preparation of halogenated hydrocarbons by reactions involving an increase in the number of carbon atoms in the skeleton
- C07C17/272—Preparation of halogenated hydrocarbons by reactions involving an increase in the number of carbon atoms in the skeleton by addition reactions
- C07C17/275—Preparation of halogenated hydrocarbons by reactions involving an increase in the number of carbon atoms in the skeleton by addition reactions of hydrocarbons and halogenated hydrocarbons
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C19/00—Acyclic saturated compounds containing halogen atoms
- C07C19/08—Acyclic saturated compounds containing halogen atoms containing fluorine
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C21/00—Acyclic unsaturated compounds containing halogen atoms
- C07C21/02—Acyclic unsaturated compounds containing halogen atoms containing carbon-to-carbon double bonds
- C07C21/04—Chloro-alkenes
- C07C21/073—Dichloro-alkenes
Abstract
Disclosed herein is a one-step process for the production of chlorinated and/or fluorinated propenes comprising: reacting (i) a dichloroethylene or a chlorofluoroethylene having the formula CHCl=CHX wherein X is Cl or F; and (ii) a methane, chloromethane, fluoromethane or chlorofluoromethane having the formula CH(4-a)Xa, wherein a is 0-3, to provide at least one chlorinated and/or fluorinated propene, wherein the process carried out at a temperature of less than 600°C and pressure equal to ambient or greater, and wherein the chlorinated and/or fluorinated propene comprises cis/trans 1,3-dichloropropene, wherein the dichloroethylene or chlorofluoroethylene comprises cis/trans 1,2-dichloroethylene and the methane, chloromethane, fluoromethane or chlorofluoromethane comprises methyl chloride. the formula CH(4-a)Xa, wherein a is 0-3, to provide at least one chlorinated and/or fluorinated propene, wherein the process carried out at a temperature of less than 600°C and pressure equal to ambient or greater, and wherein the chlorinated and/or fluorinated propene comprises cis/trans 1,3-dichloropropene, wherein the dichloroethylene or chlorofluoroethylene comprises cis/trans 1,2-dichloroethylene and the methane, chloromethane, fluoromethane or chlorofluoromethane comprises methyl chloride.
Description
PROCESS FOR THE PRODUCTION OF CHLORINATED AND/OR FLUORINATED
PROPENES
FIELD
The present invention relates to processes for the production of chlorinated and/or
fluorinated propenes.
BACKGROUND
Chlorinated and/or fluorinated propenes are known to be useful as monomers in
the manufacture of plastics and resins and also find use as chemical intermediates in the
cture of, e. g., hydrofluorooleflns. Many such compounds are also known to be useful
as cides and insecticides, and in fact, this may be their predominant use.
The commercial availability of these nds may be undesirably limited by the
processes typically utilized in their manufacture. For example, chlorinated and/or fluorinated
propanes have been reacted with oxygen and in the presence of a catalyst and at high
temperatures to produce chlorinated propenes. Desired chlorinated and/or fluorinated
propenes have also been obtained by dehydrochlorinating trichloropropenes in the ce
of oxygen or by reacting dichloropropenes with ne and/or allyl chloride and/or
propenes to provide the d nated propene. However, all of these processes
are complicated multi-step processes, and many require the use of catalysts and thus, the
removal of one or more catalysts from the product.
The process most commonly relied upon for the production of one exemplary
nated propene, l,3-dichloropropene, is actually a s for the production of allyl
chlorides. In such processes, the thermal chlorination of e provides about 70—85%
selectivity to allyl chloride and 15—30% dichlorinated byproducts. Up to about 50% of the
ucts, in turn, may typically comprise about 50% l,3-dichloropropene, with the
remainder consisting of other chlorinated propenes, l,2-dichloropropane, six carbon olefins
and other chlorinated six carbon compounds.
Although this process accounts for a large majority of the production of 1,3-
dichloropropene, it is suboptimal at least because it links the production of 1,3-
dichloropropene to the production rate and demand for allyl chloride. The conventional
process can also be found lacking when the end product is desirably a single isomer rather
than a racemic mixture. The cis isomer of l,3—dichloropropene is known, for example, to be
about twice as active as a nematocide as the trans . However, while the cis isomer is
slightly more volatile than the trans isomer, and therefore should be separable by fractional
distillation, it has been found that both this distillation and any subsequent isomerization of
the trans isomer are greatly d by the presence of a small proportion of six carbon
olefins that boil very close to the boiling temperature of the dichlorinated propene fraction.
Although fied, one—step ses have been developed for the manufacture
of nated and/or fluorinated propenes, these processes can have limited commercial
applicability due to their limited throughput. Whether multi-step or one-step, many of the
conventional manufacturing processes for the production of chlorinated and/or fluorinated
propenes may typically result in the formation of large quantities of on by-products that
must then be separated from the t and disposed of, typically at great e, further
limiting their commercial potential.
It would thus be desirable to provide improved processes for the production of
chlorinated and/or fluorinated propenes. More particularly, such processes would provide an
improvement over the current state of the art if they could by decoupled from the
manufacture of ts in which they are produced as by—products, or as a portion of a
mixture of by-products from which their separation is ult. Cost savings and/or
improvements in reaction selectivity would also provide commercial advantage and be
appreciated by the art.
BRIEF DESCRIPTION
The present invention provides ent processes for the production of chlorinated
and/or fluorinated es. Advantageously, the processes are one—step processes, thereby
providing significant time, operating and capital cost savings over conventional multi-step
processes for the production of chlorinated propenes. Further, the present processes provide
a reaction mixture from which the chlorinated and/or fluorinated propene(s) are more easily
separated and/or purified to provide the desired end product than conventional processes, and
so, onal cost savings can be seen.
More specifically, the processes comprise reacting a dichloroethylene or a
chlorofluoroethylene with a methane, methane, ethane, or chlorofluoromethane
2012/039906
to provide the nated or fluorinated e. The dichloroethylene or
chlorofluoroethylene has the formula CHCl=CHX, where X is C1 or F, while the methane,
chloromethane, fluoromethane or chlorofluoromethane may desirably have the formula CH(4_
a)Xa, wherein a is 0-3. The chlorinated or fluorinated propene may, in some embodiments,
have the formula CHX=CH-CH(3_a)Xa wherein a is 0—3.
In one embodiment, the dichloroethylene or chlorofluoroethylene comprises
ciS/trans—1,2—dichloroethylene and the methane, chloromethane, fluoromethane or
chlorofluoromethane comprises methyl chloride. In such embodiments, as well as others, the
chlorinated and/or fluorinated propene may desirably comprise ans 1,3—dichloropropene.
The present process provides a crude product more easily ref1ned than that of
conventional processes. That is, while one conventional process for the production of cis—
1,3—dichloropropene, the tion of allyl chloride, produces cis—1,3—dichloropropene as a
by-product in a mixture further comprising chlorinated propenes, 1,2—dichloropropane, six
carbon olefins and other chlorinated six carbon compounds, the present process provide a
crude product comprising cis/trans—1,3—dichloropropene as well as the principal ducts
trichloropentadiene and trichloroheptadiene. As a result, the desired dichloropropene can be
separated using chlorination and/or a simple distillation.
Desirably, the processes will be conducted at ambient pressures or greater, or at a
pressure of least 200 psig, or at least 250 psig. The ature of the processes may
ageously be lower than those utilized in conventional processes, i.e., the temperature
may be less than 600 0C, or less than 500°C, or less than 400°C. In some embodiments,
diluents may be ed to reduce the ature within the reactor and, if the same is
desired, may be chosen from an inert diluents, CH(4_a)Xa, HCl, or combinations of these.
sts may be ed in the process, and in those embodiments where the same
is desired, free radical initiators, such as those comprising chlorine, e.g., carbon tetrachloride,
hexachloroethane, benzotrichloride, hexachloroacetone, chlorine, or combinations of these,
may be utilized. The ratio of CH(4_a)Xa to CHCl=CHX may advantageously be greater than
1.0. ations of one or more of elevated pressure, lower temperatures, the use of a
catalyst, and the ratio of CH(4_a)Xa to CHCl=CHX may be utilized to provide further
enhancements to the conversion rate, selectivity and/or cost savings provided by the process.
DESCRIPTION OF THE DRAWINGS
l 00 I 409405
shows a schematic diagram of a process according to one embodiment.
DETAILED DESCRIPTION
The present specification provides certain definitions and methods to better define the
present invention and to guide those of ry skill in the art in the practice of the present
invention. ion, or lack of the provision, of a ion for a particular term or phrase is not
meant to imply any particular importance, or lack thereof. Rather, and unless otherwise noted, terms
are to be understood according to conventional usage by those of ordinary skill in the relevant art.
[0015a] Reference to any prior art in the specification is not, and should not be taken as, an
acknowledgment or any form ofsuggestion that this prior art forms part of the common general
knowledge in New Zealand or any otherjurisdiction.
[0015b] As used herein, the term ise" and variations ofthe term, such as "comprising",
"comprises" and "comprised", are not intended to e other additives, components, integers or
steps.
The terms "first", "second", and the like, as used herein do not denote any order, quantity,
or importance, but rather are used to distinguish one element from r. Also, the terms "a" and
”an" do not denote a limitation ofquantity, but rather denote the presence of at least one ofthe
referenced item, and the terms "front", "back", "bottom", and/or ”top", unless otherwise noted, are
merely used for convenience ofdescription, and are not limited to any one position or l
ation.
Ifranges are disclosed, the endpoints of all ranges directed to the same component or
property are inclusive and independently combinable (cg, ranges of "up to 25 wt.%, or, more
cally, 5 wt.% to 20 wt.%," is inclusive ofthe endpoints and all intermediate values ofthe
indicate
ranges of ”5 wt.% to 25 wt.%," etc). As used herein, percent (%) conversion is meant to
change in molar or mass flow of reactant in a reactor in ratio to the incoming flow, while percent
(%) selectivity means the change in molar flow rate of product in a reactor in ratio to the change of
molar flow rate of a reactant.
Reference throughout the specification to "one embodiment” or "an embodiment" means
that a particular feature, structure, or characteristic described in tion with an embodiment is
ed in at least one embodiment. Thus, the appearance of the phrases "in one embodiment" or
"in an embodiment” in various places throughout the specification is not necessarily referring to the
l 00 1 409405
same embodiment. r, the particular features, structures or characteristics may be combined in
any suitable manner in one or more embodiments.
Further, "Ml" may be used as an abbreviation for methyl chloride, "M2" may be used as
an abbreviation for methylene chloride, "M3" may be used as an abbreviation for chloroform, and
"M4" may be used as an abbreviation for carbon hloride. Similarly,
“DCE” may be used as an abbreviation for l,2-dichloroethylene, “DCP” may be used as an
iation for l,3-dichloropropene, “DCHDE” can be used as an abbreviation for
dichlorohexadiene, “TCPDE” can be used as an abbreviation for trichloropentadiene and
“TCHTE” can be used as an abbreviation for trichloroheptatriene.
Throughout the specification, the formula CHCl=CHX wherein X is C1 or F
indicates the chloroethylene or chlorofluoroethylene, as the case may be, while the formula
CH(4_a)Xa, n a is 0-3 and each X is independently C1 or F may be used to indicate the
methane, chloromethane, fluoromethane or chlorofluoromethane. Finally, the formula
CHX=CH-CH(3_a)Xa wherein a is 0—3 and each X is independently C1 or F respectively,
tes the chlorinated and/or fluorinated propene(s).
The t invention provides efficient processes for the production of chlorinated
and/or fluorinated propenes. The t processes comprise only one step, the reaction of a
dichloroethylene or a chlorofluoroethylene with a methane, chloromethane, fluoromethane, or
chlorofluoromethane, thus, providing a significant time and materials savings as compared to
conventional ses. Additionally, the present processes may be carried out at lower
temperatures than conventional processes, thus providing a cost savings, while yet also
providing commercially acceptable throughputs not achieved by conventional high
temperature processes.
Further, the present processes provide this good product yield while also providing
low, e.g., less than 20%, or even less than 10% yield of residues/by—products. The use of
catalysts may provide r ements e.g., to conversion rates and ivity as may
the optimization of the molar ratio of the reactants.
In additional embodiments, one or more reaction conditions of the one step process
may be zed, in order to provide even further advantages, i.e., improvements in
selectivity, sion or production of reaction by—products. In n embodiments,
multiple reaction conditions are optimized and even further improvements in selectivity,
conversion and tion of reaction by—products produced can be seen.
Because of such improvements, the one—step process of the present invention may
provide conversion rates of the e, chloromethane, fluoromethane or
chlorofluoromethane of at least 2%, or 5%, or 10%, or up to 15%, or in some instances, even
up to 20% or greater, without substantially reducing selectivity to the chlorinated and/or
ated propene. Conversion rates of dichloroethylene or fluoroethylene of at least
%, or at least 10%, or at least 15%, or even up to 20% or better can be seen. Concentrations
of ties, such as redox impurities, of less than 5 mole percent, less than 2 mole percent,
and in some embodiments, even less than 0.5 mole percent may also be provided. The
t processes also singly provide selectivities to the chlorinated and/or fluorinated
propene of at least 50%, or up to 60%, up to 70%, up to 80% when chloroethylene or
chlorofluoroethylene conversion is 30% or less, or up to 95% when chloroethylene or
chlorofluoroethylene conversion is 20% or less.
The dichloroethylene or chlorofluoroethylene utilized in the present processes
bly have the formula CHCl=CHX wherein X is C1 or F. Suitable dichloroethylenes or
chlorofluoroethylenes comprise at least two hydrogen atoms. Exemplary dichloroethylenes
and chlorofluoroethylenes that may be utilized in the present process thus include cis/trans—
dichloroethylene and cis/trans—1—dichloro—2—fluoroethylene, or ations of these.
The methane, chloromethane, fluoromethane or chlorofluoromethane utilized in
the present processes desirably have the formula CH(4_a)Xa, wherein a is 0—3 and each X is
ndently C1 or F. le chloromethanes, fluoromethanes and chlorofluoromethanes
comprise at least one hydrogen atom. Thus, suitable methanes, chloromethanes,
fluoromethanes and chloromethanes e methane, methyl fluoride, methyl chloride,
methylene fluoride, methylene chloride, methyl difluoride, methyl trifluoride, chloromethane,
dichloromethane, trichloromethane, fluoromethane, difluoromethane, trifluoromethane,
chloroform, chlorodifluoromethane, dichlorofluoromethane, chlorofluoromethane, or
combinations of these.
The present processes may advantageously be utilized to produce chlorinated
and/or fluorinated propenes in one step. In some ments, the chlorinated and/or
fluorinated es that can be produced according to the present process include those
having the formula CHX=CH—CH(3_a)Xa wherein a is 0—3. Examples of these include, for
example, cis/trans—1—chloropropenes, ans— 1 —fluoropropenes, cis/trans—1,3 —
dichloropropenes, cis/trans— 1 —chloro,3 —fluoropropenes, cis/trans—3 —chloro, 1 —fluoropropenes,
cis/trans— 1,3 —difluoropropenes, cis/trans—1,3 ,3—trichloropropenes, cis/trans— 1,3 oro,3—
fluoropropenes, cis/trans— 1 —chloro,3 ,3 —difluoropropenes, cis/trans—3 ,3 —dichloro, 1—
fluoropropenes, cis/trans—,3 o, 1,3 —difluoropropenes, cis/trans— 1,3 ,3 ,3 —
tetrafluoropropenes, cis/trans—l,3,3—dichloro,3—fluoropropenes, cis/trans—l,3—dichloro,3,3—
2012/039906
difluoropropenes, cis/trans— l —chloro,3 ,3 ,3 —trifluoropropenes, ans—3 ,3 ,3 —trichloro, l—
fluoropropenes, cis/trans—3,3 —dichloro, l ,3—difluoropropenes, cis/trans—3 o, 1,3,3 —
trifluoropropenes, cis/trans— l ,3 , 3 , 3 —tetrafluoropropenes.
For example, in some embodiments wherein the chloroethylene comprises
ciS/trans—dichloroethylene, the methane, methane, fluoromethane or
chlorofluoromethane, may comprise methyl chloride, methylene chloride, chloroform,
methane, methyl fluoride, methyl difluoride, methyl trifluoride, chlorofluoromethane,
chlorodifluoromethane, and/or dichlorofluoromethane and the chlorinated and/or fluorinated
propene may comprise cis/trans—l,3—dichloropropenes, cis/trans—l,3,3—trichloropropenes,
cis/trans— l ,3 ,3 ,3 —tetrachloropropenes, ans—chloropropenes, cis/trans— l —chloro,3 —
ropenes, cis/trans— l —chloro,3 ,3 —difluoropropenes, cis/trans— l o—3 ,3 ,3 —
trifluoropropenes, cis/trans— l ,3 oro,3 —fluoropropenes, cis/trans— l ,3 —dichloro,3 ,3 —
difluoropropenes and/or cis/trans—l,3,3—trichloro,3—fluoropropenes, respectively.
In other ments wherein the dichloroethylene or chlorofluoroethylene
comprises l-chloro-2—fluoroethylene, the methane, chloromethane, fluoromethane or
chlorofluoromethane, may comprise methane, methane, dichloromethane,
trichloromethane, fluoromethane, difluoromethane, trifluoromethane, chlorofluoromethane,
dichlorofluoromethane, and/or chlorodifluoromethane and the chlorinated and/or fluorinated
propene may comprise cis/trans—l—fluoropropenes, cis/trans—3—chloro,l—fluoropropenes,
cis/trans—3 ,3 —dichloro, l —fluoropropenes, cis/trans—3 ,3 ,3 —trichloro, l —fluoropropenes, cis/trans—
l,3 —difluoropropenes, cis/trans— l ,3 ,3 —trifluoropropenes, cis/trans— l ,3 ,3 ,3 —tetrafluoropropenes,
cis/trans—3 —chloro, l ,3 —difluoropropenes, cis/trans—3 ,3 —dichloro, l opropenes, and/or
cis/trans—3 —chloro, l ,3 ,3 uoropropenes, respectively.
Reaction conditions of the one—step process that may be optimized include any
reaction condition iently adjusted, e.g., that may be adjusted via utilization of
equipment and/or materials already present in the manufacturing footprint, or that may be
ed at low resource cost. Examples of such conditions may include, but are not limited
to, adjustments to temperature, pressure, flow rates, molar ratios of reactants, use of catalysts
or initiators, etc.
In one embodiment, reaction pressure is advantageously optimized, and may
e enhanced chlorinated and/or fluorinated propene selectivities, than those carried out
at ambient or lower pressures. More specifically, improvements to at least the nated
and/or fluorinated propene selectivity are expected at pressures of r than 0 psig, or
greater than 20 psig, or greater than 35 psig, with improvement expected to increase with
increase of pressure, up to 200 psig, or up to 300 psig, or up to 400 psig, or even up to 500
psig and greater. Optimizing at least pressure of the on in this fashion is ted to
provide chlorinated and/or fluorinated propene selectivity of at least 60%, or up to 70%, or up
to 80%, or, in some embodiments, up to 95%. In other embodiments, the present processes
may be carried out at ambient pressure.
The temperature of the reaction may also be optimized, and surprising results are
expected when lowering the ature, in particular when done in combination with
pressure optimization. That is, although conventional processes typically call for
temperatures of at least 550°C, the present process may be carried out at less than 600°C, or
less than 500°C, or less than 450°C, or less than 400°C, while yet providing improvements to
reactant conversions, product selectivity and lowering the l cost associated with the use
of the r.
The molar ratio of the reactants may also be optimized. While a 1:1 ratio of CH(4_
a)Xa to CHCl=CHX or lower ratio may be used, provision of a stoichiometric excess of CH(4_
a)Xa may provide enhancements to the present process. More particularly, any molar ratio of
CH(4_a)Xa/ CHCl=CHX in which CH(4_a)Xa is t in excess may be utilized and is expected
to result in enhancements to the process, whether in the form of increases to conversion or
ivity, or decreases in the production of impurities. Molar ratios of greater than 1:1, or
greater than 1.5, or greater than 2, or even greater than 3: 1, may provide at least ental
improvements to the selectivity to the desired products. As with enhancements to
temperature, any adjustments to the molar ratio may provide synergistic effects, but at least
combinatorial enhancements, when ed in ction with increases in reaction
pressure.
Catalysts or initiators may also be utilized to enhance the present process.
Surprisingly, the utilization of the same, in particular in conjunction with any of the other
ion optimizations, does not result in an increase in the production of redox impurities
by the process, but does provide selectivities to the chlorinated and/or fluorinated propene of
at least 60%, or up to 70%, or up to 80%, or, in some embodiments, up to 90% or even
higher.
Any st or initiator capable of at least marginally enhancing the selectivity of
the inventive process for the chlorinated and/or fluorinated propene may be ed by itself
or in a combination with others. Catalysts/initiators capable of doing so are believed to
include those that are capable of removing hydrogen from methane, chloromethanes,
fluoromethanes or chlorofluoromethanes to produce the corresponding l. For example,
in the case of methyl chloride, the catalyst/initiators are capable of ng en from
methyl chloride to form a chloromethyl radical, e. g., *CHzCl. Such free radical initiators are
well known to those skilled in the art and have been reviewed, e.g., in “Aspects of some
initiation and propagation processes,” Bamford, Clement H. Univ. Liverpool, Liverpool,
UK., Pure and Applied Chemistry, (1967), 15(3—4),333—48 and Sheppard, C. S.; Mageli, O. L.
“Peroxides and peroxy compounds, organic,” Kirk-Othmer Encycl. Chem. Technol., 3rd Ed.
(1982), 17, 27—90.
Such catalysts may typically comprise one or more chlorine or peroxide groups
and/or exhibit reactor phase mobility/activity. As used , the phrase or phase
ty/activity” means that a substantial amount of the catalyst or tor is available for
generating free radicals of sufficient energy which can initiate and propagate ive
turnover of the product, chlorinated and/or fluorinated propene, within the design limitations
of the reactor.
[003 7] In general, the catalyst/initiator should have sufficient homolytic dissociation
energies such that the theoretical maximum of free radicals is generated from a given initiator
under the temperature/residence time of the process. It is especially useful to use free radical
initiators at concentrations where free radical chlorination of incipient radicals is prevented
due to low concentration or reactivity. xides offer an age of not being able to
propagate competitive processes (e.g., the free radical chlorination of methylene chloride to
form and carbon hloride).
Examples of suitable sts/initiators comprising chlorine include, but are not
limited to carbon tetrachloride, hexachloroacetone, chlorine, chloroform, hexachloroethane,
phosgene, thionyl chloride, sulfuryl chloride, trichloromethylbenzene, those comprising
perchlorinated alkylaryl functional groups, or organic and inorganic hypochlorites, including
hypochlorous acid, and t-butylhypochlorite, hypochlorite, chlorinated amines
(chloramine) and chlorinated amides or sulfonamides such as chloroamine—T®, and the like.
Combinations of any of these may also be utilized.
1000472190
Carbon tetrachloride (CC14) and chlorine gas (C12) are but two examples of
catalyst/initiators that are readily commercially available and easily integrated into the present
process, and their use can be preferred in embodiments wherein the use of a catalyst or initiator is
desired.
Examples of suitable catalysts/initiators comprising one or more peroxide groups
include hydrogen peroxide, lorous acid, aliphatic and aromatic des or hydroperoxides,
including di-t-butyl de, benzoyl peroxide, cumyl peroxide and the like.
In addition bis-azo initiators may have utility in effecting the addition of CH(4_a)Xa to
CHC1=CHX under the conditions of this invention.
[0042] er the desired catalyst or initiator, those of ordinary skill in the art are well aware of
methods of determining the appropriate concentration and method of introduction thereof. For
example, many catalysts/initiators are typically introduced into the reactor zone as a te feed,
or in solution with other reactants, e. g., CHC1=CHX, which can be evaporated prior to the reaction
zone. Also, initiators with a low boiling point can be introduced with inert gaseous diluents such as
N2.
The amount of any st or initiator utilized will depend upon the ular
catalyst/initiator chosen as well as the other reaction conditions. Generally ng, in those
embodiments of the invention wherein the utilization of a catalyst/initiator is desired, enough of the
catalyst/initiator should be utilized to provide some improvement to reaction process conditions
(e.g., a reduction in required temperature) or realized ts, but yet not be more than will
provide any additional benefit, if only for reasons of economic practicality. For purposes of
illustration only, then, it is expected in those embodiments wherein a catalyst or tor comprising
carbon tetrachloride is desirably utilized, that useful trations thereof will range from 5 ppm to
200000 ppm, or from 10 ppm to lOOOOOppm, or from 20 ppm to 50000 ppm, inclusive of all
subranges therebetween.
The process can be further enhanced by ting the process or reactor zone to pulse
laser or uous UV/visible light sources at a ngth suitable for inducing photolysis of the
radical catalyst/initiator, as taught by Breslow, R. in Organic Reaction Mechanisms W.A. Benjamin
Pub, New York p 223-224. Wavelengths from 300 nm to 700 nm of the light source are sufficient to
dissociate commercially available l initiators.
Such light sources include, e.g, Hanovia UV discharge lamps, sunlamps or even pulsed laser
beams of appropriate wavelength or energy which are configured to irradiate the reactor
chamber. Alternatively, chloromethyl radicals may be ted from microwave discharge
into a bromochloromethane feedsource uced to the reactor as taught by Bailleux et al.,
in l of Molecular Spectroscopy, 2005, vol. 229, pp. 140—144.
As ned above, the present invention es economical processes for the
production of nated and/or fluorinated propenes, i.e., n one or more of the
reaction conditions are optimized. In certain preferred embodiments, an initiator may be
utilized in conjunction with a lower temperature and increased pressure to provide a process
that results in a product stream with lower amounts of impurities. For example, the use of
carbon tetrachloride as an initiator at amounts as low as 6%, is expected to provide
dichloroethylene conversions of greater than 15% at temperatures of 420°C and res of
260 psig.
By running at temperatures lower than 600°C, or less than 500°C not only are
process cost savings provided, but lower capital costs are associated with the use of the
reactor. And yet, in these embodiments of the invention, CHCl=CHX conversions of at least
%, or at least 10%, or at least 15%, or even up to 20% or even greater can be seen, along
with )Xa conversions of at least 2%, or 5%, or 10%, or up to 20%, or in some instances,
even up to 40% or greater and chlorinated and/or fluorinated e selectivities of at least
50%, or up to 60%, up to 70%, or up to 80% when CHCl=CHX conversion is 30% or less, or
even up to 95% when CHCl=CHX conversion is 20% or less.
Surprisingly, the gas phase conditions bed herein for the production of
chlorinated and/or fluorinated propenes from the reaction of methane, chloromethanes,
fluoromethanes or chlorofluoromethanes having the formula CH(4_a)Xa wherein a is from 0-3
and chloroethylene or chlorofluoroethylenes having the formula CHCl=CHX wherein X is C1
or F show a preferred regioselectivity for the cis—1,3—dichloropropene to the corresponding
trans by 10% or the molar ratio of cis/trans of 1.1.
The present process may be conducted in any suitable reactor. Desirably, the
reactor utilized will be one wherein the reaction conditions are readily and easily altered as
desired, and also, that can function without damage or fouling at the selected conditions.
1000472190
These are ed to include near—isothermal shells and multitube reactors where the desired
temperature can be achieved by means of utilization of a heat transfer field.
tic cylindrical or tube reactors may also be used, and if used can have any
desired length to diameter aspect ratio so long as preheating to the desired reaction temperature
is possible. If an adiabatic reactor is utilized, a larger CH(4-a)Xa /CHC1=CHX ratio, e.g., 1.3 or
r, or a suitable diluents, such as inert diluents or CH(4-a)Xa, may be used in order to limit
the adiabatic temperature rise, i.e., to an se in temperature of less than 50°C, preferably an
increase in temperature of only from 10°C to 20°C. Alternatively, a series of adiabatic reactors
with at least one intercooler operatively disposed relative thereto can also be employed to obtain
the desired overall conversion while maintaining the desired ature rise within each
One embodiment of the process provided is shown in Figure 1. More particularly,
as shown in Figure 1, process 100 makes use of evaporators 102 and 106, reactor 104, quench
drum 108, and separation columns 1 10, 112, l 14 and 1 16. During ion ess 100, the
methane, chloromethane, fluoromethanes or uoromethane is evaporated and/or heated in
evaporator 102, While the dichloroethylene or chlorofluoroethylenes and any desired
st/initiator is evaporated and/or heated in evaporator 106. After vaporizing the reactants
and initiator and preheating them to the desired temperature, the reactants are fed into reactor
104 to e a desired conversion and selectivity to DCP.
[0051] The reaction mixture is then quenched in quench drum 108 to stop the reaction and
to obtain a product. The crude product is then fed to first separation column 1 10 to recover
anhydrous HCl in overhead stream 1 18. The bottom stream of first separation column 110 is
then fed to a second separation column 112 to purify unreacted CH(4-a)Xa in overhead stream
126. Overhead stream 126 is then recycled to reactor 104 after being mixed with fresh makeup
CH(4-a)Xa in evaporator 102.
Mid boiler byproducts, i.e., byproducts with boiling points between CH(4-a)Xa and
CHC1=CHX, can be purged by either side draw 120 from second separation column 112 or as a
purge from ad stream 126. The bottom stream of second separation column 112 is then
fed to third separation column 114, where unreacted CHC1=CHX is drawn overhead via line 128
to be recycled to reactor 104 after being mixed with fresh CHC1=CHX feed in
evaporator 106. Alternatively, mid boiler byproducts can also be purged from overhead line
128.
The crude DCP coming out of the bottom of third separation column 114 is further
purified from heavier byproducts as overhead stream 122 in last separation column 116.
Alternatively, before g the DCP crude to tion column 116, some of the identified
heavy byproducts in the crude such as chlorinated pentadiene and hepatriene could also be
further chlorinated to further improve the purity of the DCP in final column overhead 122.
Example I
Materials. Methyl chloride (M1) was purchased from Airgas. Hexachloroacetone
(HCA) and carbon hloride (M4) were used as received from Aldrich. 1,2-
Dichloroethylene (DCE) was purchased from Aldrich (98% purity) as a mixture of isomers
(85% trans, 15% cis) and stored under nitrogen at all times. 1,3—Dichloropropene (DCP) was
purchased from Aldrich (98% purity) as a mixture of isomers (53% cis, 47% trans).
A reactor having a reactor tube with an 0.75 inch 0D. is constructed of loy—
C material to enable high temperatures (>450 oC) and pressures (400 psig) in addition to its
resistance to corrosion by HCl. The exterior wall of the reaction zone (10 inch long, 49.5 cc
volume) is heated by band heaters controlled by thermocouples.
The reactant gases, at mixture ratio of Ml/DCE of 1 to 4, are used at temperatures from
350°C to 420°C and re of from 260 to 400psig and are mixed and preheated prior to
entering the reaction zone, which is at a ature of from 230°C to 240°C.
Below the on zone a room temperature knock-out pot (1 gallon) is installed to
collect the sate from the reactor effluent. After purging nitrogen, HCl and lights,
reaction product samples are collected for analysis.
Following each run, the reactor tube is cleaned to remove coke ts. For runs
in which total coke production is to be quantified, the coke is ted and weighed. To
assess the amount of coke suspended within a reaction product sample, all volatiles are
removed via low temperature, reduced pressure distillation followed by drying the solids
overnight in a vacuum oven.
WO 70239
The reaction product sample is y d with air to remove the bulk of any
remaining M1 or HCl. Portions of the solutions, lly dark in color, are filtered (0.1 um
PTFE membrane) to remove particles of coke suspended in the sample. The filtered sample is
then analyzed with an Agilent 6890 GC equipped with an automated sampling tower and
thermal conductivity detector (TCD). The details of the method are given below.
Column: J&W Scientific DB—5 (Cat. 122—5032) 30 m x 0.25 mm (0.25 mm
film)
Temperatures: Column: 40°C to 250°C (2 min) at 10°/min
Injector: 250°C
Detector: 275°C
Flows: Flow — 1.0 ml/min onstant fiow
Split: 100:1
Detector: TCD
Accurate wt.% analyses are possible for the following components via multipoint
calibrations with known standards: M2, M3, M4, DCE, DCP and HCA. All other reaction
products, typically heavier than DCP, are assigned the same response factor as DCP since
most are unavailable for ation. 1H NMR spectroscopy is used to confirm the identity of
the isomers of DCP working under the assumption that the trans isomers should possess a
higher JH_H(CHC1=CH-) coupling constant than the cis. Analysis of DCP in CHzClz yielded
a JH_H of ~15 Hz for the trans isomer and a JH_H of ~7 Hz for the cis isomer. The cis and trans
isomers of DCE are assigned within the GC method based on the known boiling points, 60°C
and 48°C respectively.
GC/MS analysis of the crude reaction mixture identifies the cis and trans isomers
of 1,3—dichloropropene as the major products, along with smaller amounts of C5, C6, and C7
compounds. Assignments for the number of DCE and M1 lents within each product,
along with the GC retention times, are listed in Table 1, below.
Table 1.
Retention Time Compound”l DCE Equiv.
(min) in Product
_CH3C1 H2C12 —-
(M2)
cis-CHC1:CHC1 (DCE) 1 _
trans-CHC1:CHC1 (DCE) 1 _
cis-CHC1:CH-CH2C1 (DCP) 1 1
trans-CHC1:CH-CH2C1 (DCP) 1 1
CHC1:CH-CH2-CH:CH-CH2C1
(DCHDE)
CC1:CH-CHC1-CH:CHC1(TCPDE)
CC1:CH-CHC1-CH:CHC1(TCPDE) _-
13.66 C7H5C16 (TCHTE)
” If listed, regioisomers determined Via NMR.
Upon collection of the reaction product s, crude liquid and solid coke,
conversion/selectivity assessments are available via the following calculations. Equations 1.1
and 1.2 yielded percent DCE sion and selectivity to DCP respectively, based on GC
analysis of the reaction product samples using the DCE equivalent assignments listed in
Table 9.
DCE 2 (mol% DCE derived product) * (# DCE equiv. in product)
COI’ZVb-q _
(2 (mol% DCE derived product) * (# DCE equiv. in product)) + mol% DCE
(1.1)
DCE (mol% DCP)
S6166”? — (12)
l E (mol% DCE derived product) * (# DCE equiv. in t);
Quantization of the coke ed from selected runs enables calculation of DCE
conversion to coke according to equation 1.3; a molecular weight of 24 grams per mol of
DCE consumed is estimated for the coke material. Summing the results from equations 1.1
and 1.3 yields total DCE conversion (equation 1.4).
2012/039906
DCE g coke produced * MW DCE
COnVcoke :
gDCE fed 24
(1.3)
DCE DCE DCE
Com/Tom; = Com/5., + Com/coke
(1.4)
The selectivity of DCE conversion to coke is then obtained via the percentage of
DCE converted to coke relative to total DCE conversion (equation 1.5). Total DCE
selectivity was calculated as the amount of DCE converted to DCE relative to total
sion (equation 1.6).
DCE Com/.0
Selectmk. .
= —D§E
Com/W
(1.5)
DCE DCE
DCE Com/m, *Selecth-q
Selectmd _
- —DCE
Com/Tom;
(1.6)
Inspection of the data listed in Table 2 reveals a high selectivity to DCP, greater
than 97%, based upon analysis of the liquid phase products. As highlighted by Table 1 above,
no evidence of products arising from a second addition of M1 (i.e. chloro—2—butene) is
seen, even for runs with a high M1:DCE ratio. Rather, the principle reaction byproducts are
trichloropentadiene and trichloroheptatriene.
While selectivity to DCP is quite high based on the GC analysis of the reaction
t samples, the inclusion of coke formation dramatically lowers the overall DCE
selectivity. For e, the liquid phase ivity to DCP for Run 4 (Table 2) is 97.95 at
6.9% DCE conversion. However, quantitation of the coke that forms over the course of 80 g
DCE fed suggests 2 mol% of DCE is converted to coke (22.9% selectivity), yielding an
overall DCP selectivity of 75.5% at 9.0% DCE conversion.
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As shown in Table 2, a ~l7% increase in DCE conversion is observed when the
reaction pressure is raised from 260 psig (Run 3) to 400 psig (Run 4) at constant flow rate and
feed ition. And, several comparative runs (Run l/Run 3, Run 2/Run 4, Run 8/Run 9, Run
lO/Run ll) demonstrate an se in DCE conversion (liquid phase is) as the reaction
temperature is increased.
Doubling the Ml :DCE feed ratio (Run 4/Run 6) significantly reduces coke selectivity,
~9% (Run 6) relative to ~23% (Run 4), even at higher DCE conversion. While the reaction of
DCP radical with Ml may be partially responsible for the increase in selectivity, the use of
en (Run 7) as a diluent (37% of total feed) with the rd Ml:DCE ratio of 1:1 also
leads to a significant decrease in coke selectivity (~9%) compared to an undiluted run (23% coke
selectivity).
As shown in Table 3, (Run 12), a 4.4 mol% feed of DCP in nitrogen, designed to
simulate typical outlet concentrations during DCP production from Ml and DCE, is passed
through the reactor at 400 CC and 400 psig. While analysis of the reaction product samples
(~50% l2DCE, ~ 35% TCPDE, and ~ 15% TCHTE) suggests a DCP conversion of 1.1%, the
coke that collects (1.3 g coke) from the run (87.8 g DCP fed) suggests a total DCP conversion of
8% with an 86% selectivity to coke.
These examples show that the production of chloropropene (DCP) from 1,2-
dichloroethylene (DCE) and methyl chloride (Ml) is a viable alternative process to the
production of DCP as a by-product of allyl chloride production. More specifically, these
examples show that reaction conditions including temperatures of from 390°C to 420°C and
pressures of from 200 psig to 400 psig with <5mole% of M4 initiator level are cially
. These es further show that higher temperature, pressure, Ml/DCE ratio and
initiator level is beneficial to increase reactor productivity and that high selectivity (e. g., greater
than 90%) can be achieved with high conversion of DCE.
1001409405
Claims (12)
1. A one-step process for the production of chlorinated and/or fluorinated es comprising: reacting i) a dichloroethylene or a fluoroethylene having the formula CHC1=CHX n X is C1 or F; and ii) a methane, chloromethane, fluoromethane or chlorofluoromethane having the formula CH(4_a)Xa, wherein a is 0—3, to provide at least one chlorinated and/or fluorinated propene.
2. The process of claim 1, n the chlorinated and/or fluorinated propene has the formula CHX :Clel—Cl-l(3,a)Xa wherein a is 0—3.
3. The process im l or claim 2, wherein the process is d out at a temperature ofless than 6000C.
4. The process of claim 1 or claim 2, wherein the process is carried out at ambient pressure 01' greater.
5. The s of any one of claims 1 to 4, wherein the reaction is carried out in the presence of one or more catalyst(s) and/or initiator(s), and wherein the tor ses carbon tetrachloride, chlorine, hexachloroethane, benzotrichloride, hexaehloroacetone or combinations ofthese.
6. The process of any one oi’claims l to 5, wherein the e, chloromethane, fluoromethane or clrloroflrrororiiethaiie and the ethylene or chlorofluoroethylene are provided in a ratio OFCH(4_a)Xa / CHCl=CHX of greater than or equal to 1.0.
7. The process of claim 6, wherein the reactor further makes use of a diluent to reduce the temperature within the reactor, wherein the diluent comprises an inert diluent, CH(4.a)Xa , HCl, or combinations of these.
8. The process of any one of claims 1 to 7, wherein the chlorinated and/or fluorinated propene comprises cis/trans l,3-dichlor0propene, wherein the dichloroethylene or chlorofluoroethylene comprises cis/trans 1,2—dichloroethylene and the methane, chloromethane, fluoromethane or ehlorofluoromethane comprises methyl chloride. IOO I 409405
9. The process of claim 8, wherein the methyl chloride and/or 1,2-dichloroethylene are generated for use in the process.
10. The process of claim 3, n the pressure is r than 15 psia and the process is carried out in the presence of a catalyst/initiator, and the molar ratio of CH(4.a)Xa / CHCl=CHX is greater than 1.0; wherein the CHCl=CHX and/or CH(4_a)Xa are recycled within the process, and wherein the byproducts with boiling points in between CH(4.a)Xa and CHC1=CHX are removed from the process by purging or distillation prior to recycling of CH(4—a)Xa and CHCPCHX.
l l. A chlorinated and/0r ated propene prepared by the process of any one of claims 1 to 10.
12. A process according to claim 1, ntially as herein described.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US201161494455P | 2011-06-08 | 2011-06-08 | |
| US61/494,455 | 2011-06-08 | ||
| PCT/US2012/039906 WO2012170239A1 (en) | 2011-06-08 | 2012-05-30 | Process for the production of chlorinated and/or fluorinated propenes |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| NZ617588A NZ617588A (en) | 2016-04-29 |
| NZ617588B2 true NZ617588B2 (en) | 2016-08-02 |
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