INTEGRATED PROCESS TO COPRODUCE TRANS-l-CHLORO-3,3,3-
TRIFLUOROPROPENE, TRANS-l,3,3,3-TETRAFLUOROPROPENE, AND
1,1,1 ,3,3-PENTAFLUOROPROPANE
BACKGROUND TO THE INVENTION
The use of chlorofluorocarbons or hydrochlorofluorocarbons as foam-blowing
agents has been banned due to concerns that their release damages the ozone layer. More
recently, foam-blowing (addition of a volatile material to a polymeric mixture to cause a
bubbled matrix which imparts insulation or cushioning value) has been accomplished
through use of HFC-245fa; however, concern has been raised about the Global Warming
Potential of this material.
Trans-l,3,3,3-tetrafluoropropene (HFO-1234ze (E)) and trans- l-chloro-3, 3,3-
trifluoropropene (HCFO-1233zd (E)), two low GWP molecules, have been identified as a
new generation of more environmentally friendly blowing agents. Both molecules have
other potential applications, such as for example, as solvents, refrigerants, aerosols, and
as building blocks for making other fluorinated compounds. It is foreseeable that there
will be a transition period during which all three products, i.e., HFO-1234ze (E), HCFO-
1233zd (E), and HFC-245fa, will be needed. It is, therefore, desired to develop an
integrated process in which all three products can be manufactured for efficiencies and
synergies.
Methods for separately producing these three products are known in the prior art.
U.S. Patent No. 6,844,475, which is hereby incorporated herein as a reference, teaches a
process for producing HCFO-1233zd in a liquid phase reaction at a temperature of less
than 150°C in the presence of a Lewis acid catalyst or mixture of Lewis acid catalysts,
and hydrogen chloride and HCFO-1233zd formed in the reaction are continuously
removed and the HCFO-12333zd is isolated.
The preparation of HFC-245fa is realized in a one-step process as disclosed in
U.S. Patent No. 5,574,192, or in a two-step process, as disclosed in WO 97/24307 and in
U.S. Patent No. 6,362,383. In a two-step process, HCC-240fa first reacts with hydrogen
fluoride to give HCFO-1233zd, which reacts in a second step with hydrogen fluoride to
give HFC-245fa.
The preparation of HFO-1234ze (E), from HFC-245fa is taught in U.S. Patent
Nos. 7,230,146 and 7,485,760, the disclosures of which are hereby incorporated herein by
reference.
Accordingly, the present invention provides an integrated process to co-produce
these three compounds (HCFO-1233zd, HFC-245fa, and HFO-1234ze), starting from one
feed material, namely a tetrachloropropene, or mixtures of such compounds, and the
production amount of each of the products can be easily adjusted depending on market
demand by simple adjustments of the process.
SUMMARY OF THE INVENTION
Developing an economical process for the continuous preparation of HCFO1233zd
(E) and/or HFO-1234ze (E) has been a goal of research in this field for some time.
It has now been found that HCFO-1233zd (E), HFO-1234ze (E), and HFC-245fa may be
continuously and economically co-produced via an integrated manufacturing process.
The integrated manufacturing process starts with a single or mixture of unsaturated
hydrochlorocarbon feed materials, namely 1,1,1,3-tetrachloropropene and/or 1,1,3,3-
tetrachloropropene. One benefit of this process is that it avoids intimate contact of the
compounds 1233zd (E) and 245fa, which would otherwise form an azeotropic
composition that makes it impossible to separate the components using conventional
separation techniques such as distillation.
In one embodiment of the present invention, the compounds (a) HCFO-1233zd
(E), (b) HFO-1234ze (E), and (c) HFC-245fa; are co-produced in an integrated process
using three reactor lines, starting with a single or mixture of unsaturated
hydrochlorocarbon feed materials, namely 1,1,1,3-tetrachloropropene and/or 1,1,3,3-
tetrachloropropene.
Thus, one embodiment of the present invention is an integrated manufacturing
process to coproduce HCFO-1233zd (E), HFO-1234ze (E), and HFC-245fa, starting from
a single unsaturated hydrochlorocarbon feed material or mixture of such materials. The
process includes a combined liquid or vapor phase reaction/purification operation which
directly produces HCFO-1233zd (E). In the second liquid phase fluorination reactor
HCFO-1233zd (E) is reacted with HF in the presence of catalyst to produce HFC-245fa,
with high conversion and selectivity. Optionally, a third reactor is used for
dehydrofluorination to produce HFO-1234ze (E) by contacting in the liquid phase with a
caustic solution or in the vapor phase using a dehydrofluorination catalyst. This
operation may be followed by one or more purification processes to recover the HFO-
1234ze (E) product.
This process has an economical advantage to produce HCFO-1233zd (E) over
those previously known because the HCFO-1233zd (E) product is produced in a first
reactor with a high selectivity, thus avoiding the need for separating HCFO-1233zd (E)
and HFC-245fa products which form an azeotropic composition that makes it difficult to
separate using conventional separation techniques such as distillation, thereby resulting in
high product yield losses.
The disclosed process also has an advantage in that it allows for great flexibility
in producing different amounts of each compound by adjusting the fractionation or
distribution of the crude streams from the first and second fluorination reactors.
The disclosed integrated manufacturing process is different from prior art because
it also includes the ability to recycle unreacted starting materials to maximize raw
material utilization and product yields. It also discloses the ability to isolate by-products
that may be sold for commercial value.
It should be appreciated by those persons having ordinary skill in the art(s) to
which the present invention relates that any of the features described herein in respect of
any particular aspect and/or embodiment of the present invention can be combined with
one or more of any of the other features of any other aspects and/or embodiments of the
present invention described herein, with modifications as appropriate to ensure
compatibility of the combinations. Such combinations are considered to be part of the
present invention contemplated by this disclosure.
It is to be understood that both the foregoing general description and the
following detailed description are exemplary and explanatory only and are not restrictive
of the invention as claimed. Other embodiments will be apparent to those skilled in the
art from consideration of the specification and practice of the invention disclosed herein.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 shows the three integrated reactor lines used in one embodiment of the
present invention.
Figure 2 illustrates the product distribution in "after scrubber" samples as a
function of on-stream time. The top line is trans-HFO-1234ze (mole %); the middle line
is HFC-245fa (mole %) and the bottom line is cis-HFO-1234ze (mole %).
DETAILED DESCRIPTION OF THE INVENTION
Disclosed is a fully integrated co-manufacturing process for making HCFO-
1233zd (E), HFC-245fa, and HFO-1234ze (E). Overall the co-production is a three step
process. The chemistry involves:
Step 1:
CC1 CH=CHC1 + 3HF - CF CH=CHC1 + 3HC1
1,3,3,3-tetrachloropropene 1233zd (E)
CC12=CHCC1; + 3HF - CF CH= HC1 + 3HC1
1,1,3,3-tetrachloropropene 1233zd (E)
In Step 1, the reaction 1,1,3,3-tetrachloropropene and/orl,3,3,3-tetrachloropropene,
or mixtures thereof) with anhydrous HF in excess in a vapor phase or liquid
phase reactor in such a way as to produce HCFO-1233zd (E) with a high selectivity (plus
byproduct HC1). These reactions can be catalyzed or uncatalyzed.
Step 2 :
CF CH=CHC1 + 2 HF -» CF CHCHF + HC1
1233zd (E) 245fa
In Step 2, at least a portion of the produced HCFO-1233zd (E) can be recovered
as a pure component (product) and another portion can be sent to a second fluorination
reactor where it is fluorinated with HF in the liquid phase in the presence of a strong
fluorination catalyst such as fluorinated SbCl catalyst to produce a second product,
HFC-245fa.
Step 3 :
CF3CHCHF2 CF3CH=CHF + HF
245fa 1234ze (Z and/or E)
CF3CH=CHF -» CF3CH=CHF
1234ze (Z) 1234ze (E)
In Step 3, at least a portion of HFC-245fa produced in the second fluorination
reactor can be recovered as a second desired pure component (product) and another
portion can be dehydrofluonnated to produce the desired third pure component (product)
HFO-1234ze (E). Also, as shown above, the Z-isomer (1234ze (Z)) can be converted to
the desired trans-isomer 1234ze (E) through isomerization.
The manufacturing process consists of the several major process operations as
described below. The relative positions of these process operations in the three reaction
lines are shown in Figure 1.
(1) vapor or liquid phase fluorination reaction of 1,1,3,3-tetrachloropropene
and/or 1,3,3,3-tetrachloropropene, and mixtures thereof using HF in a
first reactor with simultaneous removal of byproduct HCl and the coproduct
1233zd (E);
(2) separation of HF and heavy organics which are then fed to second
fluorination reactor;
(3) separation and purification of byproduct HCl;
(4) separation of HF which is then fed to the second fluorination reactor,
(5) purification of first product, 1233zd (E);
(6) fluorination of 1233zd (E) with HF to produce the second co-product,
245fa, in a liquid phase catalyzed reactor;
(7) purification of the second co-product 245fa (with HCl recovery and HF
recycle);
(8) dehydrofluorination of 245fa to 1234ze (E) in a third reactor (with recycle
of unreacted 245fa and isomerization of 1234ze (Z) by-product); and
(9) purification of the third co-product, 1233zd (E).
These major process operations, as well as additional operations, are discussed in
greater detail below.
The first fluorination reaction is conducted in a first reactor (RXR 1). This
reaction can be conducted in the vapor phase in the presence of a vapor phase
fluorination catalyst (such as fluorinated Cr20 3) or in the liquid phase. The liquid phase
reaction can be run in the absence of the catalyst or in the presence of a liquid phase
fluorination catalyst such as TiCl4, FeCl .
If a vapor phase reactor s utilized, then the anhydrous HF and the feed(s) of
1,1,3,3-tetrachloropropene, or 1,3,3,3-tetrachloropropene, or mixtures thereof, are
vaporized prior to entering the reactor. The product stream from the vapor phase reactor
(1233zd (E), unreacted HF, and by-product HCl) are then fed to the recycle column (2).
Preferably the reactor is constiucted from materials which are resistant to the corrosive
effects of the HF and catalyst, such as Hastelloy-C, Inconel, Monel, and Incoloy. Such
vapor phase fluorination reactors are well known in the art.
For the liquid phase fluorination reaction, an agitated, temperature-controlled
reactor is used for the contact of both feed materials and optionally with the liquid phase
fluorination catalyst. The liquid phase fluorination reactor is preferably equipped with an
integrated distillation column which permits the product to leave (along with byproduct
HCl, traces of light organics [principally 1234ze (E+Z)], and HF in the amount of slightly
above azeotropic composition), while retaining the bulk of the HF, plus under-fluorinated
organics, plus, if used, the catalyst. Preferably the reactor is constructed from materials
which are resistant to the corrosive effects of the HF and catalyst, such as Hastelloy-C,
Inconel, Monel, Incoloy, or fluoropolymer-lined steel vessels. Such liquid-phase
fluorination reactors are well known in the art.
The starting materials, 1,1,3,3-tetrachloropropene and/or 1,3,3,3-tetrachloropropene,
or mixtures thereof and HF, are fed continuously into the first fluorination
reactor. The reaction conditions (temperature, pressure, feed rates) and the HF to 1,1,3,3-
tetrachloropropene and/or 1,3,3,3-tetrachloropropene ratio are adjusted to achieve the
highest selectivity to 1233zd (E) product.
The stream exiting the first reactor (RXR 1) enters a recycle column. Here the
high boiling under-fluorinated or over-fluorinated intermediates and some HF are
separated and are fed to the second reactor (RXR 2) for further reaction. Crude 1233zd,
HF, and HCl are fed forward in the integrated process.
The stream exiting the recycle column (2) is fed to an HCl recovery column. The
HCl in this stream can then be purified and collected for sale using a low-temperature
HCl distillation column. High purity HCl is isolated and can be absorbed in de-ionized
water as concentrated HCl for sale.
The bottom stream from the HC1 column (3) that contains a crude product mixture
of 1233zd/lights and about 30 wt% to 50 wt% HF is fed to a sulfuric extractor or a phase
separator for removal of HF from this mixture. HF is either dissolved in the sulfuric acid
or phase separated from the organic mixture. HF is desorbed from the sulfuric acid/HF
mixture by stripping distillation and recycled back to the reactor. The organic mixture
either from the overhead of the sulfuric acid extractor may require treatment (scrubbing
or adsorption) to remove traces of HF before it is fed to the 1233zd (E) product recovery
train (5). Recovered HF is recycled back to first fluorination reactor (RXR 1) or is fed
forward to second fluorination reactor (RXR 2).
The purification of first desired product 1233zd (E) is performed via distillation
utilizing one or more of conventional distillation columns operating in a continuous mode.
The purified first desired product, 1233zd (E) is collected and is available for sale. The
lights and heavies are fed forward to the second fluorination reactor (RXR 2).
The reaction in RXR 2 uses a liquid phase fluorination catalyst of proper strength
to achieve the desired reaction preferentially. It has been found that a catalyst comprised
of antimony pentachloride (liquid under ambient conditions) which has been partially or
totally fluorinated by the action of anhydrous HF achieves the desired degree of
conversion without forming undesired byproducts. The catalyst fluorination is conducted
by adding a specified amount of antimony pentachloride to a non-agitated, temperaturecontrolled
reactor vessel, and adding HF by a gradual flow. A moderate amount of HC1
will be generated in the operation. Conditions: 10°C to 50°C and at about 0 psig to 100
psig pressure. Additional fluorination catalysts that can be used include in combination
with antimony pentachloride (all are partially of totally fluorinated by the action of
anhydrous HF) TiCl4, TaCl5, SbCl .
Reaction Line 2 makes use of a reaction and stripping column. The key to this
reaction is the equipment arrangement. A non-agitated, temperature-controlled reactor for
the contact of both feed materials with the liquid catalyst and an integrated distillation
column (operating in stripping mode) which permits the desired 245fa product to leave
(along with byproduct HCl and sufficient AHF to form the azeotrope), while retaining the
bulk of the HF, plus under-fluorinated and plus the catalyst is key.
Preferably the RXR 2 reactor is constructed from materials which are resistant to
the corrosive effects of the HF and catalyst, such as fluoropolymer-lined steel vessels.
Such liquid-phase fluorination reactors are well known in the art. Once the catalyst has
been prepared, the reaction can be initiated immediately upon heating to the desired
reaction temperature. The flow of HF for the catalyst preparation need not to be
discontinued while the reactor is heated to a temperature of 85°C to 115°C.
Preferably the HF feed is vaporized and superheated to provide the heat necessary
to maintain proper reactor operating temperatures. Then the addition of the organic feed
(1233zd) can be started immediately to cause continuous reaction while maintaining the
flow of HF at an amount sufficient to produce the desired product plus an excess amount
to account for losses due to azeotrope compositions of 245fa/HF that exit the top of the
integrated distillation column. The reaction runs under HF rich conditions to produce the
reaction product, 245fa.
Proper temperature control of the coolant and sufficient reflux action are
necessary for the stripping column to be effective. General operating conditions which
have been found to work well for the reaction and stripping are:
(a) operating pressure of 80 psig to 140 psig maintained by a control valve on
the exiting flow from the stripper column;
(b) reactor temperature of 85°C to 5°C, primarily supplied by superheating
the HF vapor feed with high-pressure steam to 120°C to 150°C directly
into the reaction mixture and steam flow into the reactor jacket;
(c) application of brine cooling to the heat exchanger on top of the stripper
column to induce reflux; temperature in the center portion of the stripper
about 10°C to 40°C below that in the reactor;
(d) additional heat input; and
(e) feed rate of HF to maintain reactor and stripper conditions.
The stream exiting second reactor (RXR 2) enters a recycle column. Here the
high boiling under-fluorinated or over-fluorinated intermediates and some HF are
separated and are fed back to the second reactor (RXR 2) for further reaction. Crude
245fa, HF, and HC1 are fed forward in the integrated process.
The stream exiting the recycle column (8) is fed to a HC1 recovery column. The
HC1 in this stream can then be purified and collected for sale using a low-temperature
HC1 distillation column. High purity HC1 is isolated and can be absorbed in de-ionized
water as concentrated HC1 for sale. Optionally water or caustic absorber can be used to
remove HC1 (and HF if this option is used) from the crude stream followed by a drying
column.
The bottom stream from the HC1 column (9) that contains a crude product mixture
of 245fa/light ends and about 30 wt% to 50 wt% HF is fed to a sulfuric acid extractor for
removal of HF from this mixture. HF is dissolved in the sulfuric acid and separated from
the organic mixture. HF is desorbed from the sulfuric acid/HF mixture by stripping
distillation and recycled back to the reactor. The organic mixture either from the
overhead of the sulfuric acid extractor may require treatment (scrubbing or adsorption) to
remove traces of HF before it is fed to the 245fa product recovery train ( 1 1) or fed
forward to the third dehydrofluorination reactor (RXR 3). Recovered HF is recycled
back to second fluorination reactor (RXR 2). This HF recovery step is not necessary if an
absorber (water or caustic) was used above.
Purification of the second product, 245fa, consists of two continuously operating
distillation columns. The first column is used to remove light ends, mainly 1234ze (E)
from the 245fa and the second column is used to remove the heavier components. The
light and heavy ends that are removed from the top of the first column and bottom of the
second column can both be recycled back to an earlier processing step like step (7).
Optionally light ends from the 245fa product recovery train, mainly 1234ze, can be fed to
the dehydrofluorination reactor (RXR 3).
A portion of the stream from step (10), and the light ends from the first distillation
column of step ( 1 1) are fed to one or more catalyzed vapor phase reactors where the
245fa is dehydrofluorinated to produce the desired 1234ze (E) product and HF. The
reactor(s) contains dehydrofluorination catalyst such as fluorinated Cr 0 that facilitates
the conversion of 245fa into 1234ze (E). The reaction conditions (temperature, pressure,
feed rates) are adjusted to achieve the highest yield to 1234ze (E) product. Preferably the
reactor is constructed from materials which are resistant to the corrosive effects of the HF,
such as Hastelloy-C, Inconel, Monel, Incoloy. The reactor effluent is fed forward to the
HF recovery system (13). Optionally, the dehydrofluorination reaction is conducted in a
liquid phase using caustic as a dehydrofluorinating agent. If this option is utilized, the
product stream is fed to the 1234ze (E) product recovery system (14).
The product stream exiting the dehydrofluorination reactor (RXR 3) containing
mainly 1234ze (E), 1234ze (Z), and 245fa is fed to the HF removal system. The HF from
the crude 1234ze (E) stream is removed using a water or caustic absorption unit followed
by a drying column (13). Optionally, sulfuric acid extraction system can be used to
recover HF. The acid feed crude product stream is fed forward to 1234ze (E) product
recovery train (14). The step of acid recovery is not needed if caustic solution was used
in dehydrofluorination step (12).
Purification of third product 1234ze (E) consists of two continuously operating
distillation columns. The first column is used to remove light ends (i.e., lights) that are
sent to utilization. The second column is used to remove the heavier components
(i.e.,heavies). These heavy ends that are removed from the bottom of the second column,
mainly 1234ze (Z) and unreacted 245fa, are recycled back to the dehydrofluorination
reactor (RXR 3).
The following examples are provided to further illustrate the invention and should
not be taken as limitations of the invention.
Example 1
For the experiment 450 grams of HF and 270 grams of the mixture of 50%
l,l,3,3-tetrachloropropene/50% 1,3,3,3-tetrachloropropene (15 to 1 mole ratio
HF:organics) are charged to the reactor at room temperature. The mixer is then turned on
ensuring the reactor contents are well mixed. Then the reactor is heated to 140°C, this
temperature is maintained until the completion of the reaction that is indicated by the lack
of HC1 generation. The reactor pressure is controlled in the range of 450 psig to 480 psig
by venting off the HC generated in the reaction to a dry-ice chilled dry ice trap (DIT).
At the completion of the reaction after about 4.5 hours, as determined by a lack of HCI
generation, the pressure from the reactor is vented into the DIT.
The crude product from the DIT is transferred into a 2L Monel absoiption
cylinder (frozen in dry-ice) with about 700 grams of water. The absorption cylinder is
allowed to warm up to room temperature and a sample of an organic layer that is formed
in the cylinder (aqueous and organic layers are present in the cylinder upon discharge) is
taken and analyzed by GC. GC results indicate the following composition of the reaction
products 2.48 GC% 245fa, 92.61 GC% 1233zd (E), 0.22 GC% 244fa, 2.93 GC% 1233zd
(Z). The amount of organic collected is later quantified by further analysis of the
different phases and amounted to 170 grams.
The organic remaining in the reactor after venting is recovered by quenching the
reactor with about 300 to 400 grams of water to absorb HF and HC1, and then adding
about 100 grams of carbon tetrachloride. The reactor contents are discharged into a
plastic bottle. The organic is separated from the aqueous phase by use of a separatory
funnel. The amount of heavies collected from the reactor is calculated by subtracting the
weight of CC14 added to the reactor from the total weight of organic phase collected and
amounts to 14.9 grams. GC/MS and GC analysis of the organic layer follows and
reveals 3 distinct peaks attributed to under-fluorinated species HCFC-241fa, 94.057 GC%,
HCFC-242fa, 1.760 GC%, and the starting materials (tetrachloropropenes), 4.183 GC%.
Example 2
Dehydrofluorination of 245fa
The reaction was conducted in a two inch inner diameter Monel packed-bed
reactor charged with 760 mL of fluorinated Cr20 3 catalyst. The crude product stream
exiting the reactor was fed to KOH scrubber and then to a single distillation column
operating in a continuous mode. The 1234ze (E) product together with light impurities
was collected as a distillate from the top of the distillation column. The stream consisting
mainly of unreacted 245fa and 1234ze (Z) by-product was recycled back to the reactor
from the bottom of the reboiler. The reaction was conducted at catalyst bed temperature
of 240°C to 290°C (coldest at the reactor inlet), at a reactor pressure of 5.2 psig, a
constant 245fa feed rate of 1.2 lb/h, a recycle feed rate varied between 0.8 to 0.98 lb/h to
maintain a constant liquid level in reboiler, and a constant overhead take-off rate of 1.02
lb/h (which is equivalent to a trans- 1234ze productivity of 38 lb/ft /hr).
During continuous operation, feeds and products at different sampling ports were
periodically analyzed. Table I below presents the results obtained at different reaction
stages. The overhead product contains 40 ppm to 100 ppm 1234yf, 400-500 ppm
trifluoropropyne, 99.9+% trans-1234ze, and about 70 ppm 1234zc, indicating one
distillation column is not efficient enough for product separation. See also, Figure 2.
Table I
Compositions of recycle feed, combined feed, and products at different sampling ports
Example 3
This example illustrates continuous distillation of the crude mixture consisting
essentially of HFO-1234ze (E), HFO-1234ze (Z), and HFC-245fa that was produced n
Example 2.
The distillation column consisted of a ten gallon reboiler, two inch inner diameter
by ten foot column packed with propack distillation packing and a shell and tube
condenser. The column had about 30 theoretical plates. The distillation column was
equipped with reboiler level indicator; temperature, pressure, and differential pressure
transmitters. The distillation was run at pressure of about 50 psig and differential
pressure of about 7 inches of H20 in the continuous mode.
The feed consisting essentially of HFO-1234ze (E), HFO-1234ze (Z), HFC-245fa,
and small amount of impurities was continuously fed via the inlet port at the bottom of
the distillation column at the rate of about 1.75 lb/hr. The distillate consisting essentially
of HFO-1234ze (E) and light impurity was collected from the top of the condenser at the
rate of about 1.02 lb/hr. The stream consisting essentially of HFC-245fa and HFO-
1234ze (Z) (see Table II below) was continuously taken out from the bottom of reboiler
at the rate of about 0.73 lb/hr in order to maintain the level of material in the reboiler at
about 40%. The distillation was run continuously for about 1000 hours.
REMAINDER OF PAGE INTENTIONALLY BLANK
Table II
Composition of 1234ze (E) distillation column streams
Example 4
This example illustrates the semi-batch reaction where HF is continuously fed
into a charge of titanium tetrachloride catalyst and a mixture of 50% 1,1,3,3-tetrachloropropene/
50% 1,3,3,3-tetrachloropropene .
A clean, empty ten gallon jacketed, agitated reactor of Hastelloy C construction is
prepared. This reactor is connected to a two inch inner diameter vertical, PTFE-lined pipe
containing packing material (stripper), which is in turn connected to an overhead heat
exchanger. The heat exchanger is supplied with -40°C brine circulation on the shell side.
Vapors exiting this stripper are processed through a scrubber, in which temperaturecontrolled
dilute potassium hydroxide aqueous solution is circulated. Vapors exiting this
stripper are collected in a weighed, chilled (-40°C) cylinder referred to as the product
collection cylinder (PCC), followed by a smaller cylinder in series chilled in a dry ice
bath.
For this example, 14 lbs. of anhydrous HF are first charged to the reactor for the
purpose of assuring complete fluorination of the fluorination catalyst. Next, 1.5 lbs. of
TiCl4 fluorination catalyst are added to the reactor. HC1 is immediately generated as
catalyst fluorination ensues as observed by the build-up of pressure in the reactor. After
the pressure is reduced by venting most of the HC1 from the system, 50 lbs of a 50%
l,l,3,3-tetrachloropropene/50% 1,3,3,3-tetrachloropropene mixture is added batch wise.
The reactor is then heated. At about 85°C HC1 starts to be generated indicating that the
fluorination reaction is initiated. The system pressure is controlled at about 1 0 psig.
Additional HF is then fed continuously and product is collected in the PCC until the 50%
l,l,3,3-tetrachloropropene/50% 1,3,3,3-tetrachloropropene mixture is consumed.
The GC analysis of the crude material that was collected in the PCC during the
run is as follows; 86.4% 1233zd (E); 5.5% G-244fa; 3.1% 1234ze (E); 1.5% 1233zd(Z);
1.1% 1234ze (Z); 1.1% dimer; 0.2% trifluoropropyne.
Example 5
This example illustrates the recovery of anhydrous HF from a mixture of HF,
HCFO-1233zd, and 50% l,l,3,3-tetrachloropropene/50% 1,3,3,3-tetrachloropropene
mixture according to certain preferred embodiments of the present invention.
A mixture consisting of about 70 wt.% HCFO-1233zd (E) and about 30 wt.% HF
is vaporized and fed to the bottom of a packed column at a feed rate of about 2.9 lbs per
hour for about 4 hours. A stream of about 80 wt.% sulfuric acid (80/20 H2S0 /H20 ) with
about 2% HF dissolved therein is fed continuously to the top of the same packed column
at a feed rate of about 5.6 lbs per hour during the same time frame. A gaseous stream
exiting the top of the column comprises HCFO-1233zd (E) with less than 1.0 wt.% HF
therein. The concentration of HF in the sulfuric acid in the column bottoms increases
from 2.0 wt.% to about 15 wt.%.
The column bottoms containing sulfuric acid and about 15 wt.% HF is collected
and charged into a two gallon Teflon® lined vessel. The mixture is heated to about
140°C to vaporize and flash off HF product, which is collected. The collected HF
product contains about 6000 ppm water and 500 ppm sulfur. The sulfuric acid contains
about 500 ppm of TOC (total organic carbon).
The HF collected from flash distillation is distilled in a distillation column and
anhydrous HF is recovered. The recovered anhydrous HF contains less than 50 ppm of
sulfur impurities and lees than 100 ppm water
Example 6
This example demonstrates the purification of the acid free 1233zd (E) crude
product. 92 lbs of acid free 1233zd crude material produced in Example 2 is charged to
a batch distillation column. The crude material contains about 94 GC area% and 6 GC
area% impurities. The distillation column consists of a 10 gallon reboiler, two inch inner
diameter by 10 feet propack column, and a shell and tube condenser. The column has
about 30 theoretical plates. The distillation column is equipped with temperature,
pressure, and differential pressure transmitters. About 7 lbs of a lights cut is recovered
which consists of mainly 1234ze (Z+E), trifluoropropyne, 245fa, and 1233zd (E). 82 lbs
of 99.8+ GC area% 1233zd (E) are collected. The reboiler residue amounting to about 3
lbs is mainly 244fa, 1233zd (Z), 1233zd dimmer, and 1233zd (E). The recovery of 99.8+
GC area% pure 1233zd (E) is 94.8%.
Example 7
In this example, a continuous liquid phase fluorination of a mixed stream
containing 1233zd (Z) and 1233zd (E) is demonstrated. The fluorination catalyst for the
example is SbCl .
6500 grams of SbCl5 are contained in a Teflon® -lined liquid phase reactor
equipped with a catalyst stripper, two inch inside diameter packed column and with a
condenser whose function is to return entrained catalyst, some of the unreacted HF and
some of the unreacted organic back to the reactor when the system is running in
continuous reaction mode. The reactor is 2.75-inch inside diameter x 36-inch long and is
not equipped with a mixer/agitator. The reactor is heated to about 85°C to 87°C. The
catalyst is then activated by the addition of 1500 grams of HF followed by 1500 grams of
Cl2. HC1 generated by the fluorination of the catalyst raises the reaction system pressure
to about 100 psig where it is controlled.
The continuous gaseous HF feed is started first. It is bubbled into the liquid
catalyst through a dip tube at a rate of .9 lb/hr, and when .0 lb of HF has been added,
the mixed organic feed stream is introduced. It also enters the liquid catalyst by way of a
dip tube and consist of about 95% 1233zd (E) and 5% 1233zd(Z). The mixed organic is
fed continuously at rate of 2.0 lb/hr. The mole ratio of HF to organic raw material is 7 :1.
The reaction temperature is maintained at 90°C to 95°C and the pressure is maintained at
120 psig. 245fa, unreacted organic, organic by-products, HC1, and unreacted HF exit the
top of the catstripper column. The experiment is run continuously for over 500 hours
and the average conversion of the organic raw material is greater than 99.5% while the
selectivity to 245fa reaches 99.5%. Cl2 (0.02 mole/mole organic) is continuously fed
into the reaction mixture on a periodic basis through a dip tube in order to keep the
catalyst active.
Example 8
245fa crude material exiting a 50 gallon pilot plant fluorination reaction system
was contacted with water in an absorption column to remove HC1 and HF. Only a trace
amount of acid remained. This stream was then contacted by a dilute caustic stream in a
second absorber removing the remaining acid. The stream was then passed through a
column containing XI3 molecular sieves to remove any moisture that was added to the
stream during contact with water during the acid removal step.
Example 9
The dried and acid free 245fa crude material from Example 8 was then distilled
continuously to greater than 99.95% purity using a series of two conventional distillation
columns to remove most of the low and high boiling impurities.
As used herein, the singular forms "a"', "an" and "the" include plural unless the
context clearly dictates otherwise. Moreover, when an amount, concentration, or other
value or parameter is given as either a range, preferred range, or a list of upper preferable
values and lower preferable values, this is to be understood as specifically disclosing all
ranges formed from any pair of any upper range limit or preferred value and any lower
range limit or preferred value, regardless of whether ranges are separately disclosed.
Where a range of numerical values is recited herein, unless otherwise stated, the range is
intended to include the endpoints thereof, and all integers and fractions within the range.
It is not intended that the scope of the invention be limited to the specific values recited
when defining a range.
It should be understood that the foregoing description is only illustrative of the
present invention. Various alternatives and modifications can be devised by those skilled
in the art without departing from the invention. Accordingly, the present invention is
intended to embrace all such alternatives, modifications and variances that fall within the
scope of the appended claims.
REMAINDER OF PAGE INTENTIONALLY BLANK
WHAT IS CLAIMED IS:
1. An integrated manufacturing process for the production of (E) 1-chloro-
3,3,3-trifluoropropene, (E)l,3,3,3-tetrafluoropropene, and 1,1,1,3,3-pentafluoropropane
from a starting material comprising 1,1,3,3-tetrachloropropene, 1,3,3,3-tetrachloro
propene, or a mixture thereof, comprising the steps of:
(a) in a first reactor, conducting the fluorination of a starting material selected
from the group consisting of 1,1,3,3-tetrachloropropene, 1,3,3,3-tetrachloropropene, and
mixtures thereof, to produce (E)l-chloro-3,3,3-trifluoropropene (1233zd (E)); and
optionally,
(b) in a second reactor, conducting the fluorination of 1233zd (E) to produce
1,1,1,3,3-pentafluoropropane (245fa); and optionally,
(c) in a third reactor, conducting the dehydrofluorination of 245fa to produce
(E) 1,3,3,3-tetrafluoropropene (HFO-1234ze (E)).
2. The process of Claim 1, wherein step (a) is a liquid phase reaction
performed in the absence of the catalyst.
3. The process of Claim 1, wherein step (a) is a liquid phase reaction using a
fluorination catalyst.
4. The process of Claim 1, wherein step (a) is a vapor phase reaction using a
fluorination catalyst.
5. The process of Claim 4, wherein the vapor phase fluorination catalyst is
vapor phase fluorination catalyst is fluorinated Cr20 .
6. The process of Claim 1, wherein step (b) is not optional.
7. The process of Claim 6, wherein step (b) is a vapor phase reaction using a
fluorination catalyst.
8. The process of Claim 1, wherein step (c) is not optional.
9. The process of Claim 8, wherein step (c) is a liquid phase reaction using a
caustic solution selected from the group consisting of KOH, NaOH, LiOH, Mg(OH) ,
Ca(OH)2, and CaO.
10. The process of Claim 8, wherein step (c) is a vapor phase reaction using a
dehydrofluorination catalyst selected from the group consisting of fluorinated metal
oxides, metal fluorides, and supported metal catalysts.