The systems and processes described herein relate to the formation and production of chlorotrifluoroethylene (CFO-1113 or CTFE), and more particularly to the production of CFO-1113 from HCFC-123a.
Chlorotrifluoroethylene, which is CF2═CFCl, and is often referred to as CFO-1113 or CTFE, is a monomer utilized in the field of fluororesins and fluorine rubbers. For example, CFO-1113 can be utilized in the production of polychlorotrifluoroethylene, as well as in the production of various copolymers with ethylene, vinyl acetate or vinylidene fluoride, among others.
Commonly, CFO-1113 is manufactured by dechlorination of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113). In such a reaction, CFC-113 and zinc (Zn) can be reacted in the presence of methanol to yield CFO-1113. High conversions and selectivities to CFO-1113 can be obtained in such reactions, although some by-products are also formed, including 1,2-dichloro-1,1,2-trifluoroethane (CHClF—CClF2 or HCFC-123a), trifluoroethene (HFC-1123), 1-chloro-2,2,2-trifluoroethane (CFC-133a), unreacted CFC-113, and methanol.
The systems and processes described herein relate to the formation and production of CFO-1113 from HCFC-123a. More particularly, the systems and processes described herein relate to the formation and production of CFO-1113 directly from HCFC-123a.
In one aspect, a system for producing CFO-1113 from HCFC-123a is provided that includes at least one reactor, a condenser, and a phase separator. The reactor can receive an HCFC-123a containing feed stream and a base containing feed stream. The HCFC-123a and the base can be reacted in the at least one reactor to produce reaction product vapors including CFO-1113, and a liquid effluent stream containing unreacted HCFC-123a can be removed from the at least one reactor. The condenser can receive reaction product vapors from the reactor and produces a CFO-1113 product stream. The phase separator can receive liquid effluent stream from the reactor and separate unreacted HCFC-123a to produce an unreacted HCFC-123a stream. The unreacted HCFC-123a stream can be recycled for further reaction.
In another aspect, a process for producing CFO-1113 from HCFC-123a is provided. The process includes providing a first reactor, providing an HCFC-123a containing feed stream to the first reactor, and providing a base containing feed stream to the first reactor. The process also includes, reacting the HCFC-123a and the base in the first reactor to produce reaction product vapors including CFO-1113. The process further includes removing the reaction product vapors from the first reactor, and removing a liquid effluent stream from the first reactor, where the liquid effluent stream contains base and unreacted HCFC-123a.
In a third aspect, another process for producing CFO-1113 from HCFC-123a is provided. The process includes providing a first reactor, providing an HCFC-123a containing feed stream to the first reactor, and providing a base containing feed stream to the first reactor. The process includes reacting the HCFC-123a and the base in the first reactor to produce reaction product vapors including CFO-1113, removing the reaction product vapors from the first reactor, and removing a liquid effluent stream from the first reactor, where the liquid effluent stream contains base and unreacted HCFC-123a. The process also includes providing a second reactor, providing the liquid effluent stream containing base and unreacted HCFC-123a from the first reactor to the second reactor, optionally providing additional HCFC-123a to the second reactor, and reacting the HCFC-123a and the base in the second reactor to produce reaction product vapors including CFO-1113. The process further includes removing the reaction product vapors from the second reactor, and removing a liquid effluent stream from the second reactor, where the liquid effluent stream contains base and unreacted HCFC-123a.
Specific examples have been chosen for purposes of illustration and description, and are shown in the accompanying drawings, forming a part of the specification.
The systems and processes described herein relate to the formation and production of CFO-1113. More particularly, the systems and processes described herein relate to the formation and production of CFO-1113 from HCFC-123a.
As described above HCFC-123a is a side product in the manufacture of CFO-1113 from the reaction of CFC-113 and zinc in the presence of methanol. It can thus be desirable to have a process wherein HCFC-123a is converted to useful products, preferably CFO-1113, which could increase overall process yield in such CFO-1113 production processes. The systems and processes described herein preferably derive CFO-1113 from HCFC-123a through a one step, or direct, reaction process.
For example, HCFC-123a can be reacted with a suitable base to directly form CFO-1113 and other byproducts. Suitable bases include, but are not limited to, potassium hydroxide (KOH), sodium hydroxide (NaOH), calcium oxide (CaO), and calcium hydroxide (Ca(OH)2).
HCFC-123a can be combined with potassium hydroxide (KOH) to form CFO-1113, potassium chloride (KCl), and water, as shown in reaction (1) below:
CHClF—CClF2+KOH→CF2═CFCl+KCl+H2O (1)
HCFC-123a can be combined with sodium hydroxide (NaOH) to form CFO-1113, sodium chloride and water, as shown in reaction (2) below:
CHClF—CClF2+NaOH→CF2═CFCl+NaCl+H2O (2)
HCFC-123a can be combined with calcium oxide (CaO) to form CFO-1113, calcium chloride, and water, as shown in reaction (3) below:
2CHClF—CClF2+CaO→CF2═CFCl+CaCl2+H2O (3)
HCFC-123a can be combined with calcium hydroxide (Ca(OH)2) to form CFO-1113, calcium chloride, and water, as shown in reaction (4) below:
2CHClF—CClF2+Ca(OH)2→CF2═CFCl+CaCl2+2H2O (4)
As illustrated in
In accordance with the system 100 illustrated in
In the reactor 102, the HCFC-123a and the base can be reacted at any suitable temperature, preferably at a temperature from about 40° C. to about 100° C., and more preferably at a temperature from about 50° C. to about 90° C. Reacting the HCFC-123a and base in the reactor 102 forms reaction product vapors, which can include CFO-1113, HCFC-123a, water, and other byproducts.
As illustrated in
The reaction product vapor stream can be provided to condenser 116 through one or more lines, such as lines 118 and 136. The condenser 116 can separate CFO-1113 from the reaction product vapors, and a CFO-1113 product stream can be removed from the condenser 116. As illustrated in
The system 100 can also optionally include a fractional distillation column 120. As illustrated in
In examples where the reaction of HCFC-123a and the base is conducted as a continuous reaction in reactor 102, a liquid effluent can be removed from the reactor 102 either continuously or periodically. The liquid effluent can be removed from the reactor 102 through line 126. The liquid effluent can include base, water, unreacted HCFC-123a, and byproducts of the reaction. The liquid effluent can be passed to a phase separator 124. The phase separator 124 can receive the liquid effluent and separate the unreacted HCFC-123a from the other components of the liquid effluent stream. An unreacted HCFC-123a stream can be removed from the phase separator 124 through line 130, and the remaining components of the liquid effluent stream can be removed from the phase separator 124 in a spent product stream through line 128. As illustrated in
As illustrated in
In the system illustrated in
In the system illustrated in
Reaction product vapors can be removed from the first reactor 202. The reaction product vapors can be provided directly to a first condenser 216 through one or more lines, such as lines 218 and 246. First condenser 216 can receive the reaction product vapors formed during the reaction that occurs in the first reactor 202. The first condenser 216 can separate CFO-1113 from other less volatile components of the reaction product vapors, and a CFO-1113 product stream can be removed from the first condenser 216. As illustrated in
The system 200 can also optionally include a first fractional distillation column 220. As illustrated in
In examples where the reaction of the HCFC-123a and the base is conducted as a continuous reaction in the first reactor 202, a liquid effluent can be removed from the first reactor 202 through line 224. The liquid effluent is preferably removed continuously, and can be fed to the second reactor 204. The liquid effluent can include base, water, unreacted HCFC-123a, and other byproducts. The liquid effluent stream provided from the first reactor 202 to the second reactor 204 is thus a feed stream that contains both HCFC-123a and base. The HCFC-123a and the base can be reacted in the second reactor 204 to form reaction product vapors. The reaction product vapors formed in the second reactor 204 can include CFO-1113, HCFC-123a, water, and other byproducts.
Optionally, additional HCFC-123a can be provided to the second reactor 204 by providing an HCFC-123a containing feed stream to the second reactor that is separate from the liquid effluent. The separate HCFC-123a containing feed stream can be fed to the second reactor 204 through third feed line 210. In such an example, the HCFC-123a included in the liquid effluent stream from the first reactor 202 and the HCFC-123a containing feed stream fed to the second reactor 204 can be reacted with the base in the liquid effluent stream to form the reaction product vapors. The HCFC-123a containing feed stream can be provided to the second reactor 204 at a rate or amount appropriate to supplement the HCFC-123a in the liquid effluent from the first reactor 202, to provide a total amount of HCFC-123a in the second reactor 204 that results in a mole ratio of base to HCFC-123a in the second reactor 204 of less that about 0.5:1 up to about to 3:1, preferably from about 1:1 to about 1.5:1. The HCFC-123a and base can be reacted in the second reactor 204 at any suitable temperature, preferably at a temperature from about 40° C. to about 100° C., and more preferably at a temperature from about 50° C. to about 90° C.
The reaction product vapors produced in the second reactor 204 can be removed from the second reactor 204. The reaction product vapors can be provided directly to a second condenser 228, which can receive the reaction product vapors formed during the reaction that occurs in the second reactor 204 through one or more lines, such as lines 226 and 252. The second condenser 228 can separate CFO-1113 from other less volatile components of the reaction product vapors, and a CFO-1113 product stream can be removed from the second condenser 228. As illustrated in
The system 200 can also optionally include a second fractional distillation column 234. As illustrated in
In examples where the reaction of HCFC-123a and base is conducted as a continuous reaction in the second reactor 204, a liquid effluent can be removed from the second reactor 204 through line 236 either continuously or periodically. The liquid effluent can include base, water, unreacted HCFC-123a, and other byproducts.
As illustrated in
A reaction for converting HCFC-123a to CFO-1113 was carried out in a system having a single reactor. The reactor was a continuous stirred reactor. The reaction was conducted continuously for 52 (fifty-two) hours. During the experiment, the temperature in the reactor varied between about 50° C. and about 60° C. The pressure in the reactor varied between about 30 psig and 113 psig.
During the reaction, an organic feed stream containing HCFC-123a was provided to the reactor at a flow rate of about 5 ml/min. Gas chromatography area percents of the organic feed revealed that the organic feed contained about 0.81% HFO-1113, about 95% HCFC-123a, and about 3.2% CFC-113.
During the reaction, a KOH feed stream was provided to the reactor at a flow rate of about 12 ml/min. Based upon the feed rates of the organic feed stream and the KOH feed stream, the molar ratio of KOH to HCFC-123a was calculated to be about 1, or slightly above 1. The theoretical residence time in the reactor during the reaction was calculated to be about 2 hours.
A collection vessel was used to collect spent KOH and any organic that was carried out with spent KOH. MeCl2 was added inside the collection vessel in order to trap organic. The volume of MeCl2 inside the cylinder was 20% of the total volume of liquid in collection vessel. Product and un-reacted organic was collected in collection vessel that were held in dry ice. Vapor samples were taken once an hour, and liquid samples were taken at longer intervals.
The overall mass balance of the reaction was calculated to be about 82% for HCFC-123a and about 87% for KOH. The average single pass conversion was calculated to be about 39%. Selectivity to CFO-1113 was calculated to be about 90%.
Simulation and methods known to those skilled in the art were utilized to generate the following example utilizing a plurality of reactors in series to convert HCFC-123a to CFC-1113 by reacting the HCFC-123a with KOH. Using data obtained from Example 1, a two stage system was simulated. The two stage system included a first reactor and a second reactor, as described with respect to
By utilizing the same residence time in each of the two reactors, an the overall of conversion of HCFC-123a across two reactors was calculated to be about 56%. A corresponding increase in KOH utilization was also calculated.
From the foregoing, it will be appreciated that although specific examples have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit or scope of this disclosure. It is therefore intended that the foregoing detailed description be regarded as illustrative rather than limiting, and that it be understood that it is the following claims, including all equivalents, that are intended to particularly point out and distinctly claim the claimed subject matter.