U.S. patent application number 16/023410 was filed with the patent office on 2018-10-25 for systems and processes for producing organic acids direct from beta-lactones.
This patent application is currently assigned to Novomer, Inc.. The applicant listed for this patent is Novomer, Inc.. Invention is credited to Sadesh H. Sookraj.
Application Number | 20180305286 16/023410 |
Document ID | / |
Family ID | 63853100 |
Filed Date | 2018-10-25 |
United States Patent
Application |
20180305286 |
Kind Code |
A1 |
Sookraj; Sadesh H. |
October 25, 2018 |
Systems and Processes for Producing Organic Acids Direct from
Beta-Lactones
Abstract
Provided herein are reactor systems and processes for producing
organic acids directly from beta-lactones. Such reactor systems and
processes involve the use of a heterogeneous catalyst, such as a
zeolite at vapor phase conditions. The reactor systems and
processes may use a fixed bed, moving bed or fluidized contacting
zone as reactor configurations.
Inventors: |
Sookraj; Sadesh H.;
(Cambridge, MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Novomer, Inc. |
Boston |
MA |
US |
|
|
Assignee: |
Novomer, Inc.
Boston
MA
|
Family ID: |
63853100 |
Appl. No.: |
16/023410 |
Filed: |
June 29, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15640197 |
Jun 30, 2017 |
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16023410 |
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15464346 |
Mar 21, 2017 |
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15640197 |
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62311262 |
Mar 21, 2016 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C07C 309/22 20130101;
B01J 8/067 20130101; B01J 2219/0004 20130101; C07D 307/54 20130101;
B01J 3/006 20130101; C07C 231/12 20130101; C07F 7/1804 20130101;
C07D 317/30 20130101; C07C 51/09 20130101; C07C 67/28 20130101;
C07F 7/1892 20130101; C07C 51/09 20130101; C07C 57/08 20130101;
C07C 51/09 20130101; C07C 57/04 20130101; C07C 51/09 20130101; C07C
57/52 20130101; C07C 51/09 20130101; C07C 59/58 20130101; C07C
51/09 20130101; C07C 59/68 20130101; C07C 51/09 20130101; C07C
59/62 20130101; C07C 51/09 20130101; C07C 59/42 20130101; C07C
51/09 20130101; C07C 57/13 20130101; C07C 67/28 20130101; C07C
69/145 20130101; C07C 67/28 20130101; C07C 69/78 20130101; C07C
67/28 20130101; C07C 69/54 20130101; C07C 67/28 20130101; C07C
69/593 20130101 |
International
Class: |
C07C 51/09 20060101
C07C051/09; C07C 309/22 20060101 C07C309/22; C07F 7/18 20060101
C07F007/18; C07D 307/54 20060101 C07D307/54; C07D 317/30 20060101
C07D317/30; C07C 231/12 20060101 C07C231/12 |
Claims
1. A process for producing at least one organic acid product
directly from at least one beta-lactone reagent, wherein the at
least one beta-lactone reagent is represented by the following
formula: ##STR00092## wherein R.sub.1 and R.sub.2 are independently
selected from the group consisting of H, alkyl, alkenyl, alkoxy,
alkynyl, cycloalkyl, cycloalkenyl and cycloalkynyl, wherein both of
R.sub.1 and R.sub.2 are not H at the same time, comprising the
steps: introducing at least one beta-lactone reagent to at least
one reaction vessel; contacting the at least one beta-lactone
reagent with at least one heterogenous catalyst in the at least one
reaction vessel to produce at least one organic acid; and removing
the at least one organic acid from the at least one reaction vessel
to provide at least one organic acid product.
2. The process from claim 1, wherein the heterogenous catalyst
comprises a microporous solid selected from the group including
alkaline-earth phosphates, supported phosphate salts, calcium
hydroxyapatites, inorganic salts, metal oxides, and zeolites, or
combinations thereof.
3. The process from claim 1, wherein the heterogenous catalyst
comprises an alumina-silicate molecular sieve having Lewis or
Bronsted acidity.
4. The process from claim 1, wherein the heterogenous catalyst
comprises a zeolite.
5. The process from claim 4, wherein the heterogenous catalyst
comprises Zeolite Y, beta Zeolite, ZSM-5, ZSM-11 ZSM-22, MCM-22,
ZSM-35, Zeolite A, or combinations thereof.
6. The process from claim 2, wherein the zeolite catalyst is in a
hydrogen form or in metal cation exchanged form
7. The process from claim 6, wherein the metal cations are
Na.sup.+, K.sup.+, Ca.sup.2+, Mg.sup.2+, Cu.sup.2+, Cu.sup.+.
8. The process from claim 1, wherein the at least one organic acid
product is produced continuously.
9. The process from claim 1, wherein the at least one beta-lactone
reagent is introduced to the at least one reaction vessel combined
with a solvent.
10. The process from claim 1, wherein the at least one reaction
vessel further comprises a continuous fixed-bed reactor operating
at a reduced pressure.
11. The process from claim 1, wherein the at least one reaction
vessel further comprises a continuous fixed-bed reactor configured
for receiving at least one beta-lactone reagent diluted with inert
gas
12. The process from claim 1, wherein the least one reaction vessel
further comprises a fluidized bed reactor configured to receive at
least one beta-lactone reagent diluted with inert gas such as
nitrogen.
13. The process from claim 1, wherein the least one reaction vessel
further comprises a tubular shell-and-tube reactor with a
heterogenous catalyst loaded into the tubes and heat transfer fluid
fed to the shell side to facilitate temperature control and removal
of the heat produced during the reactions.
14. The process from claim 1, wherein the beta-lactone reagent is
provided at a weight hourly space velocity of 0.1 h.sup.-1 to 2.1
h.sup.-1.
15. The process from claim 1, wherein the beta-lactone reagent is
provided at a weight hourly space velocity of 0.3 h-1 to 0.9
h-1.
16. The process from claim 1, wherein the at least one organic acid
product is continuously isolated.
17. The process from claim 1, wherein the at least one organic acid
product is produced at a yield of at least 50%.
18. The process from claim 1, wherein the at least one organic acid
product is produced at a temperature between 100.degree. C. and
300.degree. C.
19. A reactor system for producing at least one organic acid
product directly from at least one beta-lactone reagent, wherein
the at least one beta-lactone reagent is represented by the
following formula: ##STR00093## wherein R.sub.1 and R.sub.2 are
independently selected from the group consisting of H, alkyl,
alkenyl, alkoxy, alkynyl, cycloalkyl, cycloalkenyl and
cycloalkynyl, wherein both of R.sub.1 and R.sub.2 are not H at the
same time, wherein the reactor system comprises: at least one
reaction vessel configured as a continuous fixed-bed reactor or a
fluidized bed reactor defining at least one feed stream inlet and
at least one product stream outlet; said at least one reaction
vessel further defining an interior volume for receiving the at
least one beta-lactone reagent from said at least one feed stream
inlet and a retaining volume adapted for retaining the at least one
beta-lactone reagent in solid, liquid, and gaseous phases.
20. The reactor from claim 19, wherein the at least one reaction
vessel further comprises a fixed-bed reactor.
21. The reactor system from claim 19, wherein the at least one
reaction vessel further comprises a continuous fixed-bed reactor
operating at a reduced pressure for production of at least one
organic acid product.
22. The reactor system from claim 19, wherein the at least one
reaction vessel further comprises a continuous fixed-bed reactor
configured for receiving at least one beta-lactone reagent diluted
with inert solvent or gas.
23. The reactor system from claim 19, wherein the at least one
reaction vessel further comprises a fluidized bed reactor
configured to receive at least one beta-lactone reagent diluted
with inert gas.
24. The reactor system from claim 19, wherein the at least one
reaction vessel further comprises two or more sections separated by
one or more heaters.
25. The reactor system from claim 19, wherein the at least one
reaction vessel further comprises a tubular shell-and-tube reactor
with a heterogenous catalyst loaded into the tubes and heat
transfer fluid fed to the shell side to facilitate temperature
control and removal of the heat produced during the reactions.
26. The reactor system from claim 19, wherein the at least one
reaction vessel further comprises a regeneration vessel for the
regeneration of at least one heterogenous catalyst.
Description
CROSS-REFERENCES
[0001] The present application claims benefit from U.S. application
Ser. No. 15/640,197 filed Jun. 30, 2017, which claims benefit from
U.S. application Ser. No. 15/464,346, filed Mar. 21, 2017, which
claims benefit from U.S. Provisional Application No. 62/311,262,
filed Mar. 21, 2016, which are hereby incorporated by reference in
their entireties as if fully restated herein.
FIELD OF THE INVENTION
[0002] This invention generally relates to reactor systems and
processes for producing organic acids directly form
beta-lactones.
BACKGROUND OF THE INVENTION
[0003] The production and use of organic acids such as acrylic acid
(AA) has grown significantly in recent decades as the demand for
polyorganic acids such as polyacrylic acid-based superabsorbent
polymers (SAPs) has grown. SAPs are used extensively for the
manufacture of diapers, adult incontinence products, and feminine
hygiene products, as well as in agricultural applications.
[0004] Currently, commercial acrylic acid is typically derived from
propylene oxidation. Propylene is primarily a product of oil
refining and its price and availability are closely tied to crude
oil prices. Because of this, acrylic acid prices remain tied
closely to the price of oil and its fluctuations.
[0005] Thus, there exists a need in the art for alternative methods
to synthesize certain organic acids. At the same time, it would be
preferred to produce organic acids from renewable resources. U.S.
patent application publications 2015/0183708 published Jul. 2, 2015
and 2014/0018574 filed Jan. 15, 2014 disclose the production of
bio-based acrylic acid from poly-3-hydroxypropionate using a wide
variety of biologically active materials.
[0006] Other references disclose producing acrylic acid from
beta-propiolactone with inorganic catalysts. U.S. Pat. No.
3,176,042 disclosed a phosphoric acid catalyzed process to produce
acrylic acid from beta-propiolactone. Due to corrosiveness of
phosphoric acid and slow reaction rate this process is capital
intensive. Additionally, water must be fed to the reactor
continuously to maintain the composition of phosphoric acid inside
the reactor at the desired levels. This leads to the need to
separate water from the produced acrylic acid resulting in
additional equipment and operating costs.
[0007] U.S. Pat. No. 9,096,510 B2 teaches production of acrylic
acid from beta-propiolactone using a solid catalyst in at least
partial gas phase conditions.
[0008] WO20133191 teaches production of acrylic acid from
beta-propiolactone in a two-step process: at first
beta-propiolactone is polymerized to produce poly-propiolactone and
then acrylic acid is produced via thermolysis of
poly-propiolactone. This process capital intensive and has high
operating costs as highly exothermic polymerization reaction is
followed by highly endothermic thermolysis reaction.
[0009] Thus, improved methods are sought to produce certain organic
acid products, especially high purity organic acid products from
non-hydrocarbon and preferably renewable sources.
SUMMARY OF THE INVENTION
[0010] There exists a need for innovative reactor systems and
processes for producing higher purity organic acid products from
beta-lactone reagents. Advantageously, the reactor systems and
processes of the present invention provide higher purity organic
acid products from beta-lactone reagents and are economically
favorable compared to processes of the prior art.
[0011] One object of the present invention is to provide for the
processes which may produce at least one organic acid product may
be produced from at least one beta-lactone reagent.
[0012] Another object of the present invention is to provide for
the reactor systems which may be configured to produce at least one
highly pure organic acid product from at least one beta-lactone
reagent through the processes of the present invention.
[0013] Provided herein are systems and processes for producing
organic acid products from beta-lactone reagents via an improved
one-step process that is economically favorable compared to the
processes known in the art. The reactor systems and processes of
the present invention include combining a beta-lactone reagent, a
heterogenous catalyst, and optionally a solvent or diluent for
reaction in a vessel. The reactor systems and processes include
maintaining the beta-lactone reagent and any solvent or diluent in
a vapor phase while contacting the heterogenous catalyst to produce
an organic acid product.
[0014] In preferred embodiments, the heterogeneous catalyst
comprises a crystalline microporous solid. Catalysts of the type
that are specifically suited for this invention include
alkaline-earth phosphates, supported phosphate salts, calcium
hydroxyapatites, inorganic salts, metal oxides, and zeolites. In
preferred embodiments, the heterogeneous catalyst is an
alumina-silicate molecular sieve and more preferably a zeolite
having Lewis or Bronsted acidity. The zeolites can be in hydrogen
form or in cation exchanged form with suitable cations, for
example, alkali metals such as Na+ or K+ and alkali-earth cations
such as Ca2+, Mg2+, Sr2+, or Ba2+; Zn2+, Cu+, and Cu2+.
[0015] In certain preferred embodiments, the processes for
producing organic acids from beta-lactones may be performed using
reactor systems configured to include fixed bed continuous reactor
and regeneration. In certain preferred embodiments, the processes
for producing organic acids from beta-lactones may be performed
using reactor systems configured for passing vapor phase feed
streams to a fixed bed of zeolite catalyst. In certain preferred
embodiments, beta-lactones may be diluted with inert solvents
and/or inert gases prior to reaction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 depicts an exemplary process to produce an organic
acid product from a beta-lactone reagent.
[0017] FIG. 2 depicts an exemplary reaction system to produce an
organic acid product from a beta-lactone reagent according to the
processes described herein.
[0018] FIG. 3 is a process flow diagram for a fixed bed operation
of the reactor system to produce an organic acid product directly
from a beta-lactone reagent according to the processes of this
invention.
[0019] FIG. 4 is a process flow diagram for a moving bed operation
of the reactor system to produce an organic acid product directly
from a beta-lactone reagent according to the processes of this
invention.
[0020] FIG. 5 is a process flow diagram for a fluidized bed
operation of the reactor system to produce an organic acid product
directly from a beta-lactone reagent according to the processes of
this invention.
DETAILED DESCRIPTION OF EMBODIMENTS
[0021] The following description sets forth exemplary processes,
parameters and the like. It should be recognized, however, that
such description is not intended as a limitation on the scope of
the present disclosure but is instead provided as a description of
exemplary aspects.
Definitions
[0022] The term "polymer", as used herein, refers to a molecule of
high relative molecular mass, the structure of which comprises the
multiple repetition of units derived, actually or conceptually,
from molecules of low relative molecular mass. In some aspects, a
polymer is comprised of only one monomer species. In some aspects,
a polymer is a copolymer, terpolymer, heteropolymer, block
copolymer, or tapered heteropolymer of one or more epoxides.
[0023] The terms bio-content and bio-based content mean biogenic
carbon also known as bio-mass derived carbon, carbon waste streams,
and carbon from municipal solid waste. In some variations,
bio-content (also referred to as "bio-based content") can be
determined based on the following:
[0024] Bio-content or Bio-based content=[Bio (Organic)
Carbon]/[Total (Organic) Carbon] 100%, as determined by ASTM D6866
(Standard Test Methods for Determining the Bio-based (biogenic)
Content of Solid, Liquid, and Gaseous Samples Using Radiocarbon
Analysis).
[0025] As disclosed in US 20170002136 published on Jan. 5, 2017 and
filed on Jun. 30, 2016, the ASTM D6866 method allows the
determination of the bio-based content of materials using
radiocarbon analysis by accelerator mass spectrometry, liquid
scintillation counting, and isotope mass spectrometry. When
nitrogen in the atmosphere is struck by an ultraviolet light
produced neutron, it loses a proton and forms carbon that has a
molecular weight of 14, which is radioactive. This 14C is
immediately oxidized into carbon dioxide, and represents a small,
but measurable fraction of atmospheric carbon. Atmospheric carbon
dioxide is cycled by green plants to make organic molecules during
photosynthesis. The cycle is completed when the green plants or
other forms of life metabolize the organic molecules producing
carbon dioxide which is then able to return back to the atmosphere.
Virtually all forms of life on Earth depend on this green plant
production of organic molecules to produce the chemical energy that
facilitates growth and reproduction. Therefore, the 14C that exists
in the atmosphere becomes part of all life forms and their
biological products. These renewably based organic molecules that
biodegrade to carbon dioxide do not contribute to global warming
because no net increase of carbon is emitted to the atmosphere. In
contrast, fossil fuel-based carbon does not have the signature
radiocarbon ratio of atmospheric carbon dioxide. See WO
2009/155086, incorporated herein by reference.
[0026] The application of ASTM D6866 to derive a "bio-based
content" is built on the same concepts as radiocarbon dating, but
without use of the age equations. The analysis is performed by
deriving a ratio of the amount of radiocarbon (14C) in an unknown
sample to that of a modern reference standard. The ratio is
reported as a percentage, with the units "pMC" (percent modern
carbon). If the material being analyzed is a mixture of present day
radiocarbon and fossil carbon (containing no radiocarbon), then the
pMC value obtained correlates directly to the amount of bio-based
material present in the sample. The modern reference standard used
in radiocarbon dating is a NIST (National Institute of Standards
and Technology) standard with a known radiocarbon content
equivalent approximately to the year AD 1950. The year AD 1950 was
chosen because it represented a time prior to thermonuclear weapons
testing which introduced large amounts of excess radiocarbon into
the atmosphere with each explosion (termed "bomb carbon"). The AD
1950 reference represents 100 pMC. "Bomb carbon" in the atmosphere
reached almost twice normal levels in 1963 at the peak of testing
and prior to the treaty halting the testing. Its distribution
within the atmosphere has been approximated since its appearance,
showing values that are greater than 100 pMC for plants and animals
living since AD 1950. The distribution of bomb carbon has gradually
decreased over time, with today's value being near 107.5 pMC. As a
result, a fresh biomass material, such as corn, could result in a
radiocarbon signature near 107.5 pMC.
[0027] Petroleum-based carbon does not have the signature
radiocarbon ratio of atmospheric carbon dioxide. Research has noted
that fossil fuels and petrochemicals have less than about 1 pMC,
and typically less than about 0.1 pMC, for example, less than about
0.03 pMC. However, compounds derived entirely from renewable
resources have at least about 95 percent modern carbon (pMC), they
may have at least about 99 pMC, including about 100 pMC.
[0028] Combining fossil carbon with present day carbon into a
material will result in a dilution of the present day pMC content.
By presuming that 107.5 pMC represents present day bio-based
materials and 0 pMC represents petroleum derivatives, the measured
pMC value for that material will reflect the proportions of the two
component types. A material derived 100% from present day biomass
would give a radiocarbon signature near 107.5 pMC. If that material
were diluted with 50% petroleum derivatives, it would give a
radiocarbon signature near 54 pMC.
[0029] A bio-based content result is derived by assigning 100%
equal to 107.5 pMC and 0% equal to 0 pMC. In this regard, a sample
measuring 99 pMC will give an equivalent bio-based content result
of 93%.
[0030] Assessment of the materials described herein according to
the present embodiments is performed in accordance with ASTM D6866
revision 12 (i.e. ASTM D6866-12), the entirety of which is herein
incorporated by reference. In some embodiments, the assessments are
performed according to the procedures of Method B of ASTM-D6866-12.
The mean values encompass an absolute range of 6% (plus and minus
3% on either side of the bio-based content value) to account for
variations in end-component radiocarbon signatures. It is presumed
that all materials are present day or fossil in origin and that the
desired result is the amount of bio-based carbon "present" in the
material, not the amount of bio-material "used" in the
manufacturing process.
[0031] Other techniques for assessing the bio-based content of
materials are described in U.S. Pat. Nos. 3,885,155, 4,427,884,
4,973,841, 5,438,194, and 5,661,299, and WO 2009/155086, each of
which is incorporated herein by reference.
[0032] The bio-content of the organic acids produced by thermolysis
of the one or more polylactone products may be based on the
bio-content of the one or more epoxide reagents and carbon monoxide
reagents. For example, in some variations of the processes
described herein, the one or more epoxide reagents and carbon
monoxide reagents described herein may have a bio-content of
greater than 0%, and less than 100%. In certain variations of the
processes described herein, the one or more epoxide reagents and
carbon monoxide reagents described herein may have a bio-content of
at least 10%, at least 20%, at least 30%, at least 40%, at least
50%, at least 60%, at least 70%, at least 80%, at least 90%, at
least 95%, at least 96%, at least 97%, at least 98%, at least 99%,
at least 99.5%, at least 99.9%, at least 99.99%, or 100%. In
certain variations, one or more epoxide reagents and carbon
monoxide reagents derived from renewable sources may be used. In
other variations, at least a portion of the one or more epoxide
reagents and carbon monoxide reagents used is derived from
renewable sources, and at least a portion of the one or more
epoxide reagents and carbon monoxide reagents is derived from
non-renewable sources.
[0033] Definitions of specific functional groups and chemical terms
are described in more detail below. The chemical elements are
identified in accordance with the Periodic Table of the Elements,
CAS version, Handbook of Chemistry and Physics, 75th Ed., inside
cover, and specific functional groups are generally defined as
described therein. Additionally, general principles of organic
chemistry, as well as specific functional moieties and reactivity,
are described in Organic Chemistry, Thomas Sorrell, University
Science Books, Sausalito, 1999; Smith and March March's Advanced
Organic Chemistry, 5th Edition, John Wiley & Sons, Inc., New
York, 2001; Larock, Comprehensive Organic Transformations, VCH
Publishers, Inc., New York, 1989; Carruthers, Some Modern Methods
of Organic Synthesis, 3rd Edition, Cambridge University Press,
Cambridge, 1987; the entire contents of each of which are
incorporated herein by reference.
[0034] The term "aliphatic" or "aliphatic group", as used herein,
denotes a hydrocarbon moiety that may be straight-chain (i.e.,
unbranched), branched, or cyclic (including fused, bridging, and
spiro-fused polycyclic) and may be completely saturated or may
contain one or more units of unsaturation, but which is not
aromatic. Unless otherwise specified, aliphatic groups contain 1-30
carbon atoms. In some aspects, aliphatic groups contain 1-12 carbon
atoms. In some aspects, aliphatic groups contain 1-8 carbon atoms.
In some aspects, aliphatic groups contain 1-6 carbon atoms. In some
aspects, aliphatic groups contain 1-5 carbon atoms, in some
aspects, aliphatic groups contain 1-4 carbon atoms, in yet other
aspects aliphatic groups contain 1-3 carbon atoms, and in yet other
aspects, aliphatic groups contain 1-2 carbon atoms. Suitable
aliphatic groups include, but are not limited to, linear or
branched, alkyl, alkenyl, and alkynyl groups, and hybrids thereof
such as (cycloalkyl)alkyl, (cycloalkenyl)alkyl or
(cycloalkyl)alkenyl.
[0035] The term "acrylate" or "acrylates" as used herein refer to
any acyl group having a vinyl group adjacent to the acyl carbonyl.
The terms encompass mono-, di- and tri-substituted vinyl groups.
Examples of acrylates include, but are not limited to: acrylate,
methacrylate, ethacrylate, cinnamate (3-phenylacrylate), crotonate,
tiglate, and senecioate.
[0036] The term "polymer", as used herein, refers to a molecule of
high relative molecular mass, the structure of which comprises the
multiple repetitions of units derived, actually or conceptually,
from molecules of low relative molecular mass. In some aspects, a
polymer is comprised of only one monomer species. In some aspects,
a polymer is a copolymer, terpolymer, heteropolymer, block
copolymer, or tapered heteropolymer of one or more epoxides.
[0037] The term "unsaturated", as used herein, means that a moiety
has one or more double or triple bonds.
[0038] The term "alkyl," as used herein, refers to saturated,
straight- or branched-chain hydrocarbon radicals derived from an
aliphatic moiety containing between one and six carbon atoms by
removal of a single hydrogen atom. Unless otherwise specified,
alkyl groups contain 1-12 carbon atoms. In some aspects, alkyl
groups contain 1-8 carbon atoms. In some aspects, alkyl groups
contain 1-6 carbon atoms. In some aspects, alkyl groups contain 1-5
carbon atoms, in some aspects, alkyl groups contain 1-4 carbon
atoms, in yet other aspects, alkyl groups contain 1-3 carbon atoms,
and in yet other aspects alkyl groups contain 1-2 carbon atoms.
Examples of alkyl radicals include, but are not limited to, methyl,
ethyl, n-propyl, isopropyl, n-butyl, iso-butyl, sec-butyl,
sec-pentyl, iso-pentyl, tert-butyl, n-pentyl, neopentyl, n-hexyl,
sec-hexyl, n-heptyl, n-octyl, n-decyl, n-undecyl, dodecyl, and the
like.
[0039] As used herein, the term "partially unsaturated" refers to a
ring moiety that includes at least one double or triple bond. The
term "partially unsaturated" is intended to encompass rings having
multiple sites of unsaturation, but is not intended to include aryl
or heteroaryl moieties, as herein defined.
[0040] As described herein, compounds may contain "optionally
substituted" moieties. In general, the term "substituted", whether
preceded by the term "optionally" or not, means that one or more
hydrogens of the designated moiety are replaced with a suitable
substituent. Unless otherwise indicated, an "optionally
substituted" group may have a suitable substituent at each
substitutable position of the group, and when more than one
position in any given structure may be substituted with more than
one substituent selected from a specified group, the substituent
may be either the same or different at every position. Combinations
of substituents envisioned may include those that result in the
formation of stable or chemically feasible compounds. The term
"stable", as used herein, refers to compounds that are not
substantially altered when subjected to conditions to allow for
their production, detection, and, in some aspects, their recovery,
purification, and use for one or more of the purposes disclosed
herein.
[0041] In some chemical structures herein, substituents are shown
attached to a bond which crosses a bond in a ring of the depicted
molecule. This means that one or more of the substituents may be
attached to the ring at any available position (usually in place of
a hydrogen atom of the parent structure). In cases where an atom of
a ring so substituted has two substitutable positions, two groups
may be present on the same ring atom. When more than one
substituent is present, each is defined independently of the
others, and each may have a different structure. In cases where the
substituent shown crossing a bond of the ring is --R, this has the
same meaning as if the ring were said to be "optionally
substituted" as described in the preceding paragraph.
[0042] As used herein, the term "catalyst" refers to a substance
the presence of which increases the rate of a chemical reaction,
while not being consumed or undergoing a permanent chemical change
itself.
[0043] Renewable sources means a source of carbon and/or hydrogen
obtained from biological life forms that can replenish itself in
less than one hundred years.
[0044] Renewable carbon means carbon obtained from biological life
forms that can replenish itself in less than one hundred years.
[0045] Recycled sources mean carbon and/or hydrogen recovered from
a previous use in a manufactured article.
[0046] Recycled carbon means carbon recovered from a previous use
in a manufactured article.
[0047] As used herein, the term "about" preceding one or more
numerical values means the numerical value .+-.5%. It should be
understood that reference to "about" a value or parameter herein
includes (and describes) aspects that are directed to that value or
parameter per se. For example, description referring to "about x"
includes description of "x" per se.
[0048] Further, it should be understood that reference to "between"
two values or parameters herein includes (and describes) aspects
that include those two values or parameters per se. For example,
description referring to "between x and y" includes description of
"x" and "y" per se.
[0049] The mass fractions disclosed herein can be converted to wt %
by multiplying by 100.
Exemplary Embodiments of the Invention
[0050] The following description sets forth innovative reactor
systems and processes for producing organic acids from
beta-lactones. It should be recognized, however, that such
description is not intended as a limitation on the scope of the
present invention but is instead provided as a description of
exemplary embodiments.
[0051] Preferred embodiments of the processes for producing at
least one organic acid product from at least one beta-lactone
reagent, wherein the at least one beta-lactone reagent is
represented by the following formula:
##STR00001##
[0052] wherein R1 and R2 are independently selected from the group
consisting of H, alkyl, alkenyl, alkoxy, alkynyl, cycloalkyl,
cycloalkenyl and cycloalkynyl,
[0053] wherein both of R1 and R2 are not H at the same time,
[0054] include steps as follows: introducing at least one
beta-lactone reagent to at least one reaction vessel; contacting
the at least one beta-lactone reagent with at least one
heterogenous catalyst in the at least one reaction vessel to
produce at least one organic acid; and removing the at least one
organic acid from the at least one reaction vessel to provide at
least one organic acid product. Such processes may produce organic
acid products in high yields, by minimizing other by-products that
may form, such as polylactones and polyorganic acids. Such methods
produce at least one organic acid product from at least one
beta-lactone reagent in a single step reaction.
[0055] FIG. 1 illustrates a preferred embodiment of the present
invention directed to a process of producing at least one organic
acid product from at least one beta-lactone reagent, by combining a
beta-propiolactone reagent, a zeolite heterogenous catalyst, and
optionally a polymerization inhibitor; and producing acrylic acid.
In FIG. 1, the beta-propiolactone reagent is introduced to the
reaction vessel 102 and contacted with the zeolite heterogenous
reagent 104 and polymerization inhibitor to produce acrylic acid
which is removed from the reaction vessel as a product 106. In some
embodiments, process 100 is performed neat. In other variations,
process 100 is performed in the presence of a solvent.
[0056] In certain preferred embodiments, the processes of the
present invention may include steps as follows: adjusting the
operating pressure to reaction conditions for at least one reaction
vessel to provide at least one pressure controlled reaction vessel;
heating to reaction conditions at least one reaction vessel to
provide a temperature controlled reaction vessel; introducing at
least one heterogenous catalyst to at least one reaction vessel to
provide at least one catalyst charged reaction vessel; and/or
dissolving at least one beta-lactone reagent in a solvent to
provide at least one diluted beta-lactone reagent.
[0057] In preferred embodiments of the present invention, the
processes include a step for controlling the rate of the at least
one beta-lactone reagent introduced to the at least one reaction
vessel. In certain preferred embodiments, the processes include a
step for controlling the rate of addition of the at least one
beta-lactone reagent to decrease the production of undesirable
products. In certain embodiments, the processes include a step for
controlling the rate of addition of the at least one beta-lactone
reagent to minimize or suppress production of polyorganic
acids.
[0058] The amount of the at least one beta-lactone reagent
introduced to the at least one reaction vessel may be metered by
any suitable methods or techniques in the art. The suitable methods
or techniques may vary with the scale of production. For example,
the suitable methods or techniques may range from adding the at
least one beta-lactone reagent in lab scale quantities by metering
into the at least one reaction vessel via a needle valve to large
scale addition through one or more valve and manifold arrangements.
In certain embodiments, fixed-bed reactors and moving-bed reactors
may have a throughput in a range of relative weight hourly space
velocity (WHSV) of the at least one beta-lactone reagent between
0.4 to 2.1 h-1 or between 0.9 to 1.6 h-1.
[0059] In preferred embodiments, the processes of the present
invention may include a step for metering the at least one organic
acid removed to produce the at least one organic acid product. In
certain preferred embodiments, metering the removal of the at least
one organic acid produced may affect the yield of the at least one
organic acid product. In certain embodiments, metering the removal
of the at least one organic acid produced may increase yield of the
at least one acid product. In some embodiments, the step for
metering the removal of the at least one organic acid minimizes
polymerization of the at least one organic acid, and thus,
formation of polyorganic acid.
[0060] In certain preferred embodiments, the at least one organic
acid may be removed at elevated temperatures, for example, the
temperature is at least 100.degree. C., at least 150.degree. C., at
least 200.degree. C., at least 250.degree. C. or at least
300.degree. C. and may be in a range of between 100.degree. C. to
300.degree. C., between 200.degree. C. and 250.degree. C., and or
between 250.degree. C. and 300.degree. C.
[0061] In certain preferred embodiments, the processes for
producing the at least one organic acid product have a yield of at
least 50%, at least 55%, at least 60%, at least 65%, at least 70%,
at least 75%, at least 80%, at least 85%, at least 90%, or at least
95%.
[0062] In preferred embodiments, the processes for producing the at
least one organic acid product characterizable as an unsaturated
aliphatic carboxylic acid having purity of at least 95%, at least
96%, at least 97%, or at least 98%. In some variations where the
acrylic acid produced is isolated, e.g., by distillation, the
acrylic acid has a purity of at least 98%, at least 98.5%, at least
99%, at least 99.1%, at least 99.2%, at least 99.3%, at least
99.4%, at least 99.5%, at least 99.6%, at least 99.7%, at least
99.8%, or at least 99.9%. In certain preferred embodiments, the at
least one organic acid product includes at least one vinyl group
and at least one carboxylic acid group.
[0063] Preferred embodiments of the reactor systems used for
producing at least one organic acid product from at least one
beta-lactone reagent, wherein the at least one beta-lactone reagent
is represented by the following formula:
##STR00002##
[0064] wherein R1 and R2 are independently selected from the group
consisting of H, alkyl, alkenyl, alkoxy, alkynyl, cycloalkyl,
cycloalkenyl and cycloalkynyl,
[0065] wherein both of R1 and R2 are not H at the same time,
[0066] include at least one reaction vessel. In preferred
embodiments, the at least one reaction vessel comprises a
continuous fixed-bed reactor or a fluidized bed reactor. The at
least one reaction vessel may define an interior volume for
receiving material from at least one feed stream and a retaining
volume adapted for retaining matter in solid, liquid, and gaseous
phases. In some embodiments, the at least one reaction vessel may
be connected to at least one heater for providing heat to the
matter in the retaining volume. In some embodiments, the at least
one reaction vessel may be connected to at least one heater.
[0067] The reactor systems and processes for producing at least one
organic acid product from at least one beta-lactone reagent use at
least one heterogeneous catalyst such as zeolite, metal oxide,
supported acid such as phosphoric acid (solid phosphoric
acid--SPA), and/or heteropolyacid. In certain preferred
embodiments, the at least one heterogeneous catalyst comprises
silica-alumina molecular sieves, particularly those modified with
phosphate compounds. Catalysts of the type that are specifically
suited for this invention include alkaline-earth phosphates,
supported phosphate salts, calcium hydroxyapatites, inorganic
salts, metal oxides, and zeolites. In preferred embodiments, the at
least one heterogeneous catalyst is an alumina-silicate molecular
sieve and more preferably a zeolite having Lewis or Bronsted
acidity. The zeolites can be in hydrogen form or in cation
exchanged form. Suitable cations are alkali metals such as Na+ or
K+; alkali-earth cations such as Ca2+, Mg2+, Sr2+, or Ba2+; Zn2+,
Cu+, and Cu2+.
[0068] In certain preferred embodiments, the at least one
heterogenous catalyst comprises zeolite catalysts chosen from a
broad range of zeolites including zeolite framework types which may
be beneficially used to practice this invention. The different
zeolite framework types that may be most beneficially used in this
invention comprise MFI (pentasil), FAU (faujasite), MAU
(mordenite), BEA (beta) and MVW zeolite structures. Useful zeolites
from these classes may comprise one-dimensional (1D: ZSM-22),
two-dimensional (2D: MCM-22 and ZSM-35), or three dimensional (3D:
ZSM-5, ZSM-11, ZSM-5/ZSM-11, and 6-crystalline configurations. In
some embodiments, the zeolites include ZSM-5, zeolite beta, zeolite
Y, and zeolite A. In some embodiments, the zeolite has a micropore
volume of at least 30%. In some embodiments, the zeolite has a
micropore volume in the range of between 30-80% or 60 to 80%. In
some embodiments, the zeolite is a ZSM-5 zeolite or a Y zeolite
having a micropore volume in a range of from 30 to 45%.
[0069] In certain embodiments, the heterogenous catalyst is
preferably a sodium form ZSM-5 or beta zeolite that an at least
50%, at least 70% or at least 90% exchange of potassium cations
with the available cation exchange sites. In certain embodiments,
the at least one heterogenous catalyst is preferably a sodium form
ZSM-5 that has an at least 50%, at least 70% or at least 90%
exchange of potassium cations with the available cation exchange
sites and a SiO2/Al2O3 ratio in a range of between 20 and 120, of
between 20 and 50 or between 20 and 30.
[0070] In certain preferred embodiments of the present invention,
the beta-lactone reagents may have a high bio content comprised of
carbon atoms from biological sources, recycled sources, renewable
sources, and/or otherwise sustainable sources. Such sources may
include crop residues, wood residues, grasses, municipal solid
waste and algae. In some embodiments, the beta-lactone reagents may
be comprised of carbons from any source.
[0071] Table illustrated below includes Column A directed to a
non-exhaustive list of beta-lactone reagents which may undergo a
single step reaction to produce at least one organic acid
product.
TABLE-US-00001 Column A ##STR00003## ##STR00004## ##STR00005##
##STR00006## ##STR00007## ##STR00008## ##STR00009## ##STR00010##
##STR00011## ##STR00012## ##STR00013## ##STR00014## ##STR00015##
##STR00016## ##STR00017## ##STR00018## ##STR00019## ##STR00020##
##STR00021## ##STR00022## ##STR00023## ##STR00024## ##STR00025##
##STR00026## ##STR00027## ##STR00028## ##STR00029## ##STR00030##
##STR00031## ##STR00032## ##STR00033## ##STR00034## ##STR00035##
##STR00036## ##STR00037## ##STR00038## ##STR00039## ##STR00040##
##STR00041## ##STR00042## ##STR00043## ##STR00044## ##STR00045##
##STR00046## ##STR00047## ##STR00048## ##STR00049## ##STR00050##
##STR00051## ##STR00052## ##STR00053## ##STR00054## ##STR00055##
##STR00056## ##STR00057## ##STR00058## ##STR00059## ##STR00060##
##STR00061## ##STR00062## ##STR00063## ##STR00064## ##STR00065##
##STR00066## ##STR00067## ##STR00068## ##STR00069## ##STR00070##
##STR00071## ##STR00072## ##STR00073## ##STR00074##
##STR00075##
Example 1--Conversion of .beta.-methyl-.beta.-propiolactone to
trans-2-butenoic acid Using a Zeolite
[0072] This Example demonstrates the production of trans-2-butenoic
acid from bPL derivative using a zeolite.
##STR00076##
[0073] A mixture of .beta.-methyl-.beta.-propiolactone (3.0 g) and
phenothiazine (9.0 mg) is added using a needle valve to a mixture
of sulfolane (40.0 g) and Zeolite Y hydrogen (20.0 g) at about
165.degree. C. with 50 psi of carbon monoxide. Zeolite Y hydrogen
(80:1 mole ratio SiO2/Al2O3, powder S.A. 780 m2/g) is dried under
vacuum at about 100.degree. C. for one day before use.
Phenothiazine is the polymerization inhibitor used. Sulfolane is
the solvent used, and is dried over 3 .ANG. molecular sieves prior
to use. .beta.-methyl-.beta.-propiolactone is added slowly using
the needle valve over about 8.6 minutes. The reaction mixture is
heated to about 170.degree. C. to produce trans-2-butenoic
acid.
[0074] The reaction is monitored by infrared spectroscopy (IR). The
reaction is observed to be completed after about 3 hours, when no
.beta.-methyl-.beta.-propiolactone is detectable by IR.
[0075] The zeolite is then filtered off from the reaction mixture,
and a sample of the resulting mixture is dissolved in deuterium
(D2O) and chloroform (CDCl3) for nuclear magnetic resonance (NMR)
analysis. The observed vinyl peaks between about .delta. 5.80 and
about 6.47 ppm in the 1H NMR confirms the production of
trans-2-butenoic acid.
Example 2--Vapor Phase Conversion of
.beta.-methyl-.beta.-propiolactone to trans-2-butenoic acid Using
an H-ZSM-5
[0076] Vapor phase conversion of .beta.-methyl-.beta.-propiolactone
to trans-2-butenoic acid is performed in packed-bed reactor using
H-ZSM-5 (ACS Materials LLC, Si:Al=38, diameter 2 mm, surface area
>=250 m2/g) as a catalyst. 11 grams of H-ZSM-5 catalyst is
loaded into jacketed stainless steel 316 pipe reactor (ID 0.5
inch), the catalyst is supported between glass beads columns
(stainless steel wool is placed below and above glass beads).
Multi-point thermocouple is inserted through the center of the
reactor and hot oil is circulated through the reactor jacket to
maintain the desired reactor temperature.
.beta.-methyl-.beta.-propiolactone is fed to the reactor by means
of saturator: N2 at the rate of 28 g/hr is flown into the bottom of
the vessel containing liquid .beta.-methyl-.beta.-propiolactone at
a=94.degree. C., this results in .beta.-methyl-1-propiolactone feed
rate of 5 g/hr. The pressure of reactor and saturator is maintained
at 9.5 psig. The reaction products are absorbed in chilled to about
10.degree. C. dichloromethane and the solution of reaction products
in dichloromethane is analyzed by gas chromatography. The line
between the saturator and the reactor as well as the line between
the reactor and absorber are heat traced to prevent condensation of
.beta.-methyl-.beta.-propiolactone to trans-2-butenoic acid. The
reaction is conducted at the reactor temperature of about
210.degree. C. At these conditions,
.beta.-methyl-.beta.-propiolactone conversion of greater than 99.9%
is observed with selectivity of trans-2-butenoic acid product of
greater than 98% (WHSV at these conditions is 0.45 h-1).
Example 3--Conversion of 3-methyloxetan-2-one to Methacrylic Acid
Using a Zeolite
[0077] This Example demonstrates the production of methacrylic acid
from 3-methyloxetan-2-one using a zeolite.
##STR00077##
[0078] A mixture of 3-methyloxetan-2-one (3.0 g) and phenothiazine
(9.0 mg) is added using a needle valve to a mixture of sulfolane
(40.0 g) and Zeolite Y hydrogen (20.0 g) at 165.degree. C. with 50
psi of carbon monoxide. Zeolite Y hydrogen (80:1 mole ratio
SiO2/Al2O3, powder S.A. 780 m2/g) is dried under vacuum at
100.degree. C. for one day before use. Phenothiazine is the
polymerization inhibitor used. Sulfolane is the solvent used, and
is dried over 3 .ANG. molecular sieves prior to use.
3-methyloxetan-2-one is added slowly using the needle valve over
about 8.6 minutes. The reaction mixture is heated to 170.degree. C.
to produce methacrylic acid.
[0079] The reaction is monitored by infrared spectroscopy (IR). The
reaction is observed to be completed after about 3 hours, when no
3-methyloxetan-2-one is detectable by IR.
[0080] The zeolite is then filtered off from the reaction mixture,
and a sample of the resulting mixture is dissolved in deuterium
(D2O) and chloroform (CDCl3) for nuclear magnetic resonance (NMR)
analysis. The observed vinyl peaks between .delta. 5.80 and 6.47
ppm in the 1H NMR confirms the production of methacrylic acid.
Example 4--Vapor Phase Conversion of 3-methyloxetan-2-one to
Methacrylic Acid Using an H-ZSM-5
[0081] Vapor phase conversion of 3-methyloxetan-2-one to
methacrylic acid is performed in packed-bed reactor using H-ZSM-5
(ACS Materials LLC, Si:Al=38, diameter 2 mm, surface area >=250
m2/g) as a catalyst. 11 grams of H-ZSM-5 catalyst is loaded into
jacketed stainless steel 316 pipe reactor (ID 0.5 inch), the
catalyst is supported between glass beads columns (stainless steel
wool is placed below and above glass beads). Multi-point
thermocouple is inserted through the center of the reactor and hot
oil is circulated through the reactor jacket to maintain the
desired reactor temperature. 3-methyloxetan-2-one is fed to the
reactor by means of saturator: N2 at the rate of 28 g/hr is flown
into the bottom of the vessel containing liquid
3-methyloxetan-2-one at a=94.degree. C., this results in
3-methyloxetan-2-one feed rate of 5 g/hr. The pressure of reactor
and saturator is maintained at 9.5 psig. The reaction products are
absorbed in chilled to 10.degree. C. dichloromethane and the
solution of reaction products in dichloromethane is analyzed by gas
chromatography. The line between the saturator and the reactor as
well as the line between the reactor and absorber are heat traced
to prevent condensation of 3-methyloxetan-2-one to methacrylic
acid. The reaction is conducted at the reactor temperature of
210.degree. C. At these conditions, 3-methyloxetan-2-one conversion
of greater than 99.9% is observed with selectivity of methacrylic
acid product of greater than 98% (WHSV at these conditions is 0.45
h-1).
Example 5--Conversion of .beta.-chloromethyl-.beta.-propiolactone
to 4-chloro-cis/trans-2-butenoic acid Using a Zeolite
[0082] This Example demonstrates the production of
4-chloro-cis/trans-2-butenoic acid from bPL derivative using a
zeolite.
##STR00078##
[0083] A mixture of .beta.-chloromethyl-.beta.-propiolactone (3.0
g) and phenothiazine (9.0 mg) is added using a needle valve to a
mixture of sulfolane (40.0 g) and Zeolite Y hydrogen (20.0 g) at
about 165.degree. C. with 50 psi of carbon monoxide. Zeolite Y
hydrogen (80:1 mole ratio SiO2/Al2O3, powder S.A. 780 m2/g) is
dried under vacuum at about 100.degree. C. for one day before use.
Phenothiazine is the polymerization inhibitor used. Sulfolane is
the solvent used, and is dried over 3 .ANG. molecular sieves prior
to use. .beta.-chloromethyl-.beta.-propiolactone is added slowly
using the needle valve over about 8.6 minutes. The reaction mixture
is heated to about 170.degree. C. to produce
4-chloro-cis/trans-2-butenoic acid.
[0084] The reaction is monitored by infrared spectroscopy (IR). The
reaction is observed to be completed after about 3 hours, when no
.beta.-chloromethyl-.beta.-propiolactone is detectable by IR.
[0085] The zeolite is then filtered off from the reaction mixture,
and a sample of the resulting mixture is dissolved in deuterium
(D2O) and chloroform (CDCl3) for nuclear magnetic resonance (NMR)
analysis. The observed vinyl peaks between about .delta. 5.80 and
about 6.47 ppm in the 1H NMR confirms the production of
4-chloro-trans/cis-2-butenoic acid.
Example 6--Vapor Phase Conversion of
.beta.-chloromethyl-.beta.-propiolactone to
4-chloro-cis/trans-2-butenoic acid Using an H-ZSM-5
[0086] Vapor phase conversion of
.beta.-chloromethyl-.beta.-propiolactone to
4-chloro-cis/trans-2-butenoic acid is performed in a packed-bed
reactor using H-ZSM-5 (ACS Materials LLC, Si:Al=38, diameter 2 mm,
surface area >=250 m2/g) as a catalyst. 11 grams of H-ZSM-5
catalyst is loaded into jacketed stainless steel 316 pipe reactor
(ID 0.5 inch), the catalyst is supported between glass beads
columns (stainless steel wool is placed below and above glass
beads). Multi-point thermocouple is inserted through the center of
the reactor and hot oil is circulated through the reactor jacket to
maintain the desired reactor temperature.
.beta.-chloromethyl-1-propiolactone is fed to the reactor by means
of saturator: N2 at the rate of about 28 g/hr is flown into the
bottom of the vessel containing liquid
4-chloro-trans/cis-2-butenoic acid at a=94.degree. C., this results
in 4-chloro-cis/trans-2-butenoic acid feed rate of about 5 g/hr.
The pressure of reactor and saturator is maintained at about 9.5
psig. The reaction products are absorbed in chilled to about
10.degree. C. dichloromethane and the solution of reaction products
in dichloromethane is analyzed by gas chromatography. The line
between the saturator and the reactor as well as the line between
the reactor and absorber are heat traced to prevent condensation of
.beta.-chloromethyl-.beta.-propiolactone to
4-chloro-cis/trans-2-butenoic acid. The reaction is conducted at
the reactor temperature of about 210.degree. C. At these
conditions, .beta.-chloromethyl-.beta.-propiolactone conversion of
greater than 99.9% is observed with selectivity of
4-chloro-cis/trans-2-butenoic acid product of greater than 98%
(WHSV at these conditions is 0.45 h-1).
Example 7--Conversion of
.beta.-trifluoromethyl-.beta.-propiolactone to
4,4,4-trifluoro-trans/cis-2-butenoic acid Using a Zeolite
[0087] This Example demonstrates the production of
4,4,4-trifluoro-cis/trans-2-butenoic acid from bPL derivative using
a zeolite.
##STR00079##
[0088] A mixture of .beta.-trifluoromethyl-.beta.-propiolactone
(3.0 g) and phenothiazine (9.0 mg) is added using a needle valve to
a mixture of sulfolane (40.0 g) and Zeolite Y hydrogen (20.0 g) at
about 165.degree. C. with 50 psi of carbon monoxide. Zeolite Y
hydrogen (80:1 mole ratio SiO2/Al2O3, powder S.A. 780 m2/g) is
dried under vacuum at about 100.degree. C. for one day before use.
Phenothiazine is the polymerization inhibitor used. Sulfolane is
the solvent used, and is dried over 3 .ANG. molecular sieves prior
to use. .beta.-trifluoromethyl-.beta.-propiolactone is added slowly
using the needle valve over about 8.6 minutes. The reaction mixture
is heated to about 170.degree. C. to produce
4,4,4-trifluoro-cis/trans-2-butenoic acid.
[0089] The reaction is monitored by infrared spectroscopy (IR). The
reaction is observed to be completed after about 3 hours, when no
.beta.-trifluoromethyl-.beta.-propiolactone is detectable by
IR.
[0090] The zeolite is then filtered off from the reaction mixture,
and a sample of the resulting mixture is dissolved in deuterium
(D2O) and chloroform (CDCl3) for nuclear magnetic resonance (NMR)
analysis. The observed vinyl peaks between about .delta. 5.80 and
about 6.47 ppm in the 1H NMR confirms the production of
4,4,4-trifluoro-cis/trans-2-butenoic acid.
Example 8--Vapor Phase Conversion of
.beta.-trifluoromethyl-.beta.-propiolactone to
4,4,4-trifluoro-cis/trans-2-butenoic acid Using a H-ZSM-5
[0091] Vapor phase conversion of
.beta.-trifluoromethyl-.beta.-propiolactone to
4,4,4-trifluoro-cis/trans-2-butenoic acid is performed in
packed-bed reactor using H-ZSM-5 (ACS Materials LLC, Si:Al=38,
diameter 2 mm, surface area >=250 m2/g) as a catalyst. 11 grams
of H-ZSM-5 catalyst is loaded into jacketed stainless steel 316
pipe reactor (ID 0.5 inch), the catalyst is supported between glass
beads columns (stainless steel wool is placed below and above glass
beads). Multi-point thermocouple is inserted through the center of
the reactor and hot oil is circulated through the reactor jacket to
maintain the desired reactor temperature.
.beta.-trifluoromethyl-1-propiolactone is fed to the reactor by
means of saturator: N2 at the rate of about 28 g/hr is flown into
the bottom of the vessel containing liquid
4,4,4-trifluoro-cis/trans-2-butenoic acid at a=94.degree. C., this
results in .beta.-trifluoromethyl-.beta.-propiolactone feed rate of
about 5 g/hr. The pressure of reactor and saturator is maintained
at about 9.5 psig. The reaction products are absorbed in chilled to
about 10.degree. C. dichloromethane and the solution of reaction
products in dichloromethane is analyzed by gas chromatography. The
line between the saturator and the reactor as well as the line
between the reactor and absorber are heat traced to prevent
condensation of .beta.-trifluoromethyl-.beta.-propiolactone to
4,4,4-trifluoro-cis/trans-2-butenoic acid. The reaction is
conducted at the reactor temperature of about 210.degree. C. At
these conditions, .beta.-trifluoromethyl-.beta.-propiolactone
conversion of greater than 99.9% is observed with selectivity of
4,4,4-trifluoro-cis/trans-2-butenoic acid product of greater than
98% (WHSV at these conditions is 0.45 h-1).
Example 9--Conversion of .beta.-Propiolactone Derivatives to
Organic Acids Using a Zeolite
[0092] This Example demonstrates the representative production of
an organic acid from a .beta.-propiolactone derivative using a
zeolite. Exemplary reaction schemes are shown below.
[0093] A mixture of .beta.-propiolactone derivative (3.0 g) and
phenothiazine (9.0 mg) is added using a needle valve to a mixture
of sulfolane (40.0 g) and Zeolite Y hydrogen (20.0 g) at about
165.degree. C. with 50 psi of carbon monoxide. Zeolite Y hydrogen
(80:1 mole ratio SiO2/Al2O3, powder S.A. 780 m2/g) is dried under
vacuum at about 100.degree. C. for one day before use.
Phenothiazine is the polymerization inhibitor used. Sulfolane is
the solvent used, and is dried over 3 .ANG. molecular sieves prior
to use. .beta.-propiolactone derivative is added slowly using the
needle valve over about 8.6 minutes. The reaction mixture is heated
to about 170.degree. C. to produce an organic acid.
[0094] The reaction is monitored by infrared spectroscopy (IR). The
reaction is observed to be completed after about 3 hours, when no
.beta.-propiolactone derivative is detectable by IR.
[0095] The zeolite is then filtered off from the reaction mixture,
and a sample of the resulting mixture is dissolved in deuterium
(D2O) and chloroform (CDCl3) for nuclear magnetic resonance (NMR)
analysis. The observed vinyl peaks between about .delta. 5.80 and
about 6.47 ppm in the 1H NMR confirms the production of an organic
acid.
Example 10--Vapor Phase Conversion of .beta.-Propiolactone
Derivatives to an Organic Acid Using an H-ZSM-5
[0096] This Example demonstrates the representative vapor phase
conversion of a .beta.-propiolactone derivative to an organic acid
using a H-ZSM-5. Exemplary reaction schemes are shown below.
[0097] Vapor phase conversion of a .beta.-propiolactone derivative
to an organic acid is performed in packed-bed reactor using H-ZSM-5
(ACS Materials LLC, Si:Al=38, diameter 2 mm, surface area >=250
m2/g) as a catalyst. 11 grams of H-ZSM-5 catalyst is loaded into
jacketed stainless steel 316 pipe reactor (ID 0.5 inch), the
catalyst is supported between glass beads columns (stainless steel
wool is placed below and above glass beads). Multi-point
thermocouple is inserted through the center of the reactor and hot
oil is circulated through the reactor jacket to maintain the
desired reactor temperature. .beta.-propiolactone derivative is fed
to the reactor by means of saturator: N2 at the rate of about 28
g/hr is flown into the bottom of the vessel containing liquid and
organic acid at a=94.degree. C., this results in
.beta.-propiolactone derivative feed rate of about 5 g/hr. The
pressure of reactor and saturator is maintained at about 9.5 psig.
The reaction products are absorbed in chilled to about 10.degree.
C. dichloromethane and the solution of reaction products in
dichloromethane is analyzed by gas chromatography. The line between
the saturator and the reactor as well as the line between the
reactor and absorber are heat traced to prevent condensation of
.beta.-propiolactone derivative to an organic acid. The reaction is
conducted at the reactor temperature of about 210.degree. C. At
these conditions, .beta.-propiolactone derivative conversion of
greater than 99.9% is observed with selectivity of an organic acid
product of greater than 98% (WHSV at these conditions is 0.45
h-1).
##STR00080## ##STR00081## ##STR00082## ##STR00083## ##STR00084##
##STR00085## ##STR00086## ##STR00087## ##STR00088## ##STR00089##
##STR00090## ##STR00091##
[0098] In certain preferred embodiments, the reactor systems and
processes may include at least one reaction vessel comprising a
continuous fixed-bed reactor operating at a reduced pressure for
production of at least one organic acid product. In certain
embodiments, the continuous fixed-bed reactor is operated at the
pressure between 40 Torr and 250 Torr. At least one beta-lactone
reagent may be introduced to the continuous fixed-bed reactor
through at least one feed stream inlet while in vapor phase. In
certain embodiments, the at least one beta-lactone reagent is
vaporized at the temperature between 80.degree. C. and 127.degree.
C. and then introduced to the at least one feed stream inlet of the
continuous fixed-bed reactor packed with a heterogenous catalyst.
The continuous fixed-bed reactor is operated in the temperature
range from 100.degree. C. to 300.degree. C., and preferably from
150.degree. C. to 250.degree. C.
[0099] In certain preferred embodiments, the reactor systems and
processes may include at least one reaction vessel comprising a
continuous fixed-bed reactor configured for receiving at least one
beta-lactone reagent diluted with inert solvent or gas. The inert
solvent or gas may be hexane, nitrogen, argon, or helium. The
continuous fixed-bed reactor may operate at atmospheric pressure,
at the pressure below atmospheric pressure, or at the pressure
above atmospheric pressure. In some embodiments, the continuous
fixed-bed reactor is operated the pressure between 250 Torr and 50
psig. In certain preferred embodiments, the continuous fixed-bed
reactor is operated at the pressure from 5 psig to 30 psig and
temperature range from 100.degree. C. to 300.degree. C., or more
preferably from 150.degree. C. to 250.degree. C.
[0100] In certain preferred embodiments, the at least beta-lactone
reagent is introduced to the reactor in the flow of nitrogen or
another inert gas. The weight ratio of the at least one
beta-lactone reagent to inert gas is from 0.05:1 to about 1.5:1. In
some embodiments, the inert gas is introduced to the continuous
fixed-bed reactor containing the at least one beta-lactone reagent
in the liquid phase and maintained at the temperature required to
achieve the desired concentration of the at least one beta-lactone
reagent in the inert gas. Then the mixture of the at least one
beta-lactone reagent and inert gas is introduced through the feed
stream inlet of the continuous fixed-bed reactor. In other
embodiments, the at least one beta-lactone reagent is injected into
a stream of inert gas near and then introduced through inlet of the
continuous fixed-bed reactor. In preferred embodiments, the
concentration of the at least one beta-lactone reagent in inert
solution or gas is from 10% to 99%.
[0101] In certain preferred embodiments, the conversion of the at
least one beta-lactone reagent to the at least one organic acid
product is performed in the presence of a solvent or diluent. In
some embodiments, the solvent or diluent selected (i) dissolves, or
at least partially dissolves, the at least one beta-lactone
reagent, but does not react, or minimally reacts, with the at least
one beta-lactone reagent; or (ii) has a high boiling point so that
the at least one organic acid product may be distilled while
solvent remains in a reaction vessel, or a combination of (i) and
(ii). In some embodiments, the solvent is a polar aprotic solvent.
For example, the solvent may be a high boiling polar aprotic
solvent. In one variation, the solvent includes sulfolane. In some
embodiments, the at least one beta-lactone reagent may be diluted
in solvent at the ratio of about 1:1. The solvent may be dried
using any suitable methods or techniques known in the art prior to
use. A combination of any of the solvents described herein may also
be used.
[0102] In certain preferred embodiments, the reactor systems and
processes of the present invention may comprise at least one
reaction vessel configured to have more than one section and heat
exchangers installed between sections. In certain embodiments
wherein the reactor systems comprising at least one reaction vessel
are configured to have more than one section, all the at least one
beta-lactone reagent is converted inside the at least one reaction
vessel with the selectivity to at least one organic acid product
greater than 90% and preferably greater than 95% and most
preferably greater than 99%. In other embodiments, only part of the
at least one beta-lactone reagent is converted to at least one
organic acid product and another part of the at least one
beta-lactone reagent exiting the at least one reaction vessel is
left unconverted. In certain embodiments, the unconverted at least
one beta-lactone reagent can be recovered and recycled back to the
feed stream inlet of one or more sections of the reaction vessel
and/or one or more other reaction vessels. The at least one
beta-lactone reagent in certain embodiments comprising at least one
reaction vessel configured to have more than one section and heat
exchangers installed between sections is greater than 50%,
preferably, greater than 75%, and most preferably greater than 80%
and the residence time in one or more reaction vessels is in the
range from 0.1 second to 2 minutes.
[0103] In certain preferred embodiments, the reactor systems and
processes may include at least one reaction vessel configured as a
tubular shell-and-tube reactor with a heterogenous catalyst loaded
into the tubes and heat transfer fluid fed to the shell side to
facilitate temperature control and removal of the heat produced
during the reactions. In certain embodiments, the tubular
shell-and-tube reactor may be configured as a sectioned tubular
shell-and-tube reactor comprising more than one section with heat
exchangers installed between sections. In certain preferred
embodiments, all the at least one beta-lactone reagent is converted
inside the sectioned tubular shell-and-tube reactor with the
selectivity to at least one organic acid product greater that 90%,
preferably greater than 95%, and most preferably greater than 99%.
In certain embodiments, only part of the at least one beta-lactone
reagent in the sectioned tubular shell-and-tube reactor is
converted to the at least one organic acid product and another part
of the at least one beta-lactone reagent exits the sectioned
tubular shell-and-tube reactor unconverted. In some embodiments,
any unconverted at least one beta-lactone reagent can be recovered
and recycled back through a feed stream inlet of the sectioned
tubular shell-and-tube reactor. In some embodiments, the residence
time in the sectioned tubular shell-and-tube reactor is in the
range from 0.1 second to 2 minutes.
[0104] In some embodiments, a polymerization inhibitor is used in
the conversion of the at least one beta-lactone reagent to at least
one organic acid. In some embodiments, the polymerization inhibitor
may be a radical polymerization inhibitor, for example,
phenothiazine.
[0105] FIG. 2 illustrates an exemplary embodiment of a reactor
system 200 including a reaction vessel 210 defining an interior
volume configured to receive a beta-propiolactone reagent, a
zeolite heterogenous catalyst, and a polymerization inhibitor. The
reaction vessel 210 defines a retaining volume to retain the
beta-propiolactone reagent, the zeolite heterogenous catalyst, and
the polymerization inhibitor and is configured to produce acrylic
acid at an elevated temperature. Any of the temperatures described
for the processes of the present invention may be employed in the
reactor system 200. For example, in one variation, the reaction
vessel 210 is configured to produce acrylic acid at a temperature
between 170.degree. C. and 200.degree. C. Suitable reaction vessels
may include, for example, a Parr reactor.
[0106] In some variations, reaction vessel 210 is configured to
control the rate of addition of the beta-propiolactone reagent, the
zeolite heterogenous catalyst, and the polymerization inhibitor
added. For example, a mixture of the beta-propiolactone reagent and
the polymerization inhibitor may be slowly added using a control
valve to a mixture of catalyst in a solvent.
[0107] With reference again to FIG. 2, reaction vessel 210 further
includes vapor port 214. In some embodiments, the reaction vessel
210 is configured to continuously strip off at least a portion of
the acrylic acid produced, and vapor port 214 is configured to pass
acrylic acid vapors to a collection vessel 220.
[0108] With reference again to FIG. 2, the reactor system 200
further includes an acid/base scrubber 230, configured to receive
acrylic acid from the collection vessel 220. In other embodiments
of the reactor system, the acid/base scrubber 230 may be omitted.
Further, with reference to FIG. 2, elements 212, 216 and 222 are
dip tubes.
[0109] FIG. 3 illustrates a reactor system including at least one
reaction vessel comprising a fixed-bed reactor. In FIG. 3, a
beta-propiolactone reagent may optionally be admixed with a solvent
and enter the reactor system via a feed line 312. A pair of
fixed-bed reactors 310 and 313 each retaining multiple tubular beds
of catalyst are configured to receive beta-propiolactone reagent
from the feed line 312 at rate controlled by a feed pump 314 to
control the rate of addition of beta-propiolactone. The tubular
form of fixed-bed reactor is preferred for removing heat from the
catalyst bed during the reaction, but is not required and other
types of fixed-bed reactors and arrangements may be used. The
depiction of two reactors is for illustration purposes only and the
process may use a single fixed-bed reactor or any number of
fixed-bed reactors. Input line 316 may optionally supply additional
process input streams such as diluents into admixture with the
contents of line 324 to produce a reactor input stream 326.
[0110] The reactor input stream 326 undergoes heating to produce a
vapor phase feed stream. A heat exchanger 320 supplies a heat input
to reactor input stream 326. Heat may be from an internal process
stream or from an external heat source. The heating will be
sufficient to ensure that the reactor input stream is in a complete
vapor phase before it enters fixed-bed reactor 310.
[0111] The beta-propiolactone reagent is converted at least in part
to acrylic acid in fixed-bed reactor 310 and fixed-bed reactor 312.
A transfer line 330 passes an intermediate stream containing
unconverted beta-propiolactone reagent and acrylic acid along with
any additional input materials added with the beta-propiolactone
reagent to fixed-bed reactor 312. An optional heat exchanger 332
may be added to control and adjust, typically by heat removal, the
temperature of the intermediate stream before it enters fixed-bed
reactor 312. An effluent stream 334 is recovered from fixed-bed
reactor 312. Reactor effluent stream 334 contains any unconverted
beta-propiolactone, acrylic acid and any additional input materials
that may have been added to the reactor input stream 326.
[0112] Typically, a product separation section (not shown) receives
effluent stream 334 to recover the acrylic acid product. Along with
recovery of the acrylic acid product the separation section will in
most cases also recover unconverted beta-propiolactone (which is
usually recycle) and the diluent and the other additive streams
that may have been added with the feed and are still recoverable
while also rejecting unwanted by-products.
[0113] FIG. 4 illustrates a reactor system including at least one
reaction vessel comprising a moving bed reactor. More specifically,
FIG. 4 illustrates a reaction vessel 410 which defines an upper
reaction section 412 that holds a bed of heterogenous catalyst 416
and a lower reaction section 414 that holds a bed of heterogenous
catalyst 418, with both moving bed reactor beds arranged for radial
flow of reactants across each of the reaction sections.
[0114] With respect to fluid flow, reactor vessel 410 is configured
to receive a combined beta-propiolactone reagent feed stream
comprising beta-propiolactone. A feed line 420 delivers the
beta-propiolactone reagent and an additive line 426 delivers any
additives for combination into a combined feed 422 that passes
through a heater 424 configured for heating the combined feed to
ensure delivery of an all vapor phase combined feed stream to
reactor section 412. The combined feed passes through a heat
exchange vessel 430 that is provided to heat the heterogenous
catalyst that is entering the moving bed reactor vessel 410 via a
catalyst transfer line 450. The combined feed flows downward into
an annular distribution space 432 that distributes it around the
heterogenous catalyst bed 416. After the combined feed passes
through bed 416 a center pipe 436 collects an upper reactor
effluent comprising acrylic acid, unreacted combined feed and any
remaining additives for transfer from the vessel into an
inter-heater 440 via a line 438. An inter-heater 440 raises the
temperature of the first reactor section effluent and returns the
heated upper reactor effluent passes to the lower reactor section
414 via line 428. An annular space 442 distributes the heated upper
reactor effluent around the lower heterogenous catalyst bed 418. A
lower reactor effluent passes through a center pipe 444 and into
annular space 446. A line 448 recovers the lower reactor effluent
and passes it similar to recovery of acrylic acid product and
optional recycle of unconverted beta-propiolactone, recovery of
additives, and removal of by-products.
[0115] In FIG. 4, the heterogenous catalyst is periodically removed
from the bottom of the reaction vessel 410 by a catalyst removal
line 443 and replaced at the top of the reaction vessel 410 by a
catalyst transfer line 450. The heterogenous catalyst flows through
the reaction vessel by dropping from a catalyst flow line 460 and
from collection pipes 452 that withdraw heterogenous catalyst from
the annular catalyst bed 418. As catalyst drops from the bed of
heterogenous catalyst 412, transfer pipes 454 add heterogenous
catalyst from the bed of heterogenous catalyst 416 and distribute
the heterogenous catalyst around the bed of heterogenous catalyst
418. In turn, as heterogenous catalyst drops from the bed of
heterogenous catalyst 416, transfer pipes 456 replace it with
heterogenous catalyst withdrawn from heat exchange section 458 of
heat exchanger 430 that receives fresh and/or regenerated catalyst
from catalyst transfer line 450.
[0116] In certain embodiments, the reaction vessel 410 may operate
with or without continuous regeneration. In the latter case,
deactivated or partially deactivated catalyst withdrawn by the
catalyst flow line 460 may be discarded or transferred to remote
regeneration facilities located on-site or off-site for
reactivation and reuse of the spent catalyst. The catalyst transfer
line 450 will be used to supply reactivated or fresh catalyst to
the moving bed reactor vessel 410 as catalyst is withdrawn vial
catalyst flow line 460.
[0117] FIG. 4 illustrates regeneration system 462 that receives at
least partially deactivated catalyst from reaction vessel 420 via a
reactivated catalyst line 471 and returns reactivated, and
optionally treated catalyst to moving bed reactor vessel 410 via
the catalyst transfer line 450. The transfer of catalyst to the
regeneration system 462 begins with the intermittent passage of
catalyst to a lock hopper 464 through line 443 upon the opening and
closing of an upper control valve. Another control valve 463
regulates the movement of catalyst from lock hopper 464 into a lift
vessel 466. When heterogenous catalyst is ready for regeneration
transfer through reactivated catalyst line 471, control valve 463
is closed and lift gas enters lift vessel 470 via line 468 and is
carried to the bottom of lift vessel 466 by lift gas tube 470. The
lift gas carries the catalyst upward into a catalyst hopper 472 of
regeneration system 462. Lift gas disengages from the catalyst in
vessel 472 and is removed from the regeneration section 479 by
conduit 475.
[0118] Heterogenous catalyst is regenerated as it flows
intermittently from the top to the bottom of regeneration system
462. Intermittent passage of catalyst begins with the opening of a
valve 490 in a line 491 that results in catalyst from hopper 472
passing downwardly through a line 473 into an upper chamber 477 of
a combustion vessel 476 as catalyst drops into a lower portion 488
of the combustion vessel 476 to replace catalyst the dropped into a
lock hopper 492. Valve 491 isolates lock hopper 492 for transfer of
catalyst into lift vessel 496. Catalyst is transported from lift
vessel 496 into line 450 by closing valve 494 and injecting lift
gas into lift vessel 496 via line 447 in the manner previously
described.
[0119] In certain embodiments, the regeneration system passes a
regeneration gas and may optionally pass one or more treatment
and/or purge gases through the regeneration section. A baffle 467
divides the combustion vessel into the upper chamber 477 and the
lower chamber 488. The primary regeneration gas enters the
regeneration section 462 via a line 478 and passes into the bottom
of upper chamber 477, across a bed 482 of deactivation catalyst. A
line 474 withdraws the regeneration gas from the top of upper
chamber 477. Additional regeneration gas or treatment gas enter the
bottom of lower chamber 488 via line 487. An additional gas stream,
typically a treatment gas may also enter a lower contact zone 489
via a line 461. A line 479 withdraws gas from lower chamber 488
below baffle 467. Since lower contact zone 489 communicates with
combustion vessel 476 conduit 479 also withdraws gas that enter the
lower contact zone 489.
[0120] In certain preferred embodiments, the reactor systems and
processes of the present invention include at least one reaction
vessel comprising a fluidized bed reactor configured to receive at
least one beta-lactone reagent diluted with inert gas such as
nitrogen. The fluidized bed reactor includes at least one reaction
zone where the heterogenous catalyst is suspended/fluidized in the
flow of an inert gas such as nitrogen. The fluidized-bed reactor
may operate at atmospheric pressure, at the pressure below
atmospheric pressure, or at the pressure above atmospheric
pressure. In certain embodiments, the fluidized-bed reactor
operates at a pressure between 250 Torr and 50 psig, but preferably
from 5 psig to 30 psig. In certain embodiments, the fluidized-bed
reactor is operated in the temperature range from 100.degree. C. to
300.degree. C., and preferably from 150.degree. C. to 250.degree.
C. Inert gas such as nitrogen is introduced to the fluidized-bed
reactor to fluidize the heterogenous catalyst. The temperature of
the gas entering the fluidized-bed reactor can be adjusted to
maintain the reactor at the desired temperature. In preferred
embodiments, the at least one beta-lactone reagent is introduced
through at least one feed stream inlet at the bottom of the
fluidized-bed reactor and the at least one organic acid product,
by-products, and inert gas exit from the top of the fluidized-bed
reactor. In some embodiments, the inert gas is separated from the
at least one organic acid product and recycled to the at least one
feed stream inlet of the fluidized-bed reactor. In some
embodiments, the fluidized-bed reactor can be configured to include
a regeneration zone where the heterogenous catalyst may be
regenerated to be reused in subsequent reactions. The heterogenous
catalyst can be regenerated in a flow of air or dilute oxygen to
remove deposited coke. In some embodiments, deactivation of the
heterogenous catalyst may occur over time from at least one of
organic material depositing on the surface of the heterogenous
catalyst and the production of coke within the pores and on the
surface of the zeolite and/or the accumulation of polar acidic
compounds. The composition of the heterogenous catalyst along with
operating conditions, primarily temperature will determine the rate
of heterogenous catalyst deactivation by coke formation. Removal of
coke and organic material by combustion at elevated temperatures
may be incorporated to effectively restore the activity of the
heterogenous catalyst. Regeneration will typically occur at a
temperature of 450.degree. C. or higher. Preferably regeneration
will be in a range of between 450.degree. C. and 550.degree. C.
[0121] FIG. 5 illustrates a reactor system including at least one
reaction vessel comprising a fluidized bed reactor 10. FIG. 5 shows
a fluidized bed reactor 10 that includes a dilute phase transfer
zone as the catalyst contact zone which may be referred to as riser
20. The fluidized bed reactor 10 is configured for fluidized
catalyst contacting a beta-propiolactone reagent in a reaction zone
12. In the fluidized bed reactor 10 a beta-lactone feed stream is
contacted in reaction zone 12 with a heterogenous catalyst. In
certain embodiments, a regenerated heterogenous catalyst entering
from a regenerator conduit 18 contacts the beta-lactone reagent
combined feed stream comprising beta-lactone and one or more of
diluents fluidization gases, and other additives as herein
described. In certain preferred embodiments, the regenerated
heterogenous catalyst is at substantially higher temperature than
the combined feed and additional heating of the feed by contact
with the regenerated heterogenous catalyst can provide additional
fluidization to lift the heterogenous catalyst and carry up the
riser 20 of the fluidized bed reactor 12. The regenerator conduit
18 is in downstream communication with the regenerator 14. The
riser 20 has an inlet 19 in downstream communication with said
regenerator conduit 18. The regenerator conduit 19 is connected to
the FCC riser 20 at a lower end. A control valve located between
sections 18 and 19 of the regenerator conduit regulates the flow of
heterogenous catalyst out of the regenerated catalyst conduit and
provides a pressure drop that prevents any substantial flow of the
feed stream up the section 18 of the regeneration conduit.
[0122] In the FIG. 5 illustrated embodiment, spent cracking
catalyst entering from a recycle catalyst conduit 19 and a riser
inlet tube 23 is contacted with the combined beta-propiolactone
feed stream riser 20 of the fluidized bed reactor 12 without the
spent cracking catalyst undergoing regeneration. A valve at the top
of riser inlet tube 23 regulates the flow of catalyst through the
riser inlet tube 23. The spent cracking catalyst recycle will allow
additional control of the temperature and/or the activity of the
heterogenous catalyst in the fluidized bed reactor 12 and can
increase the coke concentration of the heterogenous catalyst in the
fluidized bed reactor 12 to aid in the regulation of regenerator
temperatures and heterogenous catalyst regeneration.
[0123] The recycle of spent heterogenous catalyst through the
recycle catalyst conduit can also be used to increase the ratio of
catalyst-to-feed in the fluidized bed reactor. In some embodiments,
the catalyst-to-feed weight ratio is in a range between 5 and 20
and preferably between 10 and 15. In some embodiments portions of
the beta-propiolactone feed may be fed to the riser 20 through
elevated distributors 16 and this can be used to maintain
conversion of the beta-propiolactone as the heterogenous catalyst
passes up the riser 20.
[0124] The recycle conduit 19 is in downstream communication with a
riser outlet 25. The recycle conduit 19 is connected to the riser
20 at the outlet end of the recycle conduit by riser tube 23. The
recycle conduit 19 bypasses the regenerator 14 by being in
downstream communication with the riser outlet 25 and the riser
tube 23 being in direct, downstream communication with the recycle
conduit.
[0125] Consequently, spent cracking catalyst entering the recycle
conduit 19 passes back to the riser 20 before any of it enters the
regenerator 14. The recycle conduit 19 has no direct communication
with the regenerator 14.
[0126] The acrylic acid containing product gases and spent
heterogenous catalyst in the riser 20 are thereafter discharged
from the riser outlet 25 into a disengaging chamber 27 which
contains the riser outlet. The gas stream containing acrylic acid
product is disengaged from the heterogenous catalyst in the
disengaging chamber 27 using a rough cut separator 26. Cyclonic
separators which may include one or two stages of cyclones 28 in
the fluidized bed reactor reaction chamber 22 further separate
heterogenous catalyst from acrylic acid products. Product
containing gases exit the fluidized bed reactor reaction chamber 22
through an outlet 31 for transport to downstream product separation
facilities to recover acrylic acid, recycle beta-propiolactone,
diluents and additives. In another embodiment, the recycle conduit
19 and the regenerator conduit 18 are in downstream communication
with the disengaging chamber 27. The outlet temperature of the
product containing gas leaving the riser 20 should be less than
325.degree. C. and preferably less than less than 300.degree.
C.
[0127] After separation from product containing gases, the
heterogenous catalyst falls into a stripping section 34 where an
inert gas is injected through a nozzle 35 and distributed to purge
any residual product vapor or gas. After the stripping operation, a
portion of the spent cracking catalyst is fed to the catalyst
regenerator 14 through a spent catalyst conduit 36. The catalyst
regenerator 14 may be in downstream communication with the riser
20, specifically, the riser outlet 25. In certain embodiments, a
portion of the spent heterogenous catalyst is recycled through
recycle catalyst conduit 19 to the riser 20 as previously
described.
[0128] FIG. 5 depicts a regeneration vessel 14 for the regeneration
of heterogenous catalyst having a combustor 41 as the primary zone
for the regeneration of the heterogenous catalyst by combustion of
the coke and the displacement of other volatile compounds from the
surface of the spent cracking catalyst. Other embodiments of the
invention may use other configurations and arrangement of
regenerators. In the regeneration vessel 14, a stream of
oxygen-containing gas, such as air, is introduced from line 37
through a distributor 38 to contact the coked catalyst, burn coke
deposited thereon, and provide regenerated catalyst and a gas
stream comprising the products of the combustion and generally
referred to as flue gas. Catalyst and air flow upwardly together
through the combustor 41 and along a combustor riser 40 located
within the regeneration vessel 14. The catalyst which is at least
partially regenerated is discharged through a disengager 42 to
effect an initial separation of the catalyst from the flue gas. A
series of cyclonic separation steps in cyclones 44 and 46 effect
further separation of regenerated catalyst and flue gas. The
cyclones direct the catalyst separated therein into the conduits
that extend downwardly from the cyclones and are referred to as
diplegs. The flue gas which is relatively free of catalyst exits
cyclones 44, 46 and flows out of the regenerator vessel 14 through
line 48. Regenerated heterogenous catalyst is recycled back to the
reactor riser 20 through the regenerated catalyst conduit 18.
[0129] The flue gas will typically contain carbon dioxide, water
vapor, and lesser amounts of carbon monoxide. Depending on the type
and the erosion properties of the catalyst the flue gas may also
contain small amounts of extremely fine catalyst particles
typically in the range of between 0.2 and 2 micrometers which in
some applications will require additional treatment of the flue gas
for removal of such particles.
[0130] The embodiments described herein are not intended to be
limited to the aspects shown, but are to be accorded the widest
scope consistent with the principles and features disclosed
herein.
* * * * *