U.S. patent application number 13/557398 was filed with the patent office on 2012-11-22 for process for toluene and methane coupling in a microreactor.
This patent application is currently assigned to FINA TECHNOLOGY, INC.. Invention is credited to James R. Butler.
Application Number | 20120296133 13/557398 |
Document ID | / |
Family ID | 41065749 |
Filed Date | 2012-11-22 |
United States Patent
Application |
20120296133 |
Kind Code |
A1 |
Butler; James R. |
November 22, 2012 |
PROCESS FOR TOLUENE AND METHANE COUPLING IN A MICROREACTOR
Abstract
A process for making ethylbenzene and/or styrene by reacting
toluene with methane in one or more microreactors is disclosed. In
one embodiment a method of revamping an existing styrene production
facility by adding one or more microreactors capable of reacting
toluene with methane to produce a product stream comprising
ethylbenzene and/or styrene is disclosed.
Inventors: |
Butler; James R.;
(Spicewood, TX) |
Assignee: |
FINA TECHNOLOGY, INC.
Houston
TX
|
Family ID: |
41065749 |
Appl. No.: |
13/557398 |
Filed: |
July 25, 2012 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
13286271 |
Nov 1, 2011 |
8269053 |
|
|
13557398 |
|
|
|
|
12047930 |
Mar 13, 2008 |
8071836 |
|
|
13286271 |
|
|
|
|
Current U.S.
Class: |
585/323 ;
29/401.1; 585/435; 585/453 |
Current CPC
Class: |
C07C 5/48 20130101; C07C
5/48 20130101; B01J 2219/00862 20130101; C07C 2/84 20130101; B01J
19/0093 20130101; B01J 2219/00783 20130101; C07C 2/84 20130101;
C07C 15/46 20130101; B01J 2219/00835 20130101; C07C 2/66 20130101;
C07C 2/66 20130101; C07C 2/84 20130101; Y10S 585/943 20130101; Y10S
585/921 20130101; C07C 15/073 20130101; C07C 15/46 20130101; B01J
2219/00873 20130101; C07C 15/073 20130101; Y10T 29/49716 20150115;
C07C 15/46 20130101 |
Class at
Publication: |
585/323 ;
585/435; 585/453; 29/401.1 |
International
Class: |
C07C 2/64 20060101
C07C002/64; B01J 14/00 20060101 B01J014/00; B23P 23/00 20060101
B23P023/00; B01J 10/00 20060101 B01J010/00 |
Claims
1. (canceled)
2. (canceled)
3. (canceled)
4. (canceled)
5. (canceled)
6. (canceled)
7. (canceled)
8. (canceled)
9. The process of claim 6, wherein toluene is removed from the
second product stream and recycled as an inlet stream to the one or
more microreactors.
10. (canceled)
11. (canceled)
12. (canceled)
13. (canceled)
14. (canceled)
15. (canceled)
16. (canceled)
17. (canceled)
18. (canceled)
19. (canceled)
20. (canceled)
21. (canceled)
22. (canceled)
23. (canceled)
24. (canceled)
25. (canceled)
26. (canceled)
27. A method of revamping an existing styrene production facility
comprising; providing an existing production facility; and adding
one or more microreactors to said facility, wherein said one or
more microreactors are capable of reacting toluene with methane to
produce a first product stream comprising ethylbenzene and/or
styrene.
28. The method of claim 27, further comprising sending the first
product stream comprising ethylbenzene to the existing styrene
production facility for further processing to form styrene.
29. The method of claim 27, wherein the existing styrene production
facility comprises a separation apparatus to remove at least a
portion of any benzene from the first product stream, an alkylation
reactor to form ethylbenzene by reacting benzene with ethylene, and
a dehydrogenation reactor to form styrene by dehydrogenating
ethylbenzene.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates generally to a process for the
production of ethylbenzene and styrene.
[0003] 2. Description of the Related Art
[0004] Styrene is an important monomer used in the manufacture of
many of todays plastics. Styrene is commonly produced by making
ethylbenzene, which is then dehydrogenated to produce styrene.
Ethylbenzene is typically formed by one or more aromatic conversion
processes involving the alkylation of benzene.
[0005] Aromatic conversion processes, which are typically carried
out utilizing a molecular sieve type catalyst, are well known in
the chemical processing industry. Such aromatic conversion
processes include the alkylation of aromatic compounds such as
benzene with ethylene to produce alkyl aromatics such as
ethylbenzene. Typically an alkylation reactor, which can produce a
mixture of monoalkyl and polyalkyl benzenes, will be coupled with a
transalkylation reactor for the conversion of polyalkyl benzenes to
monoalkyl benzenes. The transalkylation process is operated under
conditions to cause disproportionation of the polyalkylated
aromatic fraction, which can produce a product having an enhanced
ethylbenzene content and a reduced polyalkylated content. When both
alkylation and transalkylation processes are used, two separate
reactors, each with its own catalyst, can be employed. The
alkylation and transalkylation conversion processes can be carried
out in the liquid phase, in the vapor phase or under conditions in
which both liquid and vapor phases are present.
[0006] In the formation of ethylbenzene from alkylation reactions
of ethylene and benzene, other impurities and undesirable side
products may be formed in addition to the desired ethylbenzene.
[0007] These undesirable products can include such compounds as
xylene, cumene, n-propylbenzene and butylbenzene, as well as
polyethylbenzenes, and high boiling point alkyl aromatic
components, sometimes referred to as "heavies," having a boiling
point at or above 185.degree. C. As can be expected, reduction of
these impurities and side products is important. This is especially
true in the case of xylene, particularly the meta and para xylenes,
which have boiling points that are close to that of ethylbenzene
and can make product separation and purification difficult.
[0008] Ethylene is obtained predominantly from the thermal cracking
of hydrocarbons, such as ethane, propane, butane or naphtha.
Ethylene can also be produced and recovered from various refinery
processes. Ethylene from these sources can include a variety of
undesired products, including diolefins and acetylene, which can
act to reduce the effectiveness of alkylation catalysts and can be
costly to separate from the ethylene. Separation methods can
include, for example, extractive distillation and selective
hydrogenation of the acetylene back to ethylene. Thermal cracking
and separation technologies for the production of relatively pure
ethylene can account for a significant portion of the total
ethylbenzene production costs.
[0009] Benzene is obtained predominantly from the hydrodealkylation
of toluene which involves heating a mixture of toluene with excess
hydrogen to elevated temperatures (500.degree. C. to 600.degree.
C.) in the presence of a catalyst. Under these conditions, toluene
can undergo dealkylation according to the chemical equation:
C.sub.6H.sub.5CH.sub.3+H.sub.2.fwdarw.C.sub.6H.sub.6+CH.sub.4 This
reaction requires energy input and as can be seen from the above
equation, produces methane as a byproduct, which is typically
separated and used as fuel within the process.
[0010] In view of the above, it would be desirable to have a
process of producing ethylbenzene, and styrene, which does not rely
on thermal crackers and expensive separation technologies as a
source of ethylene. It would also be desirable if the process was
not dependent upon ethylene from refinery streams containing
impurities which can lower the effectiveness and can contaminate
the alkylation catalyst. It would further be desirable to avoid the
process of converting toluene to benzene with its inherent expense
and loss of a carbon atom to methane.
SUMMARY
[0011] One embodiment of the present invention is a process for
making ethylbenzene which involves reacting toluene and methane in
one or more microreactors to form a first product stream comprising
ethylbenzene and/or styrene. The first product stream may also have
one or more of benzene, toluene, methane, or styrene present. The
process may comprise at least one separation process for at least
partial separation of the components of the first product
stream.
[0012] Methane may be separated from the first product stream which
may be recycled back to the microreactors or may be utilized as
fuel within the process. Toluene may also be separated from the
first product stream and recycled to the microreactors. At least a
portion of the components of the first product stream can be
further processed in a styrene production process. The reactors can
include a reaction zone and can be capable of dissipating heat to
maintain the reaction zone within a desired temperature range for
reacting toluene and methane to form ethylbenzene and/or
styrene.
[0013] A further embodiment of the invention is a method of
revamping an existing styrene production facility by adding one or
more microreactors capable of reacting toluene with methane to
produce a new product stream containing ethylbenzene. The new
product stream containing ethylbenzene may then be sent to the
existing styrene production facility for further processing to form
styrene. The existing styrene production facility can include
separation apparatus to remove at least a portion of any benzene
from the new product stream, an alkylation reactor to form
ethylbenzene by reacting the benzene with ethylene, and a
dehydrogenation reactor to form styrene by dehydrogenating
ethylbenzene.
[0014] Yet another embodiment of the present invention is a process
for making ethylbenzene which includes reacting toluene and methane
in one or more microreactors to form a first product stream
comprising one or more of ethylbenzene, styrene, benzene, toluene
and methane. The first product stream is sent to a separation zone
where at least a portion of any methane and toluene are removed for
recycle to the one or more microreactors. At least a portion of the
benzene is removed from the first product stream and at least a
portion of the benzene removed is reacted with ethylene in an
alkylation reactor to form ethylbenzene. The ethylbenzene is
dehydrogenated in one or more dehydrogenation reactors to form
styrene.
[0015] The one or more microreactors may have one or more reaction
zones and be capable of dissipating heat to maintain one or more of
the reaction zones within a desired temperature range to promote
reacting toluene and methane to form ethylbenzene and/or styrene.
The one or more microreactors can comprise a plurality of
microstructured panels creating a reaction zone comprising a
plurality of microchannels. A portion of the microstructured panels
can create reaction zones comprising a plurality of reaction zone
microchannels and a portion of the microstructured panels can
create a plurality of cooling microchannels for the flow of a
cooling medium capable of dissipating heat to maintain the reaction
zones within a desired temperature range for reacting toluene and
methane to form ethylbenzene. The plurality of microstructured
panels can be arranged in an alternating manner so the reaction
zone microchannels and the cooling microchannels are capable of
dissipating heat to maintain the reaction zones within a desired
temperature range for reacting toluene and methane to form
ethylbenzene.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a schematic block diagram illustrating a process
for making ethylbenzene and styrene.
[0017] FIG. 2 is a schematic block diagram illustrating a process
for making ethylbenzene and styrene according to an embodiment of
the present invention.
[0018] FIG. 3 is an illustrated example of a microstructured
panel.
[0019] FIG. 4 is an illustrated example of two microstructured
panels, each having microchannels, one for reactants and the other
for a cooling medium.
DETAILED DESCRIPTION
[0020] Referring first to FIG. 1, there is illustrated a schematic
block diagram of a typical alkylation/transalkylation process
carried out in accordance with the prior art. A feed stream of
toluene is supplied via line 10 to reactive zone 100 which produces
product streams of methane via line 12 and benzene via line 14. The
benzene via line 14 along with ethylene via line 16 are supplied to
an alkylation reactive zone 120 which produces ethylbenzene and
other products which are sent via line 18 to a separation zone 140.
The separation zone 140 can remove benzene via line 20 and send it
to a transalkylation reaction zone 160. The benzene can also be
partially recycled via line 22 to the alkylation reactive zone 120.
The separation zone 140 can also remove polyethylbenzenes via line
26 which are sent to the transalkylation reaction zone 160 to
produce a product with increased ethylbenzene content that can be
sent via line 30 to the separation zone 140. Other byproducts can
be removed from the separation zone 140 as shown by line 32, this
can include methane and other hydrocarbons that can be recycled
within the process, used as fuel gas, flared or otherwise disposed
of. Ethylbenzene can be removed from the separation zone 140 via
line 34 and sent to a dehydrogenation zone 180 to produce styrene
product that can be removed via line 36.
[0021] The front end of the process 300, designated by the dashed
line, includes the initial toluene to benzene reactive zone 110 and
the alkylation reactive zone 120. It can be seen that the input
streams to the front end 300 include toluene via line 10, ethylene
via line 16 and optionally oxygen via line 15. There can also be
input streams of benzene from alternate sources other than from a
toluene reaction, although they are not shown in this embodiment.
The output streams include the methane via line 12 which is
produced during the conversion of toluene to benzene in reactive
zone 110 and the product stream containing ethylbenzene via line 18
that is sent to the back end of the process 400. The back end 400
includes the separation zone 140, the transalkylation reaction zone
160 and the dehydrogenation zone 180.
[0022] Turning now to FIG. 2, there is illustrated a schematic
block diagram of one embodiment of the present invention. Feed
streams of toluene supplied via line 210 and methane supplied via
line 216 are supplied to one or more microreactors 200 which
produces ethylbenzene along with other products, which can include
styrene. In some embodiments an input stream of oxygen 215 may be
supplied to the microreactors 200. The output from the microreactor
200 includes a product containing ethylbenzene which is supplied
via line 218 to a separation zone 240. The separation zone 240 can
separate benzene that may be present via line 220 which can be sent
to an alkylation reaction zone 260. The alkylation reaction zone
260 can include a transalkylation zone. The separation zone 240 can
also remove heavy molecules that may be present via line 226. The
alkylation reaction zone 260 can produce a product with increased
ethylbenzene content that can be sent via line 230 to the
separation zone 240. Other byproducts can be removed from the
separation zone 240 as shown by line 232, this can include methane
and other hydrocarbons that can be recycled within the process,
used as fuel gas, flared or otherwise disposed of. Ethylbenzene can
be removed from the separation zone 240 via line 234 and sent to a
dehydrogenation zone 280 to produce styrene product that can be
removed via line 236. Any styrene that is produced from the
reactive zone 200 can be separated in the separation zone 240 and
sent to the dehydrogenation zone 280 via line 234 along with the
ethylbenzene product stream, or can be separated as its own product
stream, (not shown), bypassing the dehydrogenation zone 280 and
added to the styrene product in line 236.
[0023] The front end of the process 500 includes the one or more
microreactors 200 which can be in series or parallel arrangements.
The input streams to the front end 500 are toluene via line 210 and
methane via line 216 and optionally oxygen via line 215. The output
stream is the product containing ethylbenzene via line 218 that is
sent to the back end of the process 600. The back end 600 includes
the separation zone 240, the alkylation reaction zone 260 and the
dehydrogenation zone 280.
[0024] A comparison of the front end 300 of the prior art shown in
FIG. 1 against the front end 500 of the embodiment of the invention
shown in FIG. 2 can illustrate some of the features of the present
invention. The front end 500 of the embodiment of the invention
shown in FIG. 2 has a single microreactor zone 200 rather than the
two reactive zones contained within the front end 300 shown in FIG.
1, the reactive zone 100 and the alkylation reactive zone 120. The
reduction of one reactive zone can have a potential cost savings
and can simplify the operational considerations of the process.
[0025] Both front ends have an input stream of toluene, shown as
lines 10 and 210. The prior art of FIG. 1 has an input stream of
ethylene 16 and a byproduct stream of methane 12. The embodiment of
the invention shown in FIG. 2 has an input stream of methane 216.
The feed stream of ethylene 16 is replaced by the feed stream of
methane 216, which is typically a lower value commodity, and should
result in a cost savings. Rather than generating methane as a
byproduct 12 which would have to be separated, handled and disposed
of, the present invention utilizes methane as a feedstock 216 to
the microreactor 200.
[0026] A comparison of the back end 400 of the prior art shown in
FIG. 1 with the back end 600 of the embodiment of the invention
shown in FIG. 2 can further illustrate the features of the present
invention. It can be seen that the back end 400 of the prior art
shown in FIG. 1 is essentially the same as the back end 600 of the
embodiment of the invention shown in FIG. 2. They each contain a
separation zone, an alkylation reaction zone and a dehydrogenation
zone and are interconnected in the same or essentially the same
manner. This aspect of the present invention can enable the front
end of a facility to be modified in a manner consistent with the
invention, while the back end remains essentially unchanged. A
revamp of an existing ethylbenzene or styrene production facility
can be accomplished by installing a new front end or modifying an
existing front end in a manner consistent with the invention and
delivering the product of the altered front end to the existing
back end of the facility to complete the process in essentially the
same manner as before. The ability to revamp an existing facility
and convert from a toluene/ethylene feedstock to a toluene/methane
feedstock by the modification of the front end of the facility
while retaining the existing back end can have significant economic
advantages.
[0027] The microreactor 200 of the present invention can comprise
one or more single or multi-stage microreactors. In one embodiment
the microreactor 200 can have a plurality of microreactors
connected in series (series-connected microreactors). Additionally
and in the alternative, the microreactors may be arranged in a
parallel fashion. The microreactor 200 can be operated at
temperature and pressure conditions to enable the reaction of
toluene and methane to form ethylbenzene, and at a feed rate to
provide a space velocity enhancing ethylbenzene production while
retarding the production of xylene or other undesirable products.
The reactants, toluene and methane, can be added to the plurality
of series-connected microreactors in a manner to enhance
ethylbenzene production while retarding the production of
undesirable products. For example toluene and/or methane can be
added to any of the plurality of series-connected microreactors as
needed to enhance ethylbenzene production.
[0028] The microreactor 200 can be operated in the vapor phase. One
embodiment can be operated in the vapor phase within a pressure
range of 4 psia to 1000 psia. Another embodiment can be operated in
the vapor phase within a pressure range of atmospheric to 500
psia.
[0029] The feed streams of methane and toluene can be supplied to
the microreactor 200 in ratios of from 2 to 50 moles methane to
toluene. In one embodiment the ratios can range from 5 to 30 moles
methane to toluene.
[0030] In one embodiment of the invention oxygen is added to the
microreactor 200 in amounts that can facilitate the conversion of
toluene and methane to ethylbenzene and styrene. The oxygen content
can range from 1% to 50% by volume relative to the methane content.
In one embodiment the oxygen content can range from 2% to 30% by
volume relative to the methane content.
[0031] In one embodiment the microreactor 200 of the present
invention can comprise multiple microreactors and oxygen can be
added to the plurality of series-connected microreactors in a
manner to enhance ethylbenzene and/or styrene production while
retarding the production of undesirable products. Oxygen can be
added incrementally to each of the plurality of series-connected
microreactors as needed to enhance ethylbenzene and/or styrene
production, to limit the exotherm from each of the microreactors,
to maintain the oxygen content within a certain range throughout
the plurality of microreactors or to customize the oxygen content
throughout the plurality of microreactors. In one embodiment there
is the ability to have an increased or reduced oxygen content as
the reaction progresses and the ethylbenzene and/or styrene
fraction increases while the toluene and methane fractions
decrease. There can be multiple series-connected microreactors
which are arranged in a parallel manner.
[0032] The oxygen can react with a portion of the methane and
result in a highly exothermic reaction. The heat generated by the
exothermic reaction can be regulated to some extent by the use of
microreactors which can have a large surface area to reactant
contact area ratio. The small contact area for the reactants can
result in a short residence time for the reaction, which in some
embodiments can be as short as less than a second. The shortened
residence time and large surface area to reactant contact area
ratio can facilitate heat dissipation from the microreactor. These
factors, along with the ability for incremental oxygen addition to
the plurality of series-connected microreactors, can be used to
control the reaction temperatures within a range to facilitate the
production of ethylbenzene and/or styrene and reduce the production
of undesired components. Microreactors with integrated cooling can
also be used, thus a short residence time reactor with an
integrated heat exchanger can be used.
[0033] When a plurality of series-connected microreactors are
utilized, counter-flow micro heat exchangers can be used to
dissipate heat and provide temperature control for the reaction. In
one embodiment a plurality of series-connected microreactors are
utilized and one or more counter-flow micro heat exchangers are
located between two or more of the microreactors used to dissipate
heat and provide temperature control for the individual
microreactors and the overall reaction. One temperature range to
facilitate the production of ethylbenzene and/or styrene is from
550.degree. C. to 1000.degree. C. Another temperature range to
facilitate the production of ethylbenzene and/or styrene is from
600.degree. C. to 800.degree. C. The heat generated by the
exothermic reaction can be removed and recovered to be utilized
within the process.
[0034] In one embodiment the microreactor zone 200 of the present
invention can comprise one or more single or multi-stage
microreactors which can contain one or more single or multi-stage
catalyst sites. The catalyst that can be used in the microreactor
200 can include any catalyst that can couple toluene and methane to
make ethylbenzene and/or styrene and are not limited to any
particular type. It is believed that the oxidation reaction of
toluene and methane can be accelerated by base catalysis. In one
non-limiting example the catalyst can comprise one or more metal
oxides. In one non-limiting example the catalyst can contain a
metal oxide which is supported on an appropriate substrate. It is
believed that with a metal oxide catalyst the oxygen/oxide sites
can function as the active reaction centers which can remove
hydrogen atoms from the methane to form methyl radicals and from
the toluene to form benzyl radicals. The C8 hydrocarbons can be
formed as a result of cross-coupling between the resulting methyl
and benzyl radicals. The catalysts may contain different
combinations of alkali, alkaline earth, rare earth, and/or
transition metal oxides. In another non-limiting example the
catalyst can comprise a modified basic zeolite. In yet another
non-limiting example the catalyst can be a base zeolite, such as an
X, Y, mordenite, ZSM, silicalite or AIPO4-5 that can be modified
with molybdenum, sodium or other basic ions. The zeolite catalyst
may or may not contain one of more metal oxides.
[0035] A catalyst can be introduced into one or more parts of the
process. In one embodiment the microchannels of the microreactor
can have a catalyst deposited or impregnated on or within them. The
catalyst can also be affixed to an article, such as a rod, that can
be contained or inserted into the microreactor in a manner which
can contact the catalyst with the reactant streams. Alternatively,
a process for wash coating a carrier with catalyst can be used
where the carrier is capable of contacting the reactants within one
or more of the microreactors. The catalyst can be contacted with
the reactants at one or more points of the plurality of
series-connected microreactors. The catalyst can alternately be
contacted with the reactants at one or more points between the
plurality of series-connected microreactors, such as for example at
a location between two microreactors in conjunction with a
counter-flow micro heat exchanger.
[0036] Referring now to FIG. 3, the microreactor can comprise a
number of microstructured panels 700 that can have recesses or
channels of small depth that serve as flow channels or
microchannels 710. These types of microreactors can be similar to
typical plate-and-frame type heat exchangers known in the art, but
of much smaller size. In one embodiment the microreactor panels 700
can range from about 30 to 50 mm in length and from about 30 to 50
mm in height. The microreactor panels 700 can be constructed by
micro-machining or etching a panel made of metals, silicon, glass
or ceramic materials, which can be referred to as a substrate
material. Microchannels 710 can be etched or otherwise formed in a
pattern on the surface 712 of the substrate panel material. In one
embodiment the number of microchannels formed on the surface of the
panel can range from 10 to 5000. The microchannels 710 can be in
fluid communication with openings through the panels which can
serve as inlet 714 and outlet 716 passages between the
microreactors and/or microchannels so that the reactants can enter
and exit the microchannels. The panel 700 may also have pass-though
holes 718, 720 that can allow a fluid or gas to pass through the
panel 700 without being in contact with the panel inlet 714, outlet
716 or the microchannels 710. The pass-though holes 718, 720 in one
embodiment have a diameter of from 0.5 mm to 2.0 mm. The width and
depth of the microchannels 710 in one embodiment can range from 100
.mu.m to 300 .mu.m while the total depth of the panel 700 can range
from 400 .mu.m to 600 .mu.m. In another embodiment the width and
depth of the microchannels can range from 100 .mu.m to 500 .mu.m
while the total depth of the panel 700 can range from 700 .mu.m to
1 mm. In yet another embodiment the width and depth of the
microchannel can range from 300 .mu.m to 600 .mu.m while the total
depth of the panel 700 can range from 800 .mu.m to 1.5 mm or more.
The width and depth of the microchannels do not have to be
consistent or have the same dimensions of the other microchannels.
While in some embodiments the width may be of a larger dimension
than the depth, in other embodiments the depth may be of a larger
dimension than the width. If plugging is a concern, having the
depth and width of the microchannels be of similar dimension to
create a more uniform cross sectional flow area of the microchannel
may be desired.
[0037] In yet another embodiment the microreactor panels 700 can
range from about 300 mm to 900 mm in length and from about 300 mm
to 900 mm in height. The width of the microchannel 710 of these
larger panels can be as large as 5 mm while the depth of the
microchannel 710 would still be limited to a dimension less than
that of the substrate panel material. The size of the panels and
dimensions of the microchannels can vary greatly while still being
within the scope of the present invention.
[0038] Referring now to FIG. 4, in one embodiment a reactant inlet
stream 740 supplies an inlet stream 742 to the microchannels 710 of
panel 700. The reactants can flow through the microchannels 710 and
exit panel 700 in outlet stream 744 to combine in the product
stream 750. The reactant inlet stream 740 can pass through the
opening 814 of panel 800 without being in contact with the fluids
flowing through the microchannels 810 of panel 800. The product
stream 750 can likewise pass through the opening 816 of panel 800
without being in contact with the fluids flowing through the
microchannels 810 of panel 800. A cooling medium stream 840
supplies an inlet stream 842 to the microchannels 810 of panel 800.
The cooling medium can flow through the microchannels 810 and exit
panel 800 in outlet stream 844 to combine in the cooling medium
exit stream 850. The cooling medium inlet stream 840 can pass
through the opening 718 of panel 700 without being in contact with
the reactants flowing through the microchannels 710 of panel 700.
The cooling medium outlet stream 850 can pass through the opening
720 of panel 700 without being in contact with the reactants
flowing through the microchannels 710 of panel 700. The
microreactor would comprise a plurality of panels that are pressed
together in a manner to enable the reactants and cooling medium
stream to be contained within their respective flow paths and not
in communication with each other. A gasket material, a solder
material, or a brazing material can be used to provide a seal
between the panels.
[0039] Multiple microreactors can be utilized in a facility. In one
embodiment the number of panels can range from 2 to 100. In an
alternate embodiment the number of panels can range from 100 to
3000. In a commercial scale petrochemical plant the number of
panels that can be used can reach hundreds or thousands, with up to
a million channels or more per reactor.
[0040] As can be seen in FIG. 4, in one embodiment the microreactor
can comprise alternating panels, to provide reactant flow through
the microchannels of every other panel, while a different fluid,
such as a cooling medium, can be flowing through the alternate
panels. The different fluid, such as a cooling medium, can be
flowing through the alternate panels in a counter-flow or
co-current flow in relation to the reactant flow. Dissipation of
the exotherm is through the panel material that make up the
microchannel walls containing the reactants and into the cooling
medium that is flowing through the microchannels created by the
adjacent panels. This enables a rapid heat dissipation and the
ability to control the reaction temperature within the microchannel
in a manner that conventional reactors can not achieve.
[0041] The substrate material used for panel construction can act
as a catalyst, or the microchannels may be coated with a catalyst
layer, for example by using a wash coating or thin-film deposition
of a catalyst material within or adjacent to the microchannels. A
catalyst material can also be placed within a recess of the panel
material that is in fluid contact with the reactants flowing
through the microchannels, such as just before the reactants enter
the microchannels.
[0042] Other types of microreactors can be used within the scope of
the present invention. The description of multiple panel
microreactors is not meant to be a limiting example of the
microreactor. Another microreactor that can be used is a Falling
Film microreactor which utilizes a multitude of thin falling films
flowing through a multi-channel reactor.
[0043] Microreactors can be provided by sources such as Atotech
located in Berlin, Germany; Velocys located in Plain City, Ohio,
USA; Microinnova located in Graz, Austria; and Ehrfeld Mikrotechnik
BTS GmbH located in Wendelsheim, Germany. Further, other types or
brands of microreactors can be used in conjunction with the present
invention.
[0044] The foregoing description of certain embodiments of the
present invention have been presented for purposes of illustration
and description. It is not intended to be exhaustive or limit the
invention to the precise form disclosed, and other and further
embodiments of the invention may be devised without departing from
the basic scope thereof. It is intended that the scope of the
invention be defined by the accompanying claims and their
equivalents.
* * * * *