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Патент USA US2406908

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Sept 3» 1945-
P. scHmELER Erm.
Filed Nov; 28, 1942
2 `Sheets-Sheet 1
f‘ ? A'rroRNÉv
V sq». 3, 194e.
P. s'cHlDELER er AL
Filed NOV. _28, 1942
2 Sheets-Sheet 2
PMT/Pf „fcf//ßa4 if? .
Patented Sept. 1946
‘ j_ 2,406,908
UNITED . vs’ra'rss 4iëli‘rizliii' ortica
Pierre Schldeler, New York, and Ralph S. ‘Bich
ax-dson, Scarsdale, N. Y., assigner; to Chemical
ConstructionV Corporation, New York, N. Y., a
>corporation of Delaware
Application November 28, 1942, Serial No. V467,258
z claims. ' (ci. ca_-ass)
, This invention relates to the manufacture of
gas with or without diluents of anydesired type,
formaldehyde by the ' catalytic conversion or .
longitudinally through a relatively narow vertical
oxidation of >methanol vapor andhas as its object 1
the provision of a method and apparatus for >con
trolling the reaction temperature in relatively .
large sizes of burner units. .'I'he method is further .
catalystannulus while passing a stream of tem~ '
perature regulating gas such as `hot or cold air
or hot products of combustion at relatively high
.velocity in heat exchange relation with one or .
both of the vertical surfaces of the annulus, Y
characterized by the provision of means for the
sudden ycooling of the products of the reaction;
-preferably in a direction opposite to that of the
In modern formaldehyde manufacture it is now
ñow of the reaction gas mixture.v The hot gas
the practice to carry out the partial combustion
mix-ture from the catalyst is thenpassed into a
`of methanol inthe presence of catalystscontain
cooler which is preferably constructed as» any in
ing copper, silver or other mild oxidation, tegral part of the converter, and after the pre
catalysts. The reaction between methanol and
liminary cooling step the mixture may-be passed
oxygen may produce not only formaldehyde and
to a recovery system adapted to-absorb the re
water but also carbon oxides, 'water and carbon
maining formaldehyde in‘ water andto recover ~
if the temperature of the reaction is not main
V.for reusel any unconverted methanol if _de
tained suitably. It is customary, therefore, to
control the heat of reaction by circulating through
Our invention will be illustrated in greater de
, the catalyst a methanol-air mixture containing a
tail with~ reference to >the accompanying draw-y
considerable excess 'of methanol vapor and to use'` 20 ings, which show a catalytic converterl employing Ä
' a large >number of converters of relatively small>
the principles thereof. This converter also con
dimensions and low capacity so thaty the heat
tains a number of features of design and con
\ generated by the reaction may- be dissipated from
struction which‘ constitute an important part of.4
the surface of the converters without causing an
,our invention, as will subsequently be explained.
Vundesirable high catalyst temperature.
. The necessity of ei'nploying7 a large number of
Figfl is a diagrammatic elevation of one em
bodiment _ofthe converter of our invention in
which the internal assembly is shown in dotteîi
converters of small size is avoided bythe present
invention, which provides a method and appara-7
tus for,obtaining_close control of the reaction
ì temperatures throughout the entire volume of the
catalyst bed. We have found that the course of
Qn the drawings,
Fig. 251s a section on the une z-.t cf Fig, 1;` and,V
the partial oxidation of methanol -to formalde
v .
Fig. 3 is a vertical section of a part of the as
_hyde in the presence of a catalyst such as copper, » " sembly of Fig. 1 on a slightly larger scale.
silver and the like can Jbe closely controlled at
`the optimum temperature valuesby employing
a catalyst-bed in the form of a ’relatively narrow
annulus through which the reaction gas mixture
Referring to Figs. 1 and 3 the' converter desig
nated generally by >reference numeral I comprises
two vertical concentric shells 2 and 3 which denne
a vertical annulus I containing an annular bed
is passed longitudinally while' applying a tempera
of catalyst of any suitable composition. . The
ture regulating gas to one or both of the outer
outer shell 2 is flanged at its upper and lower
surfaces of the annulus. This method provides 40 edges 6 Áand 1 while the inner shell 3 is extended
both for the application of_ a cooling gas to pre
upwardly beyond the outer shell and terminates
vent undue temperature rise during operation
against’a. cover plate 8 having ansoutlet I9 there
>oi the converter and the application of a heating
in. The outer and inner shells 2 and 3 are rigidly '
gas inthe same manner when starting up the
fastened together by twosets of radial bars 9 asy
converter or at any other _time that additional 45 is more clearly shown in Fig. 2. An annular
heating may, be necessary. By this method it is
screen i0 divided in sections is supported on the'
possible to obtain a large dailyoutput of form
lower of the 4two 'setsof bars 9 and serves to re
aldehyde in a converter> of very large unit .I tain the catalyst while permitting .passage =of the
capacity, thus simplifying the operating condi
oxidation products therethrough.
tions within the plant.> In fact, there is no present 50
limitation to the size of unit which may be con
The process of our invention therefore com
prises the steps of passing a gas mixture contain-
ing methanol and air or other oxygen-containing
The inner shell 3 'containsit removable baille
structure I3 which is separated from the` gases
leaving the catalyst by partition i i and is adapted
to directand maintain a ilow of temperature
regulating gas at relatively high velocity over the
55 inner ysurface of the innershell I in a direction
countercurrent to that of the ilow of the reaction
gases over the catalyst.
The vertical baiiie structure consists essentially
of a vertical tube I4, the lower end of which is
enlarged as at I5 to form with the tube I a rel
atively narrow annular channel I6. The upper
end of the tube I4 is provided with gasìinlet I1
while a series of perforations I8 at its enlarged.l
' cooler 2l. -A valve in the outlet pipe 36 permits
a close control in the back pressure of the con
verter, which is an important factor when `sev
eral converters are operated in parallel, and the
immediate cooling of the hot reacted gases -permits the use of a control valve of ordinary con
struction at this point.
Because of the extremely uniform distribution
of the reaction gas mixture over a single _annular
lower end serve to project streams of cooling gas
of uniform depth it is possible to load
against the inner wall of the annulus formed 10 catalyst
the catalyst heavily with a gas mixture having
by the shell 3 at an area adjacent the lower part
.those ratios of methanol to oxygen or air which
of the catalyst. The temperature regulating gas
are best suited for the maximum yields of form
then passes upwardly through the narrow chan
aldehyde with minimum quantities of byprod
nel I6 and is removed through the outlet I9.
uots. The temperature conditions resulting from
The reaction gas mixture is admitted to the
the use of such mixtures can be adjusted to any
converter through gas-distributing pipe 20 which
desired degree by regulating the quantity and
surrounds a flanged cylindrical shell 2| mounted
temperature of the `air introduced through the
on the upper flange 6 of the outer converter shell
air inlet I1.
3 and which is provided with a series of holes 23
From the foregoing detailed description it is
of suitable diameter for even distribution of the 20 evident that the converter shown on the draw
incoming gas mixture. The upper part of the
ings illustrate in detail the principles of our in
cylindrical shell- 2I is turned inwardly as lat 24
vention. By providing the catalyst in the form
and provided with a packing ring 26 to flt tightly
of a, vertical annulus we obtain a maximum of
against the upper portion of the inner converter
cooling surface consistent with the volume of
shell 3 and form therewith a gas inlet passage in
catalyst necessary for large scale production, and
communication with the catalyst chamber 4.
it should be noted that i‘lns or other cooling ele
In order to preheat the catalyst to reaction
may be attached to the surface of the
vtemperatures in starting up the converter, the
outer converter shell 2 opposite the catalyst 5 if
central bañle structure It is provided with a gas ' additional cooling should prove to be necessary
inlet pipe 26 which terminates in a combustion 30 or desirable. The reaction gas mixture intro
chamber 21 formed by the enlarged lower por
duced through the valve 21 is evenly distributed
tion 'I5 of the pipe I4. Hydrocarbon gas or other
by the orifices 23 in the inlet section 2I of the
fuel entering through the pipe 26 is ignited
converter and passes vertically through the en
through a port (not shown) and burned by air
depth of the- annular catalyst bed, while
admitted through the inlet pipe I1, and the pas
air or other gas under slightly positive pressure
sage of the hot products of
is introduced at I'I' and passes through the open
the chamber 21 and holes I8 and channel I6 . ing I8 and upwardly lthrough the narrow chan
heats the catalyst to the proper temperature.
nel I8 in counterc'urrent heat exchanging rela
Heat may be applied to the catalyst in this man
tion with the reaction gas mixture in the an-y
ner when starting up the converter and may. also 40
be employed whenever the partial combustion of - nular passage 4.
What we claim is:
methanol is not suiiicient to heat the catalyst
1. Apparatus for the manufacture of formal
to the desired operating temperature.
comprising in combination inner and
Improved yields of formaldehyde accompanied
outer concentric shells defining al catalyst an
by considerably smaller quantities of undesirable 45 nulus,
means for passing a reaction gas mixture
` byproducts are obtained when the hot reaction
containing methanol and oxygen vertically
gas mixture from" the catalyst is cooled immedi
through said catalyst annulus, and a vertical tube
ately Vwith a minimum of exposure to hot cata
within said inner- shell having openings at the
lytic surfaces. We therefore provide a cooler 28
end thereof adapted to conduct a ñow of
Vas a part of the catalytic converter. This cooler 50 lower
a temperature regulating gas along the inner
may advantageously be in the form of a tubular
surface of said inner shell adjacent the catalyst
condenser provided with a water-inlet 29, a water
containing area.
outlet 30 and a large number of vertical cooling
2. Apparatus for the manufacture of formal
tubes extending between upper and lower
comprising in combination inner and
headers 32 and 33 and serving to produce a rapid 55 dehyde
outer concentric shells defining a catalyst con
cooling of the _reacted gases. condensate formed
taining annulus, means withiny said inner shell
in the tubes 3l can be removed through pipe 34
for passing a ñow of temperature regulating gas
while the relatively cooled gases are taken oif
the inner surface of said shell opposite the
through outlet pipe 35 and may be passed to any
suitable absorbing apparatus for the separation 00 catalyst-containing annulus, and a cooler located
immediately following said catalyst-containing
of unconverted methanol and recovery of form
annulus ,and adapted for shock cooling of the
aldehyde. In some cases a direct cooler in the
reacted gases.
form of a small packed tower provided with
means for recirculating water or cooled conden
sate over the packing may be lsubstituted for the 65
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