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Патент USA US2412096

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Dec. 3, 1946. ’
i
w. w. oDELL.
PROCESS
^
'2,412,096
TREATING HYDROCARBONS
Filed Jan. 22, 194s
z sheets-sheet 1
er
di/mAf-v2a1n‘me
Dec. 3, 1946.
2,412,096
w. w. oDELL
PROCES§ FOR TREATING HYDROCARBONS
Filed Jan. 22, 1943
2 Sheets-Sheet 2
ma» Qmw
Invenl‘otf
Patented Dec. 3, 1946
UNITED ASTATES >l’lxTElaT ortica
PROÓESS FOR TREATING HYDROCARBONS Y
william w. odell, El Dorado, Ark.; assigner to'
Lion Oil' Company, a corporation of Delaware
Application January 22, 1943, serial No. 473,192
4 claims. (c1. 26o-_666)
2
My invention relates to an apparatus and proc
ess for treating hydrocarbons. In particular it
deals with thermal reactions lwhereby hydrocar
bons of relatively high molecular weight yield
products of relatively low molecular weight and
includes cracking. More specifically the inven-`
.tion has to do with the production of unsaturated
hydrocarbons. and aromatic hydrocarbons from
petroleum products such asnaphthas, kerosene,
gasoline, fractions comprising chiefly a single
hydrocarbon which may be saturated or unsatu
rated. The novelty of the invention relates to
Y means and method whereby particular products
such as oleflns, dioleflns, and certain aromatic
`can -be used eifectively if proper conditions are
provided to remedy the defects enumerated.
For any particular hydrocarbon there is a
definite temperature above whichV it can not> be
conñned in contact with iron for an appreciable
period of time without dissociation or cracking
occurring. In my process the hydrocarbon
’treated is heated in tubesto a temperature some
what below this limit and the final desired boost
in temperature ls caused to' occursuddënly by
directl contact with hotter `gases in a refractory
lined chamber and Ithe mixture is immediately
cooled. In this manner the vapors of the hydro
an excessive evolution of lhydrogen and/or car
carbon being .treated are heated to the desired
or optimum temperature -for -the production of
butadiene. employing controllédprief time of \
bon; it alsol relates- to the economy of materials
_exposure of the vapors to the action of high tem
hydrocarbons can be effectively produced without
‘of construction.
i
`
-
One of the objects of this invention is the pro
duction of butadiene economically. Other objects .
will become .apparent from the disclosures made
herein.
.
_
In attempting to duplicate the results reported
by numerous investigators, who presented results
of laboratory studies, I ñnd lthat because of the
diii'erence in ratios of pipe surface to pipe volume
for different sizes of pipe the results obtained in
perature While the life of the tubes or pipes in '
Ywhich the said vapors are initially heated is con
served. The gases produced in the process are
used in the process but I find that they *must be ‘
used in a definite manner in order to produce the _
Y desired results, which I believe to be new. ‘
A “hook-up” or flow diagram is shown'in Figure
1 which depicts one .procedure for practicing mi* '
small tubes .can not be duplicated in large tubes
invention. Figure 2 shows in' somewhat greater
detail and in elevation', but diagrammatically, lthe
reaction chamber in which the hydrocarbon being
.because of the impossibility of duplicating with
processed attains its maximum, temperature; a ~ v
large tubes the conditions existingwhen cracking’fifi portion of the outer _casing nis cut away to show .
hydrocarbons in small-size tubes. For example,
the interior in section.
the ratio of outer surface area to volume capacity _
of a unit length `of 1A-inch pipe is approximately
40 to 1, whereas .that of a 11/2-inch pipe is ap
In Figure 1, «the furnaces A and B` are- suitably
connected with a supply of fuel and air for heat
ing ythe'coils a and b which coils confine ñowing
proximately 4 to 1.
vaporstreams; the vapors of the hydrocarbon to _ ‘
Therefore the vapors can Y.
not be heated so quickly in -a large tube at tem
peratures which are attainable and which metals
_
be processed pass through coil b and a portion of"
the gas evolved in the `process passes through
coil a. The twostreams of hot aeriform fluids
will withstand, as in very small tubes such as are
commonly> used in the laboratory., I ñnd that, in
meet in reaction chamber I which chamber;`
"the production of butadiene from petroleum 40 functions both as 'a gas mixingand reaction
chamber and a- quenching chamber; the`upperA
naphtha, the optimum amount ,of time that
.portion Iof I is a combustion chamber for incom- _
naphtha vapors are in a 1A-inch pipe at approxi
pletely burning a portion of some of‘ the gas
I mately 725° C. is about one tenth of .a second
evolved in the process. 'I'he quenching iiuid is
whereas with pipe 2 inches in diameter it .takes
the‘
heavy ends or residue from the lower portionv
»much more pipe and the vapors are .thus confined
of fractionator ‘which is pumped through con-._
during the heating stage for a number of seconds
duit 2 to chamber I, any excess of this residue
in order to reach the desired temperature; under '_ above
that required as _a quenching medium is
these conditions considerable cracking occurs with
'discharged through the residue conduit. _ The
the production of large volumes'of hydrogen and 50 reaction products formed in the .reaction cham
methane which must be cooled, compressed and
berr I, along with the vaporized quench fluid,
fractionally separated from the vmore valuable
passes out adjacent the .bottom of I, through '
products._ The amount of this cracking is of the
order of ñfty percent of the naphtha bei!! .proc
conduit 3 'torfractionator _4, whereas lthe fixed
gas and light hydrocarbons pass o_u-t at .the top of essed. I find that'tubes of moderately krge size 55 Iractionator'l through a 'cooler and conduit to
3
accumulatorv4
auaoee
4
main supply of quenching iluid is controlled-by
the -"bottoms” or residue from i
valve 89. An' oiftake 88 with control valve 94`
is provided for use chieñy in starting operations,
that is, hotv products of combustion may be re
another portion being introduced into the naph-.
moved through 33 and 8_4 when the initial heat
. tha conduit I8, and the remainder passing out
ing operation is` under way; valve 94- is normally
through the aromatic distillate conduit. Gases
closed during the operation of the process pro
and vapors removed from the top of accumulator
ducing butadiene. Figure 3 ‘shows in outline an
8 are conducted to compressors 8 in which they
alternate method of discharging and quenching
are compressed toa suitable high pressure com
monly in the neighborhood of 200 pounds per 10 hot vapors from reaction chamber I, 48 being an
accumulator 5 isdivided .into streams, one por
-tion being/used as -a reñux in fractionator 4,
auxiliary quench-fluid, conduit.
square inch gage pressure. the compressed gases
are then cooled and conducted to accumulator 1.
Water is drawn `off from the bottom of accumu
lator 'I substantially as fast as it is collected. The
In the production of butadiene, practising my
invention with equipment substantially as indi
‘ .cated in Figurel 1, and employing naphtha dis
liquid hydrocarbons collecting in accumulator ‘I l5 tilling in the range 190° .to_substantially 400° F., I - >find that there are certain steps which must be
are withdrawn and pumped to a higher pressure
carefully adjusted in order to produce the desired
approximating 300 pounds per square inch gage
results and obtain the maximum yield of buta
pressure and discharged into conduit I9; the
diene. Referring to Figure 1, when the fresh
vapors and gases discharged fromV the top of
feed, namely petroleum naphtha, contains an ap
accumulator 'I pass into absorber 8 from which
preclable- amount o'f sulphur and the sulphur is
the high-boiling fraction is withdrawn“ at the
not removed before entering the system, sulphur
bottom and pumped into conduit I9 with the
gases are formed which are carried into the sys- `
high-boiling fraction from accumulator 1. 'I'he
tem chiefiy'through conduit I 'I and conduit I8,
lean fixed gases pass out of accumulator 8 through
conduit 20 and are used for fuel purposes. Fresh 25 vaporizer 25, and coil b, although some sulphur
gases are carried into the system through the gas
feed stock. for example petroleum naphtha, is
conduits I2 and I8. When such a naphtha is used
caused 'to pass through conduit I5 to sulphur
the quenching fluid in fractionator 4 becomes
removal apparatus I8 from which it is discharged
acid and has a- deleterious effect on results which
into conduit 22 pumped to a suitable pressure,
commonly about 200 pounds per square inch gage 30 seem to be caused by the tendency of the acids
formed from the sulphur gases to promote poly
pressure, and discharged into the upper portion
meri'zation. The eil'ect of this -is manifest by a
of absorber 8 functioning therein as an absorber
decrease in the yi‘eld of recoverable butadiene,
oil. The ñuids in conduit I9 are passed through
chamberÀ I9 whereinj they are heated andthe . gumming‘of the valves in compressor. 8, and the
heated fluid is conducted to the depropanizer 28. 35 deposition of solid matter of a carbonaceous
nature in the lower portion of reaction chamber
The vapors from the top of 23 are cooled and
- conducted into accumulator II, the high-boiling
- I.
For the purpose of eliminating these tenden- '
v.cies it is necessary. to treat the supply of naphtha
fraction from the accumulator II is discharged
used in this process for the removal of sulphur '
back into the depropanizer as a reiiuxing medium
whereas the gaseous fraction is discharged at the 40 compounds; sulphur removing equipment `is indi
cated at I8.
` `top oi' accumulator II into conduit I2`which con
ducts the major portion, approximately ninety
I ilnd that when the air and gas .
supplied to the combustion chamber of reaction
chamber I are not carefully mixed and in pro
per cent of itäto the pipe coil a in furnace A,
portions whereby the air is less than sufficient
the remaining ten per "cent being conducted
through conduit I8 and gas-air mixing chamber 45 for the complete combustion of the gasthere
l 2I wherein it is mixed with somewhat less air
. is a tendency for nitric oxide to form as one of
the products of combustion; when this condition
exists the nitric oxide in the presence of moisture
and some oxygen forms acid which is> not only'`
catalytic -to the formation of polymers and gummy
’matter from unsaturated- hydrocarbons but it also-
than enough for its complete combustion; the
gas-air mixture from 2I is discharged into the
combustion chamber of I. The high-boiling frac-`
tion from the depropanizer 28v discharging from 50
the bottom thereof is cooled and passed into the
debutanizer 24. from which the vapor fraction is
removed at substantially the top thereof, cooled,
and conducted to accumulator I4. A portion of
the condensate accumulating in I4 is recirculated 55
as a refluxing medium to the upper portion of
debutanizer 34, the remainder being discharged
as a butadiene cut In this example, from which
butadiene is recovered. IThe high-boiling frac
-
combines directly with unsaturated hydrocar
bons. Here again~gummy matter deposits on the
valves in’compressor 8 in operation. In order to
avoid this condition I employ less air «than is re
quired for the complete combustion of .thegas
in the gas-air mixture supplied to mixing cham
ber 2| and t0 the reaction chamber I; under
these conditions there is no detectable amount of
tion from the lower portion of the debutanizer is '60 nitric oxide in the products of combustion. The
1 discharged into conduit I‘I> from which a portion
' amount of gas recirculated through conduit Il
is recirculated. after'cooling. to the upper portion
of absorber 8. the remainder passing into conduit
I8 from which it is discharged into »vaporizer 25;v
and employed for combustion in the combustion
chamber of reaction chamber I is a ratherl dell-_
nite amountrelative tothe amount _ofnaphtha
' the vapors from 2B are. conducted directly into 65 processed. Ii' an excess is used a large amountv
-' of gaseous products must be cooled and com
coil >b of furnace B.
,
pressed, which in turn calls for more equipment
In Figures 2 and 3 the same system of number
including compressors, and the yield of butadiene
decreases. If too little gas is burned in the com
lows: checker brick contact material for promot
ing combustion of the gas supplied at'the top of 70 bustion chamber of I,-_t.he optimum temperature
reaction chamber I is shown at 21; bustlepipes
is not- attained in the reaction zone of chamber I
and again thev butadiene recovery is decreased.
28 and 29 are employed for admitting` the quench
Although` this optimum amount -oi! gas to be
ing fluid-- and they are soconnected that either
` ` ing is employed with"additional numbers as fol
1 one can be employed alone or both used together
burned is not exactly the same for all raw mate- 1
by _the proper control of valves 3| and 82; the 75 rials processed, I‘iìnd that in treating naphtha _
anaoao
5
6
as in this example the amount of gas-burned
muy and causing `the not products of combus
in the combustion chamber of I for obtaining
'the optimum yield of butadiene is that amount
which is equivalent to less than ten per cent of
the heat of‘combustion of said naphtha; I have
tion to pass into the swirling mixing fluids. Pro- '
vision is made for completing the combustion
-reactions in the upper portion of reaction cham
ber I before the products of combustion contact
been able to obtain said results with an amount
the fluids from coils a and b.
of gas equivalent in heating value to approxi
mately 1.5 per cent ofthe heat of combustion
'may be íemployed for this purpose although I
ñnd that a _checker-brick system is satisfactory;
of the naphtha.
checker bricks are shown> at 2l in Figure 2.
.
'
Natural gas or other combustible gas which
is substantially lfree from sulphur compounds can
be used as the fuel gas supplied to mixing cham
ber 2I of-Figure 1, b'ut it should not contain a
large percentage of inert matter. Gas contain
Various means
In the quenching operation conducted by in
troducing a. .quenching fluid` into reaction cham
ber I as through valves 30, 3| and 32 of Figure 2,
it is only necessary-that fluid‘ flowing through
reaction chamber I containing the reaction prodi
ing hydrogen is particularly satisfactory because
ucts be cooled to a temperature below about 600°
F. It is important that the quenching fluid be
of the formation of water vapor by its combus
non-acid as regards mineral acids or certain acids
tion. It will be noted that in using gas from ac
cumulator II through conduits I2 and Il as fuel , known to promote polymerization of unsaturated
hydrocarbons; phenolic acids are not of this type.
gas supplied to mixing chamber 2| said fuel gas
is substantially free from nitrogen, carbon mon 20 It is »found that the high-boiling residue fromv
' fractionator l of Figure 1 is a satisfactory
oxide, and carbon dioxide which latter gases are
quenching fluid particularly when it is main
removed from the system through offtake 20
tained in a neutral or alkaline condition, namely
from absorber 8. Steam maybe introduced along
when deleterious acidic components of said resi
with the fuel gas admitted to mixing chamber 2_I
but I find that it is more satisfactory to intro 25 due are maintained at a minimum. Under cer
duce this steam in the recycle gas supplied to
tain conditions it develops that the addition ofv
neutralizing agents to the recirculated quenching
pipe coil a for two reasons, namely, to avoid the
fluid is beneficial; such 'neutralizing agents in
delayed combustion effect which steam causes
clude ammonia, amino compounds, and certain
.when mixed directly with fuel gas, and to mini
mize4 the -tendency of carbon to form when the 30 nitrogen bases. When compounds of calcium,
recycle gas is heated in coil a. For a given unit
capacity reaction chamber I is designed to give
magnesium, sodium- or similar compounds are
used as acid neutralizing agents the products of
the optimum time of contact of the hot products
neutralization as well as any excess of the neu
tralizing agent should be -removed from the
from coils a and b, however, final adjustment of 35 quenching fluid before said fluid is introduced
into reaction chamber I-of the figures. It is im
said time of contact can be made by introduc
of combustion with the hot gases and vapors '
ing the quenching fluid into the reaction cham
portant to note that the use of the high-.boiling
ber I at'selected levels; the reasons for this are
productsl from fractional-,or 4 as quenching me
dium is not a requirement of this invention, other
high-boiling liquid can beused as Well. It is
perhaps obvious. Means for introducing the
quenching fluid into chamber I of the figures are
shown at two separate levels but of course ar
rangements could readily be made to provide a
greater degree of regulation by the'use of inlet
ports- for the quenching fluid at a greater num- l
advantageous to ñrst partially cool the hot stream
by vaporizing` water therein before quenching
with said high-boiling liquid to avoid cracking.
In the production of butadiene as outlined in
ber of levels. When operating with petroleum
the foregoing the yieldV of butadiene per unit of
naphtha as the raw material and promoting re
raw material usedl in the process is appreciably
increased when butane is introduced- as one of
actions favorable for the production of butadiene
the time of contact of the hot gases with the
naphtha vapors in reaction chamber I prior to~
vthe reactants. In processing petroleum naphtha
as outlined good results are obtained, from the
quenching is approximately one-tenth of one sec 50 simultaneous use of `butane, when said butane is
introduced along with the recycle gas into vcoil
ond at the high temperature of about 1350" F.;
the lower the temperature the greater the time ` a. The yield of butadiene, when the lbutane is
employed in this manner, is higher than when
of contact required, Within the temperature range the same amount of butane is introduced along
at which butadiene is formed. When the flow of
gases, vapors, and air to reaction chamberl I are 55 with the naphtha vapor into coil l?. This is im
portant and I believe a novel feature of my in.
adjusted and operation is under way the fine
vention. The butane used with the recycle gas
adjustment of temperature in the mixing zone of
may be from any source but can conveniently lbe
reaction chamber I is most advantageously ob-l
obtained after removing the butadiene from the
tained by adjustment of the valvel in the-air sup-v 1'
ply conduit to mixing chamber 2|. An effective 00 butadiene cut, 'which cut is recovered as one of '
the valuable products of reaction.
Way of accomplishing this result is to employ
It is desirable in the operation of this invention
an auxiliary supply of air to mixing chamber 2I
to heat the gases passing through coil a in fur
with a thermally'operated valve which opens v
nace A of Figure 1_ to as high a temperature as
and closes as the temperature indicated by a
'pyrometen the thermocouple of which is located 65 practicable; one is'not only limited as to the tem
perature attainable, vby the compositionof the
in'the gas vapor mixing zone of reaction cham
tubes employed in the construction of coil a, but
ber I,'decreases or increases respectively. The
by the properties of the gases passing through
coil a. Cracking of the gases with the formation
shown in the figures for the purpose of simplicity.
It is essential in promoting these reactions at 70 of carbon in coil a is to be avoided or atleast
elevated temperature-that, the gases and vapors
reduced to a minimum, which minimum should
represent a very small per cent of the gas passed.
introduced into reaction chamber I of the figures
Accordingly it is advantageous to use somev steam
be thoroughly mixed therein before 'the mixture
is quenched; this isaccomplished'by introducing
with the recycle gas flowing to coil a. The volume
the gas and vapors from coils a and b tangen 76 of steam employed preferably should not be
. mechanical details of this operation are not
, I '
2,412,098
greater than the volume of gases passed there
withl through coil a in the production of buta- _
diene as outlined. The steam thus used reduces
the tendency for carbon to form and permits the
use of somewhat higher temperatures in coil a
lthan would otherwise be found satisfactory.
Burning the fuel gas used, with insufiicient air
‘carbons form with the minimum amount of di
oleñns; (d) the production of alcohols, glycols.
aldehydes and certain other oxidation products
are dependent upon arrested combustion and
therefore the variables should be so adjusted that
the desired amount of oxidation ìcan occur by»
contacting the reactant hydrocarbon with >suiii
for complete combustion of said gas, produces
cient oxygen in proper dilution at the tempera
ture and time of contact found to be favorable.
sufficient hydrogen, which, in-contact with the
hot refractory 21, reduces oxides of nitrogen to 10
It .is- possible to make styrene, indene, cyclo
pentadiene and other products of similar nature
lwater and nitrogen.
I
In the foregoing the description has been Ñdi
practicing this linvention by adjusting the oper
rected largely, by way of example, to the produc
ating variables and supplying the proper mate
tion of butadiene, which material is adapted for
rial for processing. These named materials are
use in >making rubber-like products and other
produced in optimum amounts when all> of the
materials, but it is intended that the scope ofthe
aromatic distillate is returned to the reaction
invention be broader than this. For example, it
chamber I of Figure 1, through coil b except that
is possible to produce, by changes in operating
used for refluxing in fractionator I, using the
procedure, temperature, raw materials, arid time
- fresh charge naphtha as “make up” to keep the
of contact of the fluids, such materials as naph 20 process going. They are recovered from locations
in the system compatible with their boiling points
thenic acids, aldehydes, alcohols, acetylene, and
particular unsaturated and aromatic hydrocar
and the temperature and pressure conditions pre- \
bons. Again it is possible to re-form hydrocar
vailing.
. bon gases byy reaction of said hydrocarbon gases
Before defining my claims I call attention to
with steam forming carbon monoxide and hydro 25 another particular product which can be- made '
gen. In the latter case a longer time of contact
practicing this invention, in a number of dif
ferent grades accordingly as the temperatures
is desired than in making butadiene, hence the '
and other operating variables are altered,`namely
volume of the chamber in which the re-forming
carbon black. Most of the operations alluded to
reactions ,occur should be larger than is _required
in making butadiene. Naphthenic acids are prod 30 in the foregoing are carried out most advan
~tageously by employing superatmospheric pres-v
ucts of oxidation of hydrocarbons and their` pro
sure in the reaction chamber I of the figures
duction depends upon the control of the tem
perature, the amount of oxygen contacting the‘ ' and this pressure is of the order of fifteen to
seventy pounds -gage in most cases. In the pro
vapors of said hydrocarbons and the time the
mixture is maintained at an elevated tempera 35 duction of carbon black the operation maybe
ture. Referring to Figure 2, in the production of _ variedl appreciably fromy the above described pro
cedure within the confines of my invention. For
the naphthenic acids it is not necessary to pro
example, combustion of a fuel gas is promoted in
mote all of the combustion reactions in the top
the upper portion of reaction chamber I by in
lportion of reaction chamber l but on the con
trary, it is preferable to promote some of the com-- 40 troducing said fuel gas and air for its combustion I
through mixing chamber 2i of Figure 1. Gases,
bustion in a lower zone; this is particularly true
vapors, ora gas adapted to yield carbon black
when the major reactanty hydrocarbons are
pyrogenetically, after being preheated in the
passed through reaction coils a and b shown in
heating coils a and b,îare introduced into reac
Figure 1. In this case'it is preferable to pass
tion chamber I and into the stream of hot prod
more of the recycle gas through I3 and mixing
ucts of combustion passingtherethrough. Many
chamber 2| ~of Figure 1 than is used in this man
of the advantages of maintaining high pressures
ner in the vproduction of butadiene and somewhat
more steam can be used in coil _a. ,'Lower tem
peratures are employed in both coils a and b when
- vproducing the naphthenic acids than when pro` ducing butadiene. Without elaborating exten
' .\ `sively as to the particular products that can be
do not prevail inthe production of carbon -black -
particularly when the hydrocarbon reactants are
Y 50 converted very largely into their elements hy
made by control of .the numerous variables it
drogen and carbon. In this case the hydrocar
bon admitted through the ’said coils a and b may -
vbe expanded into reaction chamber I and the
seem sufficient to state that the products ' >resultant effluent gas stream removed through
are numerous even employing a single raw ma 65 oiïtake conduit 3 may be at lower pressure than '
normally prevails in the production of butadiene.
terial plus the recycle gas. - By varying the nature
f. lwould
of the _raw materials used a wide variety of valu
able products are obtainable in employing this
invention. The optimum temperature to be em
ployed for any particular product can readily be 00
determined by experiment. The relative sizes of.
the combustion chamber and the mixing zone of ’
reaction chamber'l of Figure 1 vary according
to the products sought. For the guidance oflone
The quenching fluid, making carbon, is prefer
ably water and the fractionator l of Figure 1
4is in this case a carbon separator such as an
electric precipitator which is operated at a tem-'
perature and pressure at which water is in the
vapor phase. The characteristics of carbon pro
duced in :this manner vary appreciably according -
to: the temperature'in the reaction chamber;
skilled in the art in practicing this invention it- ' relative amounts of hydrocarbon, products of
combustion, and recycle gas; the duration of the
can be stated in general that (a) high’tempera
elevated‘temperature in reaction‘chamber I prior
~matic compounds: (b) high temperatures of the
reactions ar'e promoted in the reaction chamber `
.reactants in the said mixing zone with a very
I; the amount of steam employed in the recycle
gas; and according tothe adjustment of othervariables. -Accordingly the procedure of opera
tion for producing carbon black can best be vde
briei'~ time of contact favorthe production of un'
l ,
period of. time the reactant gases are at the
' tures in the mixingzone of reaction chamber I
and an appreciable time of contactl of the re->
actants in this zone favor the production of aro
saturated hydrocarbons; (c) employing lower ,
temperatures in the mixing zone and an appre- _
cable time of contact in said zone oien'n hydro 75
to quenching; the pressure under which the
termined by experiment. changing the operating
Veficaces
variables and selecting the carbon best -adapted
for a particular use.
-
'
I Ífind that, under certain conditions, when
operating with temperatures in the hot zone or .
reaction zone of reaction chamber I of Figure 1 y
bordering on the upper limit for producing reac
tion products, the recirculation of the heavy
residue from fractionator I as a quenching me
10
- ucts of combustion are mixed with the’heated
vapors of the propylene stream in a mixing zone
`adjacent the catalyst bed and the united stream
- at a temperature approximating 1325° to 1350° F.
is immediately passed through the said catalyst
-bed at a'rather high velocity and immediately
quenched. The time that'any given unit of the
united stream is incontact with the catalyst bed
is very brief, in fact, the` propylene should not
dium is not satisfactory. Under these condi- tions the formation and deposition of carbon 10 be maintained at a high temperature for more
occurs in the lower portion of chamber I and , than a fraction of a second in order to obtain
optimum results. 'I'he gaseous products of re
in the oiftake therefrom for the stream of reac
tion products. 'When' attempting vto cool with ¿ ' action are removed from chamber I 'in the united
A suitable catalyst
for' promoting this reaction is copper, brass, and
water, using the heat of vaporization of water
- stream Áas outlined above.
as means of absorbing the heat of the hot gaseous
stream, the volume of the vapor of the evap
orated water is so great that fractionator l must
' certain metals of group 6 of the periodic table.
be relatively, extremely large. This diñiculty, I
iind, can be overcome .by dividing the stream of
hot gaseous reaction products, cooling one por
tion completely, that is, to a temperaturerof about
150° F. by contact with water, immediately con
tacting the cooled gas, flowing as a stream, with
the uncooled portion thereof, the division of the
hot gas stream being such that the final partly
cooled mixture carries sufficient heat for satis
factory operation of the fractionator 4. Actually
satisfactory results are obtained. when the divi
sion is in two substantially equal portions. Al
though this procedure is no_t presented in detail
in the drawings, it is shown in Figure 2 that a
portion of the cooled‘y gas can be withdrawn from
lA unique eñect is attained when employing a
lcatalyst in the manner outlined herein. The y
major portion of the heat required in the process
is supplied external of the reaction chamber,
namely, it is applied by heating the reactant fluids
in separate furnaces while confined in pipe coils;
the- reactants are brought into the reaction cham
ber adjacent- the catalyst before they are ñnally
heated to that temperature which is optimum for
25
catalytic reaction to occur by causing them to mix
with a hotter gas just as they enter the bed of
catalyst. In this manner I find it is possible to
eliminate >losses due to prolonged heating at ele
30 vated temperatures and to obtain the maximum
yields of valuable reaction products includingl
butadiene. In this manner a minimum amount
of combustion products are required in the reac
tion chamber and the catalyst bed is maintained
hot gaseous reaction products to be discharged 35 at an elevated temperature by virtue of the sen'
sible heat of the united streams of hot gases pass
from chamber I through offtake 31, and immedi-"ing therethrough. The use lof metal catalysts,
ately mixed with th`e cooled gas from conduit 38.
lpreferably in the form of spheres, is particularly
In this procedure valve 40 is open and the mix
_advantageous in practicing this invention because,
ture of cooled and hot gases is conducted to the
fractionator 4 in the usual manner.`
40 being good heat conductors, they help minimize
local overheating and provide a more uniform
It has long been recognized that catalysts can v
the lower oiftake 3 y¿by closing valve 36, partly
opening valve 35, and thus causing some o_f-the
be effectively úsled in promoting chemical reac
tions, and the applicant finds that catalysts can
temperature in the catalyst bed.
-
Somewhat summarily but for the purpose of
y clearness the major steps of the operation of this
also „be effectively used in employing his inven
tion. Many high temperature reactions occur 45 invention are brieñy presented as follows: Refer
substantially as well or as completely without
„ ring to Figure 1, employing petroleum naphtha as
catalysts as with them, although this is not
strictly true when maintaining the reactants at
high temperatures for very brief periods of time.
.the initial raw material, the said naphtha is
treated for the removal of sulphur compounds in
Accordingly, it is advantageous, under certain
sets of conditions, to employ suitable catalysts in
introduced into the system preferably at the upper 'A
portion of absorber 8 wherein it is used as an ab
the reaction zone of reaction chamber I of Figure
sorber oil, ultimately reaching the vapnrizer 25 1
sulphur removing apparatus I6, after which it is
through conduit I8; the vapors from vaporizer 25
preferably preheated are conducted to coil b in
operation comprises passing the hot reactant
iiuids into the reaction chamber I undercondi 55 furnace B wherein they are heated to a tempera
ture below 1300" F. and preferably not over 1280°
tions adapted to cause them to immediately mix
F., discharging from said coil b into reaction
with the freshly generated hot VproductsA of com
chamber .I at a temperature preferably below
bustion also produced in said chamber I and
1300" F. Simultaneously gaseous products from
conducting the united streams directly into a bed
of contact material, which material is preferably ' 60 the depropanizver, which gases are substantially
free from carbon dioxide, carbon monoxide, hy
a catalyst adapted to catalyze the reaction being
drogen an'd nitrogen, are conducted as recycle gas
promoted and quenching the said united stream
into coil a wherein they are heated as a. stream to
immediately after contact with said catalyst in
a temperature above' 1300° F., the temperature
said reaction chamber Í I.
„
being that at which the gases can most economi
For the purpose of avoiding vagueness, an
2. In other words, employing a catalyst, the
05
example of the procedure, which, it is believed, , , cally be heated without destroying valuable com
ponents thereof; employing a one inch pipe as coil
comes stri'ctly within theA confines of this inven
a the temperature of the gas leaving coil b can be
` tion, is the productionvof butadiene from unsatu
as high as 1450° F. but with larger tubes such as a
'rated hydrocarbons such as propylene. Refer
ring to Figure 2 a stream of reactant ñuid com 70 two inch tube the temperature of the heated gases
leaving coil b should preferably be at about 1400°
_prising propylene is introduced into reaction
F. The gas stream discharged from coil `a passes
chamber I after first being heated in coil a to
directly into reaction chamber I wherein it im
a ,temperature below 1300o F. Combustible fluid
mediately mixes with the hot vapors discharged A
is burned in the upper portion of reaction cham
ber ylas outlined above and the hot gaseous prod 75 therein from coil -b. Simultaneously combustible
2,412,096
.
11
I
gas is‘introduced into the 'upper portion of the
l2
4
`
, reaction chamber I and caused to burn therein
said liquid passes on in the liquid phase with the
gas stream, as from reaction chamber I_to irac
with insuiñcient air for its complete combustion
tionator 4, the design _and arrangement oi' equip
and the products oi' combustion are immediately
discharged as a stream into the mixing gas and
vapors from coils a and b. VThe amount of gas
burnedinthe upper portion of reaction chamber
ment should obviously be such that conduit l for
conducting the quenched gas along with anv'liq
uid quenching iluid should preferably drain from
I to 4 in order to prevent accumulation of liquid
I being preferably that amount only which will
in I. When quenching gases at high tempera
give to the united stream of gas and vapors, after
ture, about 1200° F..and higher, I find it is unique
mixing, a temperature above 1350“ F., the opti 10 1y advantageous to use water for the first stage
mum temperature varying with the product
of quenching,_cooling`to -a degreewhereby the
sought and the raw material employed. Em
high-boiling` hydrocarbons used for the subse
ploying the said petroleum naphtha as the' initial
quent stage of cooling is not appreciably cracked
raw material and making butadiene, the optimum
in said stage. This is accomplished, referring to
temperature of the united stream in reaction 15 Figure 2*, by opening valve 45 in water pipe 44,
chamber I appears to be within the range 1350“ to
for the ñrst stage of cooling, and opening valves
30 and 3| for .the hydrocarbon used'in the sec
1450°'F. with a time of contact prior to quenching
ond stage of cooling, in which stage the gas
of about one-tenth of one second, whereas with
somewhat higher temperatures the time of con
stream is cooled from about 1000° F. to less than
,
'
tact, that is, the duration of time at which the 20 600° F.
united stream is retained at the high tempera
Having described my invention so that one
skilled in the art can practice it employing hydro
ture prior to quenching, must be appreciably lower.
carbons subject to thermal reaction as raw mate
' One-hundredth of one secondis suiñcient time of
contact at a temperature of the order of 1500° F.
'I'he hot gas stream containing the reaction prod
ucts are-- immediately quenched in the said reac
tion chamber I with the suitable quenching fluid
which may comprise the' heavy fraction recovered
from the bottom of fractionator -4. The stream
containing the reaction products is conducted to
fractionator 4 and on through a separatory sys
tem wherein the valuable components thereof can
rial, I claim:
25
`
1. A substantially
continuous process for pro- l
.
moting thermal vapor phase, hydrocarbon re
actions in an elongated upright reaction cham-
ber containing solid contact material, comprising,
passing at least one aeriform stream comprising
a preheated hydrocarbon in the vapor phase suit
able "for thermal reaction, at an elevated tem
perature, into a reaction zone intermediate the
be removed and recovered. The products which
may be recovered include, besides butadiene, in
ends of said reaction chamber, simultaneously in
troducing into another portion of said reaction
this example, benzol, vtoluol, xylol,'buty1ene and y35 chamber another stream comprising a mixture
" other hydrocarbon compounds. Separate recov-l
of `a combustible iiuid and oxygen in which the
ery equipment is’not shown in the Figure 1 be
cause invention is not claimed thereon, but it
.oxygen is-somewhat less than enough for com- «
seems desirable to point out that aromatic com
moting combustion in the latter stream, causing f
the latter stream comprising burning nuid to '
pounds are produced in this system and that they
_ are separately or collectively recoverable and that
plete combustion of said combustible` fluid, .pro
pass through a porous bed of hot refractory solids '
their recirculation into the system as through coil
in said chamber wherein combustion reactions»
b of `furnace B is not necessary to the successful
are substantially completed, causing the stream .
operation of this invention. All of the gases and
of hot freshly generated products of combustion _
vapors introduced into reaction chamber I dur ¿5to mix intimately with the nrst named stream
ing the’opèration of the process are preferably>
while at an elevated temperature in said 'reac
admitted under superatmospheric pressurefcom
tion zone whereby at least-one valuable reaction
monly of the order of fifteen yto seventy pounds
product is formed, immediately after a briei' re- .
gage pressure. A catalyst maybe used for pro
action period quenching the resultant nstream to
moting the thermal reaction in reaction chamber
I;1in many cases this is advantageous and infl,50 minimize polymerization, recovering from the
quenched stream saidyalua-ble-product and re
.others it is not required; acatalyst appears to be
circulating
at least a portion of the other com
more eil‘ective in the lower temperature range at.
bustible reaction products substantially free from
which operations may be conducted than in the
nitrogen, carbon- monoxide and carbon dioxide
-upper ` temperature range._ The temperature of
the catalyst bed 42 of Figure 2 is maintained by 55 into ‘said reaction chamber _as a part'of one ofi
said streams..
virtue of the sensible heat of the fluid stream ilow
2. A substantiallycontinuous process i’or' pro
ing through it; the mean temperature of the bed
is usuallysomewhat lower than that of the fresh- ` moting thermal vapor phase, _hydrocarbon reac-tions in an elongated upright reaction chamber,
1y mixed, hot’gases in the united stream. It is
understood that the use of a catalyst can be
omitted as a part of the process without aiïecting
the invention. Under certain -_sets- o_f conditions,
30 comprising, passing substantially-~ continuously a
stream initially containing reactant vapor phase
hydrocarbons tangentiallyl into an intermediate-
particularly when there is an appreciable amount- . reaction zone of said chamber while they are at
an eleva ed temperature thereby causing them to
oi' coke or carbon formed and deposited in the
catalyst mass it is preferable to either eliminate -65 -mix in s id zone by a whirling motionl'simulta
_ the catalyst or use a. catalyst mass which provides A
neously introducing into an upper adjacent com-ÃV
, bustion zone of said'chamber substantially con
a. less tortuous p ath than a poured bed of small- ‘
I tinuously a second stream initially comprising a
size solids.
mixture of- combustible gas and air, initiating '
Referring to Figure 1, it has been pointed out 70 combustion
in> said second stream and passing it _
that a quenching iluid can be used, employing
downwardly into a porous bed of hot contact
this invention, whereby the fluid is completely _ solids conilned in said chamber thereby promot
vaporized or only partly vaporized.
'
en the
_ing completion of combustion reactions, vimme
complete heat of vaporization of the que ch liq
diately passing the stream of hot combustion
uid is not utilized in the quenching operation and 75 products after combustion reactions are substan
Aamante
y
~
14
13
tially completed downwardly into the hot whirl
ing hydrocarbon stream in said zone and causing
a combined mixed stream to form in said zone
having a higher temperature `than the iirst named
stream but being at least at vreaction temperature,
immediately passing the combined stream sub
stantially continuously into intimate Contact with
refractory contact material in said reaction zone
forl a period of time of the order of 0.01 to 1.0
second causing reaction to occur therein forming
at least one valuable reaction'product in said
combined stream, immediately quenching said
stream suñicient to retard undue polymerization
of said product and recovering said’ product
therefrom, meanwhile maintaining said refrac
tory contact material at substantially reaction `
temperature by the sensible heat of the said com
bined stream.
3. A substantially continuous process for pro-v "
moting thermal vapor phase hydrocarbon re
actions and'forming valuable reaction products
in an upright reaction chamber, comprising, pass
ing substantially continuously a preheated
stream initially containing a reactant vapor
phase hydrocarbon tangentially into an inter
mediate reaction zone of said chamber, simulta- '
neously similarly introducing into said zone sub-1
stantially continuously a second preheated
stream initially containing a gaseousl hydrocar
bon of lower molecular weight than the aforesaid
hydrocarbon along with steam thereby causing
the streams to mix in said zone by 'a whirling mo
tion, simultaneously introducing into an adjacent
along with allow molecular weight hydrocarbon q
gas, immediately quenching the latter stream in
a lower zone of said chamber to retard polymer#
ization of the reaction products, removing the
quenched stream from'the chamber, recovering
said products from the quenched stream separate
from said low molecular weight hydrocarbon and
returning at least a portion of the said low mo
lecular Weight hydrocarbon substantially free
from nitrogen, carbon monoxide and carbon .
dioxide to said reaction zoneas a part of said `sec- '
ond stream'.
4. A substantially continuous processA for pro
moting thermal vapor phase hydrocarbon reac
tions in an upright reaction chamber, which proc
ess comprises continuously passing a stream con- I
taining a preheated hydrocarbon vapor from an
external source into a mixing zone located inter- 4
mediate the ends of the chamber, continuously
introducing into an upper portion of said cham
ber another stream comprising a mixture of a
combustible iiuid and oxygen, the amount of
oxygen being insu?iicient to completely oxidize
said. combustible material, promoting combustion
in the latter stream While passingl said stream
through a porous bed of hot refractory solids in
said chamber until substantially all the oxygen
has reacted with combustible materials, then
.passing said hot combustion- products directly
into the/mixing zone and causing the two streams
of hot gases to commingle therein, passing the
combined stream of hot gases into a reaction zone
containing solid contact material located just
upper combustion zone of said chamber substan
below the mixing zone and reacting the gases
tially continuously a stream initially containing , Ll whereby at least one valuable reaction product is
premixed combustible gas and air, initiating com
bustion in said stream and passing'it directly into
produced, continually passing -the composite
stream containing the reaction product down
wardly through .the chamber from the reaction
confined in said chamber thereby promoting
zone and immediately after leaving the reaction
completion of combustion reactions between said 40 zone quenching said composite‘stream by ad'
gas and air therein, immediately ‘passing the
mitting a cooling fluid into direct contact with
stream ofhot combustion products from lthe up
said stream, then removing the quenched stream
per combustion zone into the whirling mixing ' from the chamber, recovering the valuable re
streams in the intermediate reaction zone there
action product from the quenched stream, sepa
by heating them to a higher temperature forming
rating from the stream a quantity of combustible
a combined stream, immediately passing the com
iluid substantially free from nitrogen, carbon
bined stream substantially continuously into con
monoxide and carbon dioxide and recirculating
and through a porous bed of hot contact material
tact with a porous bed of hot catalyst in said zone
for a period of time of the order of 0.01 to 1.0 sec
ond causing said thermal -reactions to occur in .
said stream substantially while in contact with
said hot catalyst forming said reaction products
at least a portion of said combustible fluid free
from nitrogen, carbon monoxide and carbon di
oxide with the hydrocarbon vapor introduced into
the reaction zone.
'
WILLIAM W. ODELL.
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