close

Вход

Забыли?

вход по аккаунту

?

Патент USA US3084028

код для вставки
3,084,023
United States Patent 0 "
Patented Apr. 2, 1963
2
1
should be present in the range of about 0.001 to 2 per
cent by weight of the catalyst metal and support, where a
3,084,023
TREATMENT OF GASES
Holger C. Andersen, Morristown, Philip L. Romeo, Sr.,
(lid Bridge, and Duane R. Steele, Newark, NJ, as
signors, by mesne assignments, to Engelhard Industries,
Inc, Newark, N..l., a corporation of Delaware
No Drawing. Filed Mar. 11, 1960, Ser. No. 14,176
2 Claims. (Cl. 23-6)
support is employed, preferably about 0.002 to 1 percent
by weight of the catalyst metal and support. The sup—
port for the catalyst metal may be in the form of pellets,
powder or granules, and preferably comprises activated
alumina. The supported catalyst may be prepared in any
suitable manner, i.e. by treating the carrier or support with
a solution of a suitable metal compound, and then re
This invention relates to the preferential removal of
ducing the metal compound to metal. Nickel catalyst
impurities from a gaseous admixture of hydrogen and 10 may, because of the lower cost, contain from 1 to 80
carbon monoxide, without substantial loss of either hy
percent nickel.
drogen or carbon monoxide; more particularly, the inven
The reaction temperature required for efficient puri?ca
tion relates to the removal of objectionable impurities
tion varies with. conditions, especially the sulfur content of
such as acetylenics, dienes, both in linear and ring con
the stream, but is typically in the range of about 100 to
?guration of carbon atoms, nitrogen oxides, and sulfur 15 , 250° C., and it is necessary that any oxygen present he
containing compounds such as COS and CS2.
less than the stoichiometric quantity required for oxida
In the process of the present invention, the objection-'
tion of the carbon monoxide to carbon dioxide, preferably
able impurities are removed, but no carbon monoxide or
much less than the stoichiometric quantity required, in
hydrogen is removed, except inadvertently. For example,
order to avoid loss of valuable carbon monoxide.
if oxygen is present, some carbon dioxide or Water may 20
The reaction pressure may be in the range of atmos
be formed under the reaction conditions, but such water
and carbon dioxide products are generally harmless and, if
pheric to about 300 p.s.i.g., or higher, and the space
velocity may be in the range of about 1000 to 20,000
desired, may be readily removed. If oxygen is present,
standard volumes of gas per volume of catalyst per hour,
a low concentration is required, i.e. less oxygen, prefer
preferably 4,000 to 15,000 standard volumes per volume,
ably much less, than the stoichiometric quantity required 25 these
space velocities being measured at 32° F. and at
for oxidation of carbon monoxide to carbon dioxide.
atmospheric pressure.
An important industrial gas is coke oven gas having
the following typical composition:
Under the reaction conditions of the process of the in
vention, the impurities in the gaseous stream are hydro
Mol percent
genated to the following products:
H2 _______________________________________ __ 51
Nz-l-Ar ___________________________________ __ 11
Impurity
co ______________________________________ __ 10
02
___
____
-__
____ __
NO ______________________________ ..
on4 _____________________________________ __ 25
can ________________ __, ___________________ __
2
02a,
0.2
_ ____
_ _ _ _ __
_
Product
0.8
02112“...
plus small concentrations of many other compounds. The
process of the present invention is applicable to the puri
tication of this gas, and is also applicable to the puri?ca
NHa.
a 02114, CzHs.
Dienes___
_
COS _____________________________ __
Ole?ns.
HES.
The ethylene is slightly decreased at low carbon monoxide
levels, preserved at moderate carbon monoxide levels, and
increased at high carbon monoxide levels. The process of
the invention is applicable to gases containing 5 to 98
percent carbon monoxide, and 2 to 90 percent hydrogen,
the balance consisting of inert gases such as nitrogen,
argon, carbon dioxide, methane and smaller quantities of
tion of a wide range of other gaseous mixtures in which
carbon monoxide and hydrogen are important constituents.
For example, removal of acetylene and nitric oxide can,
by means of the present invention, be achieved from a
stream containing 95 percent carbon monoxide and 4 45 ethylene and the impurities previously mentioned; oxygen
percent hydrogen.
may or not be present.
In addition to the removal of impurities, the process of .
The preferred catalysts are related to the removal of
the present invention is highly selective with respect to
ethylene, i.e. the ethylene content is either substantially
completely preserved or, in some cases, actually increased.
speci?c impurities in the following manner:
Impurity to be removed
This is an important feature of gas treatment where the
ethylene is to be used subsequently for producing 'com-_
02H; only ______________________________ __
pounds such as ethylene oxide, polyethylene, and the like. '
It is important to remove the impurities listed above as
Preferred catalysts
Pd.
Ru.
Pd+Ru, Pt.
Ru.
such removal will prevent vapor-phase gum formation,
Pd+Ru.
which is a nuisance and may be hazardous as some de
posited gums will explode. The nuisance from the gums
Nickel catalysts are also effective in these puri?cations.
However, they tend to ignite when exposed to air after
use in a reducing atmosphere, and this pyrophoric prop
is particularly found in small lines and burner nozzles.
The importance of removing such gums deposited from
the vapor of coke oven gas is seen in a currently used proc
ess of allowing the gums to deposit in a large vessel placed 00 erty makes the use of nickel hazardous as compared with
in the line, from which the gums are periodically removed. _
If a cold box is used, solid acetylene may accumulate there
in causing a particularly serious explosion hazard.
The process of the present invention consists of passing
the platinum metals. Furthermore, the nickel catalyst
. tends to crumble in use, converting the catalyst pellets
into powder which blocks passage of the gas in the re
a gaseous mixture over a catalyst consisting of one or 65
more metals of the platinum group, or nickel, with or
without a support. The platinum metals which have
been found to be especially e?icacious are platinum, pal
ladium and ruthenium. Suitable catalyst supports in
actor.
The invention will be further illustrated by reference
to the following speci?c examples, in which all gaseous
percentages are by volume:
EXAMPLE I
cludes alumina, silica, kieselguhr, silica gel, diatomaceous 70 To demonstrate the eifect of CO on selectivity,
earth and the like.
For optimum conversion, the catalyst precious metal
3,084,023
.3
4
mixtures were passed ‘over 0.5 percent Ru ‘on ‘A: "activated
alumina pellets at a pressure of 1 atmosphere and a
space velocity of 8000 s.c.f.h./c,f. _ Analyses ofthe ef
This example shows Pd to be especially effective for
CZHZ removal and Ru to be good for NO removal.
?uent gas for CZHZ and C2H4 showed the following:
EXAMPLE IH
5
1
Inlet
u
.
.
A combination
of palladium
and ruthenium catalyst
.
.
Outlet
was employed to result, in good removal of NO, CZHZ
Percent
Per-
Per~
.
Temp,
00
cent
OtH’
cent
CIH4
H,
CH4
2.0 1
2.07
24.
84
13.5
13 5
>
0
0.2
,
4.0
0.23
0. 23
‘
L
.
0'21
.
_:
‘
1'95
81
'
P-p-rn.
Per-
0 0,
0,111
cent
02m
1
175
‘ 14g
1,530
‘egg
15
1
320
13
205
1°
02
1'76
57‘
31
0.2
_ 1.87
42
23
I 225
180
'60
Q 16'
1'55
' 24
14
' fgg
ljgg
1
205
.
-
x 360
<30
33
-
‘
- (1.20
<
265
and
COS.
.
Further,
a, vlife test was made with variations
.
.
1n pressure and sulfur content. The stream consisted es
10 sentially of 59.8, P ercent
H , 10 P ercent CO, 28 P ercent
_
_y 2
CH4, 2.0 percent C2H4, 0.2 percent CZHZ, and 30-70
ppm NO
A gas ?ow of 32 LPH (NTP) was used, through a bed
6
.
F
.
'
.
.
'
L94
consisting of 5 mil’. oflPyrex glassbeads, 4 ml. of 0.015
1. 72
is;
1502
15 percent Pd on 1/a act1vated alumina catalyst, and 4 ml.
of 0.5 percent Ru on 1/8" activated alumina catalyst.
Table I summarizes the impurity removal. The presence
1.32‘
converted largely to H28, which 1s removable by means
‘
of oxygen improved removals. The carbonyl sul?de was
20 such as caustic scrubbing.
Table I
i
'
Running
'
'
hours
Inlet additions
.Pressure,
p.s.i.g.
_
0
0
0
I
>P.p.>m
Percent
00s
01
-.
0
' 0
0
0
100
0
,
.0.
20
0.2
0
20
'0
0
,0
20
20
0.1
0.17
0
0
0
(100
0
100
Out1et,p.p.m.
Cat.
temcp,
°
.
NO
(31H:
COS
C2114
Other
-
' 0‘
0.20
0.2a __
'
'WIFrH' 1'00 anaemia FOR 1' HOUR‘ new 0.
186
0.2.
1111:; .data show tthat, ,as the: CO increases, ‘an, ‘increasing 50
fraction of the, ethylene content‘is retained, under. condi
tions resulting _in acetylene removal'to th'elimit of ‘detec
tion in this experiment.
' 1110
<0.3
0.01
0.2
2%
...... -_
0.2
155
<0. 02
0.2
235
______ __
EXAMPLE IV
_ A coke oven‘ gas was passed over nickel catalyst con
taining '_ about 60 percent nickel at a space velocity of
;'14,Q00‘s.c_.f:h_.'/'c.f. and ‘160 p.s.i.g.lpressure. At 260° C.,
EXAMPLE ‘II
It,.,'j.,...
.
55 ‘the ‘impurities were removed as follows:
A coke oven type gascontaining _5_6 ‘percent H2, 31.5
CH4, 10.5 CO,,,2 C2H.;, 0.2 CzH-z and 30'p.p.m. NO was
C2112, from 2000 p.p.m. to <2 p.p.m.
NO, from 61 p.p.m. to <0.03 p.p.m.
COS, from 73 p.p.m. to 16 p.p.m.
passed at atmospheric pressure'over various catalysts, and
Mimpuriti'es were dét'ériminedwin vthe 'e?iuént gas as fol- 60
‘ lows:
the 2.00 percent C2H4 present remained in the puri?ed
gas.
‘ EXAMPLE V
'Space
Catalyst
s.c.f.h./c.f.
m 0.010 percent Pd on }/s"_
‘activated
alumina
0 .5peum'
t Pt
rcen
on
'
V"
s
spheres.
0.5 percent Ru on }/s"
pellets.
alumlna
N0
{
I
E?‘lu- 'P.p.m. 65
‘
° 0. i
12,500
acxtivated alumina
activated
Te" 1).
_- Velocity,
-
8,000 {
173
'11
274
13
204
i 0. 0
235
eat
Gaff:
61H;
cent C2H4 and 30 p.p.m. NO was passed over 0.5 percent
‘ Pt on %" activated alumina catalyst pellets at atmospheric
<2 ...... .
...... _.
0 mip'ressure and 8000 s.c.f.h./c.f. ‘At 202° C., the CZHZ
2.9 ______ __ >8,900
:
,
{
8,000
‘A ‘gas consisting of 94 percent CO, 4 percent H2, I
percent N2, 0.02 percent 02, 0.5 percent C2H4, 0.1 per
169
<0.2 ______________ __
232 _---_'___
<5
18,800
was removed ‘to <2 p.p.m., and at 218° C., the NO was
removed to <0.3 p.p.m. Good puri?cation was also 0b
taincd in the ‘presence of 0.1 percent COS.
At a pressure of 320 p.s.i.g., removal of both CZHZ
75 and NO over the 0.5 percent Pt catalyst to limits of de
3,084,023
5
6
100° 0., 0.05% cam-0.05% C2H4--0.096% C4H8
210° 0., <0.002% C2H2—0.04% c2H.,_0.010% C4H6
225° 0., <0.0002% c2H2_0.05%c2H,-<0.005% 04H,
tection occurred at 182° C., with a gas of the following
composition:
80% CO
Butene-l was found in the puri?ed gas by infrared
10% C02
4% H2
4% CH4
analysis.
Similar results were found with nickel catalyst.
It will be obvious to those skilled in the art that many
modi?cations may be made within the scope of the present
0.3% COS
0.1% CzH-z
0.2% 02
invention without departing from the spirit thereof, and
10 the invention includes all such modi?cations.
What is claimed is:
1. A process for the preferential removal of acetylene,
nitrogen oxides and carbonyl sul?de as impurities from
admixture with a hydrogen- and carbon monoxide-con
tent increased by as much 'as 600 p.p.m. ‘as a result of 15 taining gas, which comprises contacting the gas contain
5-30 p.p.m. NO
In ‘a life test conducted at 300 p.s.i.@g., the ethylene con
‘acetylene hydrogenation.
ing impurities consisting essentially of acetylene, nitro
gen oxides and carbonyl sul?de in the absence of ‘any
EXAMPLE VI
A gas mixture consisting of 10 percent CO, 60 per
added reducing gas with a supported catalyst containing
palladium and ruthenium as catalytically active metal de
cent Hz and 30 percent N2 was led over a container of 20 posited on a solid catalyst support, the catalytically active
cyclopentadiene, and thence over 0.5 percent Ru on 1%"
meta-l being present in the range of about 0.001 percent
activated valumina catalyst pellets at 8000 hourly space
velocity. The cyclopentadiene content, estimated at ap
proximately 3 percent, was reduced to the following
values:
120° C. catalyst temperature-4300 p.p.m.
150° C. catalyst temperature-1040 p.p.m.
175° C. catalyst temperature-—260 p.p.m. (limit of sen
sitivity)
EXAMPLE VII
to 2 percent by weight based on catalytic metal plus sup
port, at a temperature in the range of about 100°-300°
_ C., any oxygen present in the gas being less than the
stochiometric quantity required for oxidation of carbon
monoxide to carbon dioxide.
2. A process ‘according to claim 1 in which the gas
30
A mixture containing 60 percent H2, 10 percent CO,
0.05 percent C2H2, 0.05 percent C2H4 and 0.1 percent buta
diene (balance N2) was passed at 7200 s.c.f.h./c.f., over
0.5 percent Ru on 1/8" activated alumina catalyst pellets 3
at atmospheric pressure. The following impurity con
centrations were found in the effluent:
contains, by volume, 2 to 90 percent hydrogen and 5 to
98 percent carbon monoxide.
References Cited in the ?le of this patent
UNITED STATES PATENTS
1,962,485
2,910,343
Dely ________________ __ June 12, 1934
Childers etal ___________ __ Oct. 27, 1959
2,957,925
Oettinger _____________ __ Oct. 25, 1960
Документ
Категория
Без категории
Просмотров
0
Размер файла
362 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа