U.S. patent application number 17/221387 was filed with the patent office on 2021-08-05 for method for producing hydrocyanic acid and device for producing hydrocyanic acid.
This patent application is currently assigned to Mitsubishi Chemical Corporation. The applicant listed for this patent is Mitsubishi Chemical Corporation. Invention is credited to Shimpei Kato, Yoshikazu Sawada.
Application Number | 20210238049 17/221387 |
Document ID | / |
Family ID | 1000005566298 |
Filed Date | 2021-08-05 |
United States Patent
Application |
20210238049 |
Kind Code |
A1 |
Kato; Shimpei ; et
al. |
August 5, 2021 |
Method for Producing Hydrocyanic Acid and Device for Producing
Hydrocyanic Acid
Abstract
Provided are a method for producing hydrocyanic acid and a
device for producing hydrocyanic acid, which can improve a yield of
the hydrocyanic acid in a vapor phase contact ammoxidation reaction
of methanol. The method for producing hydrocyanic acid includes a
step of obtaining hydrocyanic acid by a vapor phase contact
ammoxidation reaction by supplying a raw material gas including
methanol in a fluidized bed reactor (1) through a raw material gas
disperser (7) disposed in the fluidized bed reactor (1) and
bringing the methanol into contact with ammonia and oxygen in the
presence of a metal oxide catalyst, in which the raw material gas
disperser (7) has one or more pores for releasing the raw material
gas into the fluidized bed reactor (1), and the number of pores per
unit cross-sectional area of the fluidized bed reactor (1) is 10 to
45 pieces/m.sup.2.
Inventors: |
Kato; Shimpei; (Tokyo,
JP) ; Sawada; Yoshikazu; (Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Mitsubishi Chemical Corporation |
Tokyo |
|
JP |
|
|
Assignee: |
Mitsubishi Chemical
Corporation
Tokyo
JP
|
Family ID: |
1000005566298 |
Appl. No.: |
17/221387 |
Filed: |
April 2, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/JP2020/007074 |
Feb 21, 2020 |
|
|
|
17221387 |
|
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B01J 2208/00539
20130101; B01J 8/24 20130101; B01J 8/0055 20130101; B01J 27/199
20130101; B01J 8/0025 20130101; B01J 2208/0092 20130101; C01C
3/0241 20130101 |
International
Class: |
C01C 3/02 20060101
C01C003/02; B01J 8/24 20060101 B01J008/24; B01J 8/00 20060101
B01J008/00; B01J 27/199 20060101 B01J027/199 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 27, 2019 |
JP |
2019-034279 |
Claims
1. A method for producing hydrocyanic acid, comprising: a step of
obtaining hydrocyanic acid by a vapor phase contact ammoxidation
reaction by supplying a raw material gas containing methanol in a
fluidized bed reactor through a raw material gas disperser disposed
in the fluidized bed reactor, and bringing the methanol into
contact with ammonia and oxygen in the presence of a metal oxide
catalyst, wherein the raw material gas disperser has one or more
pores for releasing the raw material gas into the fluidized bed
reactor, and the number of pores per unit cross-sectional area of
the fluidized bed reactor is 10 to 45 pieces/m.sup.2.
2. The method for producing hydrocyanic acid according to claim 1,
wherein the number of pores per unit cross-sectional area of the
fluidized bed reactor is 20 to 35 pieces/m.sup.2.
3. The method for producing hydrocyanic acid according to claim 1,
wherein a diameter of the pore is 1 to 12 mm.
4. The method for producing hydrocyanic acid according to claim 1,
wherein the raw material gas disperser is a pipe type disperser, a
rectifier pipe is attached to the raw material gas disperser at a
position having the pore, and the raw material gas released from
the pore is supplied into the fluidized bed reactor through the
rectifier pipe.
5. The method for producing hydrocyanic acid according to claim 1,
wherein the raw material gas contains methanol and ammonia.
6. The method for producing hydrocyanic acid according to claim 1,
wherein an oxygen-containing gas is supplied from a bottom of the
fluidized bed reactor.
7. The method for producing hydrocyanic acid according to claim 1,
wherein the metal oxide catalyst contains at least iron, antimony,
phosphorus, and vanadium.
8. The method for producing hydrocyanic acid according to claim 7,
wherein the number of moles of vanadium is equal to or more than
0.6 when the number of moles of iron in the metal oxide catalyst is
10.
9. The method for producing hydrocyanic acid according to claim 8,
wherein the metal oxide catalyst has a composition represented by
the following Formula (I):
Fe.sub.aSb.sub.bP.sub.cV.sub.dMo.sub.eCu.sub.fW.sub.gA.sub.hE.sub.iG.sub.-
jO.sub.k(SiO.sub.2).sub.l (I) wherein Fe, Sb, P, V, Mo, Cu, W, O,
and Si represent iron, antimony, phosphorus, vanadium, molybdenum,
copper, tungsten, oxygen, and silicon, respectively, A represents
at least one element selected from the group consisting of Mg, Zn,
La, Ce, Al, Cr, Mn, Co, Ni, Bi, U, and Sn, E represents at least
one element selected from the group consisting of B and Te, G
represents at least one element selected from the group consisting
of Li, Na, K, Rb, Cs, Ca, and Ba, subscripts a, b, c, d, e, f, g,
h, i, j, k and l represent atomic ratios, and when a=10 is assumed,
b=12 to 30, c=1 to 30, d=0.6 to 3, e=0 to 0.3, f=0 to 5, g=0 to 3,
h=0 to 6, i=0 to 5, j=0 to 3, l=0 to 200, and k is an oxygen atomic
ratio required to satisfy the atomic valence of each of the
elements excluding silicon.
10. The method for producing hydrocyanic acid according to claim 1,
wherein the metal oxide catalyst contains at least molybdenum and
bismuth.
11. The method for producing hydrocyanic acid according to claim
10, wherein the metal oxide catalyst has a composition represented
by the following Formula (II):
Mo.sub.mBi.sub.nFe.sub.oJ.sub.pL.sub.qM.sub.rQ.sub.sO.sub.t(SiO.sub.2).su-
b.u (II) wherein Mo, Bi, Fe, O, and Si represent molybdenum,
bismuth, iron, oxygen, and silicon, respectively, J represents at
least one element selected from the group consisting of Ni, Co, Zn,
Mg, Mn, and Cu, L represents at least one element selected from the
group consisting of La, Ce, Pr, Nd and Sm, M represents at least
one element selected from the group consisting of Li, Na, K, Rb,
and Cs, Q represents at least one element selected from the group
consisting of Ca, Sr, Ba, Cd, Ti, Zr, V, Nb, Ta, Cr, W, Ge, Sn, Y,
Al, Ga, Ru, Rh, Pd, Re, Os, Ir, Pt, Ag, B, P, Sb, and Te,
subscripts m, n, o, p, q, r, s, t, u represent atomic ratios, and
when m=12 is assumed, n=0.1 to 5, o=0.1 to 10, p=2 to 12, q=0.01 to
5, r=0.01 to 2, s=0 to 10, u=20 to 200, and t is an oxygen atomic
ratio required to satisfy the atomic valence of each of the
elements excluding silicon.
12. The method for producing hydrocyanic acid according to claim 1,
wherein the methanol is brought into contact with ammonia and
oxygen at a temperature of 300.degree. C. to 500.degree. C.
13. The method for producing hydrocyanic acid according to claim 1,
wherein the methanol is brought into contact with ammonia and
oxygen at a pressure of 0 to 200 kPa (gauge pressure).
14. A device for producing hydrocyanic acid by a vapor phase
contact ammoxidation reaction by bringing methanol into contact
with ammonia and oxygen in the presence of a metal oxide catalyst,
the device comprising: a fluidized bed reactor configured to
accommodate the metal oxide catalyst and to perform the vapor phase
contact ammoxidation reaction, one or more raw material gas
dispersers disposed in the fluidized bed reactor, and a raw
material gas supply unit configured to supply a raw material gas
containing methanol to the raw material gas disperser, wherein the
raw material gas disperser has one or more pores for releasing the
raw material gas into the fluidized bed reactor, and the number of
pores per unit cross-sectional area of the fluidized bed reactor is
10 to 45 pieces/m.sup.2.
15. The device for producing hydrocyanic acid according to claim
14, wherein the raw material gas contains methanol and ammonia.
16. The device for producing hydrocyanic acid according to claim
14, the device further comprising: an oxygen-containing gas supply
unit configured to supply an oxygen-containing gas from a bottom of
the fluidized bed reactor.
Description
[0001] This application is a continuation filing of, and claims
priority under 35 U.S.C. .sctn. 111(a) to, International
Application No. PCT/JP2020/007074, filed on Feb. 21, 2020, and
claims priority under 35 U.S.C. .sctn. 119 to Japanese Patent
Application No. 2019-034279, filed on Feb. 27, 2019, the entireties
of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The present invention relates to a method for producing
hydrocyanic acid and a device for producing hydrocyanic acid.
Description of the Related Art
[0003] As an industrial method for producing hydrocyanic acid,
there is a method of ammoxidating methanol. In an ammoxidation
reaction of methanol, an optimum temperature range of the reaction
is generally narrow, and a calorific value due to the reaction is
large. Therefore, a fluidized bed reactor is often used for the
ammoxidation reaction of methanol because of its good temperature
controllability and high productivity that enable it to treat a raw
material gas of a high concentration.
[0004] JP H10-152463 A discloses a method of supplying an
oxygen-containing gas from a supply port which is at a bottom
thereof to form a fluidized bed having a fluidized solid density of
50 to 300 kg/m.sup.3 and a gas flow velocity of 1 m/s or less at
the supply port of the raw material when ammoxidating a raw
material such as methanol with a fluidized bed reactor, and of
supplying the raw material from another supply port (a pore opening
portion of a gas disperser) at a predetermined position above the
supply port of the oxygen-containing gas.
SUMMARY OF INVENTION
Technical Problem
[0005] When methanol is ammoxidated through vapor phase contact in
the presence of a metal oxide catalyst, a region in the fluidized
bed reactor where oxygen is relatively deficient with respect to
methanol and a large amount of methanol remains unreacted and a
region where oxygen is present in relative excess to methanol and
produces a large amount of by-products are formed, and as a result,
a yield of hydrocyanic acid throughout the fluidized bed reactor
becomes low.
[0006] An object of the present invention is to provide a method
for producing hydrocyanic acid, which can improve a yield of the
hydrocyanic acid in a vapor phase contact ammoxidation reaction of
methanol and a device for producing hydrocyanic acid.
Solution to Problem
[0007] As a result of repeated examinations by the present
inventors, it was found that a yield of hydrocyanic acid can be
improved by setting a density of pores of the disperser that
supplies a raw material gas containing methanol into the fluidized
bed reactor, that is, the number of pores per unit cross-sectional
area of the fluidized bed reactor, within a specific range, and
thereby the present invention was completed.
[0008] JP H10-152463 does not disclose the number of pore opening
portions of a gas disperser.
[0009] The present invention has the following aspects.
[0010] [1] A method for producing hydrocyanic acid, including a
step of obtaining hydrocyanic acid by a vapor phase contact
ammoxidation reaction by supplying a raw material gas containing
methanol in a fluidized bed reactor through a raw material gas
disperser disposed inside the fluidized bed reactor, and bringing
the methanol into contact with ammonia and oxygen in the presence
of a metal oxide catalyst, in which the raw material gas disperser
has one or more pores for releasing the raw material gas into the
fluidized bed reactor, and the number of pores per unit
cross-sectional area of the fluidized bed reactor is 10 to 45
pieces/m.sup.2.
[0011] [2] The method for producing hydrocyanic acid according to
[1], in which the number of pores per unit cross-sectional area of
the fluidized bed reactor is 20 to 35 pieces/m.sup.2.
[0012] [3] The method for producing hydrocyanic acid according to
[1] or [2], in which a diameter of the pore is 1 to 12 mm.
[0013] [4] The method for producing hydrocyanic acid according to
any one of [1] to [3], in which the raw material gas disperser is a
pipe type disperser, a rectifier pipe is attached to the raw
material gas disperser at a position having the pores, and the raw
material gas released from the pore is supplied into the fluidized
bed reactor through the rectifier pipe.
[0014] [5] The method for producing hydrocyanic acid according to
any one of [1] to [4], in which the raw material gas contains
methanol and ammonia.
[0015] [6] The method for producing hydrocyanic acid according to
any one of [1] to [5], in which an oxygen-containing gas is
supplied from a bottom of the fluidized bed reactor.
[0016] [7] The method for producing hydrocyanic acid according to
any one of [1] to [6], in which the metal oxide catalyst contains
at least iron, antimony, phosphorus, and vanadium.
[0017] [8] The method for producing hydrocyanic acid according to
[7], in which the number of moles of vanadium is equal to or more
than 0.6 when the number of moles of iron in the metal oxide
catalyst is 10.
[0018] [9] The method for producing hydrocyanic acid according to
[8], in which the metal oxide catalyst has a composition
represented by the following Formula (I).
Fe.sub.aSb.sub.bP.sub.cV.sub.dMo.sub.eCu.sub.fW.sub.gA.sub.hE.sub.iG.sub-
.jO.sub.k(SiO.sub.2).sub.l (I)
[0019] Here, Fe, Sb, P, V, Mo, Cu, W, O, and Si represent iron,
antimony, phosphorus, vanadium, molybdenum, copper, tungsten,
oxygen, and silicon, respectively, A represents at least one
element selected from the group consisting of Mg, Zn, La, Ce, Al,
Cr, Mn, Co, Ni, Bi, U, and Sn, E represents at least one element
selected from the group consisting of B and Te, G represents at
least one element selected from the group consisting of Li, Na, K,
Rb, Cs, Ca, and Ba, subscripts a, b, c, d, e, f, g, h, i, j, k and
l represent atomic ratios, and when a=10 is assumed, b=12 to 30,
c=1 to 30, d=0.6 to 3, e=0 to 0.3, f=0 to 5, g=0 to 3, h=0 to 6,
i=0 to 5, j=0 to 3, l=0 to 200, and k is an oxygen atomic ratio
required to satisfy the atomic valence of each of the elements
excluding silicon.
[0020] [10] The method for producing hydrocyanic acid according to
any one of [1] to [6], in which the metal oxide catalyst contains
at least molybdenum and bismuth.
[0021] [11] The method for producing hydrocyanic acid according to
[10], in which the metal oxide catalyst has a composition
represented by the following Formula (II).
Mo.sub.mBi.sub.nFe.sub.oJ.sub.pL.sub.qM.sub.rQ.sub.sO.sub.t(SiO.sub.2).s-
ub.u (II)
[0022] Here, Mo, Bi, Fe, O, and Si represent molybdenum, bismuth,
iron, oxygen, and silicon, respectively, J represents at least one
element selected from the group consisting of Ni, Co, Zn, Mg, Mn,
and Cu, L represents at least one element selected from the group
consisting of La, Ce, Pr, Nd and Sm, M represents at least one
element selected from the group consisting of Li, Na, K, Rb, and
Cs, Q represents at least one element selected from the group
consisting of Ca, Sr, Ba, Cd, Ti, Zr, V, Nb, Ta, Cr, W, Ge, Sn, Y,
Al, Ga, Ru, Rh, Pd, Re, Os, Ir, Pt, Ag, B, P, Sb, and Te,
subscripts m, n, o, p, q, r, s, t, u represent atomic ratios, and
when m=12 is assumed, n=0.1 to 5, o=0.1 to 10, p=2 to 12, q=0.01 to
5, r=0.01 to 2, s=0 to 10, u=20 to 200, and t is an oxygen atomic
ratio required to satisfy the atomic valence of each of the
elements excluding silicon.
[0023] [12] The method for producing hydrocyanic acid according to
any one of [1] to [11], in which the methanol is brought into
contact with ammonia and oxygen at a temperature of 300.degree. C.
to 500.degree. C.
[0024] [13] The method for producing hydrocyanic acid according to
any one of [1] to [12], in which the methanol is brought into
contact with ammonia and oxygen at a pressure of 0 to 200 kPa
(gauge pressure).
[0025] [14] A device for producing hydrocyanic acid by a vapor
phase contact ammoxidation reaction by bringing methanol into
contact with ammonia and oxygen in the presence of a metal oxide
catalyst, the device including: a fluidized bed reactor configured
to accommodate the metal oxide catalyst and to perform the vapor
phase contact ammoxidation reaction, one or more raw material gas
dispersers disposed in the fluidized bed reactor, and a raw
material gas supply unit configured to supply a raw material gas
containing methanol to the raw material gas disperser, in which the
raw material gas disperser has one or more pores for releasing the
raw material gas into the fluidized bed reactor, and the number of
pores per unit cross-sectional area of the fluidized bed reactor is
10 to 45 pieces/m.sup.2.
[0026] [15] The device for producing hydrocyanic acid according to
[14], in which the raw material gas contains methanol and
ammonia.
[0027] [16] The device for producing hydrocyanic acid according to
[14] or [15], further including an oxygen-containing gas supply
unit configured to supply an oxygen-containing gas from a bottom of
the fluidized bed reactor.
Advantageous Effects of Invention
[0028] According to the method for producing hydrocyanic acid and
the device for producing hydrocyanic acid of the present invention,
it is possible to improve a yield of hydrocyanic acid in a vapor
phase contact ammoxidation reaction of methanol.
BRIEF DESCRIPTION OF DRAWINGS
[0029] FIG. 1 is a schematic configuration diagram of a device for
producing hydrocyanic acid according to an embodiment.
[0030] FIG. 2 is a schematic top view of a raw material gas
disperser to which a rectifier pipe is attached, which is provided
in the device for producing hydrocyanic acid shown in FIG. 1.
[0031] FIG. 3 is a sectional view along line of the raw material
gas disperser shown in FIG. 2.
[0032] FIG. 4 is a graph showing results of Examples 1 and 2 and
Comparative Examples 1 and 2.
DETAILED DESCRIPTION OF THE INVENTION
[0033] Hereinafter, a method for producing hydrocyanic acid and a
device for producing hydrocyanic acid of the present invention will
be described with reference to the accompanying drawings, showing
embodiments.
[0034] A numerical value range represented by using "-" includes
the numerical values at both ends within the range.
[0035] FIG. 1 is a schematic configuration diagram of a device for
producing hydrocyanic acid (hereinafter, also referred to as "the
present production device") according to an embodiment of the
present invention. FIG. 2 is a schematic top view of a raw material
gas disperser 7 to which a rectifier pipe 8 is attached, which is
provided in the present production device. FIG. 3 is a sectional
view along line of the raw material gas disperser shown in FIG.
2.
[0036] The present production device includes a fluidized bed
reactor 1 accommodating a particulate metal oxide catalyst 2 and
performing a vapor phase contact ammoxidation reaction, an
oxygen-containing gas supply pipe 3 (oxygen-containing gas supply
unit), and an oxygen-containing gas disperser 4, a raw material gas
supply pipe 6 (raw material gas supply unit), a raw material gas
disperser 7, a rectifier pipe 8, a cyclone 9, a catalyst return
pipe 10, and a gas discharge pipe 11.
[0037] The oxygen-containing gas disperser 4, the raw material gas
disperser 7, the rectifier pipe 8, the cyclone 9, and the catalyst
return pipe 10 are each disposed in the fluidized bed reactor
1.
[0038] The oxygen-containing gas supply pipe 3 is a pipe that
supplies an oxygen-containing gas (for example, air) to the
fluidized bed reactor 1. The oxygen-containing gas supply pipe 3 is
connected to a bottom of the fluidized bed reactor 1.
[0039] The raw material gas supply pipe 6 is a pipe that supplies a
raw material gas containing methanol. The raw material gas supply
pipe 6 is connected below a center of the fluidized bed reactor 1
in a height direction and communicates with the raw material gas
disperser 7.
[0040] The oxygen-containing gas disperser 4 is disposed above a
connection position of the oxygen-containing gas supply pipe 3 of
the fluidized bed reactor 1. The oxygen-containing gas disperser 4
vertically partitions the inside of the fluidized bed reactor 1,
and is accommodated such that the metal oxide catalyst 2 can
fluidly move on the oxygen-containing gas disperser 4.
[0041] The raw material gas disperser 7 may be disposed below the
center of the fluidized bed reactor 1 in the height direction and
above the oxygen-containing gas disperser 4. A height of the raw
material gas disperser 7 may be at any position. Two or more raw
material gas dispersers 7 may be disposed to divide and supply the
raw material gas.
[0042] The rectifier pipe 8 is attached to the raw material gas
disperser 7.
[0043] The cyclone 9 is disposed in the vicinity of a top in the
fluidized bed reactor 1.
[0044] A first end portion of the catalyst return pipe 10 is
connected to the cyclone 9. A second end portion opposite to the
first end portion can be opened at any position, and for example,
can be opened between the oxygen-containing gas disperser 4 and the
raw material gas disperser 7. A flapper valve or a trickle valve
may be installed in an opening portion of the catalyst return pipe
10.
[0045] The gas discharge pipe 11 is a pipe that discharges gas from
the fluidized bed reactor 1. The gas discharge pipe 11 is connected
to the top of the fluidized bed reactor 1 and communicates with the
cyclone 9.
[0046] The cyclone 9 may be a series multi-stage cyclone in which
two or more cyclones are connected in series. In a case where the
cyclone 9 is a series multi-stage cyclone, the gas discharge pipe
11 communicates with a last stage cyclone among the cyclones
constituting the series multi-stage cyclone.
[0047] As the metal oxide catalyst 2, a known metal oxide catalyst
can be used as the metal oxide catalyst used for the vapor phase
contact ammoxidation reaction of methanol in the fluidized bed
reactor.
[0048] An average particle size of the metal oxide catalyst 2 is
preferably 30 to 200 .mu.m. A lower limit of the average particle
size is more preferably equal to or more than 40 .mu.m, and an
upper limit is more preferably equal to or less than 100 .mu.m.
[0049] A bulk density of the metal oxide catalyst 2 is preferably
0.5 to 2 g/cm.sup.3. The lower limit of the bulk density is more
preferably equal to or more than 0.7 g/cm.sup.3, and the upper
limit is more preferably equal to or less than 1.5 g/cm.sup.3.
[0050] The metal oxide catalyst 2 preferably has high activity. For
example, a highly active catalyst having a reaction rate constant
of 3 s.sup.-1 or more when the ammoxidation reaction, which is an
index of activity, is used as a primary reaction of methanol is
preferable.
[0051] Preferable examples of the metal oxide catalyst 2 include a
metal oxide catalyst containing at least iron, antimony,
phosphorus, and vanadium. Such a metal oxide catalyst is excellent
in terms of reaction rate and reduction deterioration
resistance.
[0052] In a metal oxide catalyst containing at least iron,
antimony, phosphorus, and vanadium, in view of hydrocyanic acid
being reliably obtained at a high yield and a high selection rate
over time even if a methanol concentration is increased, when the
number of moles of iron in the metal oxide catalyst is 10, the
number of moles of vanadium is preferably equal to or more than
0.6, and more preferably has a composition represented by the
following Formula (I).
Fe.sub.aSb.sub.bP.sub.cV.sub.dMo.sub.eCu.sub.fW.sub.gA.sub.hE.sub.iG.sub-
.jO.sub.k(SiO.sub.2).sub.l (I)
[0053] Here, Fe, Sb, P, V, Mo, Cu, W, O, and Si represent iron,
antimony, phosphorus, vanadium, molybdenum, copper, tungsten,
oxygen, and silicon, respectively, A represents at least one
element selected from the group consisting of Mg, Zn, La, Ce, Al,
Cr, Mn, Co, Ni, Bi, U, and Sn, E represents at least one element
selected from the group consisting of B and Te, G represents at
least one element selected from the group consisting of Li, Na, K,
Rb, Cs, Ca, and Ba, subscripts a, b, c, d, e, f, g, h, i, j, k and
l represent atomic ratios, and when a=10 is assumed, b=12 to 30,
c=1 to 30, d=0.6 to 3, e=0 to 0.3, f=0 to 5, g=0 to 3, h=0 to 6,
i=0 to 5, j=0 to 3, l=0 to 200, and k is an oxygen atomic ratio
required to satisfy the atomic valence of each of the elements
excluding silicon.
[0054] Another preferred example of the metal oxide catalyst 2 is a
metal oxide catalyst containing at least molybdenum and bismuth.
Such a metal oxide catalyst is excellent in terms of reaction rate
and reduction deterioration resistance.
[0055] A metal oxide catalyst containing at least molybdenum and
bismuth preferably has a composition represented by the following
Formula (II), in view of hydrocyanic acid being reliably obtained
at a high yield and a high selection rate over time even if the
concentration of methanol is increased.
Mo.sub.mBi.sub.nFe.sub.oJ.sub.pL.sub.qM.sub.rQ.sub.sO.sub.t(SiO.sub.2).s-
ub.u (II)
[0056] Here, Mo, Bi, Fe, O, and Si represent molybdenum, bismuth,
iron, oxygen, and silicon, respectively, J represents at least one
element selected from the group consisting of Ni, Co, Zn, Mg, Mn,
and Cu, L represents at least one element selected from the group
consisting of La, Ce, Pr, Nd and Sm, M represents at least one
element selected from the group consisting of Li, Na, K, Rb, and
Cs, Q represents at least one element selected from the group
consisting of Ca, Sr, Ba, Cd, Ti, Zr, V, Nb, Ta, Cr, W, Ge, Sn, Y,
Al, Ga, Ru, Rh, Pd, Re, Os, Ir, Pt, Ag, B, P, Sb, and Te,
subscripts m, n, o, p, q, r, s, t, u represent atomic ratios, and
when m=12 is assumed, n=0.1 to 5, o=0.1 to 10, p=2 to 12, q=0.01 to
5, r=0.01 to 2, s=0 to 10, u=20 to 200, and t is an oxygen atomic
ratio required to satisfy the atomic valence of each of the
elements excluding silicon.
[0057] As the oxygen-containing gas disperser 4, a known disperser
can be used, and examples thereof include a pipe type disperser
including a pipe grid type, a cap type disperser, a porous plate
type disperser, a perforated plate type disperser, and a parallel
slit plate type disperser.
[0058] As the raw material gas disperser 7, a pipe type disperser
including a pipe grid type disperser can be used.
[0059] As shown in FIG. 2, an example of the raw material gas
disperser 7 includes a pipe type disperser including a header 71
extending in a first direction (horizontal direction in FIG. 2) and
a plurality of branch pipes 72 extending on both sides in a second
direction (vertical direction in FIG. 2) orthogonal to the first
direction from the header 71. The header 71 communicates with the
raw material gas supply pipe 6, and the branch pipe 72 communicates
with the header 71.
[0060] The branch pipe 72 is formed with a pore 73 that opens
toward a lower side when the raw material gas disperser 7 is
disposed in the fluidized bed reactor 1.
[0061] The header 71 may be formed with the pore 73 that opens
toward the lower side when the raw material gas disperser 7 is
disposed in the fluidized bed reactor 1. In this case, the branch
pipe 72 may not be provided.
[0062] The number of pores 73 per unit cross-sectional area of the
fluidized bed reactor 1 (hereinafter, also referred to as "number
of pores per unit reactor cross-sectional area") is 10 to 45
pieces/m.sup.2, and is preferably 20 to 35 pieces/m.sup.2. In a
case where the number of pores per unit reactor cross-sectional
area is within this range, the yield of hydrocyanic acid in the
vapor phase contact ammoxidation reaction of methanol is
excellent.
[0063] The number of pores per unit reactor cross-sectional area is
calculated by dividing the number (pieces) of the pores 73 of the
raw material gas disperser 7 by the cross-sectional area (m.sup.2)
of the fluidized bed reactor 1. The number of pores per unit
reactor cross-sectional area can be adjusted, for example, by
changing the number of branch pipes 72 or the number of pores 73
formed in the header 71 or one branch pipe 72. The branch pipes 72
and the pores 73 are preferably provided at uniform intervals.
[0064] Here, the cross-sectional area of the fluidized bed reactor
1 represents the area of the cross section inside the fluidized bed
reactor 1 at a height at which the raw material gas disperser 7 is
disposed in the fluidized bed reactor 1. In a case where two or
more raw material gas dispersers 7 are disposed, the
cross-sectional area of the fluidized bed reactor 1 represents an
area of the cross section inside the fluidized bed reactor 1 at the
height of the raw material gas disperser 7 which is closest to the
oxygen-containing gas disperser 4. The cross section is a cross
section in a direction orthogonal to the height direction. The
cross-sectional area includes a cross-sectional area of an interior
article such as the catalyst return pipe 10. The area obtained by
subtracting the cross-sectional area of the interior article from
the cross-sectional area of the fluidized bed reactor 1 is referred
to as an effective cross-sectional area of the fluidized bed
reactor.
[0065] The cross-sectional area of the fluidized bed reactor 1 can
be appropriately selected in a range of 10.times.10.sup.-2 to 150
m.sup.2, for example.
[0066] A ratio of the area of the pores 73 (the total area of the
pores 73 in a case where there are a plurality of the pores 73) to
the cross-sectional area of the fluidized bed reactor 1 is
preferably 0.01 to 0.2 area %, and the lower limit is more
preferably equal to or more than 0.03 area % and the upper limit is
more preferably equal to or less than 0.1 area %.
[0067] In a case where the number of pores per unit reactor
cross-sectional area is 10 to 45 pieces/m.sup.2, a diameter of the
pore 73 is preferably 1 to 12 mm from a viewpoint of the yield of
hydrocyanic acid. The lower limit of the diameter of the pores 73
is more preferably equal to or more than 1.5 mm, and the upper
limit is equal to or less than 8 mm. In a case where the diameter
of the pore 73 is within this range, a pressure loss in the
disperser is within an appropriate range, and there is an advantage
in terms of the power cost of supplying the raw material gas and
the uniform dispersibility of the raw material gas.
[0068] In a case where the raw material gas disperser 7 has a
plurality of pores 73, the diameters of the plurality of pores 73
may be the same or different.
[0069] As shown in FIG. 3, the rectifier pipe 8 is attached to a
position of the pore 73 on an outer peripheral surface of the
branch pipe 72 and communicates with the branch pipe 72. In a case
where the branch pipe 72 is not provided, the rectifier pipe 8 is
attached to a position of the pore 73 on an outer peripheral
surface of the header 71 and communicates with the header 71.
[0070] An inner diameter of the rectifier pipe 8 is equal to or
more than a diameter of the pore 73 and is equal to or less than
the diameter of the pore 73+20 mm, for example.
[0071] A length of the rectifier pipe 8 is 50 to 500 mm, for
example.
[0072] A production of hydrocyanic acid using the present
production device can be carried out by the following procedure,
for example.
[0073] First, the oxygen-containing gas is supplied from the
oxygen-containing gas supply pipe 3 to the bottom of the fluidized
bed reactor 1. At this time, the supplied oxygen-containing gas is
supplied upward through the oxygen-containing gas disperser 4, the
metal oxide catalyst 2 is brought into a fluidized state, and a
fluidized bed is formed.
[0074] Subsequently, a raw material gas containing methanol and
ammonia is supplied from the raw material gas supply pipe 6. The
supplied raw material gas is introduced into the branch pipe 72 via
the header 71, and is released below the raw material gas disperser
7 from the pore 73. In addition, the raw material gas released from
the pore 73 is supplied into the fluidized bed reactor 1 through
the rectifier pipe 8. Specifically, the raw material gas released
from the pore 73 is blown out from a tip of the rectifier pipe 8
toward a lower side of the raw material gas disperser 7, and then
ascends in the fluidized bed reactor 1 while in contact with the
metal oxide catalyst 2 in a fluidized state. During this time,
methanol in the raw material gas comes into contact with ammonia in
the raw material gas and oxygen in the oxygen-containing gas, and
hydrocyanic acid (hydrogen cyanide) is generated by a vapor phase
contact ammoxidation reaction.
[0075] The generated reaction gas containing hydrocyanic acid is
introduced into the cyclone 9 together with the metal oxide
catalyst 2 entrained in a gas stream. In the cyclone 9, the
reaction gas and the metal oxide catalyst 2 are separated. The
metal oxide catalyst 2 separated by the cyclone 9 is returned to
the fluidized bed reactor 1 through a catalyst return pipe 10, and
the reaction gas is discharged from the fluidized bed reactor 1
through a gas discharge pipe 11 from the cyclone 9.
[0076] Air is usually used as the oxygen-containing gas. As the
oxygen-containing gas, oxygen-enriched air or oxygen gas diluted
with an inert gas may be used.
[0077] The raw material gas may contain a diluent such as nitrogen,
carbon dioxide, and water vapor in addition to methanol and
ammonia.
[0078] The temperature at which methanol is brought into contact
with ammonia and oxygen is preferably 300.degree. C. to 500.degree.
C. from a viewpoint of the yield of hydrocyanic acid. The lower
limit of the temperature is more preferably equal to or more than
350.degree. C., and further preferably equal to or more than
380.degree. C. In addition, the upper limit is more preferably
equal to or less than 470.degree. C. This temperature is obtained
by measuring the temperature in the fluidized bed reactor. The
measurement location may be a portion above a position (height) of
the raw material gas disperser where reaction with the metal oxide
catalyst occurs.
[0079] The pressure is preferably 0 to 200 kPa from a viewpoint of
the yield of hydrocyanic acid. The lower limit of the pressure is
more preferably equal to or more than 10 kPa, and the upper limit
is more preferably equal to or less than 150 kPa. The pressure is a
gauge pressure. This pressure is obtained by measuring the pressure
at the top of the fluidized bed reactor.
[0080] A molar ratio of oxygen to methanol (oxygen/methanol) in the
total gas supplied to the fluidized bed reactor 1 (hereinafter,
also referred to as "total supply gas") is preferably 0.8 to 2.0,
and more preferably 0.8 to 1.5, from a viewpoint of the yield of
hydrocyanic acid. In a case where air is used as the
oxygen-containing gas, a molar ratio of air to methanol
(air/methanol) is preferably 3.8 to 9.5, and more preferably 3.8 to
7.1, from a viewpoint of the yield of hydrocyanic acid.
[0081] A molar ratio of ammonia to methanol (ammonia/methanol) is
preferably 0.5 to 10 from a viewpoint of the yield of hydrocyanic
acid.
[0082] A superficial velocity of the total supply gas is preferably
10 to 200 cm/sec from a viewpoint of the yield of hydrocyanic acid.
The lower limit of the superficial velocity of the total supply gas
is more preferably equal to or more than 20 cm/sec, and the upper
limit is more preferably equal to or less than 100 cm/sec.
[0083] The superficial velocity of methanol and the superficial
velocity of ammonia are both preferably 1 to 30 cm/sec. The lower
limit of the superficial velocity of methanol and the superficial
velocity of ammonia are both more preferably equal to or more than
2 cm/sec, and the upper limit is more preferably equal to or less
than 20 cm/sec.
[0084] The superficial velocity of oxygen is preferably 2 to 42
cm/sec. The lower limit of the superficial velocity of oxygen is
more preferably equal to or more than 4 cm/sec, and the upper limit
is more preferably equal to or less than 21 cm/sec. In a case where
air is used as the oxygen-containing gas, the superficial velocity
of air is preferably 10 to 200 cm/sec. The lower limit of the
superficial velocity of air is more preferably equal to or more
than 20 cm/sec, and the upper limit is more preferably equal to or
less than 100 cm/sec.
[0085] The definition of the superficial velocity is as will be
described later in examples.
[0086] According to the method for producing hydrocyanic acid
according to the present invention, the yield of the hydrocyanic
acid can be improved.
[0087] The reason why the yield of hydrocyanic acid is improved is
considered as follows.
[0088] In the vapor phase contact ammoxidation reaction of methanol
in the fluidized bed reactor 1, a distribution state of methanol in
the fluidized bed reactor 1 and a contact state between the raw
material gas and the metal oxide catalyst 2 affect the yield of
hydrocyanic acid.
[0089] In a case where the number of pores per unit reactor
cross-sectional area is too small, the distribution of methanol in
the fluidized bed reactor 1 becomes non-uniform. Due to the
non-uniform distribution of methanol, a region in which oxygen is
relatively insufficient with respect to methanol and a large amount
of methanol remains unreacted, and a region in which oxygen is
relatively excessive with respect to methanol and a large amount of
by products are generated are generated in the fluidized bed
reactor 1, and thus the yield of hydrocyanic acid in the entire
fluidized bed reactor becomes low.
[0090] On the other hand, if the number of pores per unit reactor
cross-sectional area is too large, bubbles of the raw material gas
released from adjacent pores 73 are coalesced and the bubble
diameter becomes large. As a result, the contact between the raw
material gas and the metal oxide catalyst 2 becomes poor, and the
yield of hydrocyanic acid becomes low.
[0091] It is considered that by setting the number of pores per
unit reactor cross-sectional area within the range of the present
invention, the distribution state of methanol in the fluidized bed
reactor 1 can be made uniform, and the contact state between the
raw material gas and the metal oxide catalyst 2 can be made
favorable, and thus the yield of hydrocyanic acid is improved.
[0092] In particular, it is possible to rectify the raw material
gas by supplying the raw material gas released from the pore 73 to
the fluidized bed reactor 1 through the rectifier pipe 8, and it is
possible to prevent particles of the metal oxide catalyst from
being pulverized by reducing the flow velocity of the raw material
gas.
[0093] According to the examination by the present inventors, in
the vapor phase contact ammoxidation reaction of methanol and the
vapor phase contact ammoxidation reaction of a raw material other
than methanol, an optimum value of the number of pores per unit
reactor cross-sectional area for improving the yield becomes
different.
[0094] Hereinabove, the present invention has been described with
reference to embodiments, but the present invention is not limited
to these embodiments. For example, each configuration and a
combination thereof in the embodiments described above are
examples, and configurations can be added, omitted, and
substituted, and other changes can be made without departing from
the gist of the present invention.
[0095] For example, in the embodiments, an example in which a pipe
type disperser is used as the raw material gas disperser 7 is
shown, but as long as the raw material gas disperser 7 has the
number of pores per unit reactor cross-sectional area within the
appropriate range, and any known disperser other than a pipe type
disperser may be used. Examples of the disperser other than the
pipe type disperser include a cap type disperser, a porous plate
type disperser, a perforated plate type disperser, and a parallel
slit plate type disperser. The raw material gas disperser 7 is
preferably a pipe type disperser because the pipe type disperser is
excellent in that clogging of the catalyst can be suppressed and
that the structure is simple.
[0096] In the embodiments, an example is shown in which a raw
material gas containing ammonia together with methanol which is a
target (raw material) of vapor phase contact ammoxidation is used,
and methanol and ammonia are supplied to the fluidized bed reactor
1, but methanol and ammonia may be supplied separately. For
example, a gas supply pipe and a gas disperser for the
ammonia-containing gas is provided, and may supply the
ammonia-containing gas into the fluidized bed reactor 1 separately
from the methanol. It is preferable to use a raw material gas
containing methanol and ammonia because methanol and ammonia can be
reliably mixed.
[0097] In addition, a gas supply pipe and a gas disperser for the
oxygen-containing gas may be provided at a position other than the
bottom of the fluidized bed reactor 1, and supply the
oxygen-containing gas into the fluidized bed reactor 1, for
example. From a viewpoint of fluidization of the metal oxide
catalyst 2, it is preferable to supply the oxygen-containing gas
from the bottom of the fluidized bed reactor 1.
[0098] A cooling pipe may be provided in the fluidized bed reactor
1. By providing the cooling pipe, it is possible to easily control
the temperature inside the fluidized bed reactor 1 within the
optimum temperature range of the vapor phase contact ammoxidation
reaction. Therefore, the raw material gas containing a high
concentration of methanol can be treated, and the productivity is
improved.
[0099] Examples of the cooling pipe include a vertical cooling
pipe, a horizontal cooling pipe, and a spiral cooling pipe.
[0100] In addition, in order to favorably maintain a fluidized
state of the metal oxide catalyst 2, and from a viewpoint of
construction and maintenance, another interpolation article may be
appropriately provided in the fluidized bed reactor 1.
EXAMPLES
[0101] Hereinafter, the present invention will be described in more
detail with reference to examples, but the following examples do
not limit the scope of the present invention.
[0102] The superficial velocity (gas flow velocity) and hydrocyanic
acid yield in the present specification are defined as follows.
Superficial velocity [cm/sec]=volume velocity of supply gas under
reaction conditions [cm.sup.3/sec]/effective cross-sectional area
of fluidized bed reactor [cm.sup.2]
Yield of hydrocyanic acid [%]=(mass of carbon in generated
hydrocyanic acid [kg]/mass of carbon in supplied methanol
[kg]).times.100
[0103] Here, the effective cross-sectional area of the fluidized
bed reactor represents an area obtained by subtracting a
cross-sectional area of the interior article such as the catalyst
return pipe 10 from a cross-sectional area of a portion in which
the reaction between the raw material gas and the metal oxide
catalyst 2 occurs in the fluidized bed reactor 1.
[0104] In the production of hydrocyanic acid, a catalyst (I-1) in
which the experimental formula is
Fe.sub.10Sb.sub.19P.sub.6V.sub.1Cu.sub.2.5Mo.sub.0.1O.sub.X(SiO.sub.2).su-
b.60 (here, X is a number determined according to the atomic
valence of constituent metals) was used. The catalyst (I-1) was
prepared as follows.
[0105] (1) 247.3 g of antimony trioxide powder was weighed.
[0106] (2) 385 mL of nitric acid and 480 mL of water were mixed and
heated, and 49.9 g of electrolytic iron powder was added little by
little to dissolve the mixture. Subsequently, 54.0 g of copper
nitrate was added to this solution and dissolved.
[0107] (3) 10.5 g of ammonium metavanadate and 1.6 g of ammonium
paramolybdate were dissolved in 300 mL of water.
[0108] (4) 1,590 g of silica sol (SiO.sub.2: 20% by mass) was
weighed.
[0109] (5) The silica sol of (4), the powder of (1), and the
solution obtained in (3) were added to the solution obtained in (2)
in that order while stirring, and the pH2 was adjusted to 2 with
ammonia water having a concentration of 15% by mass. The slurry was
heat-treated at 98.degree. C. for 3 hours while stirring, and then
61.8 g of phosphoric acid (content 85% by mass) was added to the
slurry and stirred well. Subsequently, this slurry was spray-dried
using a rotary disk type spray-drying device. The obtained fine
spherical particles were fired at 200.degree. C. for 2 hours and at
500.degree. C. for 3 hours, and further fired at 800.degree. C. for
3 hours to obtain a catalyst (I-1).
Example 1
[0110] The production of hydrocyanic acid by the vapor phase
contact ammoxidation reaction of methanol was carried out by the
following procedure using a production device having the
configuration shown in FIG. 1. Here, as the raw material gas
disperser, one having a pore formed in the header was used. Table 1
shows the vapor-phase contact ammoxidation reaction conditions of
methanol in Example 1. In Table 1, "G" of "kPaG" represents a gauge
pressure (the same applies hereinafter).
[0111] The fluidized bed reactor 1 was filled with 60 kg of the
catalyst (I-1), air was supplied from the oxygen-containing gas
supply pipe 3, and a mixed gas (raw material gas) of methanol and
ammonia was supplied from the raw material gas supply pipe 6 to
perform a reaction. At this time, a molar ratio of oxygen/methanol
in the air was adjusted to 1.4 (a molar ratio of air/methanol was
adjusted to 6.5), a molar ratio of ammonia/methanol was adjusted to
1, the superficial velocity of the total supply gas was adjusted to
50 cm/sec, the superficial velocity of oxygen was adjusted to 8.2
cm/sec (the superficial velocity of air was adjusted to 38.2
cm/sec), the superficial velocity of methanol and the superficial
velocity of ammonia were adjusted to 5.9 cm/sec, the temperature
was adjusted to 430.degree. C., and the pressure was adjusted to 50
kPa at a gauge pressure.
[0112] After supplying the raw material gas, it was confirmed that
the reaction gas composition was stable, and the yield of
hydrocyanic acid was calculated from the measurement result of the
reaction gas composition at that time and used as a first reaction
(run1). Subsequently, in order to confirm the reproducibility, the
reaction gas composition was measured again to calculate the yield
of hydrocyanic acid, and was used as a second reaction (run2). The
yield of hydrocyanic acid in Example 1 is also described in Table
1.
Example 2
[0113] After the reaction of Example 1, only the temperature was
changed from 430.degree. C. to 439.degree. C. After changing the
temperature, it was confirmed that the reaction gas composition was
stable, and the yield of hydrocyanic acid was calculated from the
measurement result of the reaction gas composition at that time and
used as the first reaction (run1). Subsequently, in order to
confirm the reproducibility, the reaction gas composition was
measured again to calculate the yield of hydrocyanic acid, and was
used as a second reaction (run2). The yield of hydrocyanic acid in
Example 2 is also described in Table 1.
Comparative Example 1
[0114] The production of hydrocyanic acid by vapor phase contact
ammoxidation of methanol was carried out by the following procedure
using a production device having the configuration shown in FIG. 1.
Here, as the raw material gas disperser, one having three pores
formed in the header was used.
[0115] The production of hydrocyanic acid was performed in the same
manner as in Example 1 except that the production conditions were
changed as shown in Table 1, and after supplying the raw material
gas, it was confirmed that the reaction gas composition was stable,
and the yield of hydrocyanic acid was calculated from the
measurement result of the reaction gas composition at that time and
was used as a first reaction (run1). Subsequently, in order to
confirm the reproducibility, the reaction gas composition was
measured again to calculate the yield of hydrocyanic acid, and was
used as a second reaction (run2). The yield of hydrocyanic acid in
Comparative Example 1 is also described in Table 1.
Comparative Example 2
[0116] After the reaction of Comparative Example 2, only the
temperature was changed as shown in Table 1. After changing the
temperature, it was confirmed that the reaction gas composition was
stable, and the yield of hydrocyanic acid was calculated from the
measurement result of the reaction gas composition at that time and
used as the first reaction (run1). Subsequently, in order to
confirm the reproducibility, the reaction gas composition was
measured again to calculate the yield of hydrocyanic acid, and was
used as a second reaction (run2). The yield of hydrocyanic acid in
Comparative Example 2 is also described in Table 1.
TABLE-US-00001 TABLE 1 Comparative Comparative Example 1 Example 2
Example 1 Example 2 run1 run2 run1 run2 run1 run2 run1 run2
Superficial velocity of cm/sec 50 50 50 50 50 50 50 50 total supply
gas Inner diameter of reactor mm 210.7 210.7 210.7 210.7 210.7
210.7 210.7 210.7 Number of pores pieces 1 1 1 1 3 3 3 3 Number of
pores per pieces/m.sup.2 29 29 29 29 86 86 86 86 unit reactor
cross-sectional area Diameter of pore mm 2.5 2.5 2.5 2.5 2.5 2.5
2.5 2.5 Temperature .degree. C. 430 430 439 439 428 428 439 439
Amount of catalyst kg 60 60 60 60 60 60 60 60 Pressure kPaG 50 50
50 50 50 50 50 50 Molar ratio of -- 1.4 1.4 1.4 1.4 1.4 1.4 1.4 1.4
oxygen/methanol Molar ratio of -- 1 1 1 1 1 1 1 1 ammonia/methanol
Yield of hydrocyanic % 88.4 88.6 88.2 88.2 87.3 87.0 86.9 87.0
acid
[0117] FIG. 4 shows the relationship between the number of pores
per unit reactor cross-sectional area and the yield of hydrocyanic
acid in each of Examples 1 and 2 and Comparative Examples 1 and
2.
[0118] As can be seen from Table 1, the reaction conditions of
Example 1 and Comparative Example 1 and the reaction conditions of
Example 2 and Comparative Example 2 are almost the same except for
the number of pores per unit cross-sectional area of the fluidized
bed reactor.
[0119] However, as can be seen from FIG. 4, Examples 1 and 2 in
which the number of pores per unit reactor cross-sectional area was
10 to 45 pieces/m.sup.2 had a higher yield of hydrocyanic acid than
Comparative Examples 1 and 2 in which the number of pores per unit
cross-sectional area of the fluidized bed reactor was 45
pieces/m.sup.2.
[0120] That is, according to the present invention, it was
confirmed that the yield of hydrocyanic acid in the vapor phase
contact ammoxidation reaction of methanol was improved.
REFERENCE SIGNS LIST
[0121] 1: Fluidized bed reactor [0122] 2: Metal oxide catalyst
[0123] 3: Oxygen-containing gas supply pipe [0124] 4:
Oxygen-containing gas disperser [0125] 6: Raw material gas supply
pipe (raw material gas supply unit) [0126] 7: Raw material gas
disperser [0127] 8: Rectifier pipe [0128] 9: Cyclone [0129] 10:
Catalyst return pipe [0130] 11: Gas discharge pipe [0131] 71:
Header [0132] 72: Branch pipe [0133] 73: Pore
* * * * *