Organic compounds -- part of the class 532-570 series – Organic compounds – Nitriles
Reexamination Certificate
2000-03-02
2001-03-20
McKane, Joseph K. (Department: 1626)
Organic compounds -- part of the class 532-570 series
Organic compounds
Nitriles
C558S323000
Reexamination Certificate
active
06204407
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention is directed to a novel process for the ammoxidation of a mixture of alcohols to a mixture of nitriles. In particular, the present invention is directed to increasing the yield and, preferably, the ratio of co-product hydrogen cyanide and acetonitrile produced during the ammoxidation of propylene to acrylonitrile.
There are several patents which address the issue of the injection of methanol or ethanol into a fluid bed reactor to produce hydrogen cyanide or acetonitrile. In addition, these references further disclose that the methanol or ethyl alcohol may be introduced into a fluid bed reactor to increase the co-product hydrogen cyanide or acetonitrile while manufacturing acrylonitrile. For example, U.S. Pat. Nos. 3,911,089; 4,485,079 and 5,288,473 are directed to the ammoxidation of methanol to produce hydrogen cyanide by injection of the methanol into the fluid bed reactor containing the ammoxidation catalyst suitable for the manufacture of acrylonitrile. Each of these references teach that methanol injection can be made simultaneously with the manufacture of acrylonitrile. In addition, Japanese Patent Applications 74-87,474; 79-08,655; and 78-35,232 relate to similar methods of increasing the yield of hydrogen cyanide during the manufacture of acrylonitrile. Japanese Patent Application 2[1990]-38,333 is directed to improving acetonitrile yields by injecting acetone and/or ethyl alcohol into an ammoxidation reactor containing ab ammoxidation catalyst. The process disclosed in the Japanese Patent Application includes simultaneously injecting the acetone and/or ethyl alcohol into the ammoxidation reactor while manufacturing acrylonitrile. All of these patents are concerned with the production of either additional hydrogen cyanide or acetonitrile.
The present invention is directed to a process which increases the yield of one or both main co-products (i.e. HCN and acetonitrile) during the manufacture of acrylonitrile while (1) saving on the raw material costs associated with the increase in co-product yields and (2) achieving the same or better conversion and selectivity to the desired co-products (on a carbon basis) as one obtains with the use of neat alcohols such as methanol/ethanol. The relative amounts of hydrogen cyanide and acetonitrile can be controlled by the process of this invention.
We have found, unexpectedly, that the use of crude alcohol mixtures can attain a desirable increase in the production of acetonitrile and hydrogen cyanide during the production of acrylonitrile.
SUMMARY OF THE INVENTION
It is the primary object of the present invention to provide a process for substantially increasing the yields of one or more of the co-products hydrogen cyanide and acetonitrile produced during the manufacture of acrylonitrile from propylene or propane.
It is an object of the present invention to provide a process for the conversion of a mixture of crude alcohol containing methanol, ethanol, other alcohols and water into hydrogen cyanide and acetonitrile during the manufacture of acrylonitrile without substantially affecting the yield of the acrylonitrile.
It is a further object of this invention to provide a process for the conversion of an alcohol comprising ethanol into acetonitrile, with or without the inclusion of methanol. Methanol can be included in the ethanol in an amount desired to adjust the relative amounts of hydrogen cyanide and acetonitrile co-products that are produced. Thus, when the need for hydrogen cyanide increases, methanol or additional methanol can be added to the ethanol feed mixture to achieve enhanced amounts of hydrogen cyanide. Alternatively, if additional production of acetonitrile is desired relative to hydrogen cyanide, the amount of ethanol in the alcohol feed can be increased to enhance the relative amount of acetonitrile produced.
Additional objects and advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by the practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
To achieve the foregoing objects in accordance with the purpose of the present invention as broadly described herein, the method of the present invention comprises introducing a hydrocarbon selected from the group consisting of propylene and propane, a crude alcohol comprising a mixture of C
1
to C
4
alcohols, ammonia and oxygen-containing gas into reaction zone (e.g. fluid bed reactor) to react in the presence of a catalyst (e.g. fluid bed catalyst) to produce a reactor effluent comprising acrylonitrile, hydrogen cyanide and acetonitrile, passing the reactor effluent containing acrylonitrile, hydrogen cyanide and acetonitrile into a quench column to cool the reactor effluent, and recovering the acrylonitrile, acetonitrile and hydrogen cyanide from the quench column.
In a preferred embodiment of the present invention, the mixture of crude alcohols is supplied using crude ethanol, crude propanol and/or crude methanol. For purposes of the present invention, crude ethanol includes a mixture of alcohols comprising ethanol, propanol, butanol and water. A typical source of commercially available crude ethanol contains 86.34% ethanol, 1.025% I-propanol, 1.266% N-butanol and 11.37% water. While not being particularly limited to this composition, any crude ethanol, propanol and/or methanol mixture is suitable in the practice of the present invention. It is preferred that the crude alcohol also contains water, preferably at least about 3 weight percent, more preferably at least about 5 weight percent, thereby further reducing the cost of operation of the process of the present invention. One of the unexpected benefits of the practice of the present invention is the discovery that the co-product selectivity and conversion results obtained utilizing a crude alcohol are the same or better (on a carbon to carbon basis) when compared to the results obtained using a pure alcohol feed.
In the practice of the present invention, it is envisioned that any ammoxidation catalyst can be utilized to achieve the desired results of increasing the yield of co-product acetonitrile and hydrogen cyanide. Typical ammoxidation catalysts can be generalized by the following two formulae:
A
a
B
b
C
c
D
d
Mo
12
O
x
where
A=Li, Na, K, Cs, TI and combinations thereof, preferably Cs and K
B=Ni, Co, Mn, Mg, Ca and combinations thereof, preferably Ni, Co and Mg
C=Fe, Cr, Ce, Cu, V, Sb, W, Sn, Ga, Ge, In, P and combinations thereof, preferably Fe, Cr and Ce
D=Bi and/or Te, preferably Bi
a=0.14.0, preferably 0.1 to 0.5, especially preferred being 0.1 to 0.2
b=0.1-10.0, preferably 5 to 9, especially preferred being 6 to 8, and
c,d=0.1-10.0, preferably 0.5 to 4, especially preferred being 0.5 to 3;
and
A
a
B
b
Sb
12
O
x
where
A=Fe, Cr, Ce, V, U, Sn, Ti, Nb and combinations thereof, preferably Fe, V, Sn and Ti
B=Mo, W, Co, Cu, Te, Bi, Zn, B, Ni, Ca, Ta and combinations thereof, preferably Mo and Cu
a=0.1-16, preferably 2 to 12, especially preferred being 4 to 10
b=0.0-12, preferably 1 to 10, especially preferred being 2 to 6, and the value of x depends on the oxidation state of the elements used.
The catalyst can be used either unsupported, or be supported with silica, alumina, titania, zirconia and the like; however, silica is the preferred support. Typically, catalysts envisioned as suitable in the practice of the present invention are disclosed in U.S. Pat. Nos. 3,642,930; 4,485,079; 3,911,089; 4,873,215; 5,134,105 and 5,093,299, herein incorporated by reference.
Reference will now be made in detail to the present preferred embodiments of the invention.
REFERENCES:
patent: 3911089 (1975-10-01), Shiraishi et al.
patent: 4485079 (1984-11-01), Brazdil et al.
Godbole Sanjay P.
Seely Michael J.
Suresh Dev D.
McKane Joseph K.
Murray Joseph
Nemo Thomas E.
The Standard Oil Company
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