Organic compounds -- part of the class 532-570 series – Organic compounds – Nitriles
Patent
1997-10-07
1999-02-02
Richter, Johann
Organic compounds -- part of the class 532-570 series
Organic compounds
Nitriles
C07C25300
Patent
active
058667083
DESCRIPTION:
BRIEF SUMMARY
This application is a 371 of PCT/JP96/00945 filed Apr. 5, 1996.
TECHNICAL FIELD
The present invention relates to a process for producing an .alpha.,.beta.-unsaturated nitrile which comprises the ammoxydation of propylene, isobutylene, tertiary butyl alcohol, propane or butane to prepare an .alpha.,.beta.-unsaturated nitrile having the same number of carbon atoms as the olefin, paraffin or tertiary alcohol used as a starting material in a high yield.
More particularly, the present invention relates to a process for producing an .alpha.,.beta.-unsaturated nitrile using a novel reactor for effecting the gas phase reaction of ammonia, an oxygen-containing gas and an olefin, tertiary butyl alcohol or paraffin over a fluidized bed to produce an unsaturated nitrile such as acrylonitrile and methacrylonitrile, wherein the reactor is arranged such that the pressure loss in an orifice attached to the jetting portions in an oxygen-containing gas dispersing plate or pipe and the pressure loss in an orifice attached to jetting portions in a pipe for dispersing a mixture of ammonia, and an olefin, tertiary butyl alcohol or paraffin (hereinafter referred to as "mixed gas") are controlled.
BACKGROUND ART
Ammoxydation has long been industrially practiced. Many improvements have been made for ammoxydation from the standpoint of catalyst. However, few proposals have been made for the structure of an apparatus (sparger) for supplying and spraying the starting material. It is disclosed in U.S. Pat. No. 4,801,731 (JP-A-2-258 (The term "JP-A" as used herein means an "unexamined published Japanese patent application")). All these proposals feature the disposition of an oxygen gas exit orifice and a propylene/ammonia exit orifice opposed to each other.
British Patent 1,265,770 describes the provision of a sparger disposed in the form of a ring on the peripheral portion of the reactor. However, the object of this arrangement is to prevent the accumulation of a catalyst on the peripheral portion of the reactor. No reference is made to reactivity.
Few proposals have been made for the structure of dispersing plate or dispersing pipe. In particular, the pressure loss in a dispersing plate or dispersing pipe is disclosed in Daizo Kunii, Fluidization Engineering, Octave Levenspiel, John Wiley & Sons. Inc., page 87 (1969). In this reference, 0.1 times the pressure loss in a fluidized bed is recommended as the pressure loss required for fluidized gas dispersing pipe or dispersing plate. However, it was found that if gases are supplied through two systems in an industrial scale apparatus having a column diameter of not less than 3 m, the distribution of the supplied gas concentration is localized under the foregoing conditions, resulting in the reduction of the yield of the objective unsaturated nitrile.
DISCLOSURE OF THE INVENTION
An object of the present invention is to provide a process for producing an .alpha.,.beta.-unsaturated nitrile by an ammoxydation reaction, particularly by the supply of reaction gases through two system, in which the conversion of the reaction is enhanced by focusing the local distribution of concentration of reaction gases in the reactor.
The above and other objects and effects of the present invention will be more apparent from the following description.
The present invention relates to a process for producing an .alpha.,.beta.-unsaturated nitrile, the process comprising the step of: isobutylene, a paraffin selected from propane and butane, and tertiary butyl alcohol; ammonia; and an oxygen-containing gas, in a reactor at a high temperature in a gas phase over a fluidized bed, so as to prepare an .alpha.,.beta.-unsaturated nitrile having the same number of carbon atoms as the hydrocarbon as a starting material, said reactor vessel, an oxygen-containing gas dispersing plate or pipe and a mixed gas dispersing pipe for dispersing a mixed gas of the hydrocarbon and said ammonia, controlled to the range of from 0.6 to 3.0 times a pressure loss in the fluidized bed.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 s
REFERENCES:
patent: 4801731 (1989-01-01), Jordan
patent: 4849537 (1989-07-01), Ramachandran et al.
patent: 4849538 (1989-07-01), Ramachandran et al.
patent: 5256810 (1993-10-01), Rowe et al.
Ohta Masanobu
Shimizu Hideyuki
Asahi Kasei Kogyo Kabushiki Kaisha
Murray Joseph
Richter Johann
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