JPS5891023A - Separation of gas - Google Patents

Abstract

PURPOSE:To economically separate and recover high purity CO from a gaseous mixture by separating CO from the mixture in the form of a metallic carbonyl compound and decomposing the carbonyl compound. CONSTITUTION:A metal forming a metallic carbonyl compound such as Ni, Fe, W or Co is used. For example, when Ni is used, a gaseous mixture F1 contg. CO is fed to a reactor 1 kept at about 45-50 deg.C and brought into contact with active Ni(F2) obtd. by thermally decomposing nickel formate to react Ni with CO, forming Ni(CO)4. The resulting gaseous mixture is introduced into a module 2 for separation provided with asymmetric separating membranes made of polyvinylidene fluoride, and in the module 2 the Ni(CO)4 is separated. It is thermally decomposed at about 200 deg.C in a decomposition tower 3 to recover CO, and the resulting active Ni is recycled to the reactor 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel method for separating carbon monoxide.

Regarding the separation of carbon monoxide, cryogenic separation methods, liquid preparation cleaning methods, and the like have been conventionally known. Recently, the 0O8ORB method, etc., which can economically recover high-purity co, has been developed.

The present invention relates to an economical method for separating high-purity carbon monoxide that differs from conventional methods.

That is, carbon monoxide in a gas mixture containing carbon monoxide is reacted with a metal that forms a metal carbonyl compound to form a metal carbonyl compound, and only the metal carbonyl compound is separated by a separation membrane or by other methods. This method of separating carbon monoxide is characterized by decomposing it into carbon monoxide and metal at a humidity higher than the decomposition humidity of a metal carbonyl compound, and separating only -carbon oxide.

Metals that form metal carbonyl compounds include Ni and F.
e, W, Co, Mu, V, Nb, Mo, Tc, Ru,
Rh, Ta.

Or, Os, ■r, etc. can be used. When these metals or metal compounds are reacted with carbon monoxide, Kinjo carbonyl compounds are formed. The metal itself also combines with carbon monoxide to form a neutral carbonyl compound, but the method of forming a metal carbonyl compound is to reduce the metal oxide with hydrogen etc. without losing its activity and convert it into metal powder or grains. It is desirable to react carbon monoxide with the active metal obtained by adjusting or pyrolyzing the metal compound. The reaction between the active metal thus obtained and carbon monoxide is carried out under reaction conditions ranging from room temperature to 200° C. and from normal pressure to about 300° C. depending on the type of carbonyl. For example, in the Ni carbonyl compound, gaseous nickel carbonyl u
1(co)4 can be obtained. Since a metal carbonyl compound easily decomposes when heated, it is possible to separate the obtained metal carbonyl compound into carbon monoxide and metal by heating the metal carbonyl compound to a temperature higher than the respective decomposition humidity.

Next, a method for separating the metal carbonyl compound reacted with Co in the mixed gas from other mixed gases will be explained.

Separation methods include extracting it in liquid form and separating it from other mixed gases in gaseous form using a separation membrane, but from the viewpoint of energy efficiency, it is desirable to use a separation membrane. As for the method of separating metal carbonyl compounds from other mixed gases using a separation membrane, a conventionally known method using an asymmetric membrane or a composite membrane can be applied. It is necessary to select the optimal separation membrane depending on the type of metal carbonyl compound and mixed gas, but - by converting carbon oxide into a metal carbonyl compound, the molecular weight becomes larger than that of normal gas, making it difficult to mix with other mixed gases. It becomes possible to perform separation efficiently.

[Metal carbonyl compounds separated by other methods can be heated above the decomposition temperature and decomposed into metal and carbon i-oxide to obtain carbon oxide with high purity. The metal separated from carbon monoxide by thermal decomposition remains activated, and it is economically effective to react with the supplied mixed gas again and reuse it.

The following will be explained according to examples.

Example L 0040%, N230%, 0 shown as F□ in Figure 1
Mixed gas of 30% H4 at 80℃~l OOtl, la
N1 in a live honey state obtained by thermally decomposing nickel formate at 200°C under the conditions of tm (indicated by F2 in Figure 1) was reacted in the reaction vessel 1 shown in Figure 1 to produce N1 (00,), 40 %N2
A mixed gas of 30%, OH, and 30% was obtained. From this mixed gas, N and 1(Co, )4 were separated by a separation module 2 consisting of a vinylidene fluoride asymmetric membrane shown in FIG. , the concentration of separated Nt(,co)4 was 85%, and the remaining gas was N2:10% OH4:15%. A mixed gas containing 85% N1(Co)4 was completely decomposed at 200°C in the decomposition column 3 shown in Figure 1 to obtain CO containing 10% N, 15% C and H4. . At the same time, it was obtained by decomposition and recycled.

[Brief explanation of drawings]

FIG. 1 is a flow sheet showing an example of the present invention. Reaction can...1 Separation module...2 Decomposition tower...3 Patent Applicant: Toyo Viki Meidai Company

Claims (4)

[Claims] (1) A gas separation method characterized by converting carbon monoxide in a mixed gas into a metal carbonyl compound, separating the metal carbonyl compound from other gases, and then decomposing the metal carbonyl compound and separating carbon monoxide. . (2) The separation method according to claim 1, in which the metal carbonyl compound is separated from other mixed gases using a separation membrane. (3) The metal carbonyl compound is Ni, Fe, W,
Co, Mn. v, Nb, Mo, Tc, Ru, Rh, T
The separation method according to claim 1, wherein the separation method is obtained from metals such as a, W, Re, Os, and R. (4) The separation method according to claim 1, wherein the metal obtained by decomposing the metal carbonyl compound is re-reacted in a mixed gas containing carbon monoxide and recycled.