JPH0338531A - How to remove mercaptans - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for removing mercaptans from mixtures containing trace amounts of mercaptans.

[Problems to be Solved by the Prior Art and the Invention] Mercaptans emit a characteristic odor even when present in extremely small amounts, posing problems in handling. The common methods for removing mercaptans contained in hydrocarbons, aromatic compounds, etc. include sulfuric acid washing, alkaline washing, and water washing, but these methods require complicated steps and are inert to sulfuric acid and alkalis. It has limitations such as it cannot be used unless it is liquid.

Furthermore, it is also difficult to completely remove only mercaptan by selective extraction, distillation, etc.

Therefore, it has been desired to develop a simple and effective method for removing mercaptans.

[Means for solving problems]

The present invention is a mercaptan removal method characterized by treating a mixture containing a trace amount of mercaptan as an impurity with a lead compound and/or a copper compound.

Examples of lead compounds used in the present invention include dilead tetroxide,
Examples include lead oxide, lead dioxide, and mixtures thereof.

Examples of copper compounds include copper carboxylates such as copper formate, copper acetate, copper citrate, copper oleate, and copper naphthenate.
[I) Salt is preferred. In addition, for example, inorganic copper salts such as sulfuric acid steel and chlorinated steel, copper complexes such as copper acetylacetonate, and mixtures thereof can also be used. These lead and copper compounds are effective when used alone or in combination.

Examples of the mercaptan-containing mixture of the present invention include hydrocarbons such as hexane, octane, petroleum ether, benzene, toluene, xylene, ethylbenzene, naphthalene, and tetralin, and halogenated hydrocarbons! , alcohols, ethers, acetals, ketones, esters such as methyl acetate and methyl butyrate, carboxylic acids such as acetic acid, propionic acid and butyric acid, phenols, water and mixtures thereof.

Examples of the mercaptan include methyl mercaptan, ethyl mercaptan, propyl mercaptan, butyl mercaptan, octyl mercaptan, and mixtures thereof.

In carrying out the present invention, first a lead and/or copper compound is added to a mixture containing a trace amount of mercaptan.

A mixture containing trace amounts of mercaptan is usually about 0
．． This means that it contains 3% by weight or less of mercaptan, but it may contain more than this.

It is preferable to use the lead and copper compounds in the form of powder, granules, or the like.

The amount of lead and/or copper compound added is preferably 0.05 to 5 parts by weight per 1 part by weight of mercaptan contained as an impurity.

The mixture with the addition of lead and/or copper compounds is then maintained, preferably with stirring, for 0.5 to 10 hours. The treatment temperature is 0 to 60°C, preferably room temperature to 40°C.

By this treatment, mercaptan contained as an impurity can be removed.

The obtained treatment liquid can also be distilled. in this case,
After removing lead and/or copper compounds by filtration, centrifugation, etc., or without removing lead and/or copper compounds, distillation can be performed as is.

The present invention will be explained in more detail with reference to Examples below.

Example 1 7200 g of hexa containing 11000 pp of butyl mercaptan was placed in a 300 m1 Mitsuro flask equipped with a stirrer, 0.5 g of dilead tetroxide was added, and the mixture was heated at 25°C and 30 Orpm.
Stir for an hour. After the treatment, a Liebig condenser was attached and about 98% hexane was removed by simple distillation, and the distillate was quantified for butyl mercaptan by hydrogen flame gas chromatography, and it was found to be below the quantification limit (10 pp).

Example 2 As a result of replacing hexane with toluene in Example 1 and treating the same pond in the same manner, butyl mercaptan was not detected in the distillate.

Example 3 In Example 1, hexane was replaced with acetic acid and dilead tetroxide was replaced with acetic acid steel. Butyl mercaptan was not detected in the liquid after treatment.

Example 4 In Example 1, hexane was replaced with ethyl acetate, and dilead tetroxide was replaced with copper II heptanoate. Butyl mercaptan was not detected in the treated liquid or in the distillate obtained by simple distillation in the same manner as in Example 1.

Example 5 The same procedure as in Example 3 was carried out except that acetic acid was replaced with water. Butyl mercaptan was not detected in the liquid after treatment.

Example 6 The same procedure as in Example 1 was carried out except that butyl mercaptan was replaced with octyl mercaptan, and hexane was replaced with water. No octyl mercaptan was detected in the liquid after treatment.

Claims (1)

[Claims] 1. A method for removing mercaptan, which comprises treating a mixture containing a trace amount of mercaptan with a lead compound and/or a copper compound. 2. The method according to claim 1, characterized in that distillation is carried out after the mercaptan-containing mixture has been treated.