JPS592319B2 - Rubber volatile oil manufacturing method - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for producing rubber volatile oil.

More specifically, the present invention relates to a method for producing a low-toxicity rubber volatile oil containing naphthenic hydrocarbons as a main component and containing few aromatic hydrocarbons such as benzene, toluene, and xylene.

Traditionally, rubber volatile oil is generally a hydrorefined product of straight-run gasoline,
Reformed straight-run gasoline, residual oil obtained by extracting aromatic hydrocarbons such as benzene, toluene, and xylene from reformed straight-run gasoline with solvents such as glycols and sulfolane (hereinafter referred to as reformed aromatic extracted residual oil) ), etc., and then mixed with benzene, toluene, and xylene again to adjust the aniline point.The product is generally produced with a boiling point range of 70 to 170°C and an aniline point of 50°C or less. are doing.

In this S, the aniline point is a scale that indicates the solvency power, and the lower the value, the higher the solvency power. Generally, aromatic hydrocarbons have a low aniline point, and naphthenic hydrocarbons have a low aniline point. However, recently aromatic hydrocarbons such as benzene, toluene, and xylene have a negative effect on the human body, so in order to improve the working environment, Kohiro volatile oil with a low content of these aromatic hydrocarbons has been produced. In particular, the Ministry of Labor Ordinance's Regulations for Prevention of Hazards from Specified Chemical Substances, etc., have a Teha-Hensen content of more than 1v01%, and the Organic Solvent Poisoning Prevention Regulations, which have a total of more than 5wt% of toluene and xylene, have been strongly requested. Due to its negative effects on the human body, its handling is strictly restricted.

Therefore, it is strongly desired to produce a rubber volatile oil that does not exceed these contents and has an aniline point of 50°C or less, preferably as low as possible, but these qualities cannot be satisfied using conventional production raw materials and production methods. I can't.

That is, 70 to 17, which is the boiling point range of normal rubber volatile oil.
Targeting the 0°C fraction, most straight-run gasoline and reformed aromatic extracted residual oil are rich in paraffinic hydrocarbons with a high aniline point, and rubber volatile oil with an aniline point of 50°C or less is produced. In order to do this, it cannot be produced unless a large amount of aromatic hydrocarbons such as benzene, toluene, and xylene are mixed with them.

We also hydrogenate reformed straight-run gasoline rich in aromatic hydrocarbons or aromatic hydrocarbons such as benzene, toluene, and xylene, and use this as raw material to produce rubber volatile oil with a high naphthenic hydrocarbon content. Although there is a method to do this, it is not practical because it requires a large amount of hydrogen when hydrogenating aromatic hydrocarbons and the raw materials themselves are expensive, increasing production costs.

The present invention was made in order to solve the above problems, and it is possible to obtain an aromatic aroma by using a conventional solvent extraction operation from the hydrorefined product of pyrolysis gasoline, which is produced as a by-product when producing ethylene, propylene, etc. by pyrolysis of hydrocarbon oil. A rubber volatile oil with an aniline point of 50°C or less, rich in naphthenic hydrocarbons, containing 1 vol% or less of benzene and 5 wt% or less of toluene and xylene in total, is produced by precision distillation of the residual oil from which group hydrocarbons have been separated. It's a method.

That is, the present invention is a conventional extraction operation using glycols, sulfolane solvents, etc. from hydrorefined pyrolyzed gasoline, which is produced as a by-product when ethylene, propylene, etc. are produced by pyrolysis of hydrocarbon oils such as straight-run gasoline. The extracted residual oil from which aromatic hydrocarbons have been removed is mainly used as a raw material for gasoline production, reformed oil production, ethylene production, etc.
However, this extracted residual oil contains a large amount of naphthenic hydrocarbons, and the content of aromatic hydrocarbons such as benzene, toluene, and xylene is small, so this extracted residual oil is subjected to precision distillation. The boiling point range is 70~170℃
This method produces rubber volatile oil containing less than 1 vol% of benzene, less than 5 wt% of toluene and xylene in total, rich in naphthenic hydrocarbons, and an aniline point of less than 50°C at a lower cost than conventional methods. This made it possible to do so.

Next, the hydrorefining used in the present invention mainly refers to
The hydrocarbon fraction No. 8 is hydrogenated using a nickel-based catalyst in the first stage, and a cobalt- or molybdenum-based catalyst in the second stage, while simultaneously removing impurities such as sulfur. It's a method.

In addition, a normal solvent extraction operation involves separating aromatic hydrocarbons such as benzene, toluene, and xylene from other components using a solvent.
Sulforane, arturpan, etc. are used.

In addition, precision distillation operation refers to, for example, removing soft hydrocarbons from the top of the first column using a precision distillation apparatus consisting of two distillation columns, and removing soft hydrocarbons from the top of the second column to obtain rubber with a target boiling point range. This is an operation to produce volatile oil.

In this case, it is acceptable to remove soft hydrocarbons and heavy hydrocarbons from the top and bottom of a precision distillation apparatus consisting of one distillation column, respectively, and produce rubber volatile oil with the desired boiling point range from the center of the column. do not have.

Further, the reason why the aniline point is set to be 50°C or lower is that if the temperature exceeds 50°C, the solubility of the rubber deteriorates.

Next, comparing the rubber volatile oil produced by the method of the present invention with the rubber volatile oil produced by the conventional method, the following table shows that the content of aromatic hydrocarbons such as benzene, toluene, and xylene is small, and the content of naphthenes is small. It can be seen that many hydrocarbons have a low aniline point, have excellent dissolving power, and can be used as a low-toxicity substitute for rubber volatile oil.

The rubber volatile oil produced by the method of the present invention, like conventional rubber volatile oils, can be used not only for manufacturing rubber products but also for paints, adhesives,
Of course, it is used in a variety of applications as a solvent for extraction, degreasing, agricultural chemicals, ink, dry cleaning, etc.

Next, embodiments of the present invention will be described in more detail with reference to flowsheet diagrams, but the present invention is not limited to the following examples unless the gist thereof is exceeded.

In the figure, when straight-run gasoline A, which is a hydrocarbon oil, is treated in a pyrolysis and distillation apparatus 1, a fraction B such as ethylene propylene, a pyrolysis gasoline fraction C1, residual oil, and other fractions are decomposed.

This pyrolyzed gasoline fraction C is further processed in the distillation apparatus 2 to produce a fraction E mainly having 5 or less carbon atoms, a fraction F mainly having 6 to 8 carbon atoms, and a fraction G mainly having 9 or more carbon atoms.
separated into

The fraction F, which mainly has 6 to 8 carbon atoms, is passed through the primary hydrorefining unit 3 and the secondary hydrorefining unit 4 to hydrogenate olefinic hydrocarbons and to obtain fractions rich in naphthenic hydrocarbons, etc. This is referred to as fraction H from which impurities have been removed.

Next, this fraction H is passed through a sulforane extractor 5 and separated into an aromatic hydrocarbon fraction I such as benzene, toluene and xylene, and an extracted residual oil fraction J.

This extracted residual oil fraction J is introduced into precision distillation equipment 6 and 7 consisting of two distillation columns, and the boiling point is 70°C from the top of column 6.
The following fraction K is separated, and the boiling point range is 70 to 70 from the top of the column.
It is separated into a fraction at 170°C and a fraction M at 170°C or higher.

This fraction is the rubber volatile oil obtained by the method of the present invention.

[Brief explanation of drawings]

The drawing is a flow sheet diagram showing an example of the method of the present invention. 1...Pyrolysis and distillation device, 2...Distillation device, 3 and 4...Hydrorefining device, 5...
...Sulforane extraction device, 6 and 7...
... Precision distillation equipment, A ... Straight-run gasoline fraction of raw material hydrocarbon oil, C ... Pyrolysis gasoline fraction,
J...Extraction residual oil fraction, L...Rubber volatile oil fraction.

Claims (1)

[Claims] 1. Aromatic hydrocarbons are separated from the hydrorefined product of pyrolyzed gasoline, which is produced as a by-product when pyrolysis of hydrocarbon oil is produced by pyrolysis, by ordinary solvent extraction, and the residual oil is separated by precision distillation. ttehensenka 1v01%
The following is a method for producing a rubber volatile oil containing a total of toluene and xylene of 5 wt % or less, rich in naphthenic hydrocarbons, and having an aniline point of 50° C. or less.