SU823418A1 - Method of purifying hydrocarbon raw materials from mercaptans - Google Patents

Description

(54) METHOD FOR CLEANING HYDROCARBON RAW FROM MERCAPTANS

: In the first case, the mercaptans are extracted from hydrocarbons in the form of mercaptides by contacting the raw material being cleaned without access, air with an alkaline solution (or with a catalyst complex) containing an alkali metal hydroxide, diethylene glycol, triethylene glycol or their mixtures and metroschlophthalocyanine. The mercaptide saturated alkaline solution (or catalyst complex) is separated from the raw material and subjected to oxidative regeneration with oxygen-containing gas. In this case, mercaptides are oxidized to disulfides, which are insoluble in the catalyst complex and separated from it by simple settling. The regenerated catalyst complex is used to extract the mercaptans from new batches of the feedstock.

In the event that a negative plumbit sample of the raw material being cleaned, such as gasoline, reactive raw material, is required, and the removal of disulfides from the purified sulfur is not required, the extraction of mercaptans from hydrocarbons with the catalyst complex is carried out in the presence of oxygen-containing gas in an amount sufficient to oxidize the mercaptans to disulfides .

Diethylene glycol and triethylene glycol offered as a polar additive are less expensive and scarce reagents in comparison with ethanol and are thermally more stable and their partial dissolution in the raw material being cleaned does not affect the quality of the purified products.

EXAMPLE 1. A 10% alkaline solution obtained after purification of n-heptane from n-butylmercaptan, containing 1.02% by weight of mercaptide sulfur, is subjected to oxidative regeneration, 200 ml of mercaptide containing is charged into the stirred reactor / alkaline solution, O, 0005 g of sodium salt of disulfophthalocyanine cobalt and diethylene glycol, triethylene glycol or mixtures thereof. The oxidation of the mercaptide is carried out at atmospheric pressure by supplying 0.3 l / min of oxygen through a sparger for 50 minutes. In this case, butyl mercaptide is oxidized to dibutyl disulfide. After separation of the dibutyl disulfide, the regenerated alkaline solution is used as an extractant to clean new batches of the feedstock.

The test results on the effect of additives of diethylene glycol, triethylene glycol and their mixtures, as well as monoethanolamine, on the acceleration of the oxidation of mercaptide to disulfides are given in Table. one.

From the table. 1 data shows that using diethylene glycol as a polar additive.

-, triethylene glycol and their mixtures can significantly accelerate the process of oxidation of mercaptans to disulfides compared with the known highly effective additives.

Example2. 100 ml of n-heptane containing 0.7% by weight of mercaptan sulfur as n-butylmercaptan and 100 ml of a catalyst complex prepared by dissolving 0.0003 g of cobalt sodium sulfophthalocyanine sodium salt in 100 ml of a 10% solution are loaded into a stirred reactor. sodium hydroxide containing diethylene glycol, triethylene glycol or mixtures thereof. The oxidation of butyl mercaptan is carried out at atmospheric pressure, supplying 0.3 l / min of oxygen through a sparger for 30 minutes. In this case, butyl mercaptan is oxidized by d-butyl - disulfide. After separation from n-heptane, the catalyst complex is used to clean new portions of the feedstock.

The results of tests on the effect of additives of diethylene glycol, triethylene glycol and their mixtures, as well as monoethanolamine, on the degree of purification of nheptane from n-butylmercaptan are given in table. 2

Data tab. 2 show that the use of diethylene glycol, triethylene glycol and their mixtures as a polar additive allows the extraction process of HOCI mercapt with simultaneous oxidation to disulfides at the level of use of the well-known high-performance, but expensive and scarce additives.

The proposed method of purification of hydrocarbons from mercaptans can be used in the gas and oil refining industries for mercaptans of various hydrocarbons in the hydrocarbon fractions and catalytic regeneration of mercaphide containing alkaline solutions obtained during the purification of natural and liquefied gases from stabilizing gases, thermal cracking and coking and other similar products of processing of high-sulfur oils and gas condensates.

PRI me R 3. Oxidative regeneration is subjected to alkaline solution. obtained after purification of the broad fraction of light hydrocarbons of gas-codensate from mercaptanoe. The spent alkaline solution of the composition, wt.%: caustic. nir 16, Oy mercaptide sulfur 2,150; the rest of the water is regenerated under the CONDITIONS given in Example 1. The mercaptide sulfur in the solution is methyl ethyl, propyl and butyl mercaptide in a ratio, rel.%: 30: 60: 9: 1, respectively.

EXAMPLE 4 An alkaline solution of the composition specified in Example 3 is subjected to oxidative regeneration. A 200 ml mercaptide-containing alkaline solution, 0.0005 g of disulfophthalocyanine sodium salt of disulfophthalocyanine and triglycol or triethylene glycol are charged to a stirred reactor. Oxidation of sodium marcaptides is carried out at atmospheric pressure, supplying 0.3 l / min of oxygen through a sparger until a mercapot1TID of 95% conversion to disulfides is achieved, and the time for solution regeneration is determined. ; The results are shown in Table. four.

J Example5. Under the conditions given in Example 2, the condensate gas cTj is purified from mercaptans. 30-280 with and

the content of mercaptan sulfur 16,131 air force.%.

fO

 The results are shown in Table. five.

.Table

Diethylene glycol

Also

 II

Triethylene glycol

Also

Diethylene glycol + triethyl glycol (1: 1)

Same Monoethanolamine

Diethylene glycol Same -

Triethylene glycol Same

- -

Diethylene glycol + glycol fl: l)

Same Monoethanolamine

0.127 87.5 0.075 92.6 0.122 88.0

87.3

0.128

92.3

0.078

1.8 92.3 0.078 4.0

0.128

87.3

0.5

/ 90,4

0.098 4.0 52.5 0.480 5.0

Table 2

94.3

0.043 96.7 0.02.5 95.6 0.033 0.048 93.6

h 96.7

0.025 95.6 0.033 93.7 0.047 0.033 95.6 93.5 0.049

Diethylene glycol + triethylene glycol (1: 1)

4.0

Table3

0.070

91.4

From the table. 1.3 and 4 data shows that the use of alkaline as an additive to alkalis in pacTB (% iy diethylene glycol, triethylene glyxsh and their mixtures during the regeneration of mercaptide-containing solutions allows for a regeneration time (50: min) to increase the degree of conversion; the degree of regeneration of the solution is 95% and accelerate the process of circulating mercaptides and disulfides ..

FROM listed in table. 2 and 5, it can be seen that using diethylene glycol as an additive to an alkaline solution, three ethyl lick OITH and their mixtures in the purification of hydrocarbons from mercaptans by extraction with an alkaline solution with simultaneous oxidation of mercaptids to disulfides allows a process with a high degree of purification.

Claims (2)

1. A method for purifying hydrocarbon feedstocks from mercaptans by oxidizing the latter with an oxygen-containing gas in an aqueous solution of alkali when heated in the presence of a phthalocyanine catalyst with a polar additive, characterized in that, in order to increase the degree of purification, as a polar additive 0 use diztilyl glycol, triztilen glycol or their mixtures. , 24 The method according to p. 1,. it is also distinguished by the fact that the polar additive is used in the amount of 0.5-4.0% of the volume of the aqueous alkali solution. five Sources of information taken into account in the examination 1. The patent of the USSR No. 355805, cl. C 10 G 27/06, 1973. 2. USSR author's certificate 0 513069, class C 10 O 27/06, 1978.