SU1567598A1 - Method of removing mercaptanes from petroleum - Google Patents

Abstract

The invention relates to petrochemistry, in particular to the purification of oil from mercaptans. The purpose of the invention is to increase the degree of purification. Cleaning lead by treating the oil with 18 - 25% aqueous solution of alkali and ethyl alcohol. The oil is further treated with a ketone selected from the group consisting of cyclohexanone, methyl ethyl ketone, methyl butyl ketone and acetophenone, taken in an amount of 0.5-1.5 mol per 1 mol of sulfur mercaptan, and formaldehyde, taken in an amount of 0.5-1.5 mol per 1 mol of mercaptan sulfur, in the presence of triethylbenzylammonium chloride, taken in an amount of 0.005 - 0.05 mol per 1 mol of mercaptan sulfur, with a volume ratio of oil - alkali aqueous solution - ethyl alcohol 4: 0.15-0.5: 0 15-0.5. The method allows to increase the degree of demercaptanization of oil 90 88.5 - 100% against 61.5% (by a known method). 1 tab.

Description

This invention relates to methods for purifying petroleum from mercaptans.

The purpose of the invention is to increase the degree of purification of oil from mercaptans.

The invention provides for the purification of oil from mercaptans by sequential treatment with an 18-25% aqueous solution of alkali, ethanol, a ketone selected from the group consisting of cyclohexanone, methyl ethyl ketone, methyl butyl ketone and acetophenone, taken in an amount of 0.5 - 1 , 5 mol per mole of mercaptan sulfur, and formaldehyde, taken in an amount of 0 mol per 1 mol of mercaptan sulfur, in the presence of triethylbenzylammonium chloride, taken in an amount of 0.005-0.05 mol per 1 mol of mercaptan sulfur, in a volume ratio of oil - waterspot creates alkali - ethanol 4: 0.15-0.5: 0,15-0,5Ukazannye reactant ratios are optimum since increasing their consumption does not lead to further increase the degree demerkaptaniza- tion and, therefore, not economically feasible. The processing time is 5 - 15 minutes, the processing temperature is 20 + 5 ° С. The presence of mercaptans in the oil is determined by potentiometric titration.

The invention is illustrated by the following examples.

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Example 1. 20 ml of oil (16.4 g) containing 0.13 wt.% Mercaptan sulfur (0.0007 mol) are placed in a round-bottomed flask equipped with a mechanical stirrer. Then, 2.5 ml of a 20% aqueous solution of sodium hydroxide, 2.5 ml of ethyl alcohol, 0.01 g (0, OOOOA mol) of triethylbenzyl ammonium chloride (TEBAH), 0.07 g (0.0007) are fed into the flask. mol) methyl butyl ketone and 0.066 g of a 32% aqueous formaldehyde solution (0.0007 mol). The mixture is stirred at. The reaction mixture is then transferred to a separatory funnel. Afterwards, the bottom layer is separated. The product (top layer) is washed to neutral, the reactions are dried with calcined calcium chloride and quantitated for mercaptans. The degree of demercaptanization is 99.2%. The smell of mercaptans is absent.

Example2. 20 ml of oil (16.2 g) containing 0.05% w / w% mercaptan sulfur (0.00025 mol) are placed in a round-bottom flask equipped with a mechanical stirrer. Then, 2.5 ml of a 25% aqueous solution of caustic soda, 2.5 ml of ethyl alcohol, 0; 003 g (0.00001 mol) of TEBACH, 0.025 (0.00025 mol) of methyl butyl ketone 0.023 g (0.00025) are fed into the flask. mol) 32% -roi formaldehyde aqueous solution o The mixture is stirred at 20 ° C for 10 minutes. The purified product is then isolated as in Example 1, and quantitated for mercaptans. The degree of demercaptanization is 99.6%.

Examples 3-23. Demercaptanse oil is carried out in the same way as in example 1 with a different ratio of reagents.

Conditions and results of cleaning are presented in the table.

When refining oil with a mercaptan sulfur content of 0.13 wt.% By the method according to a known method, the degree of sweetening is 61.5%.

The data presented in the table show that the processing of oil by the method according to the invention makes it possible to increase the degree of demercaptanization of oil in comparison with the known (8 & and 61.5%, respectively) and thereby simplify its processing. In this case, according to the table in examples 1-16, 21, methyl butyl ketone is used, in 17 and 20 - methyl ethyl ketone, in 18 and 23 - cyclohexanone, in 19 and 22 - acetophenone.

Claims (1)

Invention Formula The method of purification of oil from mercaptans by treating with an 18-25% aqueous solution of alkali and ethyl alcohol, characterized in that, in order to increase the degree of purification, the oil is further treated with a ketone selected from the group containing: cyclohexanone, methyl ethyl ketone — methylbutyl ketone and acetophenone, taken in an amount of 0.5-1.5 mol per 1 mole of mercaptan sulfur, and formaldehyde, taken in an amount of 0, 5 mol per 1 mole of mercaptan sulfur, in the presence of triethylbenzylammonium chloride, taken in an amount of 0.005- 0.05 mol per 1 mol of mercaptan sulfur, and the volume ratio of oil - alkali aqueous solution - ethyl alcohol, equal to 15-0.5: 0.15-0.5. 18% water solution caustic soda water solution caustic soda Editor M. Nedoluzhenko Compiled by M. Kolesnikov Tehred M. Khodanich Proofreader L. Patay, Order 1301 Circulation 437 VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab., 5 Production and publishing plant Patent, Uzhgorod, st. Gagarin, 101 Subscription