# Patent

## Title
Catalyst and method for alkli-free purification of oil raw materials from mercaptans

## Abstract

A catalyst for alkali-free purification of oil raw material, consisting of a metalocomplex selected from the group consisting of a solid metalocomplex and a liquid metalocomplex with a general formula (CuIICl)2O(L1)2-4(L2)1-4, where L1 is amino alcohol L2 is acetonitrol or single atom alcohol.

## Background
BACKGROUND OF THE INVENTION
The present invention relates to catalysts for purification of gaseous condensate and oil fractions from mercaptans and can be used in oil-processing and in petrochemical industry.
Usually oxidation of mercaptans is performed by oxygen or air at room or elevated temperature in the presence of homogenous or heterogeneous catalyst based on a transitional metal:

2RSH+1⁄202→RSSR+H20

Mercaptans are extracted from organic phase by strongly alkali aqueous solutions, in which at elevated temperature and pressure catalytical oxidation of mercaptans takes place, and as a catalyst salts from metals of alternating valency (Fe, Co, Ni, V, Mn, Cr) in the form of simple or complex compositions, more often phatocyanites (as disclosed for example in European patent no. 394571, German patent 3008284 and others). The catalysts of this type provide sufficiently complete removal of mercaptans. Their common disadvantage is not sufficient availability and high cost of phatocyanites, which leads to making the process of purification expensive. Moreover, the necessity to conduct the process in strongly-alkli medium leads to a significant corrosion of equipment and worsening of the properties of oil pipelines.
It is known that phtalocyanines in catalytical compositions can be replaced with other compounds of transitional metals.
A catalyst are known based on metallo-organic derivatives of metals of VIA, VIIA, and VIII groups with general formula Mea(R)x(CO)y where R is aromatic ligand, for example benzol or its alkyl derivatives, antrazen, benzpirin, phenanthren (U.S. Pat. No. 3,053,756). Disadvantages of such catalysts include their low stability, high cost and toxicity.
A catalyst for oxidating demercaptanization of carbohydrates is known which is a helate complex of a transitional metal with bi, tri, or tetra dentant ligand, containing at least one amide group (French patent 2,573,087). In particular, replaced 2-(alkyl(aryl, alkylary))-aminocarboxypyriditines and others even more complicated compounds are utilized. As a metal it can be Co, Fe, Cu, Ni, Mn. The disadvantage is a low stability of the catalyst and use for its manufacture of expensive and scarce components.
Also, catalysts of oxidating demercaptanization are known-complexes of copper with tetracyantiophenol and tetracyandentin (French patent 2591610). These catalysts provide high degree of purification, but their practical use is questionable because their very high cost and scarce availability of the components.
A method of oxidative demercaptanization are known which is performed by oxidation of mercaptans with oxygen of air in presence of helate complexes of a transitional metal (Co, Fe, Cu, Ni, Mn) with polydentan ligand from the class of amides, in particular from aminocarboxyperidines (French patent 2573087). The main disadvantage of the method with the use of this catalyst is high cost of its components.
A heterogeneous catalyst is described, based on complexes of copper with amino derivatives (aminoalcohols, aminoacids, amines) applied on a mineral carrier or activated coal (European patent 996500). The disadvantage of this catalyst is a low content of active phase on the surface of the carrier, which inevitably leads to a significant consumption of the heterogeneous catalyst.
The closest solution to the present invention is disclosed in U.S. patent no. In accordance with this patent, a catalyst of alkali-free purification of oil fractions from mercaptans is proposed, which contains a copper oxide, a complex of copper with nitrogen-containing compound of amines, aminoalcohols, aminoacids, or amids and an inert carrier. The disadvantage of this method is a complex technology for producing catalyst and a high consumption of the carrier, which makes the catalyst quite expensive.
SUMMARY OF THE INVENTION
The objective of this invention is to reduce the cost of a catalytic composition by eliminating utilization of a mineral carrier and using solid or liquid complexes which contain a copper chloride, aminoalcohol and acetonitryl or single-atom alcohol selected from isopraponal, butanol, isobutanol, and pentanol.
In accordance with the invention a catalyst is proposed for alkali-free purification of oil raw materials, consisting of a metalocomplex selected from the group consisting of a solid metalocomplex and a liquid metalocomplex with a general formula (CuIICl)2O(L1)2-4(L2)1-4, where L1 is amino alcohol, L2 is acetonitryl or single atom alcohol.
In accordance with a further feature of the invention as the aminoalcohol a compound of a general formula N(R1)(R2)(R3)(OH)1-3 is utilized, where R1=C2H4, R2=H, C2=H, C2H4, C2H5, R3=H, C2H4, CnH2n+1, where n=2-17.
In accordance with still a further feature of the invention as a single atom alcohol a substance selected from the group consisting of isopropanol, butanol, isobutanol and pentanol is utilized.
The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims.


DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention resides, in a catalyst for purification of oil raw material with the use of a metalocomplex of general formula (CuIICl)2O(L1)2-4(L2)1-4, wherein L1 is amino alcohol of the general formula N(R1)(R2)(R3)(OH)1-3, wherein R1=C2H4, R2=H, C2H4, C2H5, C2H5, R3=H, C2H4, CnH2n+1, wherein n=2-17, L2 is acetonitryl or the above mentioned alcohol.
The metal complex is synthesized in acetonitryl or alcohol starting from CuCl and aminoalcohol at 45-50° C. in air.
The catalyst actively oxidizes mercaptans and hydrogen sulfide with oxygen of air at temperature 22-120° C. and at atmospheric pressure.
The objective of the present invention can not be achieved if at least one of the above mentioned components of catalytic complex are not used or the conditions of synthesis are not complied with, for example:

    
    
        If instead of copper chloride CuCl2 is used or another salt is used (nitrate, sulfate, stearate, etc.)
        If amino alcohol is not used, the complex is not active;
        If as a solvent acetylnitryl or alcohol is not used, the activity of catalyst is reduced. For example, if acetylnitryl is replaced with chloroform, the activity of catalyst is reduced three times.
    
    


Therefore, the present invention resides in a catalyst of oxidating alkali-free demercaptanization of oil, gas condensate or oil fraction based on a metalocomplex of the above mentioned composition.
The present invention is illustrated by the following examples.
EXAMPLE 1
Producing of Solid Metalocomplex
100 ml of saturated solution of CuCl in acetonitryl (the solution contains 8 g of CuCl) is introduced into a flat-bottom container of 200 ml at room temperature, and heated to 45-50° C. With continuous steering by a magnetic stirrer, slowly (in 30-40 min) from a peeped 20 ml of solution of monoethanolamine in acetonenitryl is introduced into the container (solution is prepared by mixing of 17 ml of monoethanolamine and 100 ml of acetonitryl).
The precipitated substance of blue-green color is separated from a mother solution on a filter, dried on air and then in a drying cabinet at 100-105° C. The obtained dry complex contains 9.2-9.5 g. Before testing the solid catalyst is comminuted in a porcelain dish. This way, catalyst A is produced. Catalyst B and C were produced analogously, but instead of monoethanolamine, dimethylamineethanol ethanol and three ethanolamine were utilized
EXAMPLE 2
Production of Liquid Metalocomplex D-F
20 ml of aminoalcohol Atmer 163 which is a mixture of isomers with the composition RN(CH2CH2OH)2, where R=CnH2n+1 n=16-17 and 20 ml isobutanol is introduced into a flat bottom container. During mixing and heating to 45-50° C. in air, slowly 10 g CuCl is added. As a result, a dark-brown dense liquid is produced. Before testing, the obtained liquid complex D is dissolved in an excessive quantity of isobutanol to concentration Cu(II) 1-1.5%. Catalyst E and F are produced analogously, but instead of isobutanol, butanol and isopropanol were added.
EXAMPLE 3
Production of Liquid Metalocomplex H
20 ml of triethanolamine and 10 ml of pentanol are introduced into a flat bottom container. During heating and mixing to 50-55° C., slowly 12 g CuCl is added. As a result, a dark-green dense liquid is formed. Before testing the obtained liquid complex H is dissolved in an excessive quantity of pentanol to concentration Cu (II) 1.15%.
EXAMPLE 4
Purification of Kerosene on Solid Catalyst
A reactor with a magnetic stirrer is utilized, which is formed as a four-neck flat-bottom container with volume of 350 ml, composed OF molybdenum glass and provided with swdlwfmROE, a system of air and oxygen supply and a glass pipe for taking samples A kerosene fraction with a content of mercaptide sulfer 80 ppm, a batch of catalyst A (ratio of raw material to catalyst is 62000 ml/g) and Teflon magnetic stirrer were are introduced. The reaction time was four hours. During this time the content of sulfur was reduced to 30 ppm. The samples were taken with interval of 0.5 hour.
EXAMPLE 5
Purification of Fuel Oil of Gas Condensate on Solid Catalyst
The process was conducted as in Example 2 but instead of kerosene, fuel oil from gas condensate was used, which contained 1200 ppm of mercaptide sulfur (a gas condensate was used which was distilled in interval 56-354° C. with density 0.77 g/cm3 and content of moisture 0.04% mass). The ratio of raw material to catalyst was 7000 ml/g. The temperature of reaction was 120° C. In 1 hour the concentration of sulfur was reduced to 590 ppm.







TABLE 1







Test results of purification of kerosene and gas condensate on solid


catalyst.













Ratio of






raw






material:

Content of Mercaptan



Petroleum
Catalytical

sulfur, ppm













product to
Solution
Temperature
In Raw
After the


Catalyst
be Purified
(ml/MI
° C.
Material
Reaction















A
Kerosene
120000
70
80
 4 hours-20


A
Kerosene
62000
22
80
10 hours-40


A
Fuel Oil
7000
45
1200
10 hours-800


B
Kerosene
62000
70
80
 4 hours-25


B
Fuel Oil
7000
120
1200
 2 hours-450


C
Kerosene
100000
70
80
 4 hours-25









EXAMPLE 6
Purification of Fuel Oil from Gas Condensate with the use of Liquid Catalyst
Liquid complex D is dissolved in an excessive quantity of isobutanol to concentration Cu (II) 1%. Into the reactor described in Example 4, fuel oil was introduced with content of mercaptide sulfur 1200 ppm. The ratio of raw material to solution of catalyst 2000 ml/ml. Temperature of reaction was 100° C. In two hours the concentration of sulfur reduced to 550 ppm.
With increase of concentration of liquid complex in isobutanol to Cu (II) 1.5%, with the same conditions in 2 hours the concentration of sulfur reduced to 450 ppm.







TABLE 2







Test results of purification of kerosene and gas condensate with the


use of liquid metalocomplex.













Ratio of






raw






material:

Content of Mercaptan



Petroleum
Catalytical

sulfur, ppm













product to
Solution
Temperature
In Raw
After the


Catalyst
be Purified
(ml/MI
° C.
Material
Reaction















D
Kerosene
100000
70
80
3 hours-20


E
Kerosene
100000
22
80
3 hours-40


E
Fuel Oil
7000
120
1200
4 hours-300


F
Fuel Oil
7000
70
1200
4 hours-800


F
Fuel Oil
4000
120
1200
2 hours-200


G
Fuel Oil
7000
70
1200
4 hours-750


H
Fuel Oil
7000
120
1200
4 hours-720


D
Raw Oil **
4000
70
2300
4 hours-1600


F
Raw Oil
4000
22
2300
4 hours-1950





*Catalytic solution contains 1% Cu2+


**Oil with density of 0.80 g/cm3 with the output fraction 28-360° C. 88%, content of paraffin hydrocarbon 65%, naphten-26% was used.






Examples 7-8 show that it is not possible to keep the objects of the present invention if parameters of catalyst deviate from the parameters in accordance with the present invention.
EXAMPLE 7
Synthesis of the complex is performed as in Example 1 but instead acetonitryl, chloroform is utilized. During with the process of purification of kerosene in accordance with FIG. 2, the content of mercaptan sulfur is reduced to 60 ppm.
EXAMPLE 8
Synthesis of the complex is performed as in Example 1, but the reaction solution is not heated. When the purification is performed with Example 2, the content of mercaptide sulfur is reduced to 40 ppm.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of substances and methods differing from the type described above.
While the invention has been illustrated and described as embodied in catalyst and method for alkali-free purification of oil raw material from mercaptans, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, be applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.
What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.

## Claims

1. A method of purification of pure fractions and gas condensate from mercaptans by processing of oil raw material with air in the presence of a catalyst, comprising the steps of using a catalyst for alkali-free purification of oil raw materials, consisting of a metalocomplex selected from the group consisting of a solid metalocomplex and a liquid metalocomplex with a general formula (CuIICl)2O(L1)2-4(L2)1-4, where Li is aminoalcohol, L2 is acetonitryl or single atom alcohol, wherein as the aminoalcohol a compound of a general formula N(R1)(R2)(R3)(OH)1-3 is utilized, where R1=C2H4, R2=H, C2H4 , C2H5, R3 =H, C2H4, CnH2n+1, where n=2-17.

2. A method of purification of pure fractions and gas condensate from mercaptans by processing of oil raw material with air in the presence of a catalyst, comprising the steps using a catalyst for alkali-free purification of oil raw materials, consisting of a metalocomplex selected from the group consisting of a solid metalocomplex and a liquid metalocomplex with a general formula (CuIICl)2O(L1)2-4(L2)1-4, where Li is aminoalcohol, L2 is acetonitryl or single atom alcohol, wherein as the single atom alcohol a substance selected from the group consisting of isopropanol, butanol, isobutanol and pentanol is utilized.