CZ2001860A3 - Process for preparing calcium hydroxy alkane sulfonates - Google Patents

Abstract

The present invention is a process for the preparation of calcium hydroxy alkane sulphonates from a mixture comprising at least 20 % by weight paraffins and at least 10 % by weight olefins, comprising reacting the mixture with a sulphonating agent in a reactor, and neutralising and hydrolysing the reaction product in the presence of a calcium-containing base.

Description

Process for the preparation of calcium hydroxyalkane sulfonates

Technical field

The present invention relates to a process for the preparation of calcium hydroxyalkane sulfonates which are suitable for use as fuel and lubricating oil additives.

BACKGROUND OF THE INVENTION

The use of hydroxyalkyl sulfonates in detergent compositions is well known. For example, US-A-3 896 057 discloses the use of water-soluble salts of alkenesulfonates and hydroxyalkyl sulfonates and their corresponding acids in laundry detergents. US-A3 883 583 discloses an oil-soluble high molecular weight anionic surfactant consisting of sulfonates of aliphatic monoolefins having a carbon number in the range of 32 to 40 carbon atoms. Surfactants are mentioned as good agents for dry cleaning detergents.

EP-A-0 537 840 discloses a lubricating oil composition consisting of a major proportion of a lubricating oil and a minor proportion of an alkali metal salt selected from calcium and magnesium salts of hydroxyalkane sulfonic acid. The compounds are formed by sulfonating the internal olefins described as having from 10 to 32 carbon atoms with 15 to 19 carbon atoms olefins, with olefins having an average molecular weight of 230 being preferred.

EP-A-0 351 928 describes a process for preparing sulfonates of internal olefins, which comprises reacting an internal olefin containing from 8 to 26 carbon atoms with a sulfonating agent in

A layer reactor, in a molar ratio of sulfonating agent to internal olefin of from 1: 1 to 1.25: 1, while cooling the reactor with a cooling device not exceeding 35 ° C and neutralizing and hydrolyzing the reaction product from the sulfonation step.

The successful preparation of hydroxyalkane sulfonates is highly dependent on the efficiency of the neutralization / hydrolysis reactions. If these reactions are not carried out efficiently, immediately after sulfonation, a reaction to olefins and sulfur trioxide may occur, resulting in low yields or poor product quality.

However, in all of the above references, olefins are relatively pure, free of contaminants, which may interfere with various biphasic reactions and / or affect reaction products. For example, high levels of paraffins would be detrimental to the efficacy of sulfonation, neutralization, and hydrolysis, since paraffins have the effect of retarding these reactions. It is believed that high levels of paraffins adversely affect the direct neutralization (ring opening) of β-sultones resulting from sulfonation reactions. This may cause an unacceptably low conversion to hydroxyalkane sulfonates due to the reaction back to sulfur dioxide and internal olefin.

This phenomenon is believed to be greater when a base with limited water solubility, such as calcium hydroxide, is used in the neutralization step.

US-A-5 488 148 discloses a process for sulfonating internal olefins in the presence of a hydrocarbon solvent, but in which the sulfonated intermediate compounds are neutralized with an aqueous alkali metal hydroxide solution such as sodium hydroxide. Feedback on

-3olefins and sulfur trioxide are abolished by using an excess of alkali metal hydroxide.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide such mixtures of olefins and paraffins which are obtained from dehydrogenation equipment, such as a PACOL- (OLEX) unit or a wax-cracking unit dispensed with paraffin or a Fischer-Tropsch unit filled with natural gas, other hydrocarbons or coal. can be used directly as a raw material in the production of calcium hydroxyalkanesulfonates.

According to the present invention, there is provided a process for preparing calcium hydroxyalkane sulfonates from a mixture comprising at least 20% by weight paraffins and at least 10% by weight olefins, comprising reacting the mixture with a sulfonating agent in a reactor and neutralizing and hydrolyzing the reaction product in the presence of a calcium-containing base.

The olefins in this mixture are preferably olefins having 8 to 30 carbon atoms, more preferably olefins having 14 to 30 carbon atoms, especially 14 to 20 carbon atoms. Said base is preferably selected from calcium hydroxide, calcium carbonate, calcium acetate and calcium oxide. Calcium hydroxide is particularly preferred. This mixture may also contain from 1 to 25% by weight of oxygen products, such as those found in, for example, Fischer-Tropsch olefin / paraffin products.

The reaction products are suitable as detergents in fuel and lubricating compositions.

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In the process of the present invention, said mixture typically reacts with a sulfonating agent in a reaction vessel followed by a reaction in a stirred neutralization vessel. The final heating step may be carried out to hydrolyze any residual sultones formed in the reaction.

The feedstock commonly used in this process mimics the feedstock obtained from the PACOL- (OLEX) dehydrogenation apparatus, the wax cracker after the paraffin-introduced double bond isomerization, and more preferably the paraffins from the Fischer-Tropsch unit, e.g. from a synthesis unit of middle distillate Shell (SMDS) prior to hydrocracking, charged with methane, petroleum, residual fuel or coal using a suitable Fischer-Tropsch catalyst, if desired, after double bond isomerization. Said mixture preferably comprises from 10 wt% to 80 wt% olefins.

In a preferred embodiment of the invention, the olefins are present in the mixture with internal olefins.

The molar ratio of sulfonating agent to olefin is preferably in the range of 1: 1 to 1.25: 1.

The olefin sulfonation is preferably carried out with sulfur trioxide, preferably in a thin-film reactor. The reactor is preferably cooled to a temperature not exceeding 35 ° C, more preferably to a temperature in the range of 10 ° C to 30 ° C.

The neutralization / hydrolysis is preferably carried out with a calcium-containing base in an aqueous medium. The neutralization of the reaction product is preferably carried out with a molar excess of calcium-containing base, preferably at a base: olefin molar ratio of at least 1.2: 1, more preferably at a molar ratio of at least 1.5: 1.

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Preferably, the neutralization is carried out at a temperature of from 0 ° C to 80 ° C, more preferably at a temperature of from 30 ° C to 40 ° C.

The hydrolysis step is preferably carried out at a temperature in the range of from 100 ° C to 250 ° C, more preferably from 130 ° C to 200 ° C.

The process can be carried out batchwise, semi-continuously or continuously. The reaction usually takes place in a FFR, which is cooled by water flowing on the outer walls of the reactor. On the inner walls of the reactor, the mixture flows downwards. The sulfur trioxide is diluted by flowing nitrogen, air or any other inert gas into the reactor. The sulfur trioxide concentration is usually from 1% by volume to% by volume relative to the carrier gas. The neutralization reaction should be carried out immediately after the sulfonation reaction under high shear mixing conditions.

The following examples illustrate the invention.

Example 1

Mixture containing 76,8% w / w paraffins,% w / w oxidants and 20,2% w / w internal olefins (with chain length distribution: 5% w / w 14-olefin, 22,3% w / w 15-olefin, 31,8% by weight of olefins of 16 carbon atoms, 23,8% by weight of olefins of 17 carbon atoms,

11.7% by weight of 18-carbon olefins, 4.3% by weight of 19-carbon olefins and 1% by volume of olefins with carbon atoms) were sulfonated in a continuous, descending thin film reactor of 0.5 cm diameter and 1 meter length .

The sulfur trioxide was prepared by reacting sulfur dioxide with oxygen (dry air) on a vanadium pentoxide catalyst at a temperature of about 450 ° C.

The mixture flowed down the inside of the reactor walls as a flowing thin film downward and reacted with sulfur trioxide (the molar ratio of sulfur trioxide to olefins was 1.2: 1). The temperature of the reaction mixture was about 15 ° C. After the sulfonation process, the reaction products were introduced into a stirred suspension of sodium hydroxide in water (about 1.5 times calcium hydroxide relative to the amount of olefin feedstock).

The mixture was continuously stirred (using a Ultraturrax high shear mixer) at about 40 ° C for at least 2 hours and then transferred to a hydrolysis reactor and heated to 160 ° C for 1 hour.

Examples 2 and 3

Example 1 was repeated, but using a pure olefin mixture instead of an olefin / paraffin mixture. In Example 3, a larger downstream reactor was used.

A comparison of the sulfonation conditions in Examples 1 to 3 is shown in Table 1 and the analysis of the reaction products is shown in Table 2.

-ΊTable 1

Ex. 1 Ex. 2 Ex. 3 Sulfonation reactor FFR FFR FFR length [m] 1.0 1.0 6 Diameter [cm] 0.5 0.5 2.54 Temperature [° C] 15 Dec 15 Dec 23 to 24 SO ₃ concentration [% vol. ] 1 3 2.5 Olefin with 14 to 20 carbon atoms with 15 to 19 carbon atoms with 15 to 19 carbon atoms Molecular weight of olefin 224 230 230 Molecular weight of sulfonate 674 686 686 production capacity [mol.h ^-1 ] 0, 42 1.5 71, 3 Molar ratio SO ₃ : olefin Neutralization / hydrolysis 1,2 1,2 1.06 OH: olefin molar ratio 1.5 1.4 1.5

Due to the fact that the sulfur trioxide concentration in Example 1 decreased to accommodate the longer residence time of the diluted olefin in the falling film reactor, Table 1 shows that the sulfonation and neutralization conditions are similar in all three examples, with the molar ratio of sulfur trioxide to the olefin is within the desired range.

Table 2

Ex. 1 Ex. 2 Ex. 3 Product quantity [g] 2058 307 450 000 Quantity AM [g] 230.4 54.3 109 000 Yield (% mol / mol) 71 81 85

Table 2 shows that the yield of calcium hydroxyalkane sulfonate using olefin / paraffin mixtures (Ex. 1) was comparable to those obtained using a mixture of pure internal olefins containing 15 to 19 carbon atoms (Ex.

3). This shows that compositions containing high levels of paraffins are suitable raw materials for the preparation of calcium hydroxyalkane sulfonates, which are suitable detergents for use in fuel and lubricating compositions.

Claims (10)

PATENT CLAIMS A process for preparing calcium hydroxyalkane sulfonates from a mixture comprising at least 20% by weight paraffins and at least 10% by weight olefin, comprising reacting the mixture with a sulfonating agent in a reactor and neutralizing and hydrolyzing the reaction product in the presence of a calcium-containing base. The process according to claim 1, wherein the olefins in the mixture are olefins having 8 to 30 carbon atoms. A process according to claim 1 or 2 wherein the mixture comprises from 10% to 80% by weight of olefins. The process according to any of the preceding claims, wherein the molar ratio of sulfonating agent to olefin is from 1: 1 to 1.25: 1. A process according to any one of the preceding claims, characterized in that the reactor is cooled to a temperature not exceeding 35 ° C. Process according to any one of the preceding claims, characterized in that the neutralization is carried out at a temperature ranging from 0 ° C to 80 ° C. Process according to any one of the preceding claims, characterized in that the hydrolysis step is carried out at a temperature of from 100 ° C to 250 ° C. The process according to any of the preceding claims, wherein the sulfonating agent is sulfur trioxide. The process according to any one of the preceding claims, wherein the calcium-containing base is present in a molar ratio of base to olefin of at least 1.2: 1. A process according to any one of the preceding claims, characterized in that the calcium-containing base is calcium hydroxide.