Methyl ester sulfonate process

General Methyl Ester Sulfonates Process Conditions.207... 

GENERAL METHYL ESTER SULFONATES PROCESS CONDITIONS... 

Hovda, K.D., Methyl Ester Sulfonation Process Optimization, Proceedings of PORIM International Palm Oil Congress, September, 1993. 

Fatty JicidFster Sulfonates. Fatty acid ester sulfonates (FAES) are generally produced from methyl esters, ie, methyl ester sulfonate (MES) and prepared via sulfonation, followed by bleaching and neutralization, in a relatively difficult and complex process ... 

FAME may in the future become a possible organic feedstock to the sulfonated to fatty acid methyl ester sulfonate (FAMES). This feedstock is naturally renewable as it is produced from oils/fats or fatty acids. There are several possible process routes for the manufacture of FAME. 

In the case of methyl ester sulfonation to produce MES, the colour of the final sulfonated product is usually very dark, and the process... 

Horie, K., New Process of Methyl Ester Sulfonate and Its Application, Proceedings of the 6th CESIO in Berlin, 2004. 

A simple yet highly effective nonbleach, two-step process had been described for purifying palm Cie ig potassium methyl ester sulfonates [54]. In the first step, water is added to the impure surfactant mixture. The temperature of the system is maintained above the Krafft point of the surfactant, so that the surfactant and associated impurities are completely solubilized. Once completely dissolved, the surfactant mixture is allowed to cool, and the potassium-neutralized methyl ester sulfonate precipitates out selectively. In the second step, the purified surfactant is recovered by gravity or pressure filtration or by centrifugation, followed by drying. 

The process significantly improves Cie ig methyl ester sulfonates analytical purity and color without raising safety or environmental concerns. It also allows for the purification of products derived from lower grade methyl esters, resolves odor issues, and does not require use of substantial amounts of solvent such as methanol. 

After bleaching, the a-sulfonated ester has to be neutralized with sodium hydroxide or some other aqueous base to obtain the salt. Hydrolysis of the ester groups is avoided if the temperature does not exceed 45 °C and the pH is between 7.5 and 9. Neutralization is thus performed in a continuous process to ensure pH control and effective heat removal [33]. The concentration of the NaOH solution has to be calculated so that a slurry is obtained that has a low viscosity so as to facilitate further processing. For example, neutralization can produce a 40% aqueous slurry of sodium palm kernel methyl ester a-sulfonate or a 25% aqueous slurry of sodium tallow methyl ester a-sulfonate [33],... 

Biodiesel is a mixture of methyl esters of fatty acids and is produced from vegetable oils by transesterification with methanol (Fig. 10.1). For every three moles of methyl esters one mole of glycerol is produced as a by-product, which is roughly 10 wt.% of the total product. Transesterification is usually catalyzed with base catalysts but there are also processes with acid catalysts. The base catalysts are the hydroxides and alkoxides of alkaline and alkaline earth metals. The acid catalysts are hydrochloride, sulfuric or sulfonic acid. Some metal-based catalysts can also be exploited, such as titanium alcoholates or oxides of tin, magnesium and zinc. All these catalyst acts as homogeneous catalysts and need to be removed from the product [16, 17]. The advantages of biodiesel as fuel are transportability, heat content (80% of diesel fuel), ready availability and renewability. The... 

As weU as in edible-oil processing, the use of organic solvents is also relevant in the synthesis of amino adds and their derivatives. In producing dipeptides such as L-aspartyl-L-phenylalanine methyl ester, better known as aspartame, from amino acids and derivatives via enzymatic processes in organic solvents such as butyl acetate and 2-methyl-2-butanol, unreacted amino acids should be recycled after the synthesis to make the process more efficient. Reddy et al. tested several commercial membranes and found a polyamide-polyphenylene sulfone composite to be promising for this appHcation. However, further research is stiU needed here to apply other membrane materials, which are more resistant towards solvents like butyl acetate [33]. 

The preparation of of-sulfo fatty acid methylesters is a two-stage process taking place at two different rates. At first, an addition compound of 1 mol of methylester with 2 mol of SO3 is formed. Then, in the following reaction, 1 mol, of SO3 is split off, to form the final ester. This sulfur trioxide will slowly react further with another methyl ester. Using the fatty acid methylester and SO3 in a molar ratio results in an undesirably long reaction time. Therefore a surplus of sulfur trioxide is used. The reaction mixture then consists of the main product, the a-sulfo fatty acid methylester and also its anhydride with SO3. By neutralization with a solution of caustic soda, on the one hand the desired sodium salt of the required ester is formed, while on the other hand the anhydride is transformed to the corresponding disodium salt and sodium methyl sulfonate. In order to achieve a complete transformation of the fatty acid methylester, a certain amount of the undesired disodium salt has to be expected. 

Improved efficiency in the synthesis of 24 was ultimately achieved via an enzymatic desymmetrization approach (Scheme 7). In the key step of this route, an asymmetric oxidation of achiral amine 41 promoted by monoamine oxidase (MAON) under an oxygen atmosphere afforded intermediate 42. In this streamlined process, sodium bisulfite was included in the enzymatic oxidation mixture to effect direct conversion to sulfonate 44. Treatment of 44 with sodium cyanide provided the trans-nitrile 43 as a single diastereomer in approximately 90% yield from pyrrolidine 41. As in the second-generation synthesis, the nitrile is hydrolyzed to the methyl ester under Pinner conditions (HCI, methanol). In the manufacturing process, the product was converted to its free base using NaOH, then crystallized as the HCI salt from i-propanol and methyl t-... 

The oxidation of 130 by oxygen under pressure was developed af lab scale. Under optimal conditions, the substrate/bisulfite mixture was added to a solution of 130 (3.9 g/1), MAON401 and catalase over 20h. Substrate 130 (65g/l) was converted to sulfonate 133 with a small amount of 131 (<10%). The enzyme reaction stream was telescoped for cyanation to afford only trans-nitrile 134 in 90% yields from 130. Subsequenfly the nitrile was transformed to the methyl ester and the product was converted to the free base 132. In the final step the free base was crysfallized to afford 135 in 56% yield and >99% ee. The conditions of the procedure were successfully applied to pilot plant scale. Compared with the resolution method in the enzymatic process the product yield was increased by 150%, raw material use was reduced by 59.8%, consumption of water was reduced by 60.7%, and the overall process waste was reduced by 63.1% [167]. 

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