Alkylbenzenesulfonic Acids

Detergents are metal salts of organic acids used primarily in crankcase lubricants. Alkylbenzenesulfonic acids, alkylphenols, sulfur- and methjiene-coupled alkyl phenols, carboxyUc acids, and alkylphosphonic acids are commonly used as their calcium, sodium, and magnesium salts. Calcium sulfonates, overbased with excess calcium hydroxide or calcium carbonate to neutralize acidic combustion and oxidation products, constitute 65% of the total detergent market. These are followed by calcium phenates at 31% (22). 

Linear alkylbenzenesulfonic acid is the largest intermediate used for surfactant production in the world. In the United States it has been determined that 2.6 g/d of material is used per inhabitant (46). Owing to the large volumes of production and consumption of linear alkylbenzenesulfonate, much attention has been paid to its biodegradation and a series of evaluations have been performed to thoroughly study its behavior in the environment (47—56). Much less attention has been paid to the environmental impact of other sulfonic acid-based materials. 

Surfactants and Detergents Uses. Perhaps the largest use of sulfonic acids is the manufacture of surfactants (qv) and surfactant formulations. This is primarily owing to the dominance of linear alkylbenzenesulfonic acid production for detergent manufacture. In almost all cases, the parent sulfonic acid is an intermediate which is converted to a sulfonate prior to use. The largest volume uses for sulfonic acid intermediates are the... 

Acids such as fatty acids and alkylbenzenesulfonic acids are neutralized with NaOH during slurry preparation to form soap and sodium alkylbenzenesulfonate, respectively. 

Chemical Designations - Synonyms Alkylbenzenesulfonic acid, sodium salt Sulfonated alkylbenzene ... 

The color of the derivative alkylbenzenesulfonic acid is clearly better. The solubility characteristics remain good. An olefin from the Pacol-Olex process (C, 0/13 olefin) is used as a starting olefin. The DeFine step is employed to reduce the diolefin content to <0.5%. With such an olefin an LAB is obtained over an aluminum chloride catalyst with a linear content of >99% and from which the sulfonation product has a biodegradability (DOC) comparable to that of other LABs[122,123].Table 25 gives typical physical-chemical data about different LAB types. 

Next, the dilution product is allowed to separate into two phases and the lower, aqueous acid layer is removed as spent acid. Much of the color produced during the sulfonation is contained in the spent acid. The upper layer in the separator, which contains around 90% alkylbenzenesulfonic acid (the remainder being primarily dissolved sulfuric acid), is also removed from the separator and neutralized with sodium hydroxide solution or with sodium carbonate solution to yield the active paste. When sodium hydroxide is used a considerable amount of heat must be removed. This is done in the third loop reactor of this process, the neutralization heat exchanger (also known as the neutralizer). If sodium carbonate solution is used, the neutralization is much less exothermic and no heat exchanger is needed at this stage. 

Linear Alcohols (12-15 Carbons) 1-Tetradecene Tetradecanol T etradecylbenzene Alkylbenzenesulfonic Acids Tetraethyl Dithiopyrophosphate Tetraethyl Dithiopyrophosphate Tetraethyl Lead Ethyl Silicate Tetraethyl Pyrophosphate Tetraethyl Dithiopyro phosphate Tetraethylene Glycol Tetraethylenepentamine Ethyl Silicate... 

Anhydrous sulfonic acids, particularly linear alkylbenzenesulfonic acids, are typically stored in stainless steel containers, preferably type 304 or 316 stainless steel. Use of other metals, such as mild steel, contaminates the acid with iron (qv), causing a darkening of the acid over time (27). The materials are usually viscous oils which may be stored and handled at 30—35°C for up to two months (27). All other detergent-grade sulfonic acids, eg, alcohol sulfates, alcohol ether sulfates, alpha-olefin sulfonates, and alpha-sulfomethyl esters, are not stored owing to instability. These are neutralized to the desired salt. 

Alkylbenzenesulfonic acids are light-colored, viscous liquids whose alkali and ammonium salts are soluble in water. The salts are neutral, relatively unaffected by water hardness, and stable toward alkaline and acid hydrolysis. Calcium and magnesium alkylbenzenesulfonates are less water-soluble than sodium or ammonium salts. They are, however, soluble in hydrocarbons and are used extensively in these media. LAS salts are stable to oxidation and can be incorporated in formulations containing oxidizing agents. Pure alkylbenzenesulfonates have been synthesized for property studies (60,61). 

Sulfonation is economically important because alkylbenzene sulfonates are widely used as detergents. Sulfonation of an alkylbenzene (R = unbranched C10-C14) gives an alkylbenzenesulfonic acid, which is neutralized with base to give an alkylbenzene sulfonate detergent. Detergents are covered in more detail in Section 25-4. 

Into a 1,000 gallon, jacketed, glass lined reactor equipped with baffles and a two speed (67 and 135 rpm) reversed impeller is introduced 200 g of Richonate 60S (a 60% aqueous slurry of sodium salts of alkylbenzenesulfonic acids) and 364 liters of deionized water, followed by... 

EINECS/ELINCS 248-289-4 271-807-5 Synonyms ABS Alkylbenzenesulfonic acid Benzenesulfonic acid, dodecyl- DDBSA n-Dodecylbenzenesulfonic acid Lauiylbenzenesul-fonic acid... 

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