SURFACTANT SYNTHESIS - LABSA

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Linear alkene benzene sulphonic acid (LABSA)

Some of the commonly used alkyl benzene derivatives include

• Linear alkyl benzene sulphonic acid

• Linear alkyl benzene sulphonate

1. Linear alkylbenzene (LAB)/ Soft alkylate:
   Linear alkylbenzene (LAB), the material used to produce LAS, is derived exclusively from petroleum derivatives: benzene and linear paraffins. Since the 1960s resulted in LAB emerging as the dominant precursor of biodegradable detergents replacing branched dodecylbenzene (DDB). LAB contains 10 to 16 carbon atoms, although generally supplied as a tighter cut, such as C12-C15, C12-C13 and C10-C13, for detergent use. Hydrotreated kerosene is a typical feedstock for high purity linear paraffins, which are subsequently dehydrogenated to linear olefins. The resulting linear mono-olefins react with benzene in the presence of a catalyst to produce the LABs. Hydrogen fluoride (HF) and aluminum chloride (AlCl3) are the two major catalysts for the alkylation of benzene with linear mono-olefins. The HF-based process is commercially dominant. Important product characteristics include the bromine index, sulfonatability, amount of 2-phenyl isomers (2-phenylalkane), the tetralin content, amount of non-alkylbenzene components, and the linearity of the product.
   
   
2. Linear Alkylbenzene Sulphonic Acid (LABSA)/ n-Dodecylbenzene
   Sulfonic Acid: LABSA is intermediate of LAB and LAS, produced on LAB sulphonation, HLAS on neutralization results in to LABS salt (LAS). Alkylbenzene sulphonate is made from the sulphonation reaction of an alkylbenzene (LAB) with a sulphonating agent (a dilute solution of SO3 in air -typically 10% SO3) in a falling film sulphonator to give the sulfonic acid (LABSA). The result of sulphonating LAB is the formation of alkylbenzene sulphonic acid (LABSA), which has the consistency of a liquid with a high active content (>97%), containing about 1% of unsulphonated matter and 1-2% of H2SO4. It represents commercially the most important supply form. The Linear alkylbenzene sulphonic acid is typically a low viscosity liquid, even at manufacturing concentrations of 96%. It can be stored for extended periods, due to the stability of the carbon–sulphur bond which makes the use of the concentrated sulphonic acid a highly cost-effective way to deliver the surfactant into a formulation. Linear alkylbenzene sulfonic acid (LABSA) is the largest-volume synthetic surfactant because of its relatively low cost, good performance, the fact that it can be dried to a stable powder and the biodegradable environmental friendliness as it has straight chain. It is one of main raw material of detergent.
   It has good decontamination and foaming property, and Linear Alkyl Benzene Sulfonic acid is stable in acidic, alkalic and some oxide solution. The degree of biodegradation is more than 90%. Linear alkylbenzene sulfonic acid is mainly used to produce household detergents including laundry powders (washing powder), laundry liquids, dishwashing liquids, dishwashing detergent and other household cleaners. It is also used in numerous industrial applications like textile cleaning agent, dyeing auxiliary (assistant); electroplating industry, leather making industry, degreasing agent (degreaser of plating); made Paper deinking agent industry, as a coupling agent and as an emulsifier for agricultural herbicides and in emulsion polymerization. 
   
   
   As the raw material of detergent, Linear Alkylbenzene Sulfonic acid is used to produce alkylbenzene sulfonic acid sodium (LAS), which has the performances of decontamination, emulsification, dispersion, wetting and foaming property.
   
   
   Thanks & Regards
   Manu & Ram

Surfactants: Basic Overview

Surfactants are the abbreviation of ‘SURFace ACTive agenTS’.

Surfactants reduce surface/interfacial tension between two phases. They have tendency to gather around the interface between two different materials by altering the properties of interface remarkably. They also reduce the interfacial tension between oil and water by adsorbing at the liquid-liquid interface. They reduce the surface tension of water by adsorbing at the liquid-gas interface. So, Surfactants serves as good mediator to settle clash between two phases which are not friends (soluble). 

Surfactants play an important role as cleaning, wetting, dispersing, emulsifying, foaming and anti-foaming agents in many practical applications and products. 

Surfactants take part in producing Soaps, Detergents, Cosmetics: Shampoos, Hair conditioners (after shampoo), Toothpastes, Fabric softeners, Emulsions, Paints, Adhesives, Inks, Deinking of recycled papers, in flotation, washing and enzymatic processes, Agrochemical formulations, Alkali Surfactant Polymers (used to mobilize oil in oil wells).

Examples:

1. The most familiar use of surfactants is in making soaps, laundry detergents, dish-washing liquids, shampoos, hair conditioners (after shampoo) and toothpastes.
2. Among the numerous uses in pharmaceuticals, surfactants used for solubilization of hydrophobic drugs in aqueous media, as components of emulsion.
3. In surfactant-based enhanced oil recovery, the oil reservoir is flooded by pumping in water containing a small percentage of surfactant(s). The surfactant(s) overcome natural capillary forces by lowering the crude oil/water interfacial tension (IFT) to an ultra-low level which allows oil globules (ganglia) in the reservoir to flow through rock pores and coalesce to form a clean oil bank. Water flooding can aid in oil recovery from 1% to between 20-40%. After water flooding, the remaining oil could either be residual oil from the area swept by water or by-passed oil which could not be swept by the flooding. A surfactant model is an Enhanced Oil Recovery (EOR) mechanism aimed at reducing the residual (remaining) oil at the water-swept zones of the reservoir.
4. Ink is a colloidal system of fine pigment particles dispersed in a solvent. During the ink manufacturing dispersants are used to obtaining a stable dispersion and to prevent the fine pigment particles from reaggregating during the grinding stage. Wetting used to control surface properties. Defoamer/ antifoaming agents used to regulate foam efficiency. Whereas in flotation de-inking dispersants separates the ink particles from the fiber surface and prevent the redeposition of separated particles on fibers; Surfactants acts as a collector to agglomerate small ink particles to large ones and change the surface of particles from hydrophilic to hydrophobic; Also they acts as a frother (froth= foam at Solid/liquid surface) to generate a foam layer at the top of a flotation cell for ink removal.
5. Other important uses are in many industrial applications for surfactants in lubricants, emulsion polymerisation, textile processing, mining flocculates, petroleum recovery, wastewater treatment and many other products and processes. Surfactants are also used as dispersants after oil spills.

Thanks & Regards
 Manu and Ram