Detergents branched-chain

A simplified flow diagram for a typical UOP linear detergent alkylation unit is shown in Figure 7. The design of this unit is similar to a unit that produces branched-chain detergent alkylate. 

About 2% of benzene consumed in 1988 was used for the manufacture of straight-chain or branched-chain detergent alkylate. Linear alkane sulfonates (LAS) are widely used as household and laundry detergents. 

Microbes could not break down branch-chain detergents, so they left foam in river water. They were replaced by straight-chain alkyl benzene sulfonates, such as sodium dodecylbenzene-sulfonate and sodium xylenesulfonate. 

Some organic compounds, notably some of those produced synthetically, are nonbiodegradable. When these substances are introduced into the environment, they simply stay in the natural waters or are absorbed by life forms and remain intact for a long time. Branched-chain detergent molecules, for example, cannot easily be decomposed by microorganisms. 

The first detergents that contained such molecules accumulated and caused noticeable foaming in rivers and streams. The branched-chain detergents were soon replaced by linear-chain alkylbenzenesulfonate detergents, which are easily decomposed by microorganisms—they are biodegradable. 

Most higher alcohols of commercial importance are primary alcohols secondary alcohols have more limited specialty uses. Detergent range alcohols are apt to be straight chain materials and are made either from natural fats and oils or by petrochemical processes. The plasticizer range alcohols are more likely to be branched chain materials and are made primarily by petrochemical processes. Whereas alcohols made from natural fats and oils are always linear, some petrochemical processes produce linear alcohols and others do not. Industrial manufacturing processes are discussed in Synthetic processes. 

Straight-chain benzene sulfonates were invented as replacements for branched-chain benzene sulfonates, which were the first detergents but which could not be easily broken down by microbes in streams, rivers, or sewage treatment plants. 

German scientists created the first detergents during the shortages of World War II. These were called branched-chain alkyl... 

Alkylation, In petrochemicals, any reaction involving the thermal or catalytic addition of an olefin to a branch-chain hydrocarbon or aromatic hydrocarbon. The most notable example in petrochemicals is the addition of ethylene or propylene to benzene to produce ethylbenzene or isopropyl benzene (cumene). Other examples include the production of detergent alkylates. 

The direct sulfation of wax olefins has been perfected in Europe but has not been commercialized to any extent in the United States. More work has been done in this country on alcohols that have been prepared by Fischer-Tropsch syntheses, oxo process reactions, and reduction of the fatty acid mixtures obtained by paraffin wax oxidation. In most instances these alcohols as well as the olefins have been branched chain or secondary products, both of which have been reported to give inferior detergent and sudsing properties (13, 2Jf). 

Of the three main types of surfactants, the anionics are by far the most commercially important class, constituting, in particular, the major surfactant type represented in laundry and hand-dishwashing detergents. Among the anionics, linear sodium alky] benzene sul-fonaie (LAS), linear alkyl sulfates, and linear alkyl ethoxy sulfates are by far the most widely used compounds. (The industry convened voluntarily to linear alkyl chains in the mid-1960s to obtain improved biodegradabilily relative to the branched chain alkylates formerly used.)... 

Branched chain surfactants are an important direction for finding surfactants that have greater solubility at low temperatures. An alcohol sulphate based on a branched Cl 7 alcohol was developed by Shell Chemical and patented for laundry use by Procter Gamble. This material is in use today and offers an important avenue to the future of detergent materials. 

Schick, M.J. and Gilbert, A. H. (1965) Effect of urea, guadinium chloride, and dioxane on the CMC of branched-chain nonionic detergents. /. Colloid Sci, 20, 464-72. 

Alkylbenzene. Alkylbenzene is an intermediate for the production of alkylbenzene sulfonate. Alkylbenzene consists of a mixture of phenyl substituted n-alkanes of 9 to 14 carbon atoms. Prior to 1965, alkylbenzene was synthesized from propylene tetramer, obtained by oligomerization of propylene. The resulting hard alkylate was a highly branched chain compound. However, the slow biodegradability of propylene tetramer-based materials soon became apparent and by 1965, most of the detergent industry had switched over to linear alkylbenzene. Extensive research has demonstrated... 

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