Alcohol continued detergency

It has been reported that the LAS/AS mixed active system was produced by continuous oleum sulfonation of LAB followed by addition of the alcohol and more oleum to provide a tandem sulfation [40]. Tallow range alcohol sulfate (Ci6-is AS) was used in the past when U.S. wash temperatures were as high as 60°C. At these wash temperatures and in phosphate-built formulations the Ci6 18 AS gave very good detergency performance [41]. However, as U.S. washing temperatures decreased, C16.,8 AS was replaced by the more soluble shorter-chain ASs, such as C12.I8 or C,4, 5. 

The desizing of water-soluble size polymers can be summarised as follows. Batchwise or continuous methods can be used in both cases an adequate supply of hot water is needed during the washing-off. Hot water and detergent are needed to remove polyfvinyl alcohol) or carboxymethylcellulose. The addition of alkali may be beneficial with carboxymethylcellulose. Alkali is essential with modified starches and acrylic acid copolymers. Polyfvinyl alcohol) can be degraded effectively by alkaline oxidation. 

One of the most important active ingredients of detergents is the sulfate or sulfonate compounds made via the oleum route. A process flow diagram is shown in Figure 9. In most cases, the sulfonation/sulfation is carried out continuously in a reactor where the oleum (a solution of sulfur trioxide in sulfuric acid) is brought into contact with the hydrocarbon or alcohol and a... 

Continuous operations are feasible and practical (1) where the organic compound (benzene or naphthalene) can be volatilized, (2) when reaction rates are high (as in the chlorosulfonation of paraffins and the sulfonation of alcohols), and (3) where production is large (as in the manufacture of detergents, such as alkylaryl sulfonates). 

If the feed is preconditioned properly, the UF flux is often quite stable. One thousand hours of continuous operation between cleanings is common. When flux decay does occur, detergent washing is usually sufficient to restore flux. In some cases, polymer solvents may be required. Proper selection of a solvent resistant membrane and/or solvents which will dissolve the latex but not affect the membrane is crucial. For PVC latex, the solvents of choice are methyl isobutyl ketone (MIBK) and methyl ethyl ketone (MEK). Styrene butadiene rubber will swell in MIBK, MEK or toluene. Polyvinyl acetate will dissolve in the low MW alcohols such as propyl alcohol. Generally, the membranes are first washed with water, then detergent, followed by another water flush. The system is then drained of all water since it will affect polymer solubility in MEK. Finally, a solvent rinse is employed. If the module is tubular, sponge balls will enhance cleaning. 

Development of the process in Germany was expedited when Ruhrchemie and I.G. Farbenindustrie pooled their facilities about 1940. Results of laboratoiy- and bench-scale operations led to the construction of a demonstration unit at Leuna employing a catalyst slurry in a continuous two-stage process with an output of metric tons of alcohds per day. The olefin feed was obtained by mild thermal cracking of soft paraffin wax from the Fischer-Tropsch synthesis. The product, a mixture of alcohols, was readily sulfonated to detergents, which were in great demand in... 

Figure 1.1 presents the consumption of the major surfactants in the world market in 1996. Along with soap, linear alkylbenzene sulphonates (LAS) remain the most bulky and cost-effective anionic surfactants. LAS will continue to be the workhorse of the detergents industry on a global basis. However, the LAS share decreases gradually their recess is occupied by alcohol-derived surfactants, first of all alcohol sulphates (AS), alcohol ethoxylates (AE) and alcohol ether sulphates (AES). In West Europe alkylphenol ethoxylates (APE) have been removed over the last two decades from a large number of household applications in view of... 

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