The Surfactant Industry

FIGURE 9.34. Synthesis of sucrose fatty acid esters. 

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There are no statistics available for microemulsion products or their aimual values, but data for the surfactant industry can be taken as a guide. Annually updated Hsts of commercial surfactants and their suppHers are available from several sources (57,58). Chemical Engineering Nem aimuaHy pubhshes a... 

By the nature of its content, with contributions from experienced practitioners, the book aims to serve as a practical reference for researchers, post docs, PhD-students and postgraduates as well as risk assessors working on surfactants in environmental laboratories, environmental agencies, the surfactant industry, the water industry and sewage treatment facilities. Each chapter includes extensive references to the literature and also contains detailed investigations. The broad spectrum of the book and its application to environmental priority compounds makes it unique in many ways. 

The PRISTINE project, and thus the content of the present book, provides policy makers and industry with detailed information on analysis and concentrations of surfactants and their degradation products in the environment. Furthermore, the book provides relevant information to all groups working in the field of surfactants in environmental laboratories, environmental agencies, the surfactant industry, water industry and sewage treatment facilities. 

Alcohols in the range C12—Ci8 are important raw materials for the production of a key group of surfactants ethoxylates, sulfates and ethoxysulfates among others. Alcohols used in the surfactant industry are primary, linear, or with different degrees of branching, and they can be produced from either petrochemical sources (ethylene or linear paraffins) or from oleochemical products (animal fats and vegetable oils). 

Other alcohols used in the surfactant industry, although of minor importance, are the Guerbet alcohols obtained by self-condensation of lower alcohols to yield products in the range of 16-26 carbons with a high degree of branching. 

Octyl- and nonylphenol are well known raw materials used in the surfactant industry since the early 1960s, mainly for the production of their corresponding ethoxylated derivatives (APE). Today, these products have lost considerable importance in this industry as a consequence of substantial environmental threats, resulting from their relatively slow biodegradation, toxicity of their biodegradation metabolites and positive endocrine-disrupting reactions. 

Ethoxylation of alcohols, alkylphenols, fatty acids, and many other organic raw materials is also a very important reaction for the surfactant industry, used to produce a broad variety of surfactants, most of which belong to the non-ionics group. The reaction with propoxylation (PO) is also practised, although to a lesser degree. The product used for ethoxylation is EO, or PO in the case of propoxylation, and is conducted using alkaline catalysts such as NaOH or NaOCH3. 

Investigation of the pronounced resistance of ABS to microbial degradation demonstrated that the branched alkyl chain derived from tetrapropylene was responsible for the longevity of ABS in the aquatic environment [74], Shortly after this discovery, the surfactant industry reacted and made attempts—in some countries additionally forced by legal restrictions—to provide an alternative surfactant with comparable functional properties, but with inherent biodegradability. The outcome was the introduction of LAS on the detergent market. After the switch from ABS to LAS in almost all nations in the mid 1960s, a substantial drop in the levels of ABS was observed [8],... 

This legislation will have an impact on the surfactant industry. There will be an extra cost of testing, an increase in work load to compile the dossiers which will put up costs and there will be cases where the product will be removed from the market place as it will no longer be commercially viable. 

The surfactant industry is well established and the amount of information on these products varies according to their use and target market. It is safe to say that many are made in large tonnages and will fall into the 100-1000 tonne bands for registration some maybe... 

The Editor would like to thank the authors of each chapter or section for their time and effort in contributing to this book which provides a state-of-the-art review of the surfactant industry. Thanks are also due to their employers, be they companies or universities, for their support and permission to publish. 

One of the major non-food uses of vegetable oils (approximately 5(X) million pounds of oil per annum in the US) is the production of soaps, detergents, and other surfactants. The solubility and other physical properties of medium-chain fatty acids and their derivatives make them especially suited for surfactant manufacture. Coconut and palm kernel oils, which contain 40-60% lauric acid (12 0), are current major feedstocks for the surfactant industry. The mechanism of synthesis of lauric and other medium-chain fatty acids in plants involves the action of a medium-chain acyl-ACP thioesterase which terminates fatty acid synthesis after a 10 or 12 carbon chain has been assembled (M. Pollard,... 

Since the alkylphenol products used in the surfactants industry border on the commodity type, margins are slim and reductions in manufacturing costs of the parent alkylphenol are a must to stave off competition, not only from other producers, but also from other nonionic surfactant types. For this reason, process development has become a fruitful area of research for the alkylphenol industry, particularly those areas that improved catalysis or reaction conditions and recovery for recycle (by isomerization or transalkylation) of by-product streams. 

Recent trends in liquid detergent formulation have resulted in the demand of LAS characterized by very low content of inorganic sulfates, and this demand has been satisfied by the surfactant industry with the implementation of the so-caUed extended aging where the sulfonic add is allowed to reach complete conversion over a time length of 2-4 h at a temperature not above 40°C. 

The surfactant industry of the future will continue to face many challenges. Commodity snrfac-tants will continue to be driven by cost and environmental safety. The market will demand reliable low-cost supply and environmental acceptance. New surfactant technology will be a portion of the future revolution in surfactants. This innovation will likely come from gas to liqnids (GTL ) technology and catalyst/process breakthrough such as those already demonstrated by Sasol. GTL is the general process name for conversion of natural gas, coal, biomass, or other carbon-containing raw materials to higher liquid hydrocarbons, and more specifically to naphtha, jet/diesel, and diesel fuel. 

It is hoped that this volume will stimulate the interest of more researchers in the academic world and the surfactant industry to intensify work in the area of PBS and to facilitate the rapid movement of developments from laboratory to pilot level, to generate novel surfactants of unique properties. 

The first two-phase titration method to come into widespread use was that of Epton [10], who used methylene blue as indicator. Methylene blue is cationic, and in the Epton method all the dye passes into the chloroform as its salt with the anionic at the beginning of the titration. In the region of the end-point it returns to the aqueous layer. Provided that the ratio of the volumes of aqueous and chloroform layers is 3 1 at the end-point, equal colour intensity in the two layers indicates equivalence between anionic present and cationic added. This is quite empirical and does not correspond with the completion of any chemical process or any clearly defined event. The more the volume ratio differs from 3 1, the greater the deviation of the observed result from true equivalence. Another difficulty is that the hues of the two layers are different, and matching them is very operator-dependent. Nevertheless, the method was the standard for many years and performed invaluable service to the surfactants industry. It is still in use in some laboratories and ASTM Method D 1681-83 [11] includes it, but ISO 2271 [7] and some of the methods described below are to be preferred. 

Areas of application of mass spectrometry in the surfactant industry include the following ... 

The surfactant industry is complex because of the multitude of markets served, diversity of product types, dynamic changes in product names and manufacturers, and the development of new products. This two-volume reference set, in its fifth edition, serves to integrate information on surfactant chemicals and materials that are presently available throughout the world. Since the publication of the last edition of this reference, many products have been discontinued or acquired by different manufacturers, thousands of new trade name products and generic chemicals have been added, and information has been added to trade name and generic chemicals that were contained in the earlier editions. 

Presently, about 50% of the surfactants used in the surfactant industry are derived from petrochemical raw materials, and the other 50% are derived from oleochemical raw materials. The most important smfactants used in consumer detergents are anionic and nonionic materials. The alcohols used are linear or essentially linear, which results in a more rapid and complete biodegradation of both oleochemical- and petrochemical-derived detergent smfactants. 

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