Surfactant production

Table 2. Volume, Value, and Growth of U.S. Sulfonated and Sulfated Surfactant Products by Class ...

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. 

Specialty sulfonic acid-based surfactants make up a rather large portion of surfactant production in the United States. Approximately 136,000 metric tons of specialty sulfonic acid-based surfactants were produced in 1992, which included alpha-olefin sulfonates, sulfobetaines, sulfosuccinates, and alkyl diphenyl ether disulfonates (64). These materials found use in the areas of household cleaning products, cosmetics (qv), toiletries, emulsion polymerization, and agricultural chemical manufacture. 

Of the cations (counterions) associated with polar groups, sodium and potassium impart water solubiUty, whereas calcium, barium, and magnesium promote oil solubiUty. Ammonium and substituted ammonium ions provide both water and oil solubiUty. Triethanolammonium is a commercially important example. Salts (anionic surfactants) of these ions ate often used in emulsification. Higher ionic strength of the medium depresses surfactant solubihty. To compensate for the loss of solubiUty, shorter hydrophobes ate used for appHcation in high ionic-strength media. The U.S. shipment of anionic surfactants in 1993 amounted to 49% of total surfactant production. 

Many benzenoid quaternary cationic surfactants possess germicidal, fungicidal, or algicidal activity. Solutions of such compounds, alone or in combination with nonionic surfactants, are used as detergent sanitizers in hospital maintenance. Classified as biocidal products, their labeling is regulated by the U.S. EPA. The 1993 U.S. shipments of cationic surfactants represented 16% of the total sales value of surfactant production. Some of this production is used for the preparation of more highly substituted derivatives (101). 

A reexamination of so-called renewabdity has shown that advantages for oleochemicals are not sufftcientiy clear (115), especially because manufacture of surfactants ia the United States accounts for only 0.03% of aimual cmde oil consumption (62). On these bases, the primary determinants of surfactant choice will continue to be cost effectiveness and availability. The 1993 U.S. market has been estimated to be worth 3.7 x 10 (110). Approximately one-half was anionic surfactant ( 1.8 x 10 ) and one-third nonionic surfactant ( 1.2 x 10 ). The balance was made up by cationics ( 1.2 X 10 ) and amphoterics ( 600 x 10 ). The U.S. International Trade Commission (116) provides a minutely detailed breakdown of surfactant production. 

The introduction of surfactant products into the environment, after use by consumers or as part of waste disposed during manufacture, is regulated by the Clean Water Act, the Clean Air Act, and the Resource Conservation and Recovery Act. In this respect, surfactants are subject to the same regulations as chemicals in general. There are, however, two areas of specific relevance to surfactants and detergent products, ie, biodegradabiUty and eutrophication. 

Surfactants in E/ectroc/eaners. Surfactants typically consist of a long-chain hydrocarbon molecule having a solubilising or water-loving group which can be anionic, cationic, or nonionic when solubilized. Thousands of surfactant products are marketed, usually under trade names (32). In commercially formulated electrocleaners, surfactants are usually anionic, and often mixtures of anionics and nonionics. 

Even today renewable resources play a dominant role as raw materials for surfactants, but only because of the great contribution made by soaps to the production of surfactants. If the soaps are left out of consideration as native surfactants, petrochemistry holds 65-70% of the production of synthetic surfactants [2]. But for the future a further increase of renewable raw materials is expected in surfactant production [3]. The main reason for this development is the superior digestibility in the environment of products produced from natural materials. The future importance of the renewable raw materials becomes evident from the fact that even now new plants are cultivated or plants are modified to obtain an improved yield. A new type of sunflower has been cultivated to obtain a higher proportion of monounsaturated oleic acid compared with doubly unsaturated linoleic acid [4],... 

It can be fundamentally stated that surfactants covering nearly all tasks can be derived from phosphoric acid. It is often only the somewhat higher price blocking the same widespread use of phosphorus-containing surfactants compared to the output of mass surfactants. The fraction of phosphorus-containing surfactants reaches about 1 % of total surfactant production. 

In the production of anionic surfactants, the analytical procedures to be adopted for quality control and/or assessment are of particular importance. Their reliability as well as their time and chemical demand is a fundamental topic for the economy and success of the surfactant production cycle. To this end the most important analyses to be done on the various types of anionic surfactants are outlined in Tables 15-19. Mention must be made of potentiometric titration of the sulfonic acid (whatever the processed feedstock), which allows one to obtain reliable results over a very short time. 

The organic feedstock suitable for surfactant production (i.e., detergent-grade alkylates, fatty alcohols, ethoxylated fatty alcohols, a-olefins, and fatty acid methyl esters) and the S03/gas are fed concurrently. 

Gerson DF, JE Zajic (1979) Comparison of surfactant production from kerosene by four species of Coryne-bacterium. Antonie van Leeuwenhoek 45 81-94. 

Council of European Surfactant Producers (CESIO) statistics [10] indicate a total surfactant production of 2.4 million tons in Europe for 1999, which were distributed in the categories shown in Table 1.5. Other information sources [11] indicate a surfactant consumption of 2.1 million tons in Europe for 1998, which compares very well with the CESIO figure. Europe is a net exporter of surfactants and a precise figure of actual European consumption is thus difficult to estimate, although information from CESIO provides data on total sales and captive use. 

Surfactants can be produced from both petrochemical resources and/or renewable, mostly oleochemical, feedstocks. Crude oil and natural gas make up the first class while palm oil (+kernel oil), tallow and coconut oil are the most relevant representatives of the group of renewable resources. Though the worldwide supplies of crude oil and natural gas are limited—estimated in 1996 at 131 X 1091 and 77 X 109 m3, respectively [28]—it is not expected that this will cause concern in the coming decades or even until the next century. In this respect it should be stressed that surfactant products only represent 1.5% of all petrochemical uses. Regarding the petrochemically derived raw materials, the main starting products comprise ethylene, n-paraffins and benzene obtained from crude oil by industrial processes such as distillation, cracking and adsorption/desorption. The primary products are subsequently converted to a series of intermediates like a-olefins, oxo-alcohols, primary alcohols, ethylene oxide and alkyl benzenes, which are then further modified to yield the desired surfactants. 

Fig. 1.2. Key derivatives and major intermediates used in surfactant production.

While fast atom bombardment (FAB) [66] and TSI [25] built up the basis for a substance-specific analysis of the low-volatile surfactants within the late 1980s and early 1990s, these techniques nowadays have been replaced successfully by the API methods [22], ESI and APCI, and matrix assisted laser desorption ionisation (MALDI). In the analyses of anionic surfactants, the negative ionisation mode can be applied in FIA-MS and LC-MS providing a more selective determination for these types of compounds than other analytical approaches. Application of positive ionisation to anionics of ethoxylate type compounds led to the abstraction of the anionic moiety in the molecule while the alkyl or alkylaryl ethoxylate moiety is ionised in the form of AE or APEO ions. Identification of most anionic surfactants by MS-MS was observed to be more complicated than the identification of non-ionic surfactants. Product ion spectra often suffer from a reduced number of negative product ions and, in addition, product ions that are observed are less characteristic than positively generated product ions of non-ionics. The most important obstacle in the identification and quantification of surfactants and their metabolites, however, is the lack of commercially available standards. The problems with identification will be aggravated by an absence of universally applicable product ion libraries. 

Restrictive disorders Interstitial thickening Hemorrhage Cellular infiltration Abnormal surfactant production... 

Phosphorus in the subsurface originates from a natural parent material or anthropogenic application on land surface (e.g., fertilizers, pesticides, surfactant products, sludge, and effluents). This element may be found in inorganic or organic forms, which are in a dynamic equihbrium with dissolved P in the subsurface liquid phase. 

As previously mentioned, amphoteric surfactants presently represent a minor fraction of the total surfactants production with only specialty uses. They are compounds with both anionic and cationic properties in aqueous solutions, depending on the pH of the system in which they work. The main types of these compounds are essentially analogs of linear alkane sulfonates, which provide numerous points for the initiation of biodegradation, and pyridinium compounds that... 

River pollution from anionic surfactants, the primarily toxic ones, is of two types (a) acute toxic pollution due to, for example, an accidental spill from a container of full-strength surfactant products, and (b) chronic pollution due to the daily discharges of municipal and industrial wastewaters. The international literature contains the result of numerous studies that have established dosages for both types of pollutional toxicity due to detergents, for most types of aquatic life such as species of fish. 

Changes in the use of builders resulting from environmental concerns have been pushing surfactant production demand. Outright legal bans or consumer pressures on the use of inorganic phosphates and other materials as builders generally have led formulators to raise the contents of... 

Treatment options include corticosteroid administration to the mother prior to a cesarean section to induce surfactant production, direct tracheal instillation of surfactant, and in the most severe cases, mechanical ventilation. 

Surfactants are used in a variety of applications, frequently in the form of dilute aqueous solutions. However, it is not cost effective to transport, store, and display in retail outlets surfactant products such as household detergents in this form. Accordingly, it is important to have products that dissolve quickly and to understand what aspects of surfactant composition and structure promote rapid dissolution. The dissolution process is more complex for surfactants than for most other materials because it typically involves formation of one or more concentrated and highly viscous liquid crystalline phases, which are not present initially and which could potentially hinder dissolution. In this article the rates and mechanisms of surfactant dissolution are reviewed and discussed. 

Replacement of the organic phase with surfactants to exploit micellar phase transfer catalysis principles (Battal et al., 1997) for the alkylation of phenol and aniline. This group had previously demonstrated the synthesis of a surfactant by micellar autocatalysis, whereby the surfactant product itself catalyses the reaction (Kust and Rathman, 1995). 

Phospholipid that is the major component of Tung surfactant, and the syndrome caused by its deficiency Dipalmitoylphosphatidylcholine (DPPC, also called dipalmitoyllecithin, DPPL) is the major lipid component of lung surfactant. It is made and secreted by type II granular pneu-mocytes. Insufficient surfactant production causes respiratory distress syndrome, which can occur in preterm infants or adults whose surfactant-producing pneumocytes have been damaged or destroyed. 

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