Surfactants from Waste Biomass

Abstract

IntroductionAs has been established in other chapters of this book, the reasons behind the search for bio-based alternatives to petroleum-based surfactants can be summarized in one word -sustainability. However, there are different ways to produce bio-based surfactants, all of which have different 'degrees' of sustainability. As an example, soaps -alkaline salts of fatty acids -can be considered bio-based surfactants, as they are derived from the saponification of triglycerides obtained from plants and animals. Methyl ester sulfonates are obtained from fatty acid methyl esters (FAMEs) which in turn are also obtained from triglycerides found in plants and animal tissues. Lecithin, lysolectihins and other phospholipids can also be extracted from plant and animal tissue. As will be explained in the next sections, bio-based surfactants can also be secreted by microbial cultures fed with specific substrates.In all the above examples, there is no question about the bio-based origin of the surfactant, its biocompatibility and its ability to quickly biodegrade. However, all these attributes are necessary but not sufficient to answer the question of sustainability. Currently there are questions being raised about the sustainability of growing crops of palm oil in southeast Asia which are currently used as feedstock for soaps and other biobased surfactants. Some of the issues being considered are reduction in biodiversity, deforestation, impact of fertilizers and pesticides, and reduction in the natural habitat for numerous species [1]. With respect to the production of biosurfactants by microorganisms (e.g. rhamnolipids and sophorolipids), valuable carbon sources such as glucose are often used. These carbon sources are expensive, and are also a food source for animals and humans. Surfactants from Renew able ResourcesEdite d by Mika e l Kje llin a nd I nge g ärd Johansson

Plant-Derived Saponins: A Review of Their Surfactant Properties and Applications

“…The synthetic chemical compound known as surfactant falls under the same category. In general, surfactants are known for increasing the cleansing power of water by reducing its surface tension, which makes them a common component of household detergents and cleaning products [6]. As well as being employed in oilfield chemicals, agricultural chemicals, pharmaceuticals, textiles, and polymerization of emulsions used in cosmetics, personal care products, food, and paper processing, they also find application in many other fields [7,8].…”

“…In general, natural surfactants are divided into two categories based on their origin: (i) natural surfactants produced by the plants and (ii) substances produced by fermentation of alkanes, oils, sugars, and waste in the presence of microbes (also called biosurfactants) [5,12]. The production of bio-surfactants is more rare because of the high cost of production and threat to food security as it uses carbon sources [6]. There is no doubt that plants are major sources of natural surfactants.…”

Waste Biomass-Extracted Surfactants for Heavy Oil Removal

“…Biosurfactants, on the other hand, are surfactants that are directly synthesized by living organisms (mainly bacteria). Examples of biosurfactants include glycolipids, rhamnolipids, sophorolipids, and saponins. , There are concerns over the true sustainability of surfactants derived from biomass like plants and animals, such as deforestation, and competitive land use for food crops. − Biosurfactant production from microorganisms often requires relatively expensive carbon sources, which can be alternatively used as food sources for animals. There are also limitations in large-scale production and purification efficiency. , …”

“…There are also limitations in large-scale production and purification efficiency. 7,10 Waste biomass is an alternative renewable source for surfaceactive materials. Large scale production of surfactants from this source is a goal.…”