Description
Currently, this study is compiled for the first time. We plan to publish the 1st edition in september 2023.
Surfactants are chemical compounds consisting of a water-repellent and a water-attracting part. Therefore, surfactants can interact with hydrophobic and hydrophilic substances: They reduce the surface tension of a liquid or the interfacial tension between two phases, such as water/air or water/oil. As surfactant chemicals, they enable, for example, the mixing of water and oil, the detachment of dirt or the formation of foam.
Bio-based surfactants are made entirely or partly from biomass, i.e. chemically or microbially from renewable carbon. In Europe, bio-based surfactants are defined by the EN 17035 standard, which was published at the end of 2021.
Four Main Types of Surfactants
Basically, all surfactants are composed of two parts, both of which can be fully or partially biobased:
- a long, hydrophobic (water-repellent) and lipophilic (fat-loving), non-polar hydrocarbon radical, usually an alkyl or alkylbenzene group (for example methyl, ethyl or propyl groups),
- a short, hydrophilic (water-loving), polar molecular group.
For fully bio-based surfactants, for example, the hydrophobic part can be obtained from coconut or palm oil and the hydrophilic part from a sugar component such as glucose or sorbitol.
The properties of a surfactant depend mainly on its functional group, the polar “head”.
To achieve certain properties, different types of surfactants are combined with each other. Surfactants are also often mixed with other chemicals that balance individual surfactant properties.
Surfactants from Biobased Raw Materials
Surfactants occur in nature. More than 90 plant families contain saponins, which form a soap-like foam when shaken with water and have therefore been used for washing for thousands of years. Examples are soap herbs, soap trees, South American soap bark trees, but also chestnuts, soybeans or quinoa. Natural surfactants are also the phospholipids found in the membranes of plant and animal cells. Strictly speaking, biosurfactants are produced by microorganisms, i.e. certain bacteria and fungi, on the basis of renewable raw materials.
Surfactants are among the first everyday products for which biogenic raw materials are already being used on a large scale. Currently, however, around half of all surfactants consumed are still manufactured from petroleum derivatives. In the context of bioeconomy and climate protection, circular economy and green chemistry, renewable raw materials for surfactants are now (again) coming increasingly into focus, especially sugar and fatty alcohols.
The biotechnological, microbial production of biosurfactants by microorganisms in bioreactors is still more expensive than chemical synthesis, but is increasingly reaching market maturity. Blends of petrochemical and biogenic chemicals are marketed as “bioattributed,” “proportionately biobased,” or “mass-balanced grades.” Surfactants on a purely vegetable basis are offered as “vegan cleaning agents”.
Bio-based surfactants promise multiple benefits:
- more independence from fossil raw materials, therefore, also greater security of supply and less volatile prices,
- opportunities for agriculture and forestry, thus also for economically weak regions,
- utilization options for organic waste and by-products, such as from the paper and wood industry or biofuel production,
- a smaller ecological footprint, as biomass absorbs CO2 during its growth and causes shorter transport distances in the case of regional production,
- partly also technical advantages, such as better compatibility with other (biogenic) materials.
Bio-based does not Necessarily Mean Environmentally Friendly
Surfactants based on renewable raw materials can be affected by controversies, such as discussions on agribusiness, pesticide use, monocultures, genetic engineering, rainforest deforestation or possible competition between food and raw material production. In principle, however, natural and organic ingredients are usually considered sustainable, have a positive environmental image and enjoy the goodwill of public opinion and legislators.
The effects and risks that surfactants and their degradation products may have on health and the environment depend primarily on their chemical structure and not on whether the carbon originally used came from fossil sources, carbon dioxide or biomass.
In general, surfactants are dangerous to aquatic organisms because they can damage the cell membranes of living organisms, e.g. the gills of fish, and increase the permeability of cells to toxic substances, such as heavy metals or pesticides. Surfactants that are poorly degraded by microorganisms, for example products with highly branched alkyl chains, cause foam mountains on water bodies. Surfactants must therefore be biodegradable, i.e. they must be able to be broken down by bacteria and fungi in wastewater treatment plants, for example, into harmless metabolic products such as water, salts and biomass. In Germany, the Detergents Act has stipulated since 1961 that surfactants in detergents must be at least 80% biodegradable when exposed to oxygen (i.e. in wastewater treatment plants). Surfactants made from renewable raw materials often have an advantage here because linear carbon chains are easily converted by microorganisms and only remain in the water for a short time. Particularly environmentally compatible surfactants are also degradable with little or no oxygen, for example in septic tanks.
In Europe (EU and EEA), the EU Detergents Regulation (Regulation (EC) No.648/2004) now applies, which stipulates complete aeorobic biodegradability for surfactants in addition to primary degradability.
→ Ceresana offers market studies on the world market for all surfactants and on individual application areas, i.e. paints and coatings, printing inks and biocides and plastic additives. A recent Ceresana study specifically addresses the market for bio-based paints and coatings. Ceresana also studied the global market for complexing agents, which are often combined with surfactants.
soon to come
soon to come
soon to come