Microalgal Biomass as a Raw Material for Producing Surfactants

Abstract

Oils were isolated from the dry biomass of microalgae (Spirulina, Botryococcus balkhashus, and wild strain of the Sugur soda lake culture). These oils were subjected to ester interchange with methanol, followed by modification with monoethanolamine and ethylene glycol. The surfactant properties of the oils obtained as reaction products were evaluated. These oils reduce the surface tension of water to 16–32 mN m⁻¹; i.e., the biomass studied is suitable as a raw material for producing biodegradable surfactants. The pyrolysis lipids of the microalgal culture samples studied can be ranked in the following order with respect to surfactant properties: Botryococcus balkhashus > Sugur culture > Spirulina. This order is associated with the composition of the lipid fractions. The quantitative parameters of the growth of the Spirulina biomass in various culture media are compared. The use of alternative resources, namely, of the source of the main biogenic element, carbon, in a culture medium (crude soda) and of geothermal hydrocarbonate water as a liquid base, increases the yield of the produced biomass.