Eco-design process to produce performing amino acids based surfactants

In the range of ionic chemical species exhibiting amphiphilic properties, Amino Acid Surfactants market size have been steadily growing over the past years reaching a value of USD 221.8 million in 2022.

Given their natural and simple structure, they show low toxicity and quick biodegradation. The combination of polar amino acids (hydrophilic moiety) and non-polar long-chain compounds (hydrophobic moiety) for building up the amphiphilic structure have produced molecules with high surface activity.

Main challenge to overcome is the manufacturing process which usually does involve the use of fatty acid chloride and a co-solvent (i.e. Schotten-Baumann acylation). 

The fatty acid chloride itself is made by halogenating fatty acid chlorinating agents, such as thionyl chloride. The production is relatively simple, but distillation is required to remove numerous impurities including the unreacted raw materials. In addition, amino acid surfactant does require a solvent to be produced (such as acetone) which may induce color and sometimes odor. 

To tackle these hurdles two options had been tested

(1) Following this first step, additional R&D tests have been done with the goal to achieve the amidification reaction using the fatty acids and not the fatty acid chloride. Although the foaming performances (Na cocoyl proline) are similar, the composition is quite different and leads to some formulation issues, especially in terms of water solubility. 

(2) A sustainable manufacturing process was developed by minimizing energy loss and avoiding the use of a co-solvent. A bio-based foaming agent was developed (Na cocoyl glutamate), and its foaming performance was evaluated versus usual industrial foamers. Foaming performance evaluated at 1% in hard water (Active Substance) was found equivalent to the same surfactant obtained with the historical process in terms of volume of foam generated while foam stability was slightly lower. Surprisingly, the foam was thicker and denser.