Executive Summary
Renewable feedstocks, including triglycerides and lignocellulose-derived sugars, can be converted to a new class of ionic surfactants, called “oleo-furan sulfonates” (OFS) by multi-step solid acid catalysis. The renewable OFS surfactant exhibits superior properties relative to conventional fossil-derived materials with higher micelle-forming efficiency, stability in cold water, and resistance to hard water. The sequential synthesis process includes catalytic hydrolysis of triglycerides, fatty acid dehydration to anhydrides, and furan acylation with anhydrides to form alkylfuran ketones, the key precursor to OFS surfactants. This technology has been demonstrated as a three-step process with independent reactors. This project aims to more efficiently prepare oleo-furan sulfonate (OFS) surfactants by combining all three chemistries (hydrolysis, dehydration, and furan acylation) into a single reactor-separator that permits integrated separation of byproduct water. All three reactions will be conducted in a vertical column containing packed trays to promote selective vaporization of light components (i.e., water). Spatially distributed throughout the column will be three catalytic zones containing hierarchical solid acid zeolite catalysts, each of which promote the chemistry specific to the composition of that zone. Water liberated from the acylation and dehydration steps at the bottom of the reactor flow upward to promote triglyceride hydrolysis, while fatty acids and anhydrides flow down to promote furan acylation. At the conclusion of this project, a detailed design of a reactive distillation system will be developed permitting tunable extents of each of the three chemistries, such that various grades of OFS surfactants can be manufactured. The project is also looking into advancing the lab-scale demonstration to the pilot-scale production.
Potential Impact
Intensification of three process steps into a single device condenses three reactors and separation systems and has the potential to achieve single-step processing of natural oils to surfactant precursors, thereby eliminating as much as two-thirds of the processing costs. This approach also further enhances the capability for rapid design and deployment by advancing design techniques of process intensified catalytic systems.
Resources
The University of Minnesota has expertise in catalyst testing, reaction kinetics, and reactor design and evaluation. The team’s work on furan acylation chemistry has pioneered the invention of the new oleo-furan sulfonate (OFS) surfactants. The team has also developed a laboratory with capability for modeling complex reacting systems with heat and mass transfer in parallel with construction and evaluation of complex process technology. Sironix Renewables has expertise in reactor construction and process synthesis with substantial experience in working with high temperature catalytic reaction systems. Expertise in complex kinetics integrated within the evaluation of process economics provides unique capability for implementing and evaluating intensified process technology as it pertains to emerging applications in the bioproducts industry.
