Extraction of Fatty Acids from Noncatalytically Cracked Triacylglycerides Using Aqueous Amines

Abstract

It has been reported that a basic aqueous solution was effective in extracting short chain C₂–C₆ fatty acids from noncatalytically cracked triacylglyceride oils. However, the extraction efficiency was not optimal over the entire range (C₂–C₁₂) of acids present in the cracking reactor organic liquid product (OLP). Therefore, an additional study was performed to explore the efficiency of solvent extraction using aqueous amines for this application. Based on the screening of several amines, two tertiary amines, trimethyl amine (TMA), and dimethyl ethanolamine (DMEA), were selected and evaluated. The extraction conditions were optimized with respect to several factors: temperature, amine concentration, and the amine-to-OLPratio (amine/OLP). Under optimal conditions, both TMA and DMEA were effective in extracting a wide range of organic acids, with TMA removing 93% of total acids and DMEA removing 100% of total acids. The amine/OLP was found to be a significant factor, as was the concentration of the amine solution. Temperature was not found to be a significant factor over the range studied. These results provide a basis for the development of a scalable, continuous process to produce a variety of C₂–C₁₂ fatty acids from biological sources.

Keywords:

• biobased materials
• liquid-liquid extraction
• short chain fatty acids

ACKNOWLEDGEMENTS

Funding from the United States Department of Agriculture under award number 2008-35504-04515, the North Dakota Soybean Council, and Bayer Crop Sciences are acknowledged. Reference herein does not necessarily constitute or imply its endorsement, recommendation, or favoring by any of the funding agencies. The contributions of instrument technicians Joe Miller and Dave Hirshmann are also acknowledged.

Notes

ND: not detected.