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ARS Home » Midwest Area » Peoria, Illinois » National Center for Agricultural Utilization Research » Bio-oils Research » Research » Publications at this Location » Publication #419446
Research Project: Development of New Value-Added Processes and Products from Advancing Oilseed Crops

Location: Bio-oils Research

Title: Synthesis of carboxylic esters via green zinc catalysts

Author
item Knetzer, Taegan
item Winfield, Demichael

Submitted to: Illinois Heartland American Chemical Society (ACS) Regional Conference
Publication Type: Abstract Only
Publication Acceptance Date: 10/2/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: The esterification of a carboxylic acid with an alkene can be catalyzed by green catalysts, such as earth abundant zinc catalysts. Esters are used in a wide range of industrial and consumer products. Cosmetics, lubricants, polymers, solvents, fragrances, flavorings, and biodiesel additives are just a few of the purposes esters fulfill. Conventional methods for producing esters includes the use of a strong acidic catalyst, usually sulfuric acid, and produces byproducts. The strong acid catalysts become waste, and the byproducts are unsafe and also need to be disposed of. Green catalysts can be used in place of sulfuric acid to avoid producing an unsafe byproduct and eliminate the use of a strong acid catalyst. Green catalysts will diminish a reliance on hazardous catalysts and can produce desirable results. Green catalysts are favored by chemists because of their environmentally friendly qualities which align with the 12 green principles. The esterification of hexanoic acid with 1-decene was used as a model reaction to study different catalysts. Each reaction was vacuum refluxed at 100 deg. for 24 hrs. Samples were analyzed using GC-FID, GC-MS, H-NMR, and C-NMR. Several zinc catalysts were tested for selectivity and conversion rates when producing 1-Methylnonyl hexanoate. ZnBr2 produced the highest conversion rate. To improve conversion and selectivity rates, ZnBr2 was paired with p-Toluenesulfonic acid in 20%, 10%, 5%, and 1% molar ratios. The most successful molar ratio was scaled up and monitored. Moving forward, catalytic ratios will be adjusted, scaled, and altered to be tested with different carboxylic acids and alkenes to find the conditions under which the esterification process will be optimized.