Irradiation of fat sources with UV light creates biomass feedstock for plastic
Samples tested included lard, tallow, olive oil, canola oil, and waste cooking oil (canola).
The researchers used UVC light to change lard, tallow, olive oil, canola oil and waste canola cooking oil into olefins.
Irradiation of animal and vegetable fats with UV light produced long chain alkenes, dienes, trienes, and glycerol as the byproduct, said the study in ACS Sustainable Chemistry & Engineering.
Many of the plastics found begin with a group of chemical raw materials termed olefins that come from petroleum.
They include ethylene, propylene and butadiene, which are building blocks for plastics like polyethylene, polyester, polyvinyl chloride and polystyrene.
Douglas Neckers and Maria Muro-Small said results show that, independent of the source of fat, irradiation using UVC light produces 1-tetradecene, 1-hexadecene, 1,7-hexadecadiene, and 1,7,10-hexadecatriene.
Acrylic acid shortage
The shortage of acrylic acid drove the need for the research, Neckers told FoodProductionDaily.com.
“As long as we have an excess supply of materials one can afford to pay but the minute there is a shortage that is what drives these experiments.
“We live in an agricultural place in Toledo, Ohio which has a large shipping port for items such as wheat, soy bean and all sorts of things."
Neckers who also owns Biosolar LLC, added that the challenge was getting yields to a practical level.
“We are photochemists, so that is what we bring to the table. There are lots of other ways to make biomass but we bring our knowledge to the party.
“There has been a lot of people interested but we need to move to the next level of practicality in terms of supply and demand.”
Yields found
The photochemical reactions, carried out in solvents that were not degassed, were followed by gas chromatography- mass spectrometry (GC-MS) to determine times of reactions and yield.
Irradiation ethyl palmitate for 1.5 hours in both hexane and ethanol produces 1-tetradecene in 34% yield. A 36% yield was observed when glyceryl tripalmitate was irradiated for 1.5 hours, suggesting that only one of the positions undergoes cleavage.
Glyceryl 1,3-dipalmitate and glyceryl monopalmitate exhibit slightly lower yields, 34% and 32% respectively, relative to their triglyceride counterpart in a higher reaction time of two hours.
These yields, although not sufficient for commercial use, are 3-fold higher than the yields observed for lard and tallow.
Glyceryl trioleate was used as a control for the unsaturated fatty acids; however, irradiation for two hours yielded in only 1%.
The data supports the hypothesis that saturated fatty acids are more reactive toward the photochemical cleavage than the unsaturated ones and reactivity depends on the position of the fatty acids on the triglyceride unit.
