The 2020 US Environmental Protection Agency (EPA) Green Chemistry Challenge awards were given out in a virtual ceremony this morning. This year, four companies and one academic researcher earned awards for their work to make chemistry more environmentally friendly in five categories. The award-winning work included a biobased synthesis of butylene glycol, a formaldehyde-free carpet adhesive, and a spider-inspired biosynthetic pesticide.
The awards were announced as part of the American Chemical Society Green Chemistry conference, held online this year due to the COVID-19 pandemic. This year’s winners “developed new and innovative green chemistry technologies that turn potential environmental challenges into business opportunities, spurring innovation and economic development,” according to an EPA spokesperson.
Genomatica, a San Diego based bioengineering company, won the greener synthetic pathways award for their work on making biobased butylene glycol. Traditional synthesis of the chemical, broadly used in the cosmetic industry, creates about 200,000 tons of greenhouse gas emissions per year and uses over 50,000 tons of acetaldehyde, produced from fossil fuels, per year. Genomatica’s new synthesis uses common sugars, including those from corn, beet, wheat, or sugarcane. The company ferments the sugars to make butylene glycol, slashing greenhouse gas emissions by about 50% compared with the conventional route. The company estimates that if all butylene glycol were made via their method, global greenhouse gas emissions would shrink by about 100,000 metric tons per year.
The EPA awarded the greener reaction conditions to the pharmaceutical company Merck & Co. for building a prodrug synthesis that eliminated the use of toxic reagents. Prodrugs are molecules that get metabolized by our bodies into an active pharmaceutical. Some hepatitis C and HIV medications are prodrugs and get synthesized through a method call pronucleotide (ProTide) synthesis. The method uses toxic and corrosive thionyl chloride, plus an excess of expensive pentafluorophenol that generates a lot of waste. Merck’s new method creates their target compounds in 90 to 92% yields without these reagents and eliminates the need for halogenated solvents entirely through strategic catalyst loading and the use of different starting materials from the traditional route.
The design of greener chemicals award went to the development of more environmentally friendly versions of chemicals called thermoset binders, which can serve as carpet adhesives and are involved in the manufacture of mineral and fiberglass products. Generally, these chemicals are based on formaldehyde or polycarboxylic acids, and they can give off toxic formaldehyde and often use small amounts of sulfuric and hypophosphorous acid as catalysts to activate them. The insulation and commercial roofing company Johns Manville created a new binder based on the reaction between renewable dextrose, fructose, and other simple sugars, bound together by the α-carbon-containing cross-linking agent glyoxal. The reaction also uses a biodegradable acid in water as a catalyst. The binder can be made in just one step instead of the traditional multistep synthesis. Also, the synthesis can be done directly at the manufacturing site, instead of beforehand like with the traditional approach, meaning this new binder creates fewer of the health and environmental hazards that come from storage and transportation.
Steven Skerlos, a professor of mechanical engineering at the University of Michigan, won this year’s academic green chemistry award for Pure-Cut, an alternative to traditional metalworking fluids that reduce the heat and friction created between cutting tools and metals. The liquids are often a water and oil emulsion and require biocides to impede microorganism growth. These added chemicals can increase the risk of cancer for workers and contain heavy metals such as lead, nickel, chromium, cobalt, or cadmium. Pure-Cut cools and lubricates metalwork with supercritical CO2, which can be collected as waste from other processes. The lubricant also works better than traditional metalworking fluids, reducing production time in some tests.
The EPA Green chemistry award for a small business went to the agricultural chemical company Vestaron Corporation for developing a novel bioinsecticide called SPEAR, which is as effective as traditional, commercially available pesticides. The compound is a cysteine-rich peptide inspired by those made by the blue mountain funnel web spider from southeastern Australia. Because the pesticide is a peptide, it will biodegrade easily into amino acids. SPEAR works against many insects but is nontoxic to mammals and some invertebrates, including honey bees. Scientists at Vestaron make the compound through fermentation with a proprietary yeast strain. The insecticide is less toxic than traditional synthetic compounds and can be another defense against pests that have grown resistant to commonly used insecticides.
The EPA Green Chemistry Challenge awards are given out each year to acknowledge chemical research and processes that apply the principles of green chemistry to design, manufacture, and use. The awards are sponsored by the EPA’s Office of Chemical Safety and Pollution Prevention, along with Green Chemistry Institute of the American Chemical Society, which publishes C&EN.
This story was updated on June 18, 2020, to specify that SPEAR is nontoxic to mammals, not all animals.