Examples of Green Chemistry
Green Chemistry applies to and impacts many fields – from pharmaceuticals to household items. Some examples of Green Chemistry successes follow. Click on the links for more information on these and other international success stories.
“Everything we do is for industry; to really bring forward inclusive and sustainable development. We believe that chemicals play an extremely important role in the performance of industry, not just the production, but in our every-day lives – in the application. We therefore must work together with industry.” - Petra Schwager, UNIDO Global Project Coordinator
The discovery of a catalytic chemical process, called metathesis, earned the Nobel Prize in Chemistry in 2005. Using much less energy, it can reduce greenhouse gas emissions for many key processes. The process is stable at normal temperatures and pressures, can be used in combination with greener solvents, and is likely to produce less hazardous waste. Further progress in the development of this process led to the Presidential Green Chemistry Challenge Award in 2012, when metathesis was demonstrated to break down natural oils and recombine the fragments into high-performance chemicals. Metathesis has implications for the manufacture of, among others, detergents.
Many chemicals, and much water and energy are needed to manufacture computer chips. A 2003 study estimated a ratio of 630:1 in terms of chemicals and fossil fuels required to make one computer chip – i.e. it takes 630 times the weight of the chip in source materials to make one chip (in comparison, the ratio for manufacturing a vehicle is 2:1).
Advances in Green Chemistry include:
- A new process that uses supercritical carbon dioxide in one of the steps of chip preparation, significantly reducing the chemicals, energy and water needed in the production process.
- Innovation using chicken feathers to make computer chips. The protein, keratin, in the feathers is used to make a fibre form that is both light and tough enough to withstand mechanical and thermal stresses. The result is a feather-based printed circuit board that works at twice the speed of traditional circuit boards. While this technology is still in the works for commercial purposes, the research has led to other uses of feathers as source material, including for biofuel.
Pharmaceutical research, besides investigating new medical solutions, also focuses on ways to reduce harmful side-effects and processes that produce less toxic waste. Some Green Chemistry successes include:
- New biocatalysts – using an enzymatic process originally developed for the treatment of type 2 diabetes but holding promise for other drugs as well – which reduce waste, improve yield and safety, and eliminate the necessity for a metal catalyst.
- A new synthesis using an engineered enzyme and low-cost feedstock for a well-known high cholesterol medicine was optimised to be more cost-effective, as well as to greatly reduce hazard and waste.
Many companies are developing plastics made from renewable, biodegradable sources. Successes include:
- New food containers made from a method where microorganisms convert corn starch into a resin that is just as strong as the rigid petroleum-based plastic used for containers such as water bottles and yogurt pots.
- Fully biodegradable bags made of a compostable polyester film with cassava starch and calcium carbonate. The bags are tear-resistant, puncture-resistant, waterproof, printable and elastic; as well as able to disintegrate into water, CO2, and biomass in industrial composting systems.
Oil-based paints containing synthetic resin made from dicarboxylic acid (known as alkyd paints), give off organic compounds. These volatile compounds evaporate from the paint as it dries and have environmental impacts. Improvements in this area include:
- Replacing fossil-fuel-derived paint resins and solvents with a mixture of soya oil and sugar cuts hazardous volatiles by half. These bio-based oils are used to replace petroleum-based solvents, creating safer paints with less toxic waste.
- Water-based acrylic alkyd paints with low volatile organic compounds that can be made from recycled soda bottle plastic, acrylics, and soybean oil. In 2010, enough of these paints were manufactured to eliminate more than 362 874 kg of volatile organic compounds.
Governments and scientific communities throughout the world recognise that the practice of green chemistry and engineering not only leads to a cleaner and more sustainable earth, but also is economically beneficial with many positive social impacts. These benefits encourage businesses and governments to support the development of sustainable products and processes. - https://www.acs.org