Green Chemistry: 12 Principles, Biodiesel and Atom Economy
Why in the news
As worries over environmental damage grow, green chemistry is gaining attention as a way to remove hazardous substances from chemical processes while improving sustainability, safety and efficiency.
Key facts
- Meaning: designing chemical products and processes that cut the use and generation of hazardous substances.
- Origin: Paul Anastas and John Warner set out the 12 Principles in 1998.
- Principles stress safer solvents and reagents, energy-efficient reactions, non-toxic products, waste prevention at source and high atom economy.
| Example | Green angle |
|---|---|
| Biodiesel (Indian Oil Corporation) | Uses non-edible Jatropha seeds with 30% oil; transesterification with methanol gives biodiesel plus glycerol |
| Catalyst choice | Sodium hydroxide makes wastewater; solid calcium oxide is 95% recoverable |
| Pharma solvents | Toluene (neurotoxic VOC) replaced by biodegradable, biomass-derived solvents such as sugarcane-based |
| Tamoxifen (BITS-Pilani, Hyderabad) | Green route with 100% atom economy; cost-effective, scalable, non-polluting |
Atom economy
- Efficient use of atoms in a reaction, aiming to minimise waste.
- Biodiesel production reaches 90%; the glycerol by-product goes into cosmetics, polymers and similar products, supporting circularity.
Exam angle
- Founders of the 12 Principles: Anastas and Warner (1998).
- Biodiesel feedstock: Jatropha; by-product: glycerol.
- Term: atom economy.