Green Chemistry and Sustainable Design

40 lessons, pages 4031–4070.

What Is Green Chemistry? — Designing chemical products and processes that reduce or eliminate hazardous substances
From Pollution Control to Pollution Prevention — Why stopping waste at source beats end-of-pipe treatment
The 12 Principles of Green Chemistry: An Overview — The Anastas and Warner framework and how the principles fit together
Principle 1: Prevent Waste — Why it is better to avoid waste than to treat or clean it up
Measuring Greenness: Why Yield Is Not Enough — Percentage yield ignores by-products, solvents and reagents
Atom Economy: The Core Idea — Percentage of reactant mass that ends up in the desired product
Calculating Atom Economy — Using balanced equations and molar masses step by step
Atom Economy of Reaction Types — Addition and rearrangement versus substitution and elimination
Atom Economy and Yield Together — Combining theoretical efficiency with practical efficiency
The E-Factor — Mass of waste per mass of product and what counts as waste
E-Factors Across the Chemical Industry — Why bulk chemicals score low and pharmaceuticals score high
Reaction Mass Efficiency and Process Mass Intensity — Wider mass-based metrics used by industry
Green Metrics in Practice: Comparing Two Routes — Applying atom economy, yield and E-factor to choose a synthesis
Less Hazardous Chemical Syntheses — Choosing reagents and routes that minimise toxicity
Designing Safer Chemicals — Keeping function while reducing toxicity to people and ecosystems
Why Solvents Matter — Solvents as the largest share of waste in many processes
Solvent Selection Guides — Ranking solvents by safety, health and environmental impact
Water as a Green Solvent — Benefits and limitations of aqueous reaction media
Supercritical Carbon Dioxide — Tunable solvent properties above the critical point and decaffeination
Ionic Liquids and Bio-Based Solvents — Low-volatility salts and solvents made from renewable feedstocks
Solvent-Free and Mechanochemical Reactions — Eliminating solvents by grinding and neat reactions
Catalysis Versus Stoichiometric Reagents — Why a catalyst used in small amounts creates far less waste
Heterogeneous Catalysts in Green Processes — Solid catalysts, easy separation and reuse
Homogeneous Catalysis and Selectivity — Soluble metal complexes that give precise, high-yield transformations
Biocatalysis: Enzymes as Green Catalysts — Mild conditions, water as solvent and high selectivity
Case Study: Greener Ibuprofen Synthesis — How a catalytic three-step route replaced a six-step stoichiometric one
Reducing Derivatives and Protecting Groups — Avoiding unnecessary steps that add reagents and waste
Design for Energy Efficiency — Running reactions at ambient temperature and pressure where possible
Alternative Energy Inputs: Microwaves, Light and Electricity — Photochemistry, electrosynthesis and microwave heating
Renewable Feedstocks — Replacing petroleum-based starting materials with biomass
Carbon Dioxide as a Chemical Feedstock — Turning a waste gas into fuels, polymers and carbonates
Design for Degradation — Products that break down into harmless substances after use
Real-Time Analysis and Inherently Safer Chemistry — In-process monitoring and accident prevention by design
Life-Cycle Thinking — Following a product from raw materials to end of life
Stages of a Life-Cycle Assessment — Goal and scope, inventory, impact assessment and interpretation
Life-Cycle Assessment in Action: Comparing Products — Trade-offs between bags, bottles and packaging choices
The Circular Economy and Chemical Recycling — Keeping materials in use and closing the loop
Green Polymers and Bioplastics — Bio-based and biodegradable plastics and their real limitations
Trade-Offs and Limits of Green Chemistry — When principles conflict and how to weigh competing goals
Green Chemistry and Sustainable Design: Unit Review — Principles, metrics, solvents, catalysis and life-cycle thinking together