Chiral and specialty building blocks: Emissions
How enzymes can shrink a drug's chemical waste
How enzymes can shrink a drug's chemical waste What this tab covers The greenhouse-gas footprint per tonne, split by lifecycle phase (feedstock, production, movement, use, end of life), the global total, other environmental impacts, levers and low-carbon routes, India's position, and where the investment opportunity lies.Per kg of chiral building block, cradle-to-gate. Intensity: indicative; ACS Green Chemistry Institute Pharmaceutical Roundtable PMI benchmarks (indicative); Wernet et al. 2010 on fine chemical LCA (indicative). Global total: not published.
Share of footprint by lifecycle phase
Feedstock 50% Production / process 45% Movement 5%Footprint by lifecycle phase
| Phase | Intensity | Share | Main sources of emissions | Notes | Source |
|---|---|---|---|---|---|
| Feedstock | not published | 50% | solvents, reagents and multistep intermediates | solvent manufacture is often the largest single item (indicative) | indicative split |
| Production / process | not published | 45% | batch reactor heating and cooling, distillation, drying, cleanrooms, solvent incineration | indicative split | |
| Movement | not published | 5% | air freight of small high-value lots | indicative | |
| Use | not applicable (consumed in synthesis) | – | |||
| End of life | waste solvent incineration counted in production | – | pharma waste streams are often incinerated | indicative |
Other environmental impacts
High waste per kg of product (E-factors of 25-100 kg per kg are typical in pharma, Sheldon, indicative); solvent emissions; metal catalyst residues; effluent with active compounds.
Levers to cut emissions
- Biocatalysis and asymmetric catalysis instead of resolution without recycle
- Racemisation and recycle of the unwanted enantiomer
- Solvent recovery and greener solvents
- Continuous flow processes
- Renewable steam and power at plants
India
Indian API and intermediate plants run largely on coal steam and grid power; some leaders publish Scope 1 and 2 targets in BRSR reports (indicative).
Emission figures are indicative global averages from the life-cycle studies named; actual footprints vary widely by site, energy mix and method.Low-carbon routes
| Route | Intensity | Cost premium | Status | Source |
|---|---|---|---|---|
| Engineered enzyme routes (e.g. sitagliptin transaminase) | cut total waste by 19% and removed rhodium and high-pressure hydrogenation in one case (Savile et al., Science 2010, indicative) | enzyme development cost up front | commercial at Merck; many other drugs (indicative) | Savile et al. 2010 (indicative) |