# Chiral and specialty building blocks: Emissions

How enzymes can shrink a drug's chemical waste

Source page: https://www.materialinsights.org/chemicals/chiral_building_blocks/emissions/

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) |

 For a climate investor Greener chiral chemistry, especially biocatalysis and continuous flow, can cut cost and waste at once, which is rare. Indian CDMOs that build enzyme engineering and flow chemistry can win business shifting from China. What has to be true: customers pay for qualification of new routes, and Indian firms keep a clean regulatory record.

## Other sections

- [Summary](https://www.materialinsights.org/chemicals/chiral_building_blocks/index.md)
- [Overview](https://www.materialinsights.org/chemicals/chiral_building_blocks/overview/index.md)
- [Correlation](https://www.materialinsights.org/chemicals/chiral_building_blocks/correlation/index.md)
- [Production route](https://www.materialinsights.org/chemicals/chiral_building_blocks/routes/index.md)
- [Production](https://www.materialinsights.org/chemicals/chiral_building_blocks/production/index.md)
- [Feedstocks](https://www.materialinsights.org/chemicals/chiral_building_blocks/feedstocks/index.md)
- [Cycles](https://www.materialinsights.org/chemicals/chiral_building_blocks/cycles/index.md)
- [Trading](https://www.materialinsights.org/chemicals/chiral_building_blocks/trading/index.md)
- [Movement](https://www.materialinsights.org/chemicals/chiral_building_blocks/movement/index.md)
- [Regulation](https://www.materialinsights.org/chemicals/chiral_building_blocks/regulation/index.md)
- [Characteristics](https://www.materialinsights.org/chemicals/chiral_building_blocks/characteristics/index.md)
- [Relationships](https://www.materialinsights.org/chemicals/chiral_building_blocks/links/index.md)