# Chlorine: Emissions

Coal grids double chlorine's carbon footprint

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

Coal grids double chlorine's carbon footprint 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. Emission intensity 1.00 t CO2e per t range 0.7-1.6 · Europe 0.71 t CO2 per t (Euro Chlor 2022 eco-profile, updated Sep 2022); coal-heavy grids in China and India push the global average towards 1.0-1.6 Global emissions per year 80.0 Mt CO2e per year 2025 · 1.0 t x about 80 Mt chlorine; the whole ECU including caustic is about 160-170 Mt

Per t of chlorine, cradle-to-gate, mass allocation between chlorine, caustic soda and hydrogen. Intensity: Euro Chlor eco-profile 2022; global value indicative (basis: 2.7-3.0 MWh per t at 0.6-0.7 t CO2 per MWh, mass allocation 46% to chlorine). Global total: derived (indicative).

#### Share of footprint by lifecycle phase
 Feedstock 5% Production / process 90% Movement 5%

#### Footprint by lifecycle phase

| Phase | Intensity | Share | Main sources of emissions | Notes | Source |
|---|---|---|---|---|---|
| **Feedstock** | about 0.05 t CO2e per t | 5% | salt mining and vacuum evaporation | salt about 0.06 kg CO2e per kg (Euro Chlor 2013 eco-profile) x 1.7 t, mass allocated | Euro Chlor eco-profile 2013 |
| **Production / process** | about 0.9 t CO2e per t | 90% | grid carbon intensity of the 2.5-2.8 MWh of electricity, plus steam for caustic | almost all indirect (scope 2) | Euro Chlor eco-profile 2022 (indicative global) |
| **Movement** | about 0.05 t CO2e per t | 5% | short rail and road hauls | most chlorine moves by pipeline across the fence | indicative |
| **Use** | not applicable | – | chlorine is a reagent | disinfection by-products (trihalomethanes) in water are a health issue, not a climate one | WHO drinking water guidelines (indicative) |
| **End of life** | not applicable to chlorine itself | – | fate of PVC and chlorinated products | incineration of PVC releases HCl and risks dioxins; chlorinated solvents and CFC precursors have ozone and toxicity legacies | indicative |

#### Other environmental impacts

Legacy mercury pollution from mercury cells; asbestos from diaphragms; acute toxicity in accidents; persistent organochlorines (PCBs, DDT, dioxins) from historic uses.

#### Levers to cut emissions

- Renewable power purchase: power is about 90% of the footprint, so a zero-carbon grid cuts it to roughly 0.1 t per t
- Oxygen-depolarised cathodes cut electricity by about 25-30% (indicative)
- Demand response: chlor-alkali cells can flex load, earning grid revenue (indicative)
- Use the hydrogen co-product (about 28 kg per t) as fuel or feedstock rather than flaring
- Close mercury and diaphragm capacity

#### India

India's chlor-alkali runs on coal-heavy grid or captive coal power, so its footprint is higher than Europe's; producers are adding solar-wind hybrid power, for example DCM Shriram's 44 MW (2024).
 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 |
|---|---|---|---|---|
| **Membrane electrolysis on renewable power** | about 0.1-0.2 t CO2e per t (indicative) | depends on power price; flexible operation may lower cost | Indian producers adding captive solar and wind (DCM Shriram about 44 MW renewables, 2024) | Indian Chemical News June 2024; indicative |

 For a climate investor Chlor-alkali is one of the largest electricity users in chemicals, so firm low-carbon power is the main lever. Indian producers with captive coal are candidates for round-the-clock renewable power contracts and storage. Oxygen-depolarised cathodes and flexible operation are proven in Europe. What has to be true is cheap firm renewable power and buyers who pay for low-carbon PVC or caustic.

## Other sections

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