# Soda ash: Emissions

Why natural ash emits far less than Solvay ash

Source page: https://www.materialinsights.org/commodities/soda_ash/emissions/

What this tab covers The greenhouse-gas footprint of the commodity at a global level, split by lifecycle phase: extraction (or farming), refining and processing, movement, usage, and recycling or end of life. Intensities are per unit of product; the global total combines intensity with world output. Also covers other environmental impacts and the main levers to cut emissions. Emission intensity 0.80 t CO2e per t range about 0.3-1.3: US natural plant direct about 0.27; UK Solvay with CHP 0.7, older Solvay 1.2; Russian ash delivered to EU over 1.3 · cradle-to-gate; global mix about 73% synthetic Global emissions per year 57.0 Mt CO2e per year 2025 · derived: 71 Mt x about 0.8 t CO2e/t; coal-based Chinese synthetic output may push it higher

Per t of soda ash, global production mix; cradle-to-gate (use-phase CO2 from glass melting listed separately). Intensity: Brunner Mond evidence to UK House of Lords 2008; US EPA 2009 TSD subpart CC; Genesis Energy (indicative). Global total: Derived from USGS MCS 2026 and the intensities above (indicative).

#### Share of footprint by lifecycle phase
 Refining / processing 100%

#### Footprint by lifecycle phase

| Phase | Intensity | Share | Main sources of emissions | Notes | Source |
|---|---|---|---|---|---|
| **Extraction** | not split; included in plant figures | – | limestone quarrying and brine wells (synthetic); underground trona mining (natural) | Small relative to processing | Brunner Mond 2008 |
| **Refining / processing** | UK Solvay plant 0.7 t: about 0.5 from energy and 0.2 process; US trona plant process CO2 0.138 t plus similar combustion CO2 | 100% | lime kilns (limestone calcination), steam for ammonia recovery and calcining; for trona, calcining releases CO2 and fuel for heat | Natural soda ash emits about 37% less GHG and uses under half the energy of synthetic | Brunner Mond 2008; US EPA 2009; Genesis Energy |
| **Movement** | about 0.1 t CO2/t from US plant to Europe (0.8 at gate to 0.9 delivered) | – | rail from Wyoming to ports, then bulk shipping | Outside gate boundary; natural ash keeps about 21% advantage delivered to Asia | Brunner Mond 2008; Genesis Energy |
| **Usage** | about 0.415 t CO2 per t soda ash when melted into glass (Na2CO3 to Na2O + CO2, stoichiometric) | – | carbonate decomposition in glass furnaces; also in flue gas desulphurisation | This process CO2 is counted in the glass sector but comes from the soda ash molecule | Stoichiometry; IPCC 2006 Guidelines approach |
| **Recycling / end of life** | not applicable to soda ash itself | – | glass cullet replaces raw batch, avoiding soda ash and its 0.415 t use-phase CO2 | Glassmakers' cullet use reduces soda ash consumption (USGS) | USGS MCS 2026 |

#### Other environmental impacts

The Solvay process leaves about 1.05 t of calcium chloride per t of soda ash (stoichiometric), usually discharged as distiller waste to sea or ponds. Ammonia losses and large water use are further issues. Trona mining leaves tailings and recovers only about 45% (room-and-pillar) or 30% (solution mining) of the ore in place.

#### Levers to cut emissions

- Shift supply to natural soda ash (about 37% lower GHG than synthetic)
- Combined heat and power in Solvay plants (UK example: 1.2 to 0.7 t CO2/t)
- New process routes such as e.Solvay, which Solvay expects to cut CO2 by about 50%
- Raise glass cullet rates to cut soda ash demand and its use-phase CO2
- Capture and reuse kiln CO2 within the process or for sodium bicarbonate

#### India

India makes only synthetic soda ash, mainly at Gujarat plants beside salt works, so its plant intensity sits at the synthetic end of the range, and imports (25-26% of supply) come mostly from China's synthetic producers (USGS MCS 2026; content_v2).
 Emission figures are indicative global averages from the life-cycle studies named; actual footprints vary widely by site, energy mix and method.

## Other sections

- [Summary](https://www.materialinsights.org/commodities/soda_ash/index.md)
- [Overview](https://www.materialinsights.org/commodities/soda_ash/overview/index.md)
- [Correlation](https://www.materialinsights.org/commodities/soda_ash/correlation/index.md)
- [Extraction](https://www.materialinsights.org/commodities/soda_ash/extraction/index.md)
- [Production](https://www.materialinsights.org/commodities/soda_ash/production/index.md)
- [Stocks](https://www.materialinsights.org/commodities/soda_ash/stocks/index.md)
- [Cycles](https://www.materialinsights.org/commodities/soda_ash/cycles/index.md)
- [Trading](https://www.materialinsights.org/commodities/soda_ash/trading/index.md)
- [Movement](https://www.materialinsights.org/commodities/soda_ash/movement/index.md)
- [Criticality](https://www.materialinsights.org/commodities/soda_ash/criticality/index.md)
- [Characteristics](https://www.materialinsights.org/commodities/soda_ash/characteristics/index.md)
- [Relationships](https://www.materialinsights.org/commodities/soda_ash/links/index.md)