# Phosphoric acid: Emissions

Low carbon, but a 200 Mt-a-year waste problem

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

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 0.50 t CO2e per t P2O5 range about 0.3-1.0 (wet process); several t for thermal acid on coal power · rock mining and beneficiation, sulphur and acid supply, evaporation and transport; steam from sulphur burners largely covers process heat Global emissions per year 23.0 Mt CO2e per year 2025 · 0.5 t/t x 45 Mt P2O5

Per t P2O5 in merchant-grade wet-process acid, cradle-to-gate. Intensity: Derived from phosphate and sulfur tiles (indicative). Global total: Derived (indicative).

#### Share of footprint by lifecycle phase
 Feedstock 60% Production / process 24% Movement 16%

#### Footprint by lifecycle phase

| Phase | Intensity | Share | Main sources of emissions | Notes | Source |
|---|---|---|---|---|---|
| **Feedstock** | about 0.30 t CO2e per t P2O5 | 60% | Rock mining, drying and beneficiation; sulphur recovery | About 3.3 t rock per t P2O5 | Indicative |
| **Production / process** | about 0.12 t CO2e per t P2O5 | 24% | Grinding, agitation, filtration and evaporation; carbonate in rock releases CO2 on digestion | Integrated sulphur burners supply most steam | Indicative |
| **Movement** | about 0.08 t CO2e per t P2O5 | 16% | Shipping rock, sulphur and acid | Indian acid imports travel 5,000-10,000 km | Indicative |
| **Use** | outside the cradle-to-gate total | – | DAP and MAP application | Ammonia in DAP carries far more CO2 than the acid | Phosphate tile |
| **End of life** | not applicable | – | Phosphorus run-off | Eutrophication of rivers and coastal waters | Indicative |

#### Other environmental impacts

Phosphogypsum of about 4.5-5 t per t P2O5, about 200 Mt a year (indicative), with radium, fluoride and cadmium; stack failures such as Piney Point, Florida (2021); fluoride emissions; eutrophication from fertiliser run-off.

#### Levers to cut emissions

- Hemi-dihydrate processes that cut evaporation steam and give usable gypsum
- Phosphogypsum use in cement, plasterboard and road base
- Recovering fluorosilicic acid as a fluorine source (US recovered 45 kt FSA in 2025)
- Recovering phosphorus from wastewater and manure (struvite)
- Using sulphur-burner power to replace grid electricity

#### India

India's acid plants import rock and sulphur, so most of the footprint is upstream; CPCB rules promote phosphogypsum use in cement and agriculture. Plant-level emission data were not found.
 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 |
|---|---|---|---|---|
| **Purified wet acid instead of thermal acid for LFP and food** | about 0.5-1 t CO2e per t P2O5 vs several t for thermal acid on coal power (indicative) | none or negative | standard outside China; growing in China | Indicative |
| **Phosphogypsum valorisation** | avoids landfill and natural gypsum mining | depends on purification | pilot and commercial plants in India, Morocco and China (indicative) | Indicative |

 For a climate investor The climate and resource opportunities are in phosphogypsum use, recovering fluorine and rare earths from phosphate streams, and purified acid for LFP made near Indian cathode plants. These need offtake from cement makers or battery makers and clear radiation and cadmium standards. Coromandel, Paradeep, OCP and Chinese LFP precursor makers are active.

## Other sections

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