Dyes: Emissions
Why coal-fired steam makes dyes surprisingly carbon heavy
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 10.0 t CO2e per t range about 5-20 · multi-step batch fine-chemical synthesis with solvent and steam use and effluent treatment; no public product LCAs found Global emissions per year 14.0 Mt CO2e per year 2025 · 10 t x about 1.35 Mt (indicative)Per t of commercial dye, cradle-to-gate. Intensity: indicative (basis: typical cradle-to-gate values for multi-step fine chemicals). Global total: derived (indicative).
Share of footprint by lifecycle phase
Feedstock 40% Production / process 55% Movement 5%Footprint by lifecycle phase
| Phase | Intensity | Share | Main sources of emissions | Notes | Source |
|---|---|---|---|---|---|
| Feedstock | about 4 t CO2e per t | 40% | aromatics, acids, intermediates | indicative | |
| Production / process | about 5.5 t CO2e per t | 55% | coal-fired steam for batch reactions and drying, effluent treatment and evaporators for zero liquid discharge | Gujarat and Chinese plants largely use coal steam (indicative) | indicative |
| Movement | about 0.5 t CO2e per t | 5% | container shipping | indicative | |
| Use | large, outside cradle-to-gate: heating dye baths and drying fabric | – | textile dyeing and finishing, often on coal boilers in Asia | dyeing uses most of the water and heat in the textile colour chain; reactive dyeing adds salt and unfixed dye to effluent | indicative |
| End of life | small direct CO2 | – | dye stays on the textile until landfill or incineration | untreated effluent colours rivers and can release toxic amines | indicative |
Other environmental impacts
Water pollution is the main impact: H acid alone makes about 30 t of phenol-laden wastewater per t; dyeing effluent carries colour, salt, alkali and metals. Worker exposure to aromatic amines.
Levers to cut emissions
- Higher-fixation reactive dyes and salt-free dyeing to cut effluent
- Digital inkjet printing, rising from 8% (2025) to a forecast 15% of textile printing by 2030
- Dope dyeing of polyester and viscose with pigments
- Electrification or biomass steam at dye plants and mills
- Process intensification (continuous flow) for intermediates
India
No national dye footprint is published; Gujarat's dye clusters rely on common effluent treatment plants and face repeated closure orders for discharge breaches (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 |
|---|---|---|---|---|
| Waterless supercritical CO2 dyeing of polyester | not published | high capital cost (indicative) | commercial in a few mills (indicative) | indicative |
| Bio-based and microbial dyes | not published | high | pilot and small commercial (indicative) | indicative |