Silicones: Emissions

Coal-powered silicon smelting dominates the 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 7.50 t CO2e per t range about 4 (silicon on hydropower) to 10 (silicon on coal power) · derived: 0.44 t silicon x 11 + 0.95 t methanol x 1.8 = about 6.5 t, plus about 1.0 t for methyl chloride, direct process, hydrolysis and distillation, and transport Global emissions per year 24.0 Mt CO2e per year 2025 · about 3.25 Mt x 7.5 t CO2e/t (derived, indicative)

Per t of siloxane (DMC equivalent), cradle-to-gate. Intensity: silicon tile and methanol tile (indicative); derived. Global total: derived.

Share of footprint by lifecycle phase

Feedstock 85% Production / process 13% Movement 1%

Footprint by lifecycle phase

Phase	Intensity	Share	Main sources of emissions	Notes	Source
Feedstock	about 6.4 t CO2e/t	85%	silicon smelting with carbon reductants and coal power in China; coal- or gas-based methanol	silicon alone about 4.8 t CO2e/t siloxane	derived from silicon and methanol tiles
Production / process	about 1.0 t CO2e/t	13%	methyl chloride synthesis, direct process heat, distillation and hydrolysis	steam and power	indicative
Movement	about 0.1 t CO2e/t	1%	container and tank shipping	small	indicative
Use	not applicable as emissions; use-phase savings often larger	–	durable; enables solar modules, insulation sealants, efficient electronics	industry LCAs claim use-phase savings exceed production emissions several-fold (indicative)	indicative
End of life	low CO2: combustion turns silicones mostly to silica, releasing about 1.2 t CO2 per t from methyl groups (calculated, indicative)	–	landfill, incineration	volatile siloxanes from personal care go to air and water; recycling to DMC is at pilot scale	calculated (indicative)

Other environmental impacts

Persistent cyclic siloxanes (D4, D5, D6) in water and sediment; chlorosilane accident risk; silicon smelting air pollution.

Levers to cut emissions

Silicon metal from hydropower or renewable power cuts the largest emission source (silicon tile: about 4-5 t CO2e/t Si on Norwegian hydro vs 11-15 t on Chinese coal).
Bio-based or low-carbon methanol (biomethanol, e-methanol).
Chemical recycling of silicone waste back to DMC (pilots by Elkem, Wacker and others; indicative).
Biocarbon reductants in silicon furnaces (Elkem; indicative).

India

India's silicone footprint is embedded in imports from China. Rapid growth in solar module, EV and construction demand will raise India's silicone use; no domestic monomer plant was found in sources reached.

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
Silicones from hydropower-based silicon (Norway, Canada, Brazil)	about 4 t CO2e/t siloxane (derived, indicative)	not published	commercial (Elkem, Wacker supply chains; indicative)	derived from silicon tile
Silicone recycling to DMC by depolymerisation	not published	not published	pilot and early commercial in Europe and China (indicative)	indicative

For a climate investor Most silicone emissions come from making silicon metal, so cleaner silicones mean cleaner silicon: smelting on renewable power with biocarbon. For India, the near-term opening is downstream formulation for solar, EV and construction, where qualification creates margin; upstream monomer plants would face Chinese cost competition. What has to be true: secure low-carbon silicon supply and customers that pay for lower embodied emissions.