DodecaGreen The Green Chemistry Portal

Carbon Intensity calculator.

Calculate the carbon intensity of a chemical process — the total greenhouse gas emissions per kilogram of product — by combining energy source emission factors with material-level contributions. All data stays in your browser.

Principle 6 guide
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What is carbon intensity — and why does it matter?

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Carbon intensity (CI) is a process-level metric that expresses the total greenhouse gas (GHG) emissions of a chemical process normalised to the mass of desired product. Measured in kg CO₂ equivalent per kg of product (kg CO₂eq kg⁻¹), it allows direct comparison of the climate impact of different synthetic routes, energy sources, and scales of production.

GoalMinimise GHG emissions per unit of product — an ideal process would have zero or even negative carbon intensity through carbon capture and use of renewable inputs.
WhyChemistry accounts for ~7% of global GHG emissions. Knowing the carbon intensity of a process identifies where decarbonisation efforts will have the greatest leverage.
HowSwitch to renewable electricity, reduce energy consumption, choose low-carbon feedstocks, eliminate high-emission solvents, and optimise yield to reduce material per kg product.

The formula

$$CI = \frac{\displaystyle\sum_{i} E_i \cdot \text{EF}_{i}^{\text{energy}} + \sum_{j} m_j \cdot \text{EF}_{j}^{\text{material}}}{m_{\text{product}}}$$
SymbolTermUnits
\(CI\)Carbon intensity of the processkg CO₂eq kg⁻¹ product
\(E_i\)Energy consumed from source $i$ (electricity, heat, etc.)kWh
\(\text{EF}_{i}^{\text{energy}}\)Emission factor for energy source $i$kg CO₂eq kWh⁻¹
\(m_j\)Mass of material $j$ used in the processkg
\(\text{EF}_{j}^{\text{material}}\)Cradle-to-gate emission factor for material $j$kg CO₂eq kg⁻¹
\(m_{\text{product}}\)Mass of isolated desired productkg

Emission factors for electricity depend on the grid mix (country / region and year). The default values here are widely cited literature estimates — update them with site-specific data for the most accurate results.

Typical carbon intensity by process type

Process / ContextTypical CI (kg CO₂eq / kg product)Key driver
Renewable-powered bulk chemicals< 0.5Green electricity, optimised yield
Bulk chemicals (fossil grid)0.5–3High-volume, relatively efficient energy use
Fine chemicals3–30Energy-intensive steps, solvent emissions
Pharmaceuticals (API)10–200+Complex synthesis, low yield, heavy solvent use
Green hydrogen (electrolysis, renewable)0.4–1Electrolyser efficiency, grid carbon intensity

Relationship to other green chemistry metrics

MetricWhat it capturesCI relationship
E-factorMass of waste per mass of productMore waste → more material emissions → higher CI
PMITotal mass input per mass of productHigh PMI means more materials contributing to CI
Carbon FootprintTotal absolute GHG emissions (kg CO₂eq)CI = Carbon Footprint ÷ Product mass
GWP100-year warming potential of a single substanceEF values in CI are GWP-weighted sums over all emissions
Space–Time YieldProductivity per reactor volume and timeHigher STY can lower CI by reducing energy per kg product

Scope boundaries

Scope 1 — Direct

  • Combustion of fuels on-site (gas burners, boilers, steam generation)
  • Process emissions (CO₂ released during reaction, solvent evaporation losses)
  • Fugitive emissions (refrigerants, compressed gas leaks)

Scope 2 — Indirect energy

  • Purchased electricity (grid emission factor × kWh consumed)
  • Purchased heat or steam from an external supplier
  • Chilled water or compressed air from an energy utility

Scope 3 (upstream supply chain and downstream use) can also be included by using cradle-to-gate emission factors for raw materials. This tool lets you mix all three scopes freely — label your entries clearly to make the boundary explicit.

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Process details

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Energy inputs

Enter each energy input (electricity, heating, cooling, compressed air, etc.). Select a preset emission factor or enter a custom value. Energy is converted to kWh for consistency — see the unit helper below if your values are in MJ or BTU.

Unit conversions: 1 MJ = 0.278 kWh  ·  1 GJ = 277.8 kWh  ·  1 BTU = 0.000293 kWh  ·  1 therm = 29.31 kWh
Energy source / type Preset EF EF (kg CO₂eq/kWh) Quantity (kWh) Emissions (kg CO₂eq)
Σ Energy emissions kg CO₂eq
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Material emissions

Enter the mass of each material used (reagents, solvents, catalysts, workup materials) and its cradle-to-gate emission factor. Select a preset from the dropdown or enter a custom value. Use the same units as your product mass in section 05.

Material name Category Preset EF EF (kg CO₂eq/kg) Mass (kg) Emissions (kg CO₂eq)
Σ Material emissions kg CO₂eq
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Product output

Enter the mass of desired product actually isolated. For co-product allocation, enter only the mass attributed to the product of interest, or use the Notes field above to describe your allocation method.

Product name Mass isolated (kg)
Σ Product mass kg denominator of carbon intensity
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Results

Carbon Intensity
kg CO₂eq / kg product
Total Emissions
kg CO₂eq
Energy Share
% of total emissions
Materials Share
% of total emissions
Carbon intensity scale (lower is better)
0 (ideal)530100+ kg CO₂eq/kg

Emissions by source type

Emissions by material category

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Detailed breakdown & interpretation

SourceType / CategoryQuantity EF (kg CO₂eq / unit)Emissions (kg CO₂eq)% of totalVisual
Enter energy and material data above to see breakdown.

Interpretation

Enter your energy inputs, materials, and product mass above to generate an interpretation.
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Save & load sessions

Sessions are stored in your browser only. No data leaves your device.

No saved sessions yet.
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Export

Export your carbon intensity calculation as a PDF report or CSV data file. PDF opens in a new tab and uses your browser's print function. CSV downloads directly.

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Where can I read more?

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References are sorted alphabetically by first author.

  1. P. T. Anastas and J. C. Warner, Green Chemistry: Theory and Practice, Oxford University Press, 1998. ISBN 978-0-19-850698-0. — Original 12 Principles; Principle 6 covers energy efficiency and use of renewable energy.
  2. Ecoinvent Centre, Ecoinvent Database v3, Swiss Centre for Life Cycle Inventories, 2023. ecoinvent.org. — Primary source for cradle-to-gate emission factors used in LCA studies.
  3. IPCC, Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report, Cambridge University Press, 2021. ipcc.ch. — Updated GWP100 values for greenhouse gases used to compute CO₂ equivalents.
  4. C. Jiménez-González et al., Org. Process Res. Dev., 2011, 15, 912–917. DOI. — PMI framework; energy and material contribution to pharmaceutical process footprints.
  5. R. A. Sheldon, Green Chem., 2018, 20, 3953–3954. DOI. — The E-factor at 25; energy efficiency and carbon footprint as emerging green metrics.
  6. UK Government / DESNZ, Greenhouse Gas Reporting: Conversion Factors 2024, Department for Energy Security and Net Zero, 2024. gov.uk. — Official UK grid and fuel emission factors updated annually.
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Contributors

Roles follow the CRediT taxonomy (Contributor Roles Taxonomy), adapted for educational software. Hover a contributor's name for a summary, or a column header for the definition of that role.

Contributor

© 2024– DodecaGreen Project. All rights reserved. · Last updated: 07/06/2026

This portal was built with the assistance of a large language model (Claude, Anthropic), which was used to generate and refine code, articulate and structure contributed ideas within the defined page format, and support iterative design decisions. All scientific content, conceptual frameworks, pedagogical choices, and final outputs were directed, reviewed, and verified by the contributors listed above.

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How do I cite this page?

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If you use this tool in teaching or published work, please cite the DodecaGreen portal as the source.

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