Quantify what fraction of solvents used in your process are recovered and recycled back into the process or recovered for reuse. A higher SRI means less solvent waste, lower costs, and a more circular process — every session stays in your browser, never on a server.
The Solvent Recycle Index (SRI) measures the fraction of solvents used in a chemical process that are recovered and recycled — either back into the same process or for use elsewhere. Because solvents typically account for 50–80% of all process mass (and an even higher proportion of waste), tracking and improving their recovery is one of the highest-leverage actions available in green process design.
| Symbol | Term | Units |
|---|---|---|
| $\text{SRI}$ | Solvent Recycle Index | % (0–100); ideal value = 100% |
| $\sum m_{\text{solvent, recycled}}$ | Total mass of all solvents actually recovered and recycled (distillation, membrane separation, etc.) | g (or kg) |
| $\sum m_{\text{solvent, used}}$ | Total mass of all solvents consumed in the process (reaction, extraction, wash, purification) | g (or kg) |
Include all solvents used at every stage: reaction medium, extraction solvents, wash solvents, recrystallisation solvents, and chromatography eluents. "Recycled" means the solvent is recovered in a usable form (pure enough for re-use), not simply neutralised or treated as waste.
| Process type / Scale | Typical SRI | Key driver |
|---|---|---|
| Large-scale industrial (bulk chemicals) | > 90% | Economically driven closed-loop systems; continuous distillation |
| Fine chemical / API manufacturing (optimised) | 60–90% | Dedicated recovery systems; some losses from residues and aqueous phases |
| Fine chemical / API manufacturing (typical) | 30–60% | Partial distillation recovery; batch processing losses |
| Academic / teaching laboratory | < 10% | No recovery infrastructure; solvents discarded as waste |
| Metric | What it measures | Complements SRI by… |
|---|---|---|
| Solvent Intensity (SI) | Net solvent mass per gram of product | Quantifying the absolute solvent burden on the product |
| E-factor (solvent contribution) | Solvent waste as part of total process waste per gram product | Placing solvent waste in the context of all process waste |
| PMI | Total mass of all inputs per gram of product | Capturing the full mass efficiency picture including solvents |
| CHEM21 solvent guide score | Hazard and regulatory score for solvent choice | Evaluating the intrinsic safety of each solvent selected |
Enter each solvent stream used in the process: reaction medium, extraction solvents, wash solvents, recrystallisation solvents, and chromatography eluents. Enter the mass recycled only if the solvent was actually recovered in a reusable form — not simply neutralised or disposed of.
| Solvent name | Use stage | Mass used (g) | Mass recycled (g) | % recycled |
|---|
Enter the mass of isolated product to calculate the net Solvent Intensity (net solvent mass per gram of product) alongside the SRI. Leave blank to calculate SRI alone.
| Solvent | Stage | Mass used (g) | Mass recycled (g) | Mass wasted (g) | % recycled | Visual |
|---|---|---|---|---|---|---|
| Enter solvent streams above to see breakdown. | ||||||
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Export your SRI 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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© 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.
If you use this tool in teaching or published work, please cite the DodecaGreen portal as the source.