The reactor (left) runs the reaction in whichever solvent you
choose — its molecules (coloured spheres) fill the vessel, dyed by
how hazardous that solvent is (red = high hazard like DCM, green =
benign like water or supercritical CO2). Downstream, a still
recovers and recycles solvent back to the reactor instead of sending
it to waste; the recycle-rate slider controls how much of the flow
loops back versus how much is lost as fresh waste (tracked by the
small particle stream leaving the top of the still).
E-factor = mass(waste) / mass(product)
PMI (process mass intensity) = mass(all inputs) / mass(product)
Energy demand ∝ ΔT(process − ambient) · (1 − recycle_fraction · 0.4)
- Solvent choice — swaps the hazard/toxicity/biodegradability profile: DCM is a volatile chlorinated solvent with high hazard; water, ethanol and supercritical CO2 (scCO2) sit far greener on the CHEM21 solvent-selection guide.
- Process temperature — higher heating/cooling duty raises energy demand and, for scCO2, must exceed its critical point (31 °C, 74 bar) to stay in the dense, low-viscosity supercritical state shown by the shimmering fill.
- Solvent recycle rate — the single biggest lever on E-factor and PMI in real plants: recovering and reusing solvent instead of buying and disposing of it fresh each batch.
- Process intensification — combining reaction and separation in fewer, smaller unit operations, cutting solvent inventory and waste further.