Solvent choice sets both the greenness score (from EHS/solvent
selection guides — water and scCO₂ scoring high, toluene low) and a
polarity-linked rate multiplier. Switching from a stirred batch
flask to a continuous microreactor boosts heat and mass transfer,
so the same chemistry runs faster and safer at the same
temperature — the essence of process intensification.
k_eff = k0 · f_solvent · f_reactor · exp[-(Ea/R)(1/T - 1/Tref)]
X(t) = 1 - exp(-k_eff · t) (first-order conversion)
- Solvent — sets both the green score and a rate multiplier from its polarity/mass-transfer properties.
- Reactor format — batch flask (bulk mixing) vs. continuous microreactor (thin channels, fast mixing and heat removal) changes the effective rate constant.
- Temperature — drives k_eff through an Arrhenius relationship.
- Reaction time — how long the batch has been running; conversion follows first-order kinetics toward 100%.
Real process chemists use exactly this reasoning — solvent
selection guides plus intensified reactor formats — to redesign
routes that are both faster and lower-hazard than the traditional
stoichiometric, VOC-solvent batch process.