Photocatalysis scales badly by multiplication, because its three governing phenomena scale differently. Light attenuates exponentially with path, transport scales with geometry, and heat scales with volume while cooling scales with area. A scale-up program is the discipline of re-answering the same questions at each step.
At lab scale, photon delivery is trivial, the lamp illuminates everything. At process scale, optical depth becomes the design: what fraction of the volume is productively illuminated, and what geometry keeps that fraction high as volume grows? Answer with attenuation measurements and ray-tracing or validated plate designs, not with hope.
Mixing times grow with scale, and catalyst suspension, gas-liquid contact and product removal all degrade if transport is merely enlarged. Answer with dimensionless analysis where possible, and always with multi-point sampling at the scaled size, agreement across the volume is the only proof.
Absorbed energy, light plus reaction enthalpy, must exit. Lab systems reject it passively; process systems need engineered thermal paths. Answer with an energy balance under real irradiation and a thermal design that holds the temperature regime the chemistry was validated in.
Each scale step surfaces the next weakest component, pumps, seals, materials, controls. The scale-up program's job is to meet those failures at pilot scale, where they are cheap lessons, not at demonstration scale, where they are headlines.
Perfectlight's engineering line runs from lab reactors to outdoor systems; see engineering solutions.
