1 × 50 KL vs 2 × 25 KL — how do you actually decide?
For the same total volume, when do you go with a single large bioreactor vs two smaller ones? Curious how people weigh CapEx (six-tenths rule) against redundancy, campaign flexibility and downstream feed smoothing in practice.
1 answer
Two ways to frame it. On pure vessel CapEx the single 50 KL usually wins by ~25–30% — the six-tenths rule (cost ∝ volume^0.6) means 2×25 KL ≈ 1.32× the cost of one 50 KL. But the split buys three things a single vessel can’t: (1) redundancy — a lost or contaminated batch costs you half, not all; (2) flexibility — run two products/strains, or stagger harvests for a steadier downstream feed; (3) easier phased build-out. Rule of thumb: single-product with steady demand and tight on capital/footprint → one big vessel. Value redundancy, multi-product, or want to de-risk a lost batch → the split, and treat the ~30% premium as insurance. The Upstream Sizing tool’s comparison shows the CapEx index and headroom for your exact numbers.
Log in to post an answer.