Acatian Blog

Technical articles for bioprocess modelling and plant decisions.

Original methods, worked examples and validation questions for engineers, scientists, educators and decision-makers across process development, MSAT, manufacturing, facility design, TEA and LCA.

Acatian EngineeringUpdated 18 September 202630 open technical publications

Every article connects engineering equations to evidence requirements, model limits and a practical decision.

New · 18 September 2026

Three practical articles for modelling, facility decisions and teaching.

Each publication declares its calculation boundary, includes a downloadable working asset and separates a screening result from validated manufacturing evidence.

New · 4 min articleBioprocess COGS scenario analysisCompare yield, release success, annual cost and good-product output without hiding the denominator.New · 4 min articleBioprocess facility-fit assessmentTest equipment, rooms, utilities, cleaning, labor, quality gates and finite-capacity timing on one declared basis.New · 4 min teaching guideTeaching mechanistic bioprocess modellingUse a transparent component balance to connect equations, process meaning, uncertainty and factory consequences.

Transport + separations

Turn rate-limiting transport into explicit process constraints.

Use time-resolved experiments and component balances to quantify mixing, oxygen transfer, membrane demand, downstream load and scale-up risk.

New · 29 min publicationDisc-stack centrifuge scale-up calculationQualified Q/(cΣ), matched throughput, harvest time, captured-solids duty and discharge cadence.26 min publicationBioreactor heat transfer calculationPeak heat load, LMTD, UA, area, installed cooling capacity, coolant flow and outage screen.21 min publicationLow-pH viral inactivation hold-time calculationValidated minimum hold, maximum product exposure, timing margins and a reproducible batch clock.22 min publicationSterile filter sizing calculationConstant-pressure Vmax fit, capacity and flow-time area, installed-area check and validation boundary.25 min publicationFed-batch feed rate calculationInteractive exponential-feed profile with biomass, pump, working-volume and oxygen-transfer constraints.24 min publicationProtein A column sizing calculationInteractive DBC, resin volume, column diameter, cycle, buffer and batch-time screen.23 min publicationDiafiltration volume calculationInteractive diavolume calculator, buffer exchange, product loss, membrane area and a reproducible UF/DF dataset.17 min publicationBioreactor mixing time calculationMulti-probe tracer normalization, strict t95, scale-up groups and a reproducible dataset.18 min publicationBioreactor kLa calculationDynamic gassing-in regression, probe response, OTR/OUR margin and a reproducible dataset.16 min guideFed-batch process simulationState balances, feed events, oxygen and heat limits, downstream load and validation.15 min guideCHO cell culture process modelGrowth, viability, mAb productivity, metabolites, scale-up and COGS.14 min guideBioreactor scale-upOTR, mixing, shear, heat removal, geometry and uncertainty.

Facility + operations

Translate the process into manufacturing reality.

Model reusable equipment, rooms, utilities, people, cleaning and customer variants instead of treating annual utilization as a fixed input.

New · 27 min publicationWFI system sizing calculationPoint-of-use demand, generator rate, storage swing, reserve margin and deterministic facility-fit screen.Role guideMSAT process modelling toolsTech transfer, site fit, manufacturing evidence and controlled change.Role guideCDMO process developmentCustomer intake, facility fit, campaigns, costs and delivery risk.Capacity guideFinite-capacity schedulingEquipment states, shared resources, queues, cleaning and campaigns.

Validation + reproducibility

Make technical claims independently inspectable.

Reference implementation

AC-REF-MAB-FB-001 publishes versioned inputs, 169 trajectory points, sensitivities, numerical balance closure, acceptance criteria and SHA-256 checksums. It demonstrates reproducible software behavior without claiming customer-specific industrial validation.

Inspect the benchmark

Model validation

Define context of use, independent evidence, acceptance tolerances, residual analysis, uncertainty, extrapolation limits, maturity and technical ownership before calling a model decision-ready.

Read the validation guide

Mass-balance discipline

Track every component, reaction, accumulation term, recycle, purge, sample and loss on one declared basis. Report per-unit residuals so plant-wide closure cannot hide local errors.

Build the mass balance

Software + economics

Evaluate the workflow as carefully as the equations.

Compare tools on an authorized reference case, keep migration controlled and connect technical changes to schedule, cost and environmental consequences.

18 min buyer guideAcatian vs SuperPro Designer vs RoeblingScope, collaboration, automation, scheduling, TEA, LCA and validation evidence.Acatian-published comparisonSuperPro Designer alternativeA current, source-linked comparison with disclosed commercial interest for teams assessing a browser-based engineering workflow.Migration benchmarkControlled SuperPro Designer migrationReconstruct one authorized model, reconcile outputs and expand only after acceptance criteria pass.Economics + impactBioprocess TEA and LCATrace materials, equipment, utilities, labor, waste and sensitivities to one reconciled process basis.Digital engineeringBioprocess digital twinSeparate design, operational and closed-loop claims while keeping data, uncertainty and validation visible.Model definitionBioreactor CFD simulationDefine geometry, mesh, multiphase physics, boundary conditions and experimental validation before interpreting fields.Review checklistBioprocess model readinessCheck balances, kinetics, equipment, scheduling, economics, uncertainty and evidence ownership.Evaluation guideBioprocess simulation softwareCompare balance closure, equipment duty, operating modes, traceability and engineering exports.

Reference implementation

Model validation

Mass-balance discipline

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