Milestone map
Milestone map
3 milestones
Define Process Objectives and Select Reaction/Separation Route
1–2 weeks (3–4 hrs/week)
State the process objective — what feed will be converted, to what product, at what purity and yield. For a reactor, identify the reaction type (batch, CSTR, PFR), operating conditions (temperature, pressure, catalyst), and key side reactions to suppress. For a separation, identify the physical property difference driving the separation (vapour pressure for distillation, solubility for extraction, size for filtration). Choose the route and document the selection rationale — alternative routes considered and why they were rejected.
Proof required
Submit your route selection document (≥600 words): the process objective, the selected reactor or separation route, operating conditions, key design assumptions, and rationale for rejecting ≥1 alternative route.
What gets checked
- Process objective states feed, product, target purity, and yield — not just 'design a reactor'
- Operating conditions are quantitative (temperature in °C, pressure in bar, catalyst type named if applicable)
- At least one alternative route is considered and rejected with a specific engineering reason
Common mistakes
- Selecting a route without justifying why alternatives were rejected — process route selection is a comparative decision, not a free choice
- Operating conditions given as ranges without justification — state the target conditions and the constraints that bound them
Resources
Foundationstart here
Depthgo deeper
What a verifier looks for
- Confirm process objective is quantitative — feed, product, purity, and yield are all stated numerically.
- Confirm operating conditions are specific and justified — not open ranges without explanation.
- Confirm ≥1 alternative route is considered and rejected with a specific engineering reason.
Size the Reactor or Separation Unit
3–4 weeks (4–5 hrs/week)
Using the design basis from M1, size the key process unit. For a reactor: calculate the required volume (CSTR uses the design equation V = F_A0 × X / (−r_A); PFR uses the integral form) and the heat removal/addition requirement. For a distillation column: calculate minimum reflux ratio (Underwood equation) and number of theoretical stages (McCabe-Thiele method or shortcut). For other separations: apply the governing design equation. Show all calculations with cited data sources.
Proof required
Submit your sizing calculations: all steps shown, design equation cited, kinetic or equilibrium data sources cited, and final equipment size (reactor volume in m³, or column theoretical stages + diameter in m).
What gets checked
- Design equation is stated explicitly with source (textbook, IChemE guide, or equivalent)
- All kinetic or equilibrium data is cited from a named source — not assumed
- Final size is in engineering units with appropriate significant figures
Common mistakes
- Sizing using only simulation output without hand calculation — the design calculation must be shown to demonstrate competence; simulation is for verification
- Equilibrium or kinetic data taken from unattributed memory — all data must be traceable to a named source
Resources
Foundationstart here
Depthgo deeper
What a verifier looks for
- Confirm design equation is stated explicitly and cited — not just a result without a method.
- Confirm all kinetic or equilibrium data sources are named — flag any unattributed data.
- Confirm hand calculation is shown — simulation output alone is not sufficient without a parallel hand calculation.
Write the Design Report and Defend Sizing Decisions
2–3 weeks (2–3 hrs/week)
Write a complete reactor or separation design report (2,000–3,000 words plus calculations appendix) covering: process objective, route selection rationale, design equations and sizing calculations, equipment specification, safety considerations (hazardous reactions, pressure containment, thermal runaway prevention), and process intensification or optimisation opportunities. Present the report to a reviewer with chemical engineering experience and respond to Q&A on the sizing assumptions and safety provisions.
Proof required
Submit your design report (2,000–3,000 words plus calculations appendix) and review record: reviewer name, role, ≥3 challenge questions about sizing assumptions or safety, and your responses.
What gets checked
- Report includes a safety section addressing the specific hazard(s) of the chosen reaction or separation (exotherm, pressure, toxic intermediate, etc.)
- Equipment specification names the key design parameters: reactor volume and material, or column diameter/height and tray/packing type
- Reviewer has chemical engineering experience and challenged sizing assumptions or safety provisions specifically
Common mistakes
- Safety section that lists generic chemical hazards without addressing the specific hazards of the chosen process — the safety section must be process-specific
- Reviewer without chemical engineering background — Q&A on CSTR vs PFR selection or McCabe-Thiele assumptions requires domain knowledge
Resources
Foundationstart here
Depthgo deeper
What a verifier looks for
- Engineering Design Triad check: M1–M3 together produce a design artifact (process route + equipment specification), an analysis artifact (sizing calculations with cited data), and a documentation artifact (design report + review record) — confirm all three types are present.
- Confirm safety section addresses the specific hazards of the chosen reaction or separation — not generic chemical safety.
- Confirm equipment specification names the key design parameters with units.
- Confirm reviewer has chemical engineering experience and challenged sizing assumptions or safety provisions.
- The Proof Accessibility Rule applies — DWSIM (free), ChemSep (free), NIST WebBook (free), IChemE free resources, and HSE free guidance are all accessible without commercial licence.