Analysis and design
Energy, economics and safety
Three ways to judge a solved design: how little energy it could use, what it would cost and earn, and what could go wrong. Each environment reads the flowsheet you just ran.
Energy: pinch analysis
- Every heating and cooling duty — heaters, coolers, condensers, reboilers, reactors — becomes a hot or cold stream, listed under Thermal streams.
- Set the minimum approach temperature, ΔTmin. LensaSim gives the hot and cold utility targets, the pinch temperature, and how far today's design is from them.
- The composite curves and grand composite curve show where heat can be recovered; Heat-integration opportunities points to recovery between the process's own hot and cold services.
- Utilities & carbon footprint gives the energy the utilities supply in a year and the CO₂ it emits — today and at the target — so the saving is in tonnes as well as gigajoules.
Move ΔTmin and watch the targets change: smaller saves energy and costs exchanger area.
Economics (Pro)
- Sizing & CAPEX — each block sized from its solved duty, flow or volume and costed by module costing on a chemical-engineering cost index basis. Untick a block to leave it out; override a size, the material or a quote.
- OPEX — raw materials, utilities, labour and the cost of manufacture.
- Profitability — NPV, IRR, payback, the cash-flow table and a one-way sensitivity.
- Assumptions — the cost index, utility prices and the finance basis, all editable; set feed and product prices to get revenue.
- The TEA report prints all of it. It is a study-class estimate: good for screening and comparing options, while an investment decision needs vendor quotations.
Safety
- Chemical hazards — each component's flammability limits, flash point, autoignition temperature, toxic level of concern and NFPA ratings.
- Stream hazards — which streams are inside their flammable range, above autoignition, or highly toxic, and the flammable inventory.
- Relief sizing — relief loads for the common scenarios and the orifice area each needs, by the API 521 and API 520 methods.
- HAZOP worksheet — guide words applied to your flowsheet, with causes, consequences and safeguards to complete.
These are screening tools: check every hazard against the Safety Data Sheet, and treat relief numbers as the starting point for a detailed design.
Something not covered here? Email us — a person replies.