REPRODUCIBLE STARTING POINTS

Give the next development decision a clear basis.

A scientific concept needs more than a promising result on its way to a product. These three small calculations help define the feed, examine a bed and a thermal requirement, and identify the evidence needed next.

All cases use synthetic demonstration inputs. They are separate examples, not measurements, operating instructions or evidence of equipment performance.

01Scientific conceptA material, reaction or process idea.
02Design basisFeed, phase, flow, conditions and sources.
03Inspect the quantitiesBalances, thermal duty, bed volume and gas flow.
04Choose the next testRecord the open question and evidence to collect.

Schematic · from concept toward a product. Each calculation has its own basis. Analysis Workspace adds a reviewed gas-outlet handoff between compatible records.

01 · GEOMETRY & FLOW

What changes when a packed bed gets longer?

Before selecting a bed geometry, ask how much volume and nominal space time each candidate provides on the same flow basis. A longer bed changes both. A conversion target still needs reaction evidence.

Bed: 10 mm diameter; 50, 100 or 150 mm length
Reference flow: 100 mL/min at 0 °C and 1.01325 bar absolute
Operating state: 250 °C and 1 bar absolute; ideal gas
Other preset inputs: Bulk density 600 kg/m³; void fraction 0.4; molecular weight 28 g/mol. Pressure drop disabled.

Calculated with the current reactor model · 3 significant figures
Length, mm	Bed volume, mL	GHSV, h⁻¹	Space time, s
50	3.93	1,530	1.21
100	7.85	764	2.43
150	11.8	509	3.64

GHSV uses reference gas flow divided by packed-bed volume. Space time uses bed volume divided by operating gas flow; it does not account for void fraction. Neither quantity predicts reaction progress.

Reproduce it

Open the reactor calculator and choose Load example.
Turn off the optional Ergun pressure-drop calculation. Leave the reference flow and operating state unchanged.
Set bed length to 50, 100 and 150 mm in turn. Compare bed volume, GHSV and space time, then expand their calculation details.

Open the reactor example

Save the same comparison as a study

In Project Builder, expand the local project library and choose Open synthetic example. In Stage B, turn off Ergun for the 100 mm candidate and choose Record calculation. In Stage C, select that candidate and choose Explore sensitivity. Set the swept input to bed length, minimum to 50 mm, maximum to 150 mm, and the number of sampled points to 3. For inventory basis, choose Hold supplied bulk density; derive catalyst mass. Run the study and inspect GHSV or space time. Export the project JSON to keep a portable copy.

The library example includes two candidates and an illustrative pressure-drop requirement. With Ergun off, that requirement remains unresolved. It does not become a PASS because another output is available.

02 · SPECIES & CONSERVATION

Where does the feed go at a specified conversion?

A proposed reaction defines a material requirement before it defines a reactor. Use methane combustion to check feed and product quantities: specify 1 mol/s CH₄ and 2 mol/s O₂ at 100% conversion, with water kept in the gas phase.

CH₄(g) + 2 O₂(g) → CO₂(g) + 2 H₂O(g)

Current Mass & Energy example · molar flow in mol/s
Species / phase	Inlet	Outlet
CH4(g)	1	0
CO2(g)	0	1
H2O(g)	0	2
O2(g)	2	0

The inlet and outlet mass flows are each 80 g/s. Carbon, hydrogen and oxygen close within the model tolerance. This follows from the specified reaction and conversion; it is not a measured validation.

A SMALL REVIEW RECORD

Define the material and thermal question

Basis: One stated reaction, specified component feeds and prescribed conversion. The preset fixes inlet and outlet conditions and keeps each selected phase.
Quantities checked: Species flows, total mass and elemental accounting. In the tool, inspect the required heat duty, its sign, temperature basis and property sources before setting a thermal requirement.
Still unresolved: The result does not establish achievable conversion, reaction rate, equilibrium composition or equipment size. A heat-duty result does not describe local temperatures or heat-transfer hardware.
Next test: Obtain reaction-performance data at the intended conditions. Check the thermal result against independent property or calorimetry data before using it for equipment decisions.

Reproduce it

Open Mass & Energy, select Methane combustion, then choose Load example.
Inspect the accepted reaction, component feed and conversion before reading the species results.
Change conversion to 50%. Check that unreacted methane and oxygen remain in the outlet. Return to 100% before comparing the table above.
Choose Save calculation to keep a named record in this browser. After later edits, use Save revision to retain the earlier inputs.

The preset also uses 298.15 K at the inlet, 800 K at the outlet and 1 bar absolute at both ends. Heat duty depends on the selected property records and these temperatures. Fixed phases exclude condensation; prescribed conversion does not predict kinetics or equilibrium.

Open the balance example

03 · DUTY & TERMINAL TEMPERATURES

What does a supplied conductance deliver?

Use two synthetic single-phase streams with equal heat-capacity rates. Rate a counterflow exchanger with supplied UA, then use the same duty in sizing mode to check that the required UA returns to the starting value.

Streams: Each mass flow 1 kg/s; each constant Cp 1 kJ/(kg·K)
Inlet temperatures: Hot 100 °C; cold 20 °C
Arrangement and conductance: Counterflow; UA = 1 kW/K
Area assumption: Design U = 500 W/(m²·K), on the declared demonstration surface basis

Calculated with the current Heat Exchanger model · 3 significant figures
Quantity	Result	Unit
Heat duty, hot to cold	40	kW
Hot outlet temperature	60	°C
Cold outlet temperature	60	°C
Log-mean temperature difference	40	K
Preliminary area	2	m²

Cp and U are explicit synthetic assumptions, not properties of a named fluid or equipment. Their applicability and phase stability are not established by this arithmetic check.

Reproduce it

Open Heat Exchanger and choose Load synthetic example, then Calculate.
Inspect the counterflow duty, outlet temperatures, terminal approaches, and optional area. Expand the U basis and scientific checks.
Switch to Sizing, enter 40 kW target duty, and calculate again. The required conductance is 1 kW/K under the same assumptions.
Choose Save calculation, then select the saved case in Analysis Workspace to review it alongside other records. Use Save revision after changes; JSON export is available for backup.

Open the heat-exchanger example

CONTINUE THE WORK

Review the source before creating a downstream basis.

Analysis Workspace brings saved balance, bed-project, and heat-exchanger records together. It retains source revisions, supports recomputation, and collects the checks and open questions in one report.

Try the supported gas-outlet handoff

In Mass & Energy, load and inspect the methane example, then choose Save calculation.
Open Analysis Workspace. Under Select saved calculation, choose that case and then Attach selected calculation.
Inspect and accept the interpreted reaction, then choose Recompute source inputs.
Review the eligible gas outlet’s mapped flow, temperature, absolute pressure, molecular weight, assumptions, and missing properties.
Confirm the mapping and choose Create and open downstream project. Continue in Project Builder with the reviewed basis already present.
Supply the bed geometry, inventory, and any required viscosity. Recompute before reviewing candidates.

The new project represents a subsequent bed. It does not overwrite the original reaction’s feed or connect the independent examples above into one design.

If you change the source and choose Save revision, the workspace identifies the newer saved version. Choose Adopt latest saved revision, then review and recompute it before creating another handoff. Earlier source records and mappings remain in history; downstream projects are not silently updated.

Use the same browser and one editing tab at a time. JSON is an optional backup or a way to move records to another device. Reopened calculations and transfer approvals remain historical until reviewed and recomputed. Heat-exchanger records can be attached and recomputed; the tools do not perform a coupled flowsheet solve.

Open Analysis Workspace Continue in Project Builder Current capabilities and future direction