Which thermodynamic method does it use?

The PENG-ROBINSON property package, over ammonia — already selected. You can switch the method on the canvas before running.

Which unit operations are in the flowsheet?

It chains K0, JT0, 2× Evap0. Every block is a real, solvable unit operation you can reconfigure, add to, or remove.

Do I need to install software or buy a license?

No. Ammonia refrigeration (−30 °C) runs entirely in your browser on MaximaLabs — free, no install, no license. Open the model to load it live and run the deterministic solver.

All guides

Cold-storage terminal, Rotterdam, Netherlands

How to simulate ammonia refrigeration (−30 °c)

A closed single-stage ammonia vapor-compression cycle serving a −30 °C load: compressor → ambient condenser → JT valve → evaporator. The charge is set via tear_specs; metrics give duty and work (COP ≈ 2). From the ChemSep casebook (Refrigeration_Ammonia-30C).

JT0

Cond0

Evap0

1
Open the ready-made model
Open the "Ammonia refrigeration (−30 °C)" model in the MaximaLabs workspace — no install, no license. It loads live on the canvas, ready to edit and run.
2
Confirm the thermodynamics
This process is modeled with the PENG-ROBINSON property package over ammonia — already selected, so the phase equilibrium and enthalpy are physically consistent from the first run.
3
Review the flowsheet
The flowsheet chains K0, JT0, 2× Evap0. Every block is a real, solvable unit op you can reconfigure on the canvas.
4
Run the simulation
Click Run. The deterministic solver converges the material and energy balances (recycles included) and fills the live stream table — the AI never invents a number.
5
Read the results and iterate
Inspect the converged streams, tweak a spec, and re-run — or ask the AI copilot to explain a result or diagnose a failed solve in plain English.

What you'll build

Thermodynamics: PENG-ROBINSON
Components: ammonia
Unit operations: K0JT02× Evap0

Open this model in the workspace

Opens live on the canvas — free, no install.

Explore the model & flowsheet

Frequently asked questions

What does the Ammonia refrigeration (−30 °C) model simulate?: A closed single-stage ammonia vapor-compression cycle serving a −30 °C load: compressor → ambient condenser → JT valve → evaporator. The charge is set via tear_specs; metrics give duty and work (COP ≈ 2). From the ChemSep casebook (Refrigeration_Ammonia-30C).
Which thermodynamic method does it use?: The PENG-ROBINSON property package, over ammonia — already selected. You can switch the method on the canvas before running.
Which unit operations are in the flowsheet?: It chains K0, JT0, 2× Evap0. Every block is a real, solvable unit operation you can reconfigure, add to, or remove.
Do I need to install software or buy a license?: No. Ammonia refrigeration (−30 °C) runs entirely in your browser on MaximaLabs — free, no install, no license. Open the model to load it live and run the deterministic solver.

More guides like this

Reference model (ChemSep)

Ammonia refrigeration cycle

A single-stage vapor-compression refrigeration loop using ammonia — the classic industrial (rather than HFC) refrigerant — condensed to subcooled liquid, throttled through a valve, and superheated back to vapor in the evaporator before recycling (inspired by ChemSep's Refrigeration_Ammonia-30C reference case).

Olefins complex, Baytown, Texas, USA

Propylene refrigeration (−30 °C)

Closed propylene cycle for −30 °C process cooling — the workhorse olefin-plant refrigerant. From the ChemSep casebook (Refrigeration_Propylene-30C).

Olefins complex, Baytown, Texas, USA

Propylene refrigeration (−50 °C)

The same propylene loop pulled to −50 °C by sub-atmospheric evaporation (0.8 bar) — COP drops as the lift grows. From the ChemSep casebook (Refrigeration_Propylene-50C).

NGL recovery plant, Permian Basin, Texas, USA

Deep ethane recovery with propane-refrigerated feed chilling

Associated gas is chilled by an external propane refrigeration package before a demethanizer recovers ethane and heavier as NGL bottoms from a methane-rich residue gas overhead — the cryogenic-chilling role Ortloff's CCS/GSP processes play ahead of the turboexpander in a real deep-ethane-recovery plant. The mechanical refrigeration loop itself (compressor/condenser/valve) isn't separately modeled here; the chiller's duty is represented directly as the feed's cooled outlet temperature (the same honest-simplification pattern used for LNG cold-box examples elsewhere in this library).

Reference model (ChemSep)

Propane refrigeration cycle

A single-stage vapor-compression refrigeration loop: propane vapor is compressed, condensed to subcooled liquid, throttled through a valve, and superheated back to vapor in the evaporator before recycling — a small makeup feed and purge close the mass balance (inspired by ChemSep's Refrigeration_* reference cases).

Illustrative refinery sour-water unit

Refinery sour water stripper (NH₃ + H₂S)

The standard refinery sour water stripper: sour water carrying ammonia and hydrogen sulfide is steam-stripped in a 10-stage column, sending both overhead as sour gas and returning stripped water fit for reuse. Runs on the new sour-water weak-electrolyte package, which is what makes the result meaningful — ammonia and H₂S suppress each other's volatility (ammonia raises pH and holds sulfide down as HS⁻; H₂S lowers pH and holds ammonia down as NH₄⁺), and heat reverses both, which is precisely why a stripper works. The two removals come out asymmetric for the real reason: H₂S strips essentially completely while ammonia, five orders of magnitude more soluble, is the duty that sets the steam rate.