How to build a process

In the following, we will describe the step-wise procedure of building a process.

1. Add or select fluids for the process

A good first step in building a process is to define all relevant fluids. The primary way to add fluids is via the Fluids button in the top left corner (or press Alt+F / Option (⌥)+F to toggle it open). You will later select those fluids in unit operations that expose a Fluid package field.

How many fluids do you need? A better question is how many different Equation of State (EoS) you need. Components that use the same EoS can often be grouped into a single process fluid.

Example: A process has three fluids: water, methane and nitrogen. We want to use the cubic PR EoS for methane and nitrogen and a multiparameter EoS for water to improve density predictions. In the Fluids dialog, we create or import two fluids:

Fluid 1: PR as EoS with nitrogen and methane as components.

Fluid 2: Multiparameter EoS with pure water as component.

The process fluid defines the EoS and component list. Feed stream compositions are specified on the feed-like unit operations that use the process fluid.

2. Define the input stream(s)

Then open a process in the Processes tab by pressing Create new, change the name from "New Process" to something more descriptive, and open the Components panel. Find Input Stream, drag it onto the canvas, and double click it to open its editor.

Tip: You don't have to open the panel manually. With nothing selected, just start typing on the canvas and the Components panel opens with your text already entered in its search box. This is the quickest way to find and drag in a unit.

Set the stream temperature, pressure, flow rate, fluid package, and composition. Once the input stream is fully defined, the validation warning disappears.

Some unit operations include a Fluid package selector. There you can:

• Pick an existing process fluid (shared across multiple units)
• Import a fluid from the Fluid Library
• Create a new fluid from scratch

If you edit a fluid that is shared by multiple units, you will be asked whether to update the shared process fluid or create a copy for the current unit.

Not all unit operations expose a fluid selector. For those that do not, they inherit the fluid from connected streams.

3. Connecting to new process units

Next, a new process unit such as a compressor can be dragged onto the canvas. The input stream can be connected to the compressor by first pressing the black dot connector point at the tip of the inlet stream arrow (a plus sign appears when close enough), and then dragging it to the black dot connector point at the inlet of the compressor. The two units are now connected by a thin arrow, which is called a stream. The next step is to define the compressor until its validation warning disappears. Repeat this process until the full process is defined. Details on the different process units can be found here.

4. Copying, pasting, and deleting units and streams

To delete, simply click on what you want to delete and then press backspace/delete.

To copy a unit, click on the unit and use Ctrl+C to copy and Ctrl+V to paste (or Cmd+C and Cmd+V on macOS).

Right-clicking on the canvas opens a context menu with additional actions:

• Undo and Redo revert or reapply your most recent changes (the same as Ctrl+Z and Ctrl+Shift+Z, or Cmd+Z and Cmd+Shift+Z on macOS).
• Paste inserts the most recently copied units at the cursor position.
• Select All selects every unit and stream on the canvas, for example so you can copy or delete them all at once.
• Fit to View zooms and pans the canvas so that the entire process (or the selected nodes) fits within the visible area.

Right-clicking directly on a unit or stream instead shows actions for that specific element, such as editing its properties, copying, or deleting it.

5. Solving the process

When all process units are appropriately connected and have a green color around them, meaning that everything is defined, the "Calculate" button can be pressed (or press Alt+Enter / Option (⌥)+Enter). Once the process has been simulated, several new buttons will appear at the top-right, next to the "Calculate" button. Some components, such as heat exchangers and flash-drums will visually change to indicate the solved state.

6. Inspecting the calculation log

When a process has been simulated, a calculation log is produced. The log is opened by clicking the button at the top-right, next to the "Calculate" button (or press Alt+L / Option (⌥)+L to toggle it).

If all goes well, the log button will be grey. If the log button is any other color, there are errors, safety hazards, or other items you should inspect in the log.

7. Safety check and analyzing results

The results can now be analyzed by pressing the Results button (or Alt+R / Option (⌥)+R), or key safety criteria can be checked simultaneously for all streams by pressing the Safety Checks button.

8. Keyboard shortcuts

Once you are comfortable with the editor, keyboard shortcuts can speed up your workflow considerably. Press ? or F1 in the editor to see this list at any time.