Configure the pressure and products for your distillation units

For each distillation unit, configure the pressure and correct number of products.

Fractionation parameters can be directly entered into the grid for each cut. Each cut requires four pieces of information:

• Product name: The name of the product stream between the previous cut point and the cut point entered in the ECP field.

• ECP: The effective cut point of the product. This corresponds to the "cut point" between this product and the next. Notice that the final product, the residue product, has no ECP. The temperature unit for ECP is governed by the default unit setting for Boiling Point. See Configure your units of measurement.
  The term ECP is defined as the effective cut point of a stage of the separation. A molecule having a boiling point equal to the ECP is equally partitioned between the product stream boiling just above that temperature and the product stream boiling just below that temperature. For example, a distillation unit may have two adjacent streams, diesel and atmospheric residue. The ECP of the lower boiling diesel stream is calculated as the boiling point of a molecule which is equally separated between the diesel and atmospheric residue. The boiling point of this molecule is not dependent on the composition of the crude being analysed - it only depends on the conditions found within the distillation unit. Hence the ECP is not crude dependent.

• Stripping and Rectifying FIs: Parameters indicating the quality of the separation at that cut point (the fractionation index). The values may range between 0.5 and 20, with higher values indicating more efficient separation. The values correspond to the number of theoretical plates in the separation. Stripping governs the amount of light components in the heavy product at a separation, while rectifying governs the amount of heavy components in the lighter product.
  To set a cut point as perfect, double click on a cut point and select Perfect from the drop-down menu. This replaces commercial fractionation with perfect cutting, setting the cut point between the streams to the value entered for the ECP.

Distillation unit parameters can be entered manually, or calculated by Assay from test run data. To use Assay to calculate the parameters, open the Distillation Unit Fitting dialog by clicking the icon for the required distillation unit. Each distillation unit in the system must be fitted separately using its own set of test run data. See Fit flowsheets.

You can also fit the whole flowsheet, rather than a single distillation unit, by clicking the icon in the Flowsheet Editor toolbar.

Click the button to add a target specification to the selected cut. Click the to remove an existing target specification from the selected cut. See Target specification.