It is now possible to schedule operations based on their finish time It is now possible to schedule operations based on their finish time. This is useful for pre-processing activities that must be completed before other operations that are on the critical path. The mode of scheduling (based on Start or Finish time) is selected using the “Start” or “Finish” option in the Schedule box (top of the dialog). Alternatively, the same can be accomplished through the “Scheduling Dependency Link” drop-down menu at the bottom of the dialog. In the past, users were forced to use negative “Time Shifts” in order to represent the equivalent of scheduling based on finish time.

QUICK SCHEDULING OF SLAVE OPERATIONS In batch processing, it is common to have multiple operations running in parallel. A transfer-in operation in a vessel procedure that represents the eluant collection of a chromatography step is a typical example. The transfer-in operation has the same duration and starts at the same time as its corresponding elution operation. The “same duration” constraint is specified in SuperPro using the “Master-Slave Relationship” option for duration specification in the Oper. Cond’s tab. The “same start-time” constraint is specified in SuperPro through the “Scheduling” tab (see figure below). A new button has been added (Sync. With Master…) to expedite the “Same-Start-Time” specification for slave operations. Clicking on the highlighted button will directly set a 'start-to-start' relationship on the timing of this operation with respect to the (already assigned) master operation.

AUTONOMOUSLY CYCLING PROCEDURES In the batch production of commodity biochemicals for which maintenance of batch integrity is not a requirement, it is common to have batch processing steps operating with a cycle time that is not related to the cycle time of the overall process (typically determined by the production fermentors). This is common with chromatography columns operating in SMB (simulated moving bed) mode, membrane filters that need periodic cleaning, rotary vacuum filters that need periodic pre-coating, etc. Basically, this is the case with cyclical units that macroscopically appear to function continuously in a batch process. This mode of operation for a procedure is specified by checking the “Cycles Independently of Main Recipe” button in the Procedure’s Data dialog. More information on the subject can be found in the ReadMe files of the Citric Acid and Lysine examples of SuperPro as well as in the manual and help facility of the application. Procedures that cycle autonomously display a clock icon on the left of their name (see figure below) that denotes their mode of operation. This icon is part of the procedure’s style and can be hidden by de-selecting the “Independent Cycle Sign” check box in the procedure’s icon style tab (right-click on the procedure’s icon and select Style \ Edit…).

Non-Ideal VLE Models Available Everywhere Use of non-ideal models for VLE (vapor-liquid equilibrium) calculations is now available in all streams and unit procedures. In previous versions that functionality was limited to few selected operations (e.g., flash, condensation, and rigorous distillation). Please note that the old short-cut method (based on normal boiling points) is still the default for most operations and streams. For streams, the rigorous option is selected through the Physical State tab of the stream’s dialog by checking the Overwrite box for Physical State (PS) Calculation Options, selecting the Rigorous option and clicking the Edit Rigorous Toolbox Options button. That displays the window shown below that enables you to make the specification. It is possible to exclude certain components (e.g., non-volatile solids) from the VLE calculations by clicking the “Exclude Components From…” button and then identifying the non-volatile components. Please note that excluded components contribute to the energy balance calculations. VLE options for procedures are specified by right-clicking on a procedure icon and selecting “Default PS Calc. Options…”. Please note that it is possible to specify the default rigorous VLE options at the flowsheet level by selecting “Edit \ Process Options \ Rigorous PS Calc. Toolbox…”. For more information on the subject, please consult the manual and the help facility of the application.

HEAT RECOVERY THROUGH VIRTUAL INTEGRATION It is now possible to match operations that require cooling at a high temperature (e.g., the condenser of a distillation column) with operations that require heating at a low temperature (e.g., heating of a raw material stream) without using explicit heat exchangers. That eliminates the utility requirement of one of the two operations and reduces the utility requirement of the other. In addition, it is possible to match a hot operation with a heating utility. This virtual integration is accomplished through the Energy Recovery Opportunities window (Edit \ Process Options \ Energy Recovery…). This functionality enables users to account for energy recovery without creating over-complicated flowsheets (the typical result of using many heat exchangers) that are difficult to converge and understand. Please note that the matching is done between operations or between an operation and a utility. If the objective is to match a hot operation with a cold stream, a heater (not a heat exchanger) must be inserted in the cold stream and then the heater (which represents the heating of the cold stream) can be matched with the hot operation. For more information on the subject, please consult the ReadMe file of the BioDiesel example of SuperPro as well as the manual and the help facility.

Small improvements 1) Remember to mention display of averaged continuous flow for streams in batch processes.