| Chemical process design engineers often depend on design software such as Chemcad, Aspen, etc., to develop safe and energy-efficient processes. However, most software does not include all unit operations modules. Thus, Chemcad introduced an Excel Unit where users can perform calculations and transfer the solution into the process flow sheet. The rigorous numerical solvers in Mathcad were used to model two different chemical reactors. Visual Basic macros were developed to embed these models into Excel as an Object Linking Embedding (OLE) object, allowing these solutions to interface with Chemcad. This approach was demonstrated using validated Mathcad models of both a Plug Flow Reactor and a Packed Bed Reactor embedded into a Chemcad process flow sheet developed for the specific process. To demonstrate that the approach was compatible with another numerical solver, a Mathematica compressor model was linked to Chemcad and compared to a built-in Chemcad compressor module. Optimum feed ratio, feed composition, space-time, and other process conditions were easily determined using the embedding/linking techniques and functional process flow sheets for the three examples considered. Thus, this approach will enable users to embed any desired unit operation and apply that operation to different applications. |
