Development of an Industrial Multitubular Fixed Bed Catalytic Reactor as Cape-open Unit Operation Model Applied to Ethene Production by Ethanol Dehydration Process
The ethene production by ethanol dehydration has been established as a promising production route. In this work a computer software simulation written in FORTRAN 95 for an industrial multitubular fixed bed reactor (MTR), applied to this production route, is embedded in process simulation environment through a C#./NET wrapper code. This wrapper code was developed in agreement with the CAPE-OPEN standards, allowing the MTR simulator to be used as a native unit operation component in any CAPEOPEN compliant simulation environment.
A Zonal Different-Time-Step Algorithm for Multi-Physics Simulation in Closed System
In the present paper, a Zonal Different-Time-Step algorithm (ZDTS) is developed to overcome the difficulties of the flow, chemical reaction and heat transfer couple simulation in a domain-closed system. The system is decomposed into reaction zone and flow zone. The CFD simulations are performed in each zone individually, using different characteristic times, the physical information is effectively passed via interpretation at the interface. A case study of shell-and-tube reactor is presented for the validation. Numerical simulation based on ZDTS is performed to understand the catalytic reaction in porous media at tube side and the flow and heat transfer of the molten salt at shell side. The effects of selected interpolation methods and asynchronous factor (Af) on the computational accuracy and efficiency are investigated. The numerical results show that the ZDTS provides the details of flow field and heat transfer at different zones, predicts the accurate positions of the stagnation zones and the dead zones accurately, and reveals the characteristic of the heat transfer between each zone. The ZDTS significantly increases the computation efficiency by 50 %, and the numerical results show good agreement with the measured results. The ZDTS can be applied for the flow, chemical reaction and heat transfer couple simulation in a closed domain.
Designing sustainable processes with simulation: the waste reduction (WAR) algorithm
Abstract The WAR algorithm, a methodology for determining the potential environmental impact (PEI) of a chemical process, is presented with modifications that account for the PEI of the energy consumed within that process. From this theory, four PEI indexes are used to evaluate the environmental friendliness of a process design. These indexes are used in a comparative manner in the process design stage to help minimize the environmental impact of that process. Eight PEI categories (four global and four toxicological) are used in the evaluation of the PEI indexes. Details for relating these categories to known or measured quantities are also presented. An illustrative case study is presented which provide an example for the intended use of the WAR algorithm within the scope of process design and simulation.