Enhancing the Value of Detailed Kinetic Models through the Development of Interrogative Software Applications

Chemical kinetics models are required to face day-to-day issues in an industrial setting due to stringent product quality, process optimization and environmental constraints. Models help in tracking plant operations and give research direction for improvement of the process. As the complexity of the model increases, it becomes difficult to understand the complete set of detailed implications it conveys. Moreover, a process engineer often requires a rapid calculation of model results in terms of plant measurable input and output variables. These issues can be especially challenging in the case of detailed kinetics models, where the once-through solution time can be of order tens of seconds. This motivated the present work which is focused on the development of user-friendly software applications to interrogate detailed kinetic models.

A user-friendly I/O (Input/Output) converter application permits execution of molecular-level composition and kinetic models in a manner which focuses on measurable inputs and outputs. This app was used to efficiently study the impact of different feed streams, operating conditions, hydrogen partial pressure and catalyst flow rate on performance of a catalytic reactor. Such I/O converter apps are process-specific as the app is dependent on the process I/O. A second application, the KME Reactor Flowsheet tool, was developed to build kinetic models based on data from a pilot or commercial reactor which can split feed streams and perform reactor bypasses. It also includes different features like splitters, heaters and reactor blocks and also can handle multiple kinetic models.

The functionality of these applications is tested to study the behavior of a catalytic reforming unit. The inputs to the model are distillation, overall and detailed PIONA, density, and reactor conditions. The outputs from the model are light-gas yields, detailed PIONA, coke, and temperature drops across each reactor bed. The I/O converter and flowsheeting applications were used to study the impact of feed variation, partial pressure of hydrogen and catalyst circulation rate on yield, composition and coke concentration in the product.