DYNAMIC MODELING AND SIMULATION OF CO2 REMOVAL SYSTEM WITH DCS BASED INTERFACE

Abstract

The fertilizer industry is one of the largest industries in Pakistan and in terms of GDP contributes the most to the economy. [1] Therefore, efficient production of urea which is a key component in a fertilizer is very much desired. The manufacture of industrial urea at FFBL requires CO2 extracted from process syngas (containing CO2, CO and H2) and Ammonia (NH3) which is formed by the reaction of H2 and N2 in a Haber-Bosch Reactor. [2] Our project relates to the first part of the equation, which is the absorption of CO2 from process-sour syngas. We were asked to dynamically model this absorption process and implement a Distributed Control System (DCS) based interface. The first part deals with conducting a parametric study on the CO2 absorption process at FFBL to decrease the regenerative heat duty of the stripper column and increase the overall recovery rate of CO2. Once that was done, we headed onto the control part and simulated it onto our process by utilizing NI LabVIEW’s unique control system environment and linking it with our system’s dynamic model on Aspen HYSYS. The parametric study was followed by us redesigning some of the equipment because this further took us to implementing better, more optimized parameters on to our absorption process. The control part objective was perhaps the trickiest to undertake because no prior literature was found on the topic of linking the above aforementioned softwares. Therefore, a third-party software, Microsoft Excel was used as a bridge between the two and its macros was edited by coding in Visual Basic (VB) to customize it for our process parameters.