Seyed Soheil Mansouri

A novel back-up control structure to manage non-routine steam upsets in industrial methanol distillation columns

Abstract Industrial methanol production plants have extensive heat integration to achieve energy efficient operations where steam generated from these heat integration operations are used to provide reboiler duty for methanol distillation columns that purify crude methanol produced into industrial AA grade methanol at a relatively high rate of product recovery. As such, fluctuation in steam supply due to non-routine process changes can lead to result in off specification distillation operations which results in significant economic losses. This work has investigated and identified the causes and consequences of these steam flow disturbances and developed two backup control structures to operate the distillation columns within specification during steam flow disturbances. One of the new control structures is based on model predictive control (MPC), while the other is a PID-based control structure with a novel supervisory layer to control the column during these non-routine process upsets. These control schemes were tested against realistic reboiler duty disturbances that can occur in an industrial process. The tests revealed that both the MPC and supervisory systems control structures are able to regulate the process, even during sudden drops in reboiler duty. However, the cost of implementation and the relative simplicity will likely favour the implementation of the supervisory control structure in an industrial environment.

Reverse osmosis for water purification and reuse in the biotechnological industry: Process design, operation and economic guidelines

Abstract In this work, a generic hierarchical computer-aided framework for techno-economic assessment of resource recovery plants for biotechnological process streams is proposed. The framework consists of five main steps that can evaluate, develop and implement a resource recovery project from concept to implementation through the systematic analysis of economic potential, technology availability and readiness as well as comprehensive net present value analysis. The application of the framework is demonstrated through a case study from the biotechnological industry where the objective was to reduce the hydraulic load on a wastewater treatment plant (WWTP), thereby investigating opportunities for process water reuse. In this case, a recovery unit is studied, where purification and concentration generates large volumes of wastewater. Reverse osmosis (RO) could ensure that the desired drinking water quality could be achieved and would enable re-use of the water in the production site for different economic purposes.

A Methodology for Development of a Pedagogical Simulation Tool used in Fermentation Applications

Abstract In this work, a holistic methodology was developed and implemented in a computeraided framework with the purpose of establishing a pedagogical simulation tool for bioprocess applications. The methodology integrates the development of a process simulator with the use of gamification elements to improve the pedagogical experience. Moreover, model development and reuse was incorporated into the framework through creating a generic model template. The application of the methodology was demonstrated by the simulation of a batch fermentation process of Saccharomyces cerevisiae cultivated under aerobic conditions with glucose as substrate, thereby, demonstrating mixed metabolism dynamics and considering the inhibition of ethanol consumption due to the presence of glucose with an integrated learning design and gamification elements. The learning experience, done with beta users with different previous levels of knowledge about fermentation processes, confirmed an interest for using gamification for training chemical engineering, biochemical engineering, and biotechnology students.

Dynamic Modeling and Analysis of an Industrial Gas Suspension Absorber for Flue Gas Desulfurization

In this work, semidry desulfurization of flue gas using a gas suspension absorber (GSA) is studied. A simple dynamic model which can properly represent the GSA was developed. In order to model the reaction kinetics, an empirical reaction rate expression was introduced. The reaction rate expression parameters were fitted to operational data from a real cement plant. A detailed statistical analysis of the parameter estimation procedure was performed, and the confidence intervals for estimated kinetic parameters were calculated. The model and reaction rate expression prediction ability was tested using another plant data set. It was verified that in spite of the simplicity of the model, very good prediction of industrial behavior was obtained. Furthermore, the dynamic analysis of the system was performed by carrying out open-loop and closed-loop simulations to verify plant dynamics. Therefore, a simple dynamic model with a reaction rate expression that is simple and efficient to use to predict the dynamics of GSA process was proposed in this work.

EIS and adjunct electrical modeling for material selection by evaluating two mild steels for use in super-alkaline mineral processing

The production of metal concentrates during mineral processing of ferrous and non-ferrous metals involves a variety of highly corrosive chemicals which deteriorate common mild steel as the material of choice in the construction of such lines, through rapid propagation of localized pitting in susceptible parts, often in sensitive areas. This requires unscheduled maintenance and plant shut down. In order to test the corrosion resistance of different available materials as replacement materials, polarization and electrochemical impedance spectroscopy (EIS) tests were carried out. The EIS numerical outputs were then transformed into an equivalent electric circuit using Z-View software, and the predictive behavior was contrasted with actual performance after long-term immersion, depicted through SEM, EDS, XRD and weight change observations. Also, results of pits and cracks, obtained with climax software-enhanced polarization resistance, and reduced capacitance added to much diminished current densities, verified the acceptable performance of CK45 compared with high priced stainless steel substitutes with comparable operational life. Therefore, CK45 can be a suitable alternative in steel constructions which are exposed to super-alkaline and corrosive environments.