Digitalize Learning via Process Simulation to Understand Process Control

Research Article

Austin Chem Eng. 2022; 9(2): 1092.

Digitalize Learning via Process Simulation to Understand Process Control

Gouws S*

Department of Chemistry, Nelson Mandela University, Summerstrand, Gqeberha, South Africa

*Corresponding author: Shawn Gouws, Department of Chemistry, Nelson Mandela University, Summerstrand, Gqeberha, South Africa

Received: October 20, 2022; Accepted: November 22, 2022; Published: November 29, 2022


Process simulation has become an important tool in training chemical engineers, operators in the chemical and industry sectors. Although various process simulation tools are available, in this study the software from Simulation Solutions. Inc. was used. This dual screen approach for student training consists of outside field operation view with interacting digital equipment and with the 2nd screen, the students can be in the control room environment changing input values. This provides the students with training in both control room adjustments of the plant and field operations adjustments. Students are supplied with a student manual that consist of Pipe and Instrument Diagrams (P&ID), standard operating procedures and troubleshooting exercises which they can follow. This article will discuss how these students benefit from process simulation training and how “What- ifs” can be used to pinpoint a potential problem. Once a problem has been identified then through simulation, the students will implement a corrective plan to successfully mitigate the risk. The feedbacks from the students suggest they have thoroughly enjoyed the interaction with the process simulation software and the “What-if” scenarios to identify the problem and use various resources to mitigate the problem. They learn how to implement strategies, solve the problem successfully and continue with the production process.

Keywords: Process simulation; Skills acquisition; Digital learning; Problem solving; Technology-enhanced learning


A: Surface Area / M2; Cp: Specific Heat Capacity; DCS: Distributed Control System; F: Friction; FC: Flow Controller; HAZOP: Hazardous Operations; Iot: Internet Of Things; LC: Level Controller; M: Mass Flow Rate; MPC: Multivariable Process Control; PFD: Process Flow Diagram; PID: Proportional, Integration And Differentiation; P&ID: Pipe And Identification Drawings; Q: Heat Coefficient; SOP: Standard Operating Procedure; SPC: Statistical Process Control; ΔT: Temperature Change Between Inlet And Outlet; ΔTln: Log Mean Temperature Difference; U: Overall Heat Co-Efficiency; UV Sonar: Ultraviolet Sonar Level Sensor; WIL: Work Ingrate Learning


Process simulation software [1] has been widely used by chemical engineers over the last decade to design a chemical plant, test and optimized the various process to ensure optimum production and minimization of waste. [2,3] With the aid of simulation technology software, students can be trained to build competence to operate a chemical plant. These tools have demonstrated an increase in awareness and an increase in their capabilities to perform their work in a chemical plant workspace.

Online teaching has become one of the major teaching mechanisms of today’s age [4,5] where technologies are around us such as Internet of Things (IoT) [6] that include smart phones and the Apps utilized on these devices, Tablets with touch button sensor screens make the technology user friendly. This allows for real time monitoring of process variables such as temperature, pressure, flow rate and levels. Artificial intelligence [7] (AI) has been utilized in a chemical plant for years to measure and monitor potential areas to mitigate risks or consequences. A challenge the students face in Diploma Chemical Process Technology program was that their training in the course was 2-dimentional. In the sense training chemical process operators in a theory class from PowerPoint slides was good to a point, but concepts and illustration of a chemical plant was not covered in such a way that the learner could leave with a good understanding but had to rely on their imagination and pictures of the equipment. Too enhance learning, simulation companies were approached to purchase an existing software package to train students in various plant procedures. Procedures that involve risk management, hazardous operations (HAZOPs), start-ups and shutdowns, mitigation of potential harm that could lead to a catastrophic event are included.

Although these students have sound knowledge in the mathematics aspects of basic process engineering and process equipment, it comes down to practical understanding of industrial process control. Therefore, it is important convert practical knowledge into practical understanding of process control loops, [8] concepts, and problem solving/troubleshooting solutions [9]. Process control has several advantages in a chemical production plant, 1) the reduction of operation cost, there might be an initial capital cost in acquiring the distributed control systems, followed by traditional and advance process control to the optimization and real-time process control systems. Secondly, to maximize profitability of the desired product to be maintained throughout the process with minimization of by-products or waste streams products.

In a classroom environment, the students are introduced to basic and advanced process control systems to develop understanding as to how a process control loop function, and how to mitigate risks associated with the process. The basic process control module covers various variable such as temperature, pressure, level, and flow. How these variables interact with one another and how the different variables operate in a cascade system to improve the process performance. Other aspects of tuning in open and close system [10] being discussed to aspects of Multivariable Process Control (MPC) and different algorisms in the process control Proportional, Integration, and Differentiation (PID) make the sense flows better.

To bridge the gap between theory and practical’s, various practical objective was developed and implemented. Three process equipment modules were chosen as process simulation tools such as heat exchanger, fluid flow and centrifugal pumps to study the process with which the students can interact. This takes place in a control room or from an outside/field operators’ perspective. The student then needs to discuss, as part of the objective, the operation mode involved in the process control.

What variables could be direct or indirectly manipulated and measured to meet the specific criteria of the process and to optimize the process towards the desired product.

Simulation software is used to simulate the operation three different processes such as fluid flow, heat exchanger and centrifugal pumps. This simulation involves identification of components in the plant environment referred to as in the field and control room environment in front of the DCS board (distributed control system). After identification the students discusses faults in the form of “Whatifs”. What-ifs are a thought process that provide an opportunity for the student to study the trending graphs and process to discover what could go wrong. The event could have been cause by equipment failure for example a stuck valve, or instrument failure where the sensor does not behave correctly and there are discrepancies between the field readings and the DCS board operator. The next objective for the students training is to set the simulation to cold start up (initiate clean start-up) and work through the start-up SOP (standard operating procedure) to have the system back online from a DCS and a field operator perspective. To have a close look at trending graphs and to act in a fast, cognitive manner to sort out a potential hazard.

The paper will provide evidence of the pedagogy process that was utilized in the learning and teaching of student training to be process operators. Feedback from students that illustrate the positives which students have learned or enjoyed from this module and the negatives in which the module could be improved to ensure a better transfer of knowledge.


As part of the Diploma Chemical Process Technology course [11] process control is vital important for operators to understand the intrigued works of a chemical plant. Process control module taught by the author to 20 x 3rd year students in the Diploma Chemical Process Technology course per year as part of a learning and teaching exit level outcome. After completing their 3rd year modules students then need to complete a Work Ingrate Learning (WIL) with a reputable chemical industry plant. Hence why process simulation is an important part of their training providing a platform where process control in a chemical plant could be understood and practiced.

During this module students will be tasked with several assignments 1) a detailed literature study on process control and HAZOP risks involved in a chemical process. 2) to draw a chemical plant by making use of MS Visio 2019 to design and layout a chemical Process Flow Diagram (PFD) and include the Pipe & Identification Drawings (P&ID). The students then need to discuss the strategy involved regarding measurements and manipulations to understand process control in a chemical plant. 3) to utilize software required from PetroSkills – Simulation Solutions [12] to perform cold starts, shut down solving troubleshoot problems that could arise in a chemical plant.

The simulation was taught in 3 sections the 1) on fluid flow, 2) heat exchange and 3) centrifugal pumps these 3 software packages were chosen to provide the students with basic process control that are utilize in most chemical plants. The fluid flow section of the training simulates two tank system, which demonstrates hydrostatic principles. The focus is on pump failures, going from a steady state flow into another tank. Pressures in each tank can be adjusted by split ratio valve controllers. The student then is tasked to do a risk assessment and draft an HAZOP study to identify potential risks and mitigation of these risks. Possible abnormalities that need to be troubleshooted such as instrument failure, equipment failure and human behavior that need to be investigate and mitigate to avoid catastrophic events.

The 2nd section on process simulation is heat exchanger. Heat exchangers are used to heat or cool a process stream. In this simulation water needs to be at a certain temperature for a customer, this is done by passing hot Dowtherm oil through a shell and tube heat exchanger to warm a cold stream of water to the desired temperature. The water and Dowtherm is controlled through flow controllers. The pedagogy involved is to train the students in the operation of heat exchangers from an outside (field) or console perspective. To improve the learner’s knowledge of fundamental engineering and operating principles, understanding of basic unit operations and improve basic operational skills.

Students in the diploma trained to be operators or technicians need to meet several learning outcomes such as 1) Describing the basic elements in a control loop, 2) describe which process variables could affect the process by manipulation or measuring the output. 3) to identify primary elements and sensors in a control loop, 4) different mode of controlling the process, 4) basic introduction to various tuning techniques mostly from a communication point to discuss with process engineers, 5) to enable the student to work through “What ifs” scenarios and troubleshoot the problem and then do recommendation to remedy the problem before escalating to a catastrophic event.

“What-ifs” scenarios are a prediction tool we adopted to facilitate the students thinking process. For example, a problem will be given such as pump or instrument failure. The students then need to provide recommendation of what possibly could go wrong and mitigate a potential solution to avoid a catastrophic consequence.

A questionnaire was distributed to the students to complete to provide feedback of the module presented, the interaction with the supervisor, student interest and overall rating of their performance.

Results and Discussion

Students were instructed to draw four process models in MS Visio, the 1) pressure control systems consisting out of two tanks connected via a centrifugal pump equipped with pressure sensors, a valve and flow controller. 2) a liquid level control system consisting of two tanks connected via a solenoid-controlled butterfly valve and level sensor to monitor the level in the receiving tank. 3) pH control system, consisting of a tank equipped with an inline pH-probe and two dosing pumps. 4) heat exchanger consisting of 4 tanks, flow controllers, thermocouples, and pumps. These 4 P&ID diagrams provide the students with good understanding on how a process control system works, the students then need to report on operational strategy, which variables are measured, and which variables need to be manipulated to control the process and to mitigate potential risks. (Figure 1 A and B) show two process systems A) the pressure system where the students need to characterize a pump and report on the operations, and B) level control system equipped with a UV sonar level sensor. These P&ID drawings teach students to identify components correctly, to write a Standard Operating Procedure (SOP), and to strategies the operational procedure in respect to process control.