Forums | Portfolio Discussions

30 June 2023, 6:27 PM

My main goal in learning in utm is to obtain all the knowledge that is required to become a chemical engineer. In the journey of learning in utm, I wish to build up and shape my own character well to suit best in the working society in future. With knowledge and good characteristics, I will be able to have a better foundation towards the journey to become a professional chemical engineer.

            At the beginning of this semester, we were divided into groups. I was in Group 5 that consists of 4 members which are Javier Tay(me), Lee Qiao Er, Joshua Lee and Ti Deng Yi. We were assigned to sit together in our respective groups and we helped each other during in completing the task given by the lecturer and completing the group assignment. The group assignment consists of many parts which requires every team member to work together and solve the problem efficiently. This assignment was quite challenging for me because there are a lot of unknowns and different compartments to solve. The first step in solving the problem is to analyse the clues given. We choose the boundary that has the least unknowns to solve the problem by doing Degree of Freedom Analysis. I also learned how to use Microsoft Excel efficiently as I wasn’t familiar on how to use it before this.

            Calculating the molar flow rate, mole fraction and mass flowrate was the toughest part for me to solve. Because I am able to understand the flow of the topic but when it comes to problem-solving, I will get confused. Sometimes I got frustrated because of stress but I keep trying to do as many problems as possible which included drawing the overall flow diagram, learn how to handle Microsoft Excel app, identifying the unknowns, calculating degree of freedom analysis and material balance calculations.

            As the first step, we must understand the objective of the problem statement. Must perform all required material balance calculations by doing the degree of freedom. We need to apply all of the knowledge we learned from the mass balance topics. Then, need to form the material balance equation where input equal of output. For some cases for example when there is only one input and one output, we need to state the assumptions before proceeding to the next step which helps to assume the same flowrate and composition of each compound for the given process system. Next, we can calculate the mass flowrate by dividing molar flowrate with molecular weight of their respective compound.

            Starting from the beginning of the semester, the first topic that we learned was Introduction to Engineering Calculations. This topic mainly focused on Unit, Dimension and Unit Conversion. This chapter was quite simple for me as I have learned in Introduction To Engineering Course in my first semester. Next topic was about Process Variable. This topic introduced us about the process unit, mass, volume, density, flowrate, chemical composition and conversion of mass, molar and volumetric flowrate. I found it hard to convert the flowrate at the beginning of the lesson but as I did more practices on the calculation, I able to solve the calculation without any problem. Chapter 4 is about the Introduction to Chemical Processes which helps us in identifying and differentiate the types of process units such as mixing, splitter, reactor, distillation, flash vaporizer, evaporator, dryer, liquid-liquid extractor and many more. We are required to identify the types of process unit used in the question given and solve the problem by using degree of freedom analysis and material balance.

            Other than that, the topic of chapter 5 is Material Balance Calculation-Fundamentals and Single Unit. In this chapter, we first learned how to draw a block flow diagram. There are a few specific symbols to be used in Mass Balance, for example, m for mass flowrate, n for molar flowrate, x for mass fraction and y for mole fraction. We also learned about scale factor (new value divided by old value) and how to assume a Basis. This chapter is quite important because it give us the fundamental knowledge on how to draw a process flow diagram. In the previous topics, what we learned was all about single unit, so this new chapter (chapter 6) introduced to us about Multiple Unit. In this chapter, we are required to draw a boundary for each compartment and identify which boundary is the most suitable to be use as the first step to start our calculation by using degree of freedom. Additionally, chapter 7 is about Material Balance Calculations for Reactive Systems. We learned about chemical reaction stoichiometry, identifying limiting and excess reactants, fractional conversion, calculating yield and selectivity. The main core in chapter 7 is calculation using Extent of Reaction Balance, Atomic Species Balance and Molecular Species Balance. This part was quite difficult for me, as I was confused on the method of calculation. I had discussions with the lecturer and my friends so that I can understand better on this chapter. Next, chapter 8 is about Single Phase System. We learned about ideal gas law, Dalton Law, Amagat Law, Virial Equation, Cubic Equation, Soave-Redlich-Kwong (SRK) Equation and Compressibility Factor Equation. This chapter required us to refer to the tables to obtain data in order to solve the calculation. Last but not least, the topic of chapter 9 is Multiphase System. We were first introduced about Antoine Equation which required us to refer to Table B.4 in the textbook to find vapor pressure. We also learned about Gibbs Phase Rule, Raoult’s Law, Bubble Point and Dew Point Calculations, Solubilities and Equilibrium Between Two Liquid Phases. Out of all the chapters in Mass Balance, this is the most challenging topic for me because there are many subtopics to be covered in this chapter and I found it hard to understand.

            Having quizzes in between the learning process really helped me understand the concept of each topic and check how well I understood the topic. I learned a lot from my mistakes in the discussion after the quiz. Individual and group assignments help me to interact with my classmates, discuss questions, and understand the reasons behind of my doubts. We were also able to exchange and compare solutions to problems. Test 1 and Test 2 were quite easy for me because of my previous subject knowledge and answers from past year's questions. Test 3 was a little tough for me because of my lack of exercise. During this time, my schedule were filled with so many tasks and projects and I was unable to manage my time. That's why I wasn't satisfied with my result on Test 3. However, due to lack of time, I was unable to answer all the questions on time. Then I realized that the practice I had been doing was not enough and I needed to practice more. We then had a peer discussion where each group had to solve a question posed by my lecturer and explain it to the other team. This session was useful for us as we were able to get acquainted with different questions with different solutions. We also had cross-group discussions to resolve the questions that were raised. Tests 2 and 3 were preceded by a review session to discuss and prepare for the tests. This mini-project had a huge impact on my understanding of mass and energy balance. I learned where and how to apply techniques and formulas to solve problems. Lastly, I would like to appreciate and thank Dr Azizul. His guidance helped me improve.