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30 June 2023, 10:59 PM

Mass balance is considered a new thing for me in this semester as I never learned about it before. The first main topic I learnt in this course was process and process variables and introduction to chemical processes. I learnt the definitions of process and process unit which are the fundamental concepts of this course. Also, I learnt the basic calculations that will be usually used in the coming chapters such as how to change mass fractions to mole fractions using a table. Then, I learnt different processes that involved mixing, splitting, reaction, and most importantly separation processes. Learning these processes, it helped me to understand better what happened to the reactant when undergoing this process and what kind of products to be produced. I felt excited when learning this main topic as it was the first course that was closely related to chemical engineering. It helped me to understand more and gain more knowledge regarding the career that I chose. These topics might sound easy, but they play a crucial role in understanding the chapters that we are going to learn. It is vital that we need clearly understand and know how many inputs and outputs of this process. During this learning process, I made notes about the processes so I can understand them clearly and remember them easily. I also jotted down some important points on the lecture notes during the lecture so I can revise back afterward. What I think I needed to improve was my activeness in class. I was quite passive during the first few classes and reluctant to respond to Dr’s questions. I realised that was not good for me as I only listened during the classes. The memories of the knowledge that I learned will be long-lasting if I respond to Dr just like what Dr mentioned to us. So, after the first few classes, I started to try responding to Dr’s questions by saying the answers together with my coursemates.

The second main topic that I learned was material balances for single and multiple units, which was the main concept of this course. By learning this topic, we were able to solve problems that is related to mixing, separating and splitting processes in single or multiple units. We need to learn how to draw the process units, how to label the process flow diagram and following the labeling given by Dr. We also learnt how to do Degree-of-Freedom analysis before solving a question so we can know are we able to fully solve this problem or not. We need to use material balances where the amount of reactant going in and coming out is the same. At first, I think it was troublesome to follow the steps given to solve the problem, writing down every information neatly on the process flow diagram and following the symbols given. However, I realised it was easier to solve the problem by following all these steps after doing a few exercises. The tidiness of the working steps also minimizes the mistakes that you will make. The concept that was hard for me to understand when I first learnt about it was recycle and bypass. But I managed to understand the concept after going through the examples in the lecture slides and doing some exercises. I still remembered we had our first individual assignment regarding single unit. I was deducted 10 marks as I forgot to change the mass percentage to mass fraction in the first question. I also made some labeling mistakes, and my calculations did not have a flow like telling a story to the marker. I was a bit scared and disappointed as Test 1 was coming during that time. I still remembered clearly what Dr commented regarding our mistakes after giving back our individual assignments because I did most of the mistakes he pointed out. It was a good thing for me as it reminded me not make these careless mistakes in Test 1 and I scored well in it. We also had our first team presentation when learning this topic. We had two team presentations, the first one was online presentation and the second one was video presentation. The first one was smooth as our team were cooperative and the question was not too complicated. The second presentation was unforgettable for me until now as we literally worked overnight for it. We thought it was just a minor mistake when we handed in our draft answer for Dr to check. But after the first correction, Dr pointed out even more mistakes which made us panic as the due date was near. We quickly decided to meet Dr virtually to get a clearer explanation regarding our mistake. After understanding our mistakes and what Dr wants, we all started to redo the question but we were stucked halfway. Fortunately, we managed to figure it out in the morning of the due date. The very first answer that we got was correct just that our working steps and process flow diagram were slightly wrong. We quickly recorded our presentation and submitted to Dr. It was an extremely unforgettable experience as we only slept a few hours to figure out the solution. From this team video presentation assignment, I learnt that we should consult Dr immediately for clearer explanation and not wasting our time figuring out what was the problem. I also learnt that effective communication skills is also very crucial because we did not blame each other for the mistakes but we worked together to solve the problem together. 2There were multiple quizzes conducted when learning this topic. The quizzes allowed me to know whether I already grasped the basics of these topic or not. Revising the topics we learned as a preparation for the quiz helped me to understand and remember the knowledge that I learned effectively. Revision is a habit that I should maintain and practice for every courses even there is no quiz.

The third main topic that I learnt was material balance calculations for reactive systems. We learnt three methods which are atomic species balance, molecular species balance and extent of reaction to solve the problems related to this topic. This topic was related to chemistry as we learnt what is fractional conversion, yield percentage and more. We need to apply the knowledge we learnt in chemistry in material balance for this topic. The processes that we deal with in this topic involved chemical equations too. The introduction of this topic was quite easy to understand as we just need to understand and memorize the formula that we need to use when solving this topic’s problem. The harder part was when we were required to use molecular species balance to solve the problem. It required more steps compared to the other two methods and we need to depend on both the chemical equations and the process flow diagram. We might made a few mistakes when using this method. One of the major learning activities related to this topic was our mini project. We need to apply all three main topics that we learned in this mini project to solve the problem in Microsoft Excel. From this project, we were able to apply what we learned during the Excel Workshop in Semester 1 to solve the problem systematically. We need to come out with a process flow diagram too according to the problem description and summary table given. We need to learn how to read the summary table to know whether our process flow diagram is correct or not. As this was a team project, we need to divide the parts evenly, so everyone gets involved. We need to make use of the formulas available in Excel to make the calculations faster as there were many process units. We learnt how to analyse which streams will have the same compositions so we can avoid repeating the same calculations again and to save time. With this project, I can know what Excel is used for in our future job and how to use it effectively to save time and energy. During this presentation of this project, as the time is limited, we had to figure out the important parts to present. In the end, the presentation went well just that our slides were bit dim. Therefore, we will take note of that and choose a brighter background for our future presentations. Furthermore, this topic was tested in Test 2 too. I only managed to finish all three questions 15 minutes before the test ends. It was a bit risky as I did not have enough time to double check my answers. From this test, I learnt that I really must control my time well during exams. I need to focus on the questions that I can score instead of thinking about the questions that I cannot solve. I must practice this in every exam so I can finish it on time with sufficient time to double check my answer.

The forth main topic that I learnt in this course is single phase system. This topic was different with the first three as it requires imagination. It involves pressure and temperature in calculations where we neglected them before this. The only phase that involved in this topic is gas. We learnt how to identify the system is in ideal or real state. Besides, we learnt distinct laws to be applied when solving the problem. This topic was hard to understand at first as it was quite abstract compared to the processes we learnt before. There were multiple laws to understand and to learn how to apply it in different questions. However, the gist of this topic was to identify whether the gas was ideal or real. Once you can identify it, you can know which law can be used to solve this problem. Furthermore, we need to know how to read the graph to obtain the compressibility factor and estimate the value as we seldom get exact value from the written value on the graph. The value that we got usually was between two values given. Hence, estimation is one of the skills I learned from this topic. The negative experience that I went through when learning this topic was, I scored badly in the quiz regarding this topic. I only flipped through the slides before the quiz as I think the formulas were all given in the textbook. However, I panicked during the quiz and messed up. I realized how unfamiliar was I with applying the formulas during the quiz and it was too late. From this experience, I learned that I need to do some exercises to when it comes to topics applying formulas. Just reading formulas was not effective enough. So, I will go through and try the exercises in the lecture slides to avoid the same mistake again in the future.

The last main topic that I learnt was multiphase system. This topic consist of four parts. This topic was harder than the previous as there were a few new terms that I did not learn before such as vapor pressure, dew point temperature and more. Moreover, it involves 2 phases which are gas and liquid. It has new different laws to be applied such as Raoult’s law. We learnt how to read phase diagram, T-x-y diagram and P-x-y diagram in the first two parts. T-x-y diagram and P-x-y diagram are helpful in solving binary gas system. Furthermore, we learnt solution of solids in liquids and equilibrium between two liquid phases. We learnt the concept of solubility, saturation, distribution coefficient and how to read phase diagram for ternary systems. I encountered difficulties when learning the first two parts of this topic as I did not really understand the concept clearly and there were a lot of formulas too. I can only apply the formulas blindly to find the answers without knowing why. I only get to understand the concept clearer after going through the lecture slides a few times and doing multiple exercises. My team had an opportunity to present our solutions during the class and this helped me to understand this topic clearer as Dr pointed out our mistakes and guided us on how to explain the concept. The later two parts, which are about solution of solids in liquids and equilibrium between two liquid phases are easier as they are not that abstract and the concept is easier to understand. We only had a team assignment for this topic and we managed to solve it together. During the discussion, we can learn from each other and explain to each other if there is anything that we did not understand. By going through this process, it is helpful for us to remember and understand the concept. Through the experiences with the team, I realizes how fun and effective the learning process can be when learning as a team. I learn that I need to take advantage of learning in a team in the future as this not only benefits us but also cultivate our team spirit which is imperative in our future workplace.

In short, this course benefits me a lot as I get to learn different skills to become a well-rounded person. Dr always emphasizes the importance of ethics during our classes and making us practice them in daily life, especially during classes. I gained a lot from this course and it is a fruitful experience. Thank you Dr Azizul for the guidance and everything.