Muhammad Zarif Abd Wahab

E-Portfolio of Elementary Principles of Chemical Processes

LECTURER: Dr. Aznizam bin Abu Bakar

SECTION: 08

The first day I come to the class, Dr Aznizam introduce the course outline to us. Then he also introduces himself. The first impression to Dr Aznizam is he seem quite strict because he scold us for not bring the reference book. But actually he is kind and funny. I enjoy in that class. And then he introduces the engineering calculation. The basic things are conversion of unit. For an example from inch to ft and from pound mass to kg. So the first quiz he gave to us is about unit conversion. He told us that in his class we usually have quizzes. Other than that, he refresh the topic that we have study in semester one. It’s all about mole fraction, mass fraction, conversion from mole to mass, from volume to mass, flow rate and molarities. Then he reminds us to do the reflection in e-portfolio and update it what we learn and get in class.

The next week, we learnt about mass balance equation. The basic thing is the process flow diagram. Dr Aznizam gave us the summary of process flow diagram that have in our syllabus. For an example is splitter, mixer, evaporator, distillation column and other else. So we need to understand from the question what process is happen and need to know how to draw and label the process flow diagram. In addition, the basic thing we have to know is BOX and BASIS. Dr Aznizam said if we not included the box and basis in the answer, the mark will be deducted about 5 to 10 marks. So we all have to take note on Dr advice. The material balance calculation is only occur in non reactive balance that’s mean mass/mole in is equal to total mass/mole out of the stream.

And then we learnt about two-unit process. The way to answer is same but the process flow diagram has more than one unit. Other than that, we learnt about degree of freedom analysis. If the degree of freedom is equal to zero, we can start the calculation to answer the question. When in two-unit process, we can do the overall mass balance equation to solve the question. Next lecturer we learnt about recycle and by pass. Recycle is the balance composition at final process unit is recycled and mixed to inlet process unit and vice versa for bypass.

Then we learnt the reactive balance calculation. In this reactive balance, we learnt the limiting reactance, excess reactant fractional conversion, extent of reaction, yield and selectivity. Actually there were three methods to solve reactive balance equation that is molecular species balance, extent of reaction and the easiest one is atomic species balance. But the most popular that always ask in question is extent of reaction. In this reactive balance calculation, the total mole in is not equal to total mole out. In addition, two-unit process can combine the reactor and the other non reactive process such as mixer, splitter, evaporator and other else. But the overall mass balance will refer to reactive balance because there is the reactor in the process.

Then we learnt about recycle and purging process in reactive balance. The next topic is about combustion. There are two combustion process which is incomplete combustion and complete combustion process. Then we have learnt the dry basis and wet basis. The different between dry basis and wet basis is the dry basis we don’t have h2o compare to wet basis. Then we were introducing about theoretical of air and oxygen. And by that information we can calculate the excess of air and excess of oxygen. But the percentage of excess air is same with the percentage of excess oxygen. That is all about chapter 4 that we learnt in class.

The next topic is single phase system that is in chapter 5. The basic thing in this chapter is PV=nRT. This equation is the ideal gas equation of state. Then we learnt about the compressibility factor equation of state. We learnt to calculate the value of z. We also learnt Kay’s Rule in this topic.

Chapter 6 is multiphase system. We learnt the phase diagram. There are three phase that is liquid, gas and solid. But the common one that always being ask in question is the liquid phase and gas phase. Then we learnt about Raoult’s Law and Henry’s Law. Other than that, we learnt about dew point and superheated. We must master how to refer the table at the back of reference book. The information given is totally importance to us.

And lastly we learnt the energy balance in chapter 7. There is kinetic energy, potential energy, heat loss or gain, work done and internal energy for closed system. For open system there is enthalpy change and the work done by the shaft. For overall in this subject, I enjoy learnt it and I think the lecturer is the best for me. He always gave us advice. Furthermore he can manage time properly to teach us this subject and can make we all understand this subject.