Journal PCP II

Throughout the semester, Dr Aznizam had given us a lot of quizzes. Actually quizzes was term used by Dr Aznizam for exercises and we do it together during the lecture time. All those quizzes help me to understand deeply the topic I have learned .It help me in having better understanding inthe topic that we just learned recently.

BALANCE ON NON REACTIVE PROCESS

For the first part, I have been introduced to hypothetical process path which a procedure to calculate the actual ∆H followed by the process for a given series of steps. The same procedure can be used to calculate ∆U for any process.

Besides, I have been introduced about psychrometric chart or humidity chart. This chart mainly shows several properties of a gas-vapor mixture and is used extensively in the analysis of humidification, drying and air-conditioning processes. This chart is for air-water system at 1 atm circumstance. My lecturer, Dr Aznizam has explained how to use this chart. 

• Dry-bulb temperature
• Absolute humidity
• Relative humidity
• Dew point
• Humid volume
• Wet-bulb temperature
• Specific enthalpy
• Enthalpy deviation

ENERGY BALANCE FOR REACTIVE PROCESS

From this chapter, I have learnt the concepts of heat of reaction or it can be called as enthalpy of reaction for a given process whether the process is exothermic(release heat) or endothermic(absorb heat). There are 3 ways to calculate the heat of reaction. Firstly, by using Hess's Law which is the easiest method among the three. This law is for calculating the desired heat of reaction for many series of undesired reaction. Somehow, I have learnt Hess's Law during my foundation which is only to calculate for 2 to 3 reaction. This time, I have to calculate the heat reaction for many series of reaction, 2nd method is using Heats of Formation and the third one is using Heat of Combustion method. All those three methods have objective of the same-calculate HEAT of REACTION.

As it names, for sure this chapter require me to do calculation for energy balance. In this chapter, there are two methods of determining the the value of Q which are Heat of Reaction Method and Heat of Formation Method. The most important thing to do energy balance is REFERENCE STATE, the reference state is( 25 degree and 1 atm). Also, for some process, I have to complete my mass balance before I can process with energy balance. So, below are the steps of performing energy balance:

           1. Basis
           2. Flow chart diagram
           3. Mass balance
           4. Reference state
           5. Inlet-outlet enthalpy table-one of important element(fogotten to mention)
           6. Energy balance..

SECOND LAW OF THERMODYNAMICS

For this chapter, the expectations to students are:

• able to define entropy and heat engine
• able to calculate the entropy changes of a given process
• able to develop isentropic, or adiabatic, efficiencies of various steady-flow engineering devices

n this chapter, for the first part, I have learnt about heat pump, heat engine and refrigerator. The most important thing is to know how to calcuate the efficiency for each device by knowing the desired output and required input.Also, I need to know to calculate the efficiency of carnot cycle(ideal) for each device. 

Besides, I have learnt entropy, and there are a lot of cases which make my head keep spinning.. there are a lot of conditions and terms such entropy generation, changes in entropy, entropy transfer, entropy is the same and more. For example, there is a case where the device is at isentropic condition. So, the entropy at 1st point and 2nd point is the same. Method to calculate entropy change for liquid/solid and ideal gas is different. 

POWER AND REFRIGERATION CYCLE

in this chapter I have been introduced about Rankine cycle which is the ideal cycle for vapor power cycles. The Rankine cycle does not involve any internal irreversibilities and consist of 4 processes:

1. Isentropic compression in a pump
2. Constant pressure heat addition in boiler
3. Isentropic expansion in turbine
4. Constant pressure in heat rejection in a condenser. 

Then, I have to do energy analysis for each devices based on 1st Law of Thermo equation which is Q + W = ∆H.

Besides, I have learnt about ideal vapor-compression refrigeration which is a most widely uses cycle for refrigerators, air conditioners and heat pumps. This cycle consist of  4 processes:

1. Isentropic compression in a compressor
2. Constant-pressure heat rejection in a condenser
3. Throttling in an expansion device
4. Constant-pressure heat absorption in an evaporator

At the end of the course I will :-

1) Ability to write basis, reference conditions and carry out unit conversion and equipment identification for various chemical processses, process variables and unit operations in chemical industry.

2) Ability to perform and solve energy balances with respect to changes in temperature, pressure and phase for non reactive process.

3) Ability to calculate the standard heat of reactions using Hess' Laws, heat of formation and heat of combustions and then solve problems for reactive processes.

4) Ability to define the entropy and then calculate the entropy changes in a given process.

5) Analyse and calculate the performance of power and refrigeration cycles.

6) Ability to conduct problem solving solution of mass and energy problem using principle of conservation.

7) Choose to commit in the preparation of learning experience process using E-portfolio.

I am so grateful that I am able to finish this subject, Principles of Chemical Process II. I really grateful learning this subject with my lecturer, Dr Aznizam Abu Bakar. He is very systematic in doing his works and very excited during teaching and learning process. I am able to understand what he had taught me during the class. Every students can asks him or stop him when he is teaching when there are parts that we do not understand. We were really enjoy his teaching skill moreover he is very funny person.Advise for our junior who will take this subject I am highly recommmended this section.
Special thanks to my lecturer for bearing with me this semester. I am sorry because sometime I come a bit late to class, although my lecturer never scold me on that, as a student I should be responsible to come earlier.. sorry Dr. :D

Test 1:11/10/2012 

-chapter 1

Test 2:08/11/2012

-chapter 2

Test 3:18/12/2012

-chapter 3