Chemical-engineering Students

Now this is an old Hollywood favorite, and I need not mention the movie title Kill Bill, I thought about this for two reasons, the one being the previously mentioned movie, the other being the fact that I am an active guy and it all started when I wondered how much blood does my heart pump per second and what kind of pressure drop does it create and one thing led to another... Being a chemical engineering student and having the mathematical capability of figuring this one out for myself I did a few calculations and got a answer, and when i tried to verify the answer somewhere on the web there where no real proof or calculations, so here is what I did. Firstly gather some constants: A good systolic heart pressure is about 100mmHg which is equivalent to 13.332 kPa Then when doing some hard cardiovascular workouts a young mans heart rate cam reach 190bpm which is 3.166 bps (beats per second) From a medical journal it is found that blood flow rates of 20-30 l/min is achie...

Its been a really long time since I made any posts, sorry for that but work sometimes gets in the way of the things I like doing, like updating my blog. This post might seem a bit stupid but I tried to find out how to do this on the web and it was quite impossible to find a easy step by step guide for making a XY plot in Aspen Plus for use in the McCabe Thiele method for designing a distillation coulomb, so I had to figure it out myself after a lot of fellow class mates had the same problem as me. So without any further a dew here is my 13 steps to making a XY plot in Aspen Plus for a binary mixture. For this example I used the old classic ethanol and water problem. Step1:  Open Aspen Plus and this is the first screen to pop up. Choose "Blank Simulation" an press "Ok" Step 1: Begin new Aspen simulation Step2:  You are now in the simulation environment and to start the simulation you need to enter the "Data Browser" (Usual simulations you would...

In principle any balance, be it in baking a cake, accounting, electrical engineering, mechanical engineering or chemical engineering is suppose to be simple, but for some reason maths always find a way to complicate things a little. So lets get the balance going. The general balance for any thing in life is as follows: EQ1: General Balance equation Before trying to visualize the math, lets first try and understand the hardware we are trying to describe mathematically. This is what a PFR (Plug Flow Reactor) looks like. FIG1: Plug Flow Reactor And this is how we are going to graphically illustrate a plug flow reactor. FIG2: Mole balance of species i in dv with these images in mind, lets try and explain the mathematics that describes it, by taking the mole balance and substituting values that is of importance to the system we obtain: EQ2: General Mole Balance with F i0 and F i being the initial and final feed rates respectively in [moles/time],...

Fugacity is supposed to be easily understood, especially because that was the main purpose of its invention. Lets just get some history straight first. In the beginning there was chemical potential, usually denoted as  μ, and defined as: Definition of Chemical Potential with G and n i being the Gibbs free energy and moles of compound i respectively. As you see  μ is used to describe the Gibbs free energy, and if you know thermodynamics you should know that Gibbs is used to describe chemical equilibrium in pure and mixed systems, if you didn't know, this is very important. The problem however with chemical potential is that it is an abstract concept, like the amount of honest bankers, in other words, it can not be directly measured. In its stead fugacity was invented by one, G.N. Lewis (Also famous for his Lewis dot structure of molecules and his mustache). G.N. Lewis Partial fugacity, is the pseudo-pressure exerted by the mixture of molecules in the vapor phase...

"Why can't a isothemal process be adiabatic?" This was the question my housemate, that studies geology and geography, asked me while studying for his thermodynamics test. As a chemical engineering student I was suppose to be able to answer him immediately, but it took me some pondering to give him a good answer. Lets consider the isothermal expansion of gas, and lets use the convention used by most thermodynamic textbooks that work (W) done by the system on the environment is said to be negative. Consider the diagram and the formula used for work done by isothermal expansion of an ideal gas and the heat formula. Isothermal expansion Work done by isothermal expansion of an ideal gas Heat formula for expansion of an ideal gas in a closed system And because, for reversible isothemal expansion the following is true: For reversible isothermal expansion  thus we can see that Q = -W, and W is not equal to 0 because the volume has changed, that mea...

I said in my previous post that I will discuss how to solve the equilibrium constant K when the enthalpy of the  reaction is not constant, but a function of temperature. That is to say: Enthalpy as a function of temperature If the above statement is true for the given system then you need to use the following, extremely long formula, I suggest doing this on excel or a similar program. To determine K T , the equilibrium constant at the new operating temperature,   use the following equation: K T when h rxn is a function of T The constants A, B, C, D and E you get from the heat capacities of the different elements in the chemical reaction with: The same goes for C, D and E From a previous post it is shown that v i is the stoichiometric coefficient of the reaction, remember that v i of the reactants are always negative and the products coefficients are always positive, this is really just convention more than anything else.  The nature ...