## Dear Mobile/Tablet Users

This site has not been optimized to work with mobile devices. Please use a laptop or desktop for the best experience, thank you for understanding!

## Welcome Intrigued Chemical Engineers!

If you are here, it could mean that you are interested in learning some chemical engineering material. Well, I am glad you are able to join me to explore what entails the chemical engineering section of andrew's notebook. Take a look below for the available topics that is/will be offered:
$\Delta E = q + w$ $\Delta S_{total} = \Delta S_{sys} + \Delta S_{sur}$ $S_{T=0} = 0$

## Thermodynamics

Thermodynamics is most likely one of the first few core classes you will be taking as an undergraduate student. In this topic, you will be learning about the laws of thermodyanmics, the different relationships between properties of heat, temperature, energy and work as well as different theorems that are used to analyze systems.

An example that can help you picture the essence of thermodynamics is with a steam turbine. In a steam turbine, fuel, containing stored chemical energy, is used to heat up water to turn it into steam. This steam, now containing potential energy, is used to spin a turbine, giving the turbine kinetic energy. This kinetic energy in the turbine is then used to turn electric generators which in equivalent to converting the kinetic energy into electrical energy!
$E_{in} - E_{out} + E_{gen} = E_{acc}$ $$\frac{dm_{in}}{dt} - \frac{dm_{out}}{dt} + \frac{dm_{gen}}{dt} = \frac{dm_{acc}}{dt}$$

## Mass & Energy Balance

Mass and energy balance is an important course for every chemical engineer to understand as it is a basis for a lot of the calculations and concepts that proceed this topic. Some of the concepts in this topic would be, as the name says, the conservation of mass and energy in a system. It might seem repetitive when doing some of the work in here, but it is worth spending that extra time mastering this concept!

Although this might seem new to you, mass and energy balance is something that happens without you even noticing it happening. Take cooking for an example, you are putting in some quantity of oil, meat, vegetables, and seasoning. You then heat up the entire pot using the stove. Now, at the end of cooking your dish, you should, theoretically end up with approximately the same amount of oil, meat, vegetables and seasoning you put in because no extra meat or vegetable is going to appear out of thin air. The heat that is in your food, pot, utensils and the heat dissipated into the atmosphere should also sum to the amount of heat given out by your stove, this is due to the law of conservation of mass and energy!
$A_{1}v_{1} = A_{2}v_{2}$ $\frac{\delta\rho}{\delta t} + \frac{\delta}{\delta x}(\rho u) = 0$ $\Delta P + \frac{1}{2} {\rho}{\Delta v^2} + {\rho}g{\Delta}h = 0$

## Fluid Mechanics

In fluid mechanics, you will learn all there is to know about, well... The movement of fluids! Fluids consists of both liquids and gases which apparently acts and moves differently at different temperatures, pressures and other possible varying factors. Since this is also one of your core classes, it is important to have this on the tip of your fingers as it is necessary to use fluid mechanics to determine how fast your fluid is flowing. This difference in fluid flow can make a major difference as to how efficient the chemical reaction you are trying to run is.

To picture fluid mechanics, you can take a look at your tap. At the given diameter of your tap opening, the fluid flow may be 1.5 m/s. But if you were to let say widen or narrow down the opening of your tap, you will see a difference in the speed of the water running out of your tap. Not to say that is all there is to fluid mechanics, but the essence of it is captured in this example and is used to calculate the different speeds in the pipes you may see or know about in industrial settings.
$q_{cond} = kA\Delta T$ $q_{rad} = {\sigma}{\epsilon}AF_{ij}(T_{i}^{4} - T_{j}^{4})$ $N_A = k_c(C_{As} - C_{A})$

## Heat & Mass Transfer

Now this is an interesting one that you may know a little bit about already. There are two obvious parts to heat and mass transfer - heat and mass. The purpose of learning how heat flows from one material to another or how mass moves from one region to another is important to understand why things move the way they do! In this topic, you will learn about coduction, convection, radiation, diffusion, etc. Which will help you see why steel conduct heat while rubber does not do much of heat transfer. There is also a reason as to why these two - heat and mass - are taught together! Do you happen to know why?

For a quick example of heat transfer, we can take a look at placing ice into hot water - the heat from the hot water will be transferred to the ice cube and increase the temperature of the ice cube, therefore melting it. For an example of mass transfer, try imagining a bowl of cake batter and putting in several drops of food coloring. As you swirl the batter around the bowl, you will slowly see that the initially concentrated food coloring will mix together with the batter and eventually make a homogeneous mixture.
$\int_{0}^{V} \frac{dV}{F_{Ao}} = \int_{0}^{X_A} \frac{dX_A}{-r_A}$ $N_{Ao}\frac{dX}{dt} = -r_AV$ $F_{Ao} - F_A + \int^V r_AdV = \frac{dN_A}{dt}$

## Chemical Reactions Engineering

Chemical Reactions Engineering... This is the true essence of chemical engineering - the topic that differs chemical engineers from other engineers! This subject where you will studying about chemical reactors and how you can optimize chemical reactions accordingly with different reactors to achieve maximum output! Remember all the extra hours you put into the previous topics? Well, you will be glad that you did, because there are interactions of fluid mechanics, heat transfer, mass transfer, reaction kinetics, thermodynamics and energy balances. This is a fun yet tough one to hash out, but trust me - it's worth it.

This is a little bit difficult to fully picture unless you have prior industrial experience. But try this for a second. Imagine a large tank that you can pour thousands and thousands of gallons of chemicals into, with an open top and a valve at the bottom that can be opened when you want to. This is what are called batch reactors, because you can pour in material in manually to make a batch of chemical blend. A batch reactor is very much similar to the pot you use to cook soup, where you can put in your stock, carrots, chicken, noodles, etc. to help you make a batch of soup. The only difference? It is 1,000 time larger!
$k_pe + k_i\int_0^t e(t)dt + k_d\frac{de}{dt}$ $G(s) = \frac{8}{s(s+2)(s+4)}$ $\frac{y(s)}{u(s)} = H(s) = \frac{K}{Ts + 1}$

## Process Dyanmics & Controls

This is a sort of combo between control engineering and chemical engineering as they are designed by control engineers but frequently used in chemical reactors introduced in chemical reactions engineering. The purpose of process controls is to achieve a production level of consistency through an economical and safe means. Most of what is learned in process controls is the tuning of controllers and how the different types of controllers may be advantageous for one reactor but bad for another.

An example of process control could be the tank fill valve in your very own toilet bowl. You know how the enough water fills in your toilet bowl once you push down on the lever to flush? The toilet never over fills such that it overspills but also does not under fill such that the water will not flush. Well this is because of how the toilet fill valve is controlled to close once a certain water level is obtained with a water level measurement!