What Actually Is Chemical Engineering?

Chocolate, power stations, paracetamol, oil rigs, beer, soap, rocket thrusters and chicken nuggets all have one thing in common – chemical engineering!

A Quick Overview

As you can see, chemical engineering is very broad and uses a healthy combination of physics, chemistry, maths and biology in a wide variety of applications to achieve a wide variety of things.

This usually involves chemical reactions (as you might expect) as well as manipulating temperatures, pressures and concentrations to make a product like petrol, beer or aspirin, or to generate useful energy such as electricity from a power station.

Chemical Engineering In The Wild

Having said all that, even after four years of studying chemical engineering, I still find it tricky to define and so I think it’s best to dive in to some real world examples of what a chemical engineer might do.

Chocolate – Did you know there are six different crystalline forms of chocolate and only one of them tastes nice? If you’ve ever had a chocolate bar melt in your pocket and then taste kinda weird afterwards, you’ll have experienced one of the five not so nice ones. A chemical engineer in a chocolate factory has to carefully control the rate at which the chocolate cools to ensure that it forms the correct kind of crystalline structure – one that tastes smooth and rich.

All the Fuels! – Whilst coal, gas and oil are very traditional chemical engineering topics, it may interest you to know that almost all renewable forms of energy involve chemical engineering. This covers everything from fermenting specially-grown crops to create bioethanol which you can put in your car, to generating biogas from the rotten veg and tea bags you throw in your household bin. Some chemical engineers also dabble in solar power, wind power and nuclear energy.

Beer and Chicken Nuggets – One of my friends who I studied alongside has a job brewing beer (including my beloved Newcastle Brown Ale) and another works in the biggest chicken factory in the UK, making chicken nuggets. If that doesn’t get you interested, I don’t know what will!

Pharmaceuticals – If all of these possibilities are giving you a headache, have no fear! Chemical engineers can make paracetamol, ibuprofen and, well, any other medicine you like to relieve your headache. A chemical engineer working in pharmaceuticals may take the salicylic acid found in the bark of willow trees and convert it to acetylsalicylic acid, or as it is known more commonly – aspirin. It’s a tricky job though as the reaction is highly corrosive, releases lots of heat and has a tendency to explode…

Chemical Process Units – The Building Blocks

Now we have a slightly clearer picture about what a chemical engineer might make, it’s time to dive into our beloved chemical process units – the core of chemical engineering. The process units can be placed together like building blocks to create a full chemical process to do, well… whatever you like! Let’s check some of them out:

Reactors – We have lots of different reactors for reacting gases, liquids, solids, mixtures, solutions, suspensions and everything in between. The reactors are where all the chemical transformations happen which convert our reactants into valuable chemical products.

Separators – Unfortunately, things never really come out perfectly pure, no matter what you’re making or how you make it. Because of this, the majority of chemical processes are not made up of reactors, but of separation units which are needed to get rid of the bits we don’t want to leave the bits we do. There are all kinds of separation units from the standard distillation columns, cyclones, filters and absorbers, to the funky units like membranes, magnetic separators and cryogenic coolers.

Mixers – Whilst there is a lot of separating, it’s also important to mix things together, like ensuring you have just the right mixture of coal and air in a power station to efficiently combust all of your fuel and generate electricity.

Heat Exchangers – Almost every chemical process under the sun requires some parts to be heated whilst other parts are cooled. In our reactors, high temperatures and pressures are often needed to achieve optimum reaction conditions, whilst for separation it is common to cool and condense certain chemicals out of a mixture. The skill is in removing heat from the units where you don’t want high temperatures, and transferring the energy to other units where heating is needed. This is essential for efficiency, low cost operation and for environmental friendliness.

What A Chemical Engineer Will Do

Chemical engineering study is mostly based around understanding the theory, design and operation of the process units, and then learning how they can be combined together to create chemical processes.

In industry, some engineers become technical experts at one particular type of process unit whilst others are more into project managing the creation and operation of full chemical processes.

As we have seen, there are many different jobs, industries and walks of life where chemical engineering can be applied, but it is all rooted in the fundamental understanding of the chemical process units.

What A Chemical Engineer Will Not Do

Despite what the name suggests, there is very little pondering over chemicals involved in chemical engineering – we leave that to the chemists! It’s much more important for an engineer to be able to optimise and design a reactor for a given reaction, rather than personally mixing things in test tubes to find out how it all works.

Tying It All Together

So there we have it, chemical engineering can be applied in a fantastic number of industries but underneath all the stainless steel and pipework, it’s all based on the same building blocks.

I hope this article has helped shed some light on the world of chemical engineering and where it can lead. If you have any questions I’d be delighted to answer them.

Thanks for taking the time to read through, I’ll see you in the comments!

Robin

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