01 | What Do Chemical Engineers Do? (Some Intuition)
During the Industrial Revolution, the need for chemical engineers was born. The demand for valuable chemicals, such as soda ash, was rising every day. Soda ash, also known as sodium carbonate, is used to make glass and soften water. In order to meet increasing demand for chemicals, current processes and methods of production needed to be improved and optimized in order to increase output.
Before the Industrial Revolution, one of the main forms of production was batch processing. Let's assume that a factory needs to make 30 fully packaged boxes.
In order to fully package a box, it has to go through 3 stages.
Now, let's assume that the factory has divided each step into a processing stage and that the factory has 9 workers in total. Therefore, 3 workers work at each stage. Because this factory uses the batch processing method, all 30 boxes must be created before they can be sent off to the packing stage. Likewise, all boxes must be packed before they can be sent off to the sealing stage.
As seen in the figure above, it takes 1 minute to complete each step. Since there are 3 workers working at each stage, 3 boxes will be worked on at a time. Therefore, it takes 10 minutes to create all 30 boxes. Then, it takes another 10 minutes to pack all of those boxes. Finally, it takes another 10 minutes for all of those boxes to be sealed. Using the batch process, it takes 30 minutes for 9 workers to fully package 30 boxes. Is this fast? Is this slow? For many people, the batch processing method intuitively feels fast. However, let's compare it to a second method known as continuous processing.
In this process, the same 9 workers are still being used. However, this time one person creates the box, then immediately passes it on to the next person to be packed, and then on to the next person to be sealed. There are no batches. The production is continuous. Therefore, after 3 minutes, the first 3 boxes will created. Every minute after that results in another 3 boxes. As a result, all 30 boxes will be fully packaged in only 12 minutes! This reduces the amount of time to package all the boxes by 60%! Continuous production is faster and more efficient than batch processing. However, batch processing may result in a higher quality end product. Hopefully, this example gives you some more intuition on what a chemical engineer does. The birth of chemical engineering allowed for continuous processing to become common place in many chemical production facilities.
02 | How Did Chemical Engineering Start?
Unit operations were the origin of chemical engineering. Many sources attribute their discovery to George E. Davis. Previously, it was believed that all chemical facilities had their own unique processes for producing chemicals. On the contrary, Davis discovered that there was actually a fundamental set of “unit operations” that all facilities followed. A unit operation is a single process that a chemical undergoes.
An example of a unit operation is distillation. A chemical undergoes several unit operations before becoming an end product. Wikipedia cites the following as unit operations:
Davis wrote about these unit operations in the first chemical engineering book ever: the “Handbook of Chemical Engineering”. Interestingly, chemical engineering is one of the few disciplines with sustainability as a core belief:
I imagine that many students may be surprised by what I have said so far. Chemical engineering has always been about making processes and facilities function more efficiently. Contrary to popular belief, it is not about creating chemicals.
Around the 1960’s, chemical engineering became a lot more analytical as transport phenomena started to become a greater focus than unit operations. What is transport phenomena? In this particular case, the specific phenomena is energy, mass, and momentum.
Therefore, transport phenomena is the study of these three phenomena during movement. Examples of courses that discuss transport phenomena are heat transfer, fluid mechanics and mass transfer. Like other branches of engineering, chemical engineering became guided by the laws of physics.
Control Systems and Process Design
Afterwards, control systems and process design became a larger part of chemical engineering. Control systems are pieces of equipment designed to control a unit operation. As an example, let's look at a home heating system. The temperature drops below a certain threshold, it's picked up by a sensor, the furnace turns on, and the house heats up again. Similar devices may be used to regulate boiler and refrigerator temperatures in a chemical facility. In process design, chemical engineers combine their knowledge of unit operations, transport phenomena, and control systems in order to create a new process. Processes often involve taking raw material and turning them into an end product.
03 | What do chemical engineers study?
You should know by now that all engineering disciplines require a strong background in mathematics. Specifically, most engineering students will study calculus, differential equations, and linear algebra. Simply put, math is the language used to communicate engineering concepts.
Chemical Reaction and Separation Engineering
Chemical reaction engineering is the study of how to design the most optimal and efficient operating conditions for chemical processes in reactors. What is a chemical reactor? It's simply a device where chemical reactions take place. However, deep knowledge of reactors is required in order to make them produce high-quality chemicals on a consistent basis. Separation is all about taking a mixture and dividing it into the different components that make it up. But, did you know that there are probably 100's of ways of separating a mixture? It's up to chemical engineers to know when and how to apply different methods of separation.
Plant Design and Construction
This is what it sounds like, the design and construction of industrial plants. Many factors go into designing a plant that is safe, efficient, and abides by all required laws and standards.
Process Design and Analysis
This is what we talked a bit about before. This topic encompasses the design and analysis of processes that take raw material and transform it into an end product.
Transport Phenomena + Material and Energy Balances
Then there is transport phenomena (AKA - heat transfer, fluid mechanics and mass transfer). Heat transfer is the study of how thermal energy is transferred between things. Fluid mechanics is the study of liquids, gases, and plasmas in equilibrium and in motion. Like energy, mass cannot be created nor destroyed. Chemical engineers study how mass and energy are conserved, and transferred between different systems.
Materials engineering is a discipline in its own right; however, many chemical engineers do study a bit of material sciences.
Lastly, there is thermodynamics which is the study of heat and temperature as they are related to work and energy.
04 | What is the future of chemical engineering?
I'll go over some emerging fields that I think are an exciting part of chemical engineering.
On top of wind and solar energy, chemical engineers are also looking into the mainstream production of alternative sources of fuel such as biofuel. Biofuels consist of using agriculture or waste as a fuel source. Technically, this form of energy should be renewable. Here's an interesting video on Algae as a biofuel:
The second exciting field is chemical biomedical engineering. For example, let’s consider burn victims who, unfortunately, lose a lot of skin tissue during their trauma. Chemical biomedical engineers have learned to artificially create tissues in devices called “bioreactors”. This would allow burn victims to replace damaged tissue.
In my article about mechanical engineering, I mentioned that mechanical engineers were working on artificial limbs that patients could use to replace the ones they’ve lost. But, did you know that not just any material can be used for these limbs? The body is incompatible with certain materials. There is an area of study in chemical biomedical engineering known as biomaterials where different materials are studied in order to determine which ones are compatible with the human body.
Oil and Gas
Despite what you may hear in popular or social media, fossil fuels are not going away any time soon. It will remain the dominant source of fuel for many years to come. However, oil companies are facing a new challenge. All of the “easy” oil that was out there is starting to decline. The oil that remains in the Earth now is a lot harder to obtain. More advanced technology will be required to go deeper into the Earth and safely recover oil. As a result, this makes the process more expensive. Therefore, chemical engineers will play a large role in making oil refining facilities more efficient and thus cut costs.
Material Science (E.g - Carbon Fibre)
One of the next big material advances will likely be in carbon fibre reinforced polymers. Carbon fibre is stronger than steel (*under specific design conditions) yet it is much lighter. If it were used in cars, for example, it could make them "lighter, more fuel efficient, and safer." However, the costs of manufacturing carbon fibre are still much too high. It’s up to chemical engineers to help determine how to make this material cheaper to produce.
Computer Process Controls
Computer process controls involves combining electronics and computers in order to control processes. An example would be to implement a control system into a pipeline that can predict and prevent pipe leakage. This field is a hybrid of software, computer, and chemical engineering.
05 | Conclusion
That concludes my study of the chemical engineering discipline. I've presented to you some of the history, courses, and future that I came across while researching chemical engineering. It's up to you to make the decision for yourself.