Thanks to our existence, all sorts of energy have been put into great use in one way or the other. Even before the beginning of evolutionary science era, energy has been that irreplaceable part of life. Could the earth have been habitable for living organisms if there is no presence of energy? Yes! You are right to have responded with “No”. Our day to day activities make use of energy and in the process, transform it from one form to another.
Energy gets transformed from one point to another. As I am making this post, a girl sitting beside me is in a potential energy and if I decide to give her a dirty slap to the extent that she lands on the floor, she has changed from being in potential energy to be in kinetic energy as she moves. I’m not wicked, it’s just that simple.
Source: Pixabay (Public domain - CCO licensed)
Well, to get the best use of this energy, it needs to be efficiently managed. Yes! Conserved. But this conservation is not about energy alone, it is about all form of matter in general. There is a phenomenal responsible for this conservation to take place efficiently. We are coming to that.
One thing we need to understand when conservation of energy is concerned is that energy conservation is totally different from conservation of energy. I know how that sounds, really. I understand that those of us in language fields would feel otherwise. Okay for instance, we take Lagos University as University of Lagos which make us think that we can refer to conservation of energy as energy conservation but the two cannot be any more different.
Steady state
When you conserve something, you save it. Probably for future use or something, you just save it without making use of it at that moment. It is the same with energy and other form of matter. But conservation of energy means energy changing from one form to another.
In general, the law of conservation states that:
Matter (could be energy) can neither be created nor destroyed but can change from one form to another.
But then, the law of conservation works alongside something we call steady state. The law of conservation ensures that the amount of input entity is always equal to that of the output regardless of which form the output is. Let’s say you are a goldsmith who uses iron ores as raw materials to get beautiful jewelries as output. As you continue to pour in a certain amount of this raw materials, that is your iron ores, you get exactly equal amount of jewelries coming out as the output regardless of the shape or design the system transform the ingredients to and at this time, you have what is called a steady state. When a system is in a steady state, the variables at input and output remain constant despite what is happening inside the system.
How about we take a look at this in a general phenomenal? Something that every reader of this post do come across (well, unless you are an alien or something worse and if you are, get off my post now!). Think of water closet sink in the toilet in your home.
Have you ever wondered why the water does not decrease or increase inside the potty sink that you sit on when defecating even you continue pass I water through the water supply? That is a real life example of how the law of conservation works alongside steady state. An equal amount of water that get passed into the system gets passed out through the designated passage way. I as much as the sink (which acts like a box or system here) is perfectly efficient, the water will neither surpass the level designed by the manufacturer of his sink.
Source: Pixabay (Public domain - CCO licensed)
I guess it is time we look at this from engineering point of view. Think of your system in question as an indestructible (or unhackable, if that pleases you) box that has been isolated from every other entity in its surrounding. It may be an engineered box that generates electricity or something else like a system that generates some other usable output. Whatever the work that is going on within this box is the reason why it is created in the first place and you know, the engineer that created this magic box wants to use every means possible to ensure that its work is efficient. To do this, the law of conservation is impacted upon this.
And we can use this law to figure out where our box can be and to operate efficiently. Our box is what engineers call a System. What is happening inside is what we call process. Everything beyond the box is known as the Surrounding. As you are running a smith system that converts iron ore or other ingredients to jewelries, you know you are running a very expensive enterprise. So, if there is something inefficient about how it works, you are going to want to know about it and fix it.
Ideally, what you have fixed in a system in the beginning is what you get at the end. Input equals output. If your box is perfectly efficient, that law of conservation tells you that the amount of steel you get at the end should weigh exactly as the ingredients you put.
So if you have a 100kg of iron and other ingredients go into your box every hour steel is coming out. You know that you are not going to get a 105kg of steel because you can’t create 5kg of matter from nowhere and you can’t have 95kg at the end either. Because everything you put into this perfect version of the box is being turned into steel and 5kg of mater can’t just disappear.
Using the law of conservation in getting perfectly efficient systems
While engineers’ main target is getting a perfectly efficient system, it turns out that they deal with systems that way more complex and this complexity is the main challenge that stands in engineers’ way of getting perfectly efficient systems. But the thing is we use the law of conservation to get systems as to perfect as possible. In other word, to get as much output from your input, as you can.
Let’s use the idea of ice block making machine here. Okay, the materials we need include a bottle (which serves as our system), some water (input), refrigerator (surrounding) and ice block itself which is the output. Like most other process, we use this system to make what we want – ice block.
One other thing to note is that most processes leave byproducts behind as they give us our desired output. To get your expected end product of ice block, unneeded drop of water and other. When coal is concerned, byproducts released by this system include ash, Nitrogen Oxide and Sulphure Oxide.
Conversion
Now, so clearly, all form of processes have a clear room for improvements. Engineers define problems like this I terms of conversion.
Conversion describes how much of our initial input was used in the process.
If all system has a conversion rate of less than 100%, it means we have some leftovers or waste. Either way, we get out end products. Let’s go back to our jewelry making. When iron ores and other ingredients of 100kg go in at a 60% conversion rate, then we have 40kg of iron left over in the process. That is a little waste of iron. This defines how much of the final product we are able to get from the initial input. In a situation where your system has a 30% yell a 100kg of the ingredients will get you 30kg of jewelry and 70kg of waste.
System balance
Another way to think about systems is in terms of balance. Engineers measure the values that go I and the values that cm out and if there is a difference they will try to figure it out. The conversion in yield only covers from the beginning and end of the process.
Accumulation
Engineering like life is usually not that simple. If you have a system that is not in a steady state, then you probably do not have the same amount of system coming in and out. Engineers use accumulation to keep track of the differences between what’s coming in and what’s going out. The basic idea of this is pretty simple. If you subtract your output from your input, you get your accumulation. If you are measuring all these in terms of mass, that simply equation is all you need. Mass goes in and whatever mass that doesn’t come out in the end is stocked in the system.
But when chemical reaction is happening inside the system (which often happens), it is more useful think about accumulation in terms of molecule. In the process, your raw material might go into some chemical reaction. They generate some molecules that don’t end in end products. Or a reaction must have consumed some molecules hiding around inside the system at one part of input.
To keep track of where all your molecules are (which are the ones accumulating inside the system), you need two more terms. These are generation and consumption. To calculate accumulation, you take the input and subtract the output as usual but then you also add the molecules that have been generated inside the chemical reactions and subtract any molecule that is being consumed. What is left over is what your accumulation is inside the system. This equation is essential in engineering. Even in its simplest form, engineers can use this equation to figure out how to improve the system. Now let’s see how it can improve ours.
System recycling
In our system are raw materials (iron ore or other ingredients) flowing in and jewelries flowing out as end product. Our goal as engineer is to make as much output as possible at the end of the process. Let’s say we begin with 100kg of iron ores with a 70% conversion rate which mean we are only making 70% of the possible output which equal 70kg of jewelries. That is not bad but not great at the same time. We will be losing out 30kg of raw materials and that could cost us a great amount of money especially when our ingredients consist of expensive material like gold silver or diamond. This is where we need a problem solving approach as an engineer and figure out how to make the process better. How about recycling the system?
We can introduce a separator into the system. This will be sorting out any leftover hiding within system and get these raw materials back into the beginning stage of the process in order to use them to get our desired end product. Remember we already got 70kg end product from our previous process. Now let’s send the remaining 30kg worth of materials that the separator brought out to the system with the new 100kg worth of raw material we intend to use in the second process. That leaves us with 130kg material going into our system.
Even if we only get 70% conversion rate for this new process, we will be having 91kg of end product this time and that gives us extra 21kg of end product thank to the separator and our recycling system in general. Although we still have 29kg of ingredient as leftover I the system, this will be reused again and again and again and of course, we get better and higher amount of output due to this great technique.
Source: Pixabay (Public domain - CCO licensed)
Well, this technique seems great but it I still not as good as we would have wanted it to be. But have thought of the contaminations that may come along with our leftovers that are being brought out the separator? In the case of jewelry making we might have not thought of this, but how about our first example, ice block making? Would the leftover water that could get iced be totally ideal to be reused directly? Or maybe if we use a more ideal situation – that of soft drinks processing system, we would get the stuff.
These contaminations that may come along with our leftovers need to be getting rid of and to get that done, we may need a purge system. Remember, just because we are following the law of conservation or any other principles of engineering does not mean everything is working out the way we want. As engineers, we encounter limitations like this and many of this and well we can walk around them. After all, engineering is all about testing our limits and getting past them as far as we can until we get things that are truly extraordinary.