Carbon Emissions to Energy; Project CARBON ZERO
As many people know, the Earth has been changing because of the human impact. Sea levels are rising, ice caps are melting, temperatures are rising, and countries are experiencing extreme weathers that have never happened before. This is all because of climate change, and more specifically, global warming. The main cause of global warming is the enormous amounts of carbon dioxide that humans emit. Each year, an average of 36 billion tons of carbon dioxide is expelled into the air, most which is produced by humans through agriculture, factories, and cars.
Today, people are attempting to reduce their carbon footprint as much as possible by carpooling, using “green energy”, reducing wasted energy, and switching to electric cars. Yes this could help the environment, but only on such a small scale because we still have millions of people producing carbon dioxide in some way. Even if the ENTIRE WORLD switched to electric only, the amount of carbon dioxide produced would still be high on the account that it takes thousands of factories to produce everyday products.
So if going electric doesn’t work, then what can?
That’s where carbon capture comes into play. Carbon capture is the process of capturing carbon dioxide from the atmosphere and transporting it to an area where it cannot enter the atmosphere again. Examples of technology like this are Net Power, Quest, and Climeworks, where each have their own system of intaking carbon dioxide, filtering it from the rest of the air, and putting it back into the ground.
By putting carbon dioxide into the ground, companies and big factories would still use fossil fuels because we can just store it underground and won’t have any consequences to using fossil fuels. With storing carbon dioxide underground, it takes a lot more power and materials to build facilities that can intake the carbon dioxide and to drill giant holes in the ground to store it, making this method very inefficient, and .
What is a better solution than keeping the carbon dioxide out of sight, out of mind?
Nowadays we are pushing towards using electric energy as a power source, whether it be through solar power, geothermal energy, or wind. But all of those have their limits. We don’t have access to the sun 24 hours a day, geothermal energy can only last so long, and wind can only produce energy when there is wind blowing.
But what if we used the one thing that is causing our downfall to our advantage?
Let’s take a trip down memory lane and go to our middle school science class where we learned about photosynthesis. Photosynthesis is the process where plants use light energy, carbon dioxide, and water into glucose and oxygen.
Leaves are the powerhouses of photosynthesis. If we zoom into a leaf, we can see that there are multiple layers that make up the leaf, but the most important layer to look at is the middle layer of leaf tissue called the mesophyll. Mesophyll is the part of the leaf where photosynthesis mainly happens.
For carbon dioxide to get into the leaf, small pores called stomata allow carbon dioxide to diffuse into the mesophyll layer.
Every mesophyll cell contains chloroplasts to carry out the reactions of photosynthesis.
Within the chloroplasts, structures with the shape of discs called thylakoids are used to absorb light energy to use for photosynthesis.
All these parts contribute to the two reactions that happen during photosynthesis, light dependent reactions, and the Calvin Cycle.
Light-Dependent Reactions
Light-dependent reactions occur in the thylakoid membrane, where there is a continuous supply of light energy. This energy is absorbed in chlorophylls to be converted into chemical energy through forming two compounds; ATP (Adenosine Triphosphate)-a molecule that stores energy, and NADPH (Nicotinamide adenine dinucleotide phosphate)-a reduced electron carrier. The outcome of light-dependent reactions is to separate the water molecules into hydrogen and oxygen using the sun’s energy.
Breakdown:
- Water and light energy is brought into a chloroplast
- Light energy is used to excite the water molecules, separating H2O into 2H and O.
- From this reaction called non-cyclic photophosphorylation, electrons are lost from the water molecule and passed through photosystems (P680 and P700 on the diagram) to be received by NADPH to create NADPH+.
- The NADPH+ and the ATPs that are created from the transfer of electrons are then used in the Calvin Cycle to create glucose.
Calvin Cycle
The Calvin Cycle takes place in the stroma, the liquid that fills a chloroplast. The Calvin Cycle uses the energy from the ATPs and NADPH+ from the previous reaction to fix carbon dioxide with the leftover hydrogens to create three-carbon sugars — glyceraldehyde-3-phosphate, or G3P, molecules — which join to form glucose.
A G3P molecule contains three fixed carbon atoms, so it takes two G3Ps to build a six-carbon glucose molecule. It would take six turns of the cycle, or 6 CO2, 18 ATP, and 12 NADPH, to produce one molecule of glucose.
So what does this have to do with anything?
For the past couple of years, many organizations have been created to plant as many trees as possible to stop global warming. Trees are one of the biggest consumers of carbon dioxide, and so if we plant enough trees, that could solve all our problems right?
Not really. On average, 25% of all carbon dioxide in the atmosphere is absorbed by plants, and another 25% is absorbed by the ocean. That leaves 50%, or 21.5 billion tons of carbon dioxide in the atmosphere from one year alone.
My team’s idea is to build a machine that can recreate photosynthesis to artificially to intake large amounts of carbon dioxide and produce electricity and water.
For this plan to work, there are a couple things to consider:
- How do we intake carbon dioxide
- How do we split water molecules?
- How do we combine the hydrogen with carbon dioxide?
- How do we get electricity from glucose and oxygen?
Over the past 60 years, research for artificial photosynthesis has been on the rise, creating newer and more efficient ways to convert carbon dioxide and water into glucose and oxygen. There are hundreds of different catalysts, water splitting techniques, and carbon dioxide combiners and absorbers to recreate photosynthesis.
For our version of artificial photosynthesis, it will go through four stages, similar to that of a plant.
- CO2 Capture from Air
- Photocatalytic Water Splitting
- Synthesizing Glucose
- Converting Glucose to Energy
CO2 Capture from Air
In our product, we use a giant fan that will push carbon dioxide from the air into a filter, where any dust particles will be removed. The carbon dioxide is then held in place while waiting for the water splitting to be done.
Photocatalytic Water Splitting
Most water splitting is done through electrolysis, where expensive metals are used as electrodes to push vast amounts of electricity into water to be split. To avoid using costly materials and large amounts of expensive metals, we are to recreate an artificial leaf made by Professor Daniel Nocera, which uses silicon strips and inexpensive metallic compounds to split water into hydrogen and oxygen. This process uses sunlight to excite the metallic catalysts, and to compensate for the sunlight lost at night, we will use solar powered lights that turn on at night to continue the process. Water will be collected through filtered rain water and will be connected to water pipes in buildings. The oxygen and hydrogen are then separated into two different tubes, the hydrogen leaving to join with the carbon dioxide, and the oxygen to be stored for later.
Synthesizing Glucose
Finishing off the artificial photosynthesis cycle, carbon dioxide and hydrogen are combined to create glucose and left over oxygen.
Converting Glucose to Energy
The glucose and oxygen are transferred over to another chamber, where anodes and cathodes are placed to intake the electricity created when the glucose is oxidized with the combination of special enzymes.
In theory, one glucose unit (C6H12O6) and some water would produce 24 electrons, which creates roughly 0.5 Volts of electricity. One ton of carbon dioxide would roughly create 310,000 Volts of electricity. To create an impact, we would need to create machines big enough to help mitigate and eventually start to decrease the amount of carbon emissions in the atmosphere.
So will climate change be solved with this one machine?
In order to intake 43 billion tons of carbon dioxide, the machine would have to be powered by a couple billion tons of water and electricity. And that’s not going to be likely anytime soon. But what it we COULD do is create hundreds of smaller machines, and start planting them in cities and factories that produce high amounts of carbon emissions. If we were to put enough machines in a heavily polluted city, we could possibly see major changes in the environment. But that’s all in the future. Who knows what could happen?
Pssstt…
Hey there! If this is your first time reading my articles, my name is Emina Awan and I’m a 15 y/o innovator working on cool projects in robotics, cars, AI, and much more!
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