Mo’ Carbon, Mo’ Problems
Tanay N -
Hey everybody! Although this past week has been riddled with challenges, we’ve found solutions, and carbon capture keeps on!
Challenges
One of the biggest challenges was the air pump. It simply stopped working, so I had to take it apart. After many attempts to re-circuit it, I eventually just ended up going to Walmart and buying a new one.
Additionally, my air tubing was initially 6 feet long, which was quite hard to handle, so I had to cut it down to only 2 feet. Furthermore, since this was the week I would start running tests in Ms. Holtzman’s classroom, I wanted to have the design fully ready for all the tests I would conduct in the future, so I sawed-in another hole on the opposite side of the unit to provide some sort of an air current. This actually ended up to an adjacent slice at the bottom of the box opening up. Fortunately, I just used this extra hole at the bottom to feed the pump and fan wires through. The below image is during the process of adding in extra holes. I also plan on making it more “aesthetically-pleasing” (painting) but will have to see if I have enough time at the end.
Success!
Putting the Calcium hydroxide powder into Lemon and seeing the CO2 bubble through the water was probably the highlight of my week. All of my work for the past month had finally come to fruition, and let me tell you, it felt really good! All “babies” need constant monitoring, so this resulted in me coming back after my 8th hour band class to make sure Lemon was running smoothly. The below images are of the final, functioning setup.
Potential Dangers and Toxicity
The hurdles don’t stop there! As you see in the above photo, the cream cheese containers are floating in the water, which means a slight disturbance to the box and they could topple, causing the Calcium hydroxide to spill into the water. This is quite dangerous, as Calcium hydroxide is a strong base, meaning the water can become corrosive and very irritating. Calcium hydroxide powder is still considered toxic/irritating, which is why I will be wearing a mask, goggles, and gloves, but is comparatively much easier to handle in powder form. If it does mix with the water, we will have to neutralize it before pouring it down the drain, which involves a strong acid such as Hydrochloric acid. You can probably see from this how the problems can exponentially grow. However, with proper laboratory techniques, I am confident that this will all run smoothly.
The Science!
As promised in the previous blog post, I will explain more of the Ion-Exchange Resins in regard to Moisture-Swing Technology in this post.
To refresh your memory, these are specifically amine-based ion-exchange resins (AERs) that can grab CO₂ when the air is dry and then release it when exposed to moisture—moisture-swing adsorption. This unique “trick” relies on tiny chemical groups (quaternary ammonium) that react with CO₂ and water in a reversible cycle.
From the papers I read thanks to the guidance of Ms. Holtzman, I found that researchers tested two types of these resins: a single-quaternary ammonium version (SQ-AER) and a double-quaternary ammonium version (DQ-AER). A common quaternary ammonium ion looks like this: N⁺(CH₃)₄. This just means that instead of NH4, the hydrogen groups are replaced by methyl groups (CH3). Here, nitrogen is bonded to four methyl (-CH₃) groups, making it a stable, charged molecule.
In the research paper, the DQ-AER turned out to be much better, capturing nearly twice as much CO₂ as the single-quaternary type. It also worked well over multiple cycles, showing great potential for long-term use. DQ-AER showed higher CO₂ capture capacity (3.41 mmol/g) than SQ-AER due to increased quaternary ammonium content (this increases surface area in the active site of the reaction).
Now, the DQ-AER and the SQ-AER are technically called Diamine-DQ-AER and Diamine-SQ-AER. The Diamine-DQ-AER is also modified with tertiary diamines. The below pictures explain amines, diamines, tertiary diamines, and Quaternary Ammonium w/ tertiary diamines, which is our Diamine-DQ-AER from the research.
I’ll go more into exactly how quaternary ammonium is created in a future blog post, as well as other Ion-Exchange Resins. Once again, I’m very grateful for Ms. Holtzman’s constant support in terms of running Lemon safely, helping me find information on topics like Ion-Exchange Resins, and guiding me through each challenge that arises. I’ll keep you all updated with the results of the first Lemon run, and I appreciate you all tuning in every week! I hope you join me in the next blog post! 🙂
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