# Sorbent #2 Prep

**Note:** This is essentially the same as Sorbent #1 Prep, but I've added the rinsing step.

**Second Note:** For more effective carbon capture, you would want to use hydroxide as your ion because of its ability to capture twice the amount of CO2 compared to carbonate. But, as I am doing this in a kitchen, I am using sodium carbonate because it's a bit safer than the highly alkaline sodium hydroxide. That being said, if you have the proper safety equipment to handle strong chemicals, feel free to follow these steps using a 1.0 molar concentration solution instead of the 0.5 molar sodium carbonate solution.

We need to "wash" and prep the sorbent because it's not ready for carbon capture directly from the factory. Fresh from the factory, the ion resin has chloride ions attached to the quaternary ammonium functional group. We need to exchange these chloride ions for carbonate or hydroxide ions. We can do this by placing the resin into a bath of either sodium carbonate or sodium hydroxide.

**Prep summary:**

First, you need to soak the ion resin in hot water for 48 hours to allow the pores to open up. Second, you need to soak the ion resin in chemical bath for 2 hours, then take it out, rinse it, and put it into a new, fresh bath. Lastly, you need to repeat the last step 5 more times, and dry it, and you're done!

**Step #1:** Gather all the necessary "ingredients":

* Sodium carbonate (at least 15g, 2.15g per wash and do NOT buy sodium bicarbonate)
* Distilled or deionized water (distilled water is $2 at Stop and Shop). You will need at least a liter of it, as you need 50mL per wash (so 300mL), and a little extra just in case.
* Ion exchange resin: <https://dws.octochemstore.com/product/amberlite-ira900-cl/> (other types should work, this is just the type I used)

**Step #2:** Gather all the necessary supplies/tools (look in the materials section for more information):

* High resolution scale
* Work area (I used a cookie sheet!)
* Beakers
* Stirring implement, like a popsicle stick
* Measuring implement
* Goggles (for the carbonate)
* Gloves (for the resin and the carbonate)
* Nut milk bag or specialized resin bag (I went the dumb way and used non-woven polyester to contain the resin). This bag has to be able to let water through, but not let the tiny, tiny little resin beads out.&#x20;
* Slow cooker or lab hotplate

**Step #3:** Follow the procedure and do some science(!):

* Put 5 grams of the resin in bag
* Fill a small beaker to the top with distilled water
* Place resin bag into beaker
* Place beaker into the slow cooker, and make sure the beaker is fully surrounded by water
* Turn slow cooker on for 48 hours, set to low, to maintain a temperature around 85 degrees Celsius
* Near the 48 hour mark, start preparing the 0.5 molar sodium carbonate solution by dissolving 2.15g of sodium carbonate in 50mL of distilled water. You are welcome to create a larger bath of sodium carbonate, I just did this to use the least number of materials.
* After 48 hours, take out the bag and rinse it with distilled water
* Immediately after rinsing it, put it into the 0.5 M solution
* 2 hours after putting the bag in the solution, take out the bag, and dump out the old solution
* Rinse the resin with distilled water
* Prepare a new solution by following the same steps
* Put bag in new solution
* Repeat last 4 steps 6-7 times to fully replace chloride ions with carbonate ions
* Let dry for 24 hours before testing

**Step #4:** Celebrate!

You've successfully created a CO2 absorbent! Now, you can put it into one of the test chambers and see if it works. But before you do that, you might want to run a fan over the sorbent to saturate it with CO2.

**How I could have done this better:**

After my results were sub-par (see Tests section), I read The Study again to see if I did anything differently from the study. And it turns out, I did. The researchers agitated the resin in the carbonate solution by presumably using a magnetic stirrer. Since I don't have one of those, **this project will be on hiatus** until I can get my hands on a stirring mechanism. I might be able to get funding to buy one, as the ones on the lower end of the price scale are \~$100. In the mean time, I will focus on documenting the process in-depth and writing some papers.

Furthermore, my results might be deterring because of the usage of the sodium carbonate bath, instead of the sodium hydroxide bath. This link shows some more information on that matter: <https://www.openairforum.org/t/potential-alternative-salts/67/3>. It could also be because I used a 0.5 M sodium carbonate solution. Maybe a 1.0 M sodium carbonate solution would perform better.&#x20;

Next, my ion exchange resin might be inadequate. I could not get my hands on the ion exchange resin that The Study used, so this might be the root of the problems. I basically just chose the cheapest one that they had, as I have no training in ion resin.&#x20;

Lastly, I still have yet to find a better way to hold the resin, as I lost a significant amount of resin in this process, probably near about 75% lossage of resin.
