ChemEd 2019

I just returned from ChemEd 2019 and I could not be happier. I had a four hour drive to think about the conference and about teaching. The complexity involved in teaching is overwhelming at times. But as I improve in teaching the complexity becomes such a joy and conferences are a huge source of that emotion. Being around some of the best chemistry teachers in the world is so intellectually stimulating to me.

Teaching is complicated. You have to understand some information, deliver that information to a novice learner and work towards their brain changing in a meaningful manner. Their brains will filter much of that information and that which does arrive successfully runs the risk of becoming forgotten. Racism, sexism and other power structures can affect both the delivery and reception of that information. Emotion and the amygdala can also interfere. Between the cognitive science and the sociology there lies chemistry. Chemistry is a beautiful subject to teach, but it is also incredibly complex. So teaching is the intersection of all of these things. A teacher has to be able to account for all of them with a collection of students that vary considerably in their initial understandings and knowledge that they can use to make new connections. There is no limit to how far you can push your cognitive limits as a teacher.

So I feel that as my preparation and experience improves, I am getting to a point where I can effectively navigate all of these. But it’s hard. And the many cycles of preparation, teaching and reflection are needed to become masterful at teaching. The ChemEd 2019 conference had so many teachers that were brilliant. To just watch them teach us was amazing. It felt like the concept from the book “Inner Game of Tennis.” My system 1 was just learning without my conscious mind interfering. But in addition to the teaching technique, there was also an abundance of creativity. An artistry or uniqueness that I loved watching and dissecting. 

My favorite part of teaching is this vast combination of cognitively demanding tasks that all require improvement. I think that teaching is the ultimate cognitively demanding profession and we talk about this too infrequently. I appreciate the sheer difficulty of doing this well and so I am incredibly happy when I get to observe someone doing this at such a high level. I find it so impressive when someone can combine so many tasks but also add in creativity. Being able to reflect and critique things afterwards with a group of teachers is the best. I also feel that the presentations have changed in the last few years. The level of elite teaching has stretched so high and I wonder if it would be fruitful to consider intentionally pushing for a localized arrangement of elite teachers to see what could be accomplished. I wonder what we could do if we intentionally arranged a cohort of teachers and gave them a working environment that was modeled after a conference like this. 

Sometimes when we teach we repeat things so frequently that complicated concepts become algorithmic and automatic. Some refer to this as saying I learn the best by teaching. But as we shift teaching into responding towards initial student models the cognitive demand becomes so much higher on teachers. It’s not just a transfer to long term memory of phrasing or algorithms. It is that deep thinking that is challenging and rewarding. And that means that the intellectual stimulation also rises with it. And I love it. I know that many avoid recommending the teaching profession, but I can’t think of a better job. There is nothing that I could do that push my thinking more than teaching does. And some of the new educational pedagogy provides such an opportunity to push yourself in ways that have not existed before. To me, the conference felt like I was surrounded by people who derived the same joy that I felt. I hope to be back at one soon.

Grass Clippings Biochar experiment

Today I tried an experiment with grass clippings where I heated the grass in a covered pot to convert the clippings into charcoal. This conversion is called biochar. The idea is that by turning the carbon in the organic material into charcoal the charcoal can be buried and prevented from gradually turning into carbon dioxide or methane. 

Figure 1: 1.8 (+/- 0.2) pounds of Dried out grass in a 5 gallon steel pot

My initial test run involved leaving the grass clippings in a pile in the yard for a week. This dried them out which removes water from the grass. I assume this will lead to more efficient and effective conversion into charcoal. I think that this also allows me to produce more charcoal as I get more organic material into the pot. It did not rain for about a week, so the grass was very dry. I forgot to take an initial photo, so Figure 1 is actually a refill after I ran my initial sample.

Figure 2: Grass clippings being converted into charcoal by heating with limited oxygen

You can use charcoal to heat the grass, but that probably eliminates the whole point of carbon capture. I picked up sticks in the yard and after a week I had enough to make a reasonable fire. The sticks will eventually turn into carbon dioxide anyways. It would be best if I could cover the fire a bit more to limit thermal energy that does not move into the pot. 

Figure 3: Grass clippings after an hour of burning

After about an hour I peeked inside. There was charcoal, but it was mostly at the bottom. I stirred the mixture a bit to try and move the grass to the bottom. At this point there was an odor coming from the pot that started to get worse. 

Figure 4: Grass clippings after about 4 hours

I did not have to continue heating much because the hot coals were effective for a while. I think that the grass converting to charcoal also produced some thermal energy increases that continued the process. 

Figure 5: Bury the charcoal in the ground

Once the grass has been converted to charcoal you can bury it. If you bury grass clippings they will decompose and turn into methane and carbon dioxide. But charcoal should remain as charcoal for quite some time. 

I ended up with 1.2 (+/- 0.2) pounds of coal. My son was mildly excited that we managed to do a real life Minecraft experiment as well. The beauty of biochar is that you’re using the grass to absorb carbon dioxide from the air and then sequestering the carbon as coal. If you mow and let the clippings sit on the lawn, the grass will decompose into carbon dioxide. If you use clippings in a compost pile the clippings will also degrade. The conversion to charcoal is the key to a more permanent removal. 

Some potential flaws are that burning fuel to capture the carbon is counterproductive. I went with sticks to avoid this. But I also bought the pot and the production of the pot and shipping probably contributed more carbon emissions than I saved. The biggest problem is that this needs to be scaled up a bit to really be effective.

Inspiration for trying this came from the book "Whole Earth Discipline" and this blog post https://www.instructables.com/id/Capture-CO2-with-Lawn-Trimmings/