Burn Biochar Burn — Disco Inferno

Having detailed our prototype and operations in the previous two blogs, we will provide a testing update this week! For easy access, our procedure for building our prototype can be found in this previous blog post and in this video. The clam chowder can mentioned in the previous blog was the perfect fit for our inner chamber as it created an airtight seal when placed inside the larger paint can. After finishing the drilling, we were able to complete our first prototype!

Pictures of the completed prototype. Things to note: the sealed fit between the two inner cans and that the bottom of the inner can will not touch the ground (allowing airflow through the bottom holes).
Last Thursday, we completed a preliminary test of our small-scale TLUD biochar kiln. Initially, we hoped to use the "husks'' that we received through a donation in the winter. However, based  on their appearance and chocolatey aroma, we suspected that the organization sent us the husks of the cocoa beans and not the pods. The initial attempt confirmed our suspicions, as the bean husks failed to ignite. As a result, we pivoted to wood chips, sticks, and leaves as feedstock, collecting them from around the PRL courtyard area. Here is a brief recap of our results, observations, and key takeaways! It was a huge moment of growth and learning for our team.

• Wood-based feedstock burned well, creating a flame through the hole in the tuna before fizzling out after approximately 10 minutes.
• The burn was not clean, creating odorous smoke.
• The tuna can on top burned, becoming dark gray and black by the end of the trial.
• After quenching the kiln with water, a small amount of black substance remained. We stored this product and will be investigating whether or not it is biochar through discussions with local biochar researchers in the coming weeks. Based on touch,  appearance, and comparison with images of Latifah's biochar, we are cautiously optimistic.
• Going forward, we plan to take a more scientific approach to the testing procedure, as we feel that we jumped into the process with inadequate forethought.
  • We just purchased a thermometer, scale, and lighter. This will allow us to systematically  carry out and document our trials. 
  • We are creating a data collection document in which we will record the mass of the feedstock, burn time, mass of the product, and internal temperature at various time intervals. 
  • With our cocoa husks from Ecuador arriving this week, we plan to retest the kiln with wood-based feedstock, as well as experimenting with the husks and corn cobs (for the Malawi project).
  • We want to consider indirect stakeholders more so will likely relocate our burns to a less trafficked area that still has access to running water for safety reasons. Or, we will use chalk and other signage to ensure that passersby are aware of our project and the dangers.

The sequence of our first burn! First picture shows us lighting the feedstock with a match, with a high density of dry leaves at the top to ensure the feedstock catches. Second picture shows the fire in action, and the third picture shows the final product.

Next Steps on our Sand Filter:
The team has identified two potential designs for our sand filter. Below are sketches of what we are envisioning:

The first design utilizes three different buckets, one with gravel, one with sand, and one with sand, gravel and biochar. We have made a plan to acquire materials and hope to make a trip to Home Depot by the time this blog is submitted. We will also consult with teaching team member Emily Wong since she worked on a similar filtration mechanism last year. ​