Producing, Characterizing and Quantifying Biochar in the Woods Using Portable Flame Cap Kilns

We're looking for solutions to the problem of woody debris, incineration, and forestry. We hope to develop methods for making biochar on site using simple technologies that are cost effective and quantifiable for determining carbon sequestration value. New technologies are being developed to make biochar in places where biomass accumulates to avoid high transportation costs.

These technologies include mechanized air curtain burners, and simple containers that are fed by hand labor or by machine. These techniques work on the principle of flame carbonization. To pay the cost of making biochar, we can apply for carbon removal credits, but quantifying the amount of biochar made under field conditions is challenging.

We need appropriate carbon accounting protocols and methods for monitoring, reporting, and verification. Methods for quantifying biochar production in the field using simple techniques have not been well-developed. This protocol provides the first steps toward robust and repeatable measurement techniques.

Our carbon accounting protocol for field verification of biochar production provides detailed information that is verified with visual evidence obtained throughout the production process. Other existing protocols have fewer controls and rely more on estimates and safety factors. Our protocol maximizes benefits for those who are doing the work.

To begin, select and note down the size of the feedstock. Choose would material less than 15 centimeters in diameter. Launch the DMRV application and click the Take A Photo button under the Feedstock section to activate the camera.

Carefully align the camera to capture the subject and click the shutter button on the display. To measure the largest piece of each feedstock type, use a firewood moisture meter to pierce the middle with its pins. Afterward, go to the DMRV application and select the Take A Photo button under the moisture meter section.

Input the value displayed from the moisture meter reading into the provided text field. Clear flammable organic material from a three-meter diameter circle on level ground. Assembled the six inner kiln panels into a cylinder using the connector brackets, and use a shovel to seal the bottom edge of the cylinder with a small berm made of mineral, dirt, or clay.

Then, attach the six heat shield panels to the connector brackets. Securely attach the kiln ID tag to the heat shield using the heat shield hardware. Identify the kilns used in the batch.

Then go to the burn preparation section and use the Take A Photo feature to capture images of the assembled kiln and its attached ID tag. Now identify smaller, dry material for the initial kiln loading. Carefully pack this material up to the brim of the kiln, saving any larger diameter material for after the first hour of the burn.

Add small, dry kindling material to the top of the loaded kiln. Use an accelerant, if necessary, and light the top of the kiln in multiple places using a match or fire starter. Once the flame cap is established, navigate to the Burn Start section of the DMRV application.

Click the Take Photo button, followed by the Submit Photo button to capture a photo. Begin by loading and lighting the kiln. Ensure the first load generates a solid bed of coals before adding more material.

Once the previous layer starts to display a film of white ash, load new material in the kiln at a steady rate. Monitor the flame closely as it guides the addition of new material, and always maintain a robust flame on top. One hour after the kiln ignition, launch the DMRV application.

Proceed to the burn quality proof section and choose the Proof Of Burn At First Hour button. Select the Take Video option and record the video for at least 30 seconds. Then, click the Submit Video button.

Place the largest material during the mid stages of the burn to ensure it chars completely. After the second hour of burning, record a 30-second video of the flame by clicking the proof of burn at second hour using the DMRV application, and submit it as shown previously. Similarly, at the end of the third hour of the burn, click the proof of burn at third hour on the application, and initiate a 30-second video of the flame.

In the final stages, when the kiln is filled with red hot glowing coals, arrange the last few layers with medium sized material to allow larger pieces to complete their charring process. To start, load and ignite the kiln and let it burn until it's filled with glowing red coals. Once the biochar reaches 10 to 20 centimeters from the top, stop burning the kiln.

Let the flame die down for 10 to 15 minutes after adding the last feed stock. Position a measuring stick vertically against the kiln wall, ensuring one end contacts the level char. In the DMRV application, navigate to the Measuring The Biochar section, and click the Take A Photo button to illustrate the char's depth inside the kiln.

Next, locate the text input field labeled, What is the reading from the top of the biochar to the top of kiln, and enter the corresponding value indicated on the measuring stick. Repeat the measurement and photo recording two times at varied kiln locations by clicking the Submit And Add Another Photo button. After the char depth measurements have been reported, capture an image of the kiln ID tag for proof.

Upon completion of the biochar batch, shovel hot glowing coals from the kiln into a metal bucket before initiating the quenching process. After determining the tear weight, use the hanging scale to get the weight of the coals and take a picture to record the weight. Gently spray water into the kiln until the heat shield is touchable.

Remove all the heat shield panels and stack them away from the workspace. While spraying water, remove a few kiln panels and disperse the char into a thin layer to trigger cooling. Remove any partially charred pieces and arrange them on one of the kiln panels in a single layer with the measuring stick laid alongside.

Using the DMRV application, take a picture of the incomplete charred pieces.