Effectiveness of Rice Husk-Activated Carbon and Case Type in Microbial Fuel Cells

In this study, rice husks were used as the anode material for microbial fuel cells (MFCs). Rice husks are crop waste that is commonly discarded or incinerated, resulting in the production and pollution of large amounts of waste. Therefore, we thought that it would be possible to produce activated carbon from rice husks at a lower cost and using it in MFCs. Rice husk-activated carbon was made by carbonizing rice husks, removing silica, and treating at high temperatures. These have realized a porous structure. This rice husk-activated carbon was wrapped in a stainless mesh to serve as an anode electrode, and an activated carbon sheet was used for the cathode to create an MFC. The open-circuit voltage of this MFC was measured once an hour and waited for it to stabilize, but the unstable state continued. We focused on the connection between rice husk-activated carbon and stainless mesh. Therefore, the MFC shape was reconstructed by making an MFC case with a 3D printer that can press the stainless mesh with rice husks from above and below at the anode part. The MFC has a stable open-circuit voltage and a power density that has increased about five times. From this, the effectiveness of the rice husk-activated carbon and the MFC case was confirmed in the MFC.