Peeva Y. and Werff. E

Ethacell — An Enzymatic Fuel Cell Concept Project

Our project’s goal was to develop a prototype of an engine, which would be sustainable, effective, and biomimetic*. The solution we came up with is an enzymatic fuel cell. Enzymatic fuel cells (EFCs) exist, but are currently in development and are quite inefficient. However, through utilizing several innovations in nano-materials and energy storage, we improved most of the parameters on our theoretical project, Ethacell. The improvements we introduced are elongating the life-span of enzymes in the fuel cell from a couple of days to as long as an year, enabling an enzymatic cascade which makes the oxidation-reaction of the fuel more efficient, and reusing the waste product of the chemical reaction in the cell.

Ethacell is a two-chamber fuel cell, which produces electric current through an alcohol (more specifically bioethanol) oxidation reaction, similar to the one occurring in the human liver. The first chamber of the fuel cell is directly connected to the anode of the electric circuit and in this chamber the fuel is oxidized. This reaction is an enzymatic cascade, which produces as many as 3 H⁺ in a single cycle. In the second chamber occurs the reduction reaction of oxygen from the air, which is needed to attract the hydrogen cations from the anode to the cathode. This movement of hydrogen cations is what enables an electric current to flow through the circuit. This first version of Ethacell is not powerful enough to directly power a vehicle, so the energy produced by the fuel cell is stored in a capsule of algae-cellulose batteries, which are constantly recharged and power the drive. The waste products of the two chemical reactions are acetate and water, which are stored in an external (to the fuel cell) container and can later be reused for medical, commercial and industrial products. The acetate produced is completely clean and non-toxic because the reaction is powered by biological catalysts (enzymes) only.

In theory, with enough time and batteries, Ehtacell can power a rocketship. However, in practice, there might occur many complications. Therefore, we are hoping that we would be able to continue our research and development of the project in the future!

For comments and questions contact Yana Peeva 11/4 (y.peeva21@acsbg.org) or Eniek van Der Werff (129495@wolfert.nl ).

NB! The project Ethacell was developed in the course and for the purposes of the Sustainergy6 Youth International Competition for Renewable Energy in Israel, organized by the Eilat Eilot company. Ethacell team: Eniek van der Werff (the Netherlands), Omer Oren (Israel), Rima Aboyoness (Israel), Yana Peeva (Bulgaria). The project was adapted for and presented at the ACS Science Fair 2020 by Eniek van der Werff and Yana Peeva.

*biomimetic - a product, which copies methods/structures/processes from Nature. The purpose of biomimicry in this project is to ensure the engineering solution and design are sustainable, non-toxic, and work perfectly in the conditions on Earth. Ethacell mimics the work of the human liver.