A study on the potential of using plant proteins as electrolytes in a biochemical cell

Abstract

We demonstrate that proteins extracted from nonedible oil meals can be used as inexpensive, renewable, and biodegradable electrolytes in biochemical cells. Electrolytes are the critical components of cells and generally made using metals, ionic, or salt solutions. These electrolytes are either expensive, harmful to the environment when disposed and/or provide poor performance. Proteins behave as anionic or cationic charge carriers depending on the environment there are in. Recent increase in the production of biodiesel from oil seeds has led to the abundant availability of protein containing oil meals. These oil meals inherently and inevitably contain the proteins and are available in large quantities at low cost. In this report, we have extracted proteins from three different oil meals. Proteins obtained were used as electrolytes with different electrodes and operating conditions. A voltage of up to 300 mV was generated using copper electrodes as both anode and cathode. Protein concentration of 10% was found to be optimum and increasing time substantially reduces the voltage for all the electrodes. Although higher voltage could be generated when dissimilar electrodes were used, the contribution from the proteins to the charge generated was minimal. Maximum current generated was about 9 mA when a 10 ohm resistor was connected as load. Utilizing proteins from nonedible oil meals will provide inexpensive and environmentally friendly electrolytes for biochemical cells. This is the first time that proteins have been used as electrolytes for biochemical cells. More importantly, we have used the byproduct generated during production of biodiesel as source for the proteins. This makes the proteins inexpensive, biodegradable and widely available. At the same time, high value addition is possible to the byproduct which will lead to lowering the cost of the biodiesel. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 961–967, 2018