Power Generation from Melon Seed Husk Biochar Using Fuel Cell

Abstract

Melon seed husk (MSH) biochar was used in a single cell direct carbon fuel cell (DCFC) as an alternative biofuel. The DCFCs belong to a generation of energy conversion devices that are characterised with higher efficiencies, lower emission of pollutants and MSH biochar as the fuel. Several analytical techniques (proximate, ultimate and thermo-chemical analysis) were employed to analyse the characteristics of the biomass fuel, their effects on the cell’s performance, and the electrochemical reactions between the fuel and the electrolyte in the system. High carbon content and calorific values are some of the parameters responsible for good performances. The performance of a lab-scale DCFC made of ceramic tubes using molten carbonate electrolyte was investigated. Binary carbonates mixture (Na2CO3-K2CO3, 38-62 mol.%) was used as electrolyte and the waste MSH carbonised at 450°C as biofuel. A practical evaluation of the fuel used in the DCFC system was conducted, for varying temperature of 100 - 800°C. The maximum open circuit voltage (OCV) was 0.71 V. With an applied load resistance and active surface area of 5.73 cm² the maximum power density was 5.50 mWcm-2 and the current density was 29.67 mAcm-2 at 800°C.

Key findings

• ▸High carbon content and calorific values of melon seed husk biochar contributed to good performance in the fuel cell.
• ▸The use of molten carbonate electrolyte and a binary carbonates mixture (Na2CO3-K2CO3, 38-62 mol.%) improved the cell's performance.
• ▸The maximum power density was achieved at a temperature of 100-800°C, with a practical evaluation of the fuel conducted at varying temperatures.

Keywords

Identifiers

DOI

10.4314/gjs.v61i2.4

Journal

Ghana Journal of Science

Year

2021