Development of microbial fuel cell using coffee grounds/ Alzeah J. Almodal, Joyce Ann J. Nacario, Jhashlyn Elizah R. Porca, John David S. Santos, and Reggie P. Sigua .--

Bachelor's thesis

College of Industrial Technology .-- Bachelor of Engineering Technology major in Electrical Technology: Technological University of the Philippines, 2024.

Includes bibliographic references and index.

Coffee grounds are thrown away after coffee brewing and they increase the organic waste
problem. Coffee grounds are still underexploited as a bioenergy source. They are
considered waste and most of the time they are dumped into landfills. The main objective
of this study is to aim to provide sustainable energy generation. The prototype is designed
and fabricated to harness the energy potential of coffee grounds, specifically focusing on
Arabica coffee grounds with less caffeine content. The construction of the battery, built
with durable acrylic, ensures both resilience and an optimal environment for microbial
activity. The prototype was evaluated by 40 respondents composed of electrical
engineering students, college professors, and chemist. The evaluation on the performance
of the developed prototype is based on the seven (7) criteria in the Technological
University of the Philippines evaluation instrument, namely Functionality, aesthetic,
workability, durability, economy, safety, and salability. The evaluation resulted with the
overall mean of 4.39 which means Very Good. This demonstrates that the electrical
potential of coffee grounds has been successfully established as a viable energy source,
generating 0.62V from a single cell utilizing just 300 grams of less caffeine Arabica coffee
grounds.

Keywords: microbial fuel cell, energy potential of coffee grounds, arabica coffee grounds,
wastewater, microbial activity