Trash to Gas: (A Study of Biogas Production From Organic Waste Using Technology)
Energy and Change- Grade:
- 7
- Teacher:
- Karen Maninang
This project examined the efficiency of different organic feedstocks in producing biogas through anaerobic digestion using a small-scale, student-designed digester system. Organic waste such as vegetable scraps, grass clippings, and cow manure is generated daily and often disposed of in landfills, where it decomposes and releases methane into the atmosphere without capturing its energy potential. Transforming organic waste into usable biogas presents an opportunity to reduce greenhouse gas emissions while generating renewable energy. The goal of this study was to compare biogas production from three commonly available organic materials under controlled experimental conditions. Three identical anaerobic digesters were constructed using 2-liter plastic bottles fitted with airtight vinyl tubing and balloon gas-collection systems. Each digester contained 200 grams of feedstock—vegetable scraps, grass, or cow manure—and 800 milliliters of dechlorinated water. Biogas production was measured daily over a 13-day period using balloon inflation as an indicator of gas volume. Ambient temperature was monitored using a BBC micro:bit to ensure environmental consistency and evaluate potential temperature effects on microbial activity. Descriptive statistical analysis, including mean, range, rate of change, and percent increase, was conducted to compare feedstock performance. Results indicated that grass produced the highest overall biogas yield and fastest rate of gas production, followed by vegetable scraps, while manure produced minimal measurable gas under the conditions tested. These findings suggest that feedstock composition plays a critical role in small-scale biogas system efficiency and that grass-based organic waste may be a more effective short-term substrate than manure in low-tech digesters. This study contributes to the understanding of waste-to-energy conversion at a small scale and demonstrates how accessible materials and embedded technology can be used to explore sustainable energy solutions.
Investigating how organic wastes like grass, vegetables, and cow manure can produce biogas shows advanced scientific thinking and strong awareness of environmental sustainability.
Your project explores a real-world process called anaerobic digestion. This is when microorganisms break down organic matter in the absence of oxygen, producing biogas — mainly methane and carbon dioxide. Methane is a combustible gas that can be used as a fuel for cooking, heating, or generating electricity. That means your experiment connects biology, chemistry, and environmental science all in one project.
I especially like that you compared different materials (grass, vegetable waste, and cow manure). That shows good experimental design because you are testing how different types of organic matter affect gas production.
Overall, this is a thoughtful, practical, and scientifically strong experiment. You showed creativity, environmental awareness, and strong experimental design. Projects like this demonstrate how science can help solve real problems in the world.
Excellent work — this is the kind of thinking that leads to future environmental scientists and renewable energy innovators!