Preventing Agricultural Fires with CO2 Sensor Technology

By Dr. Noopur JainReviewed by Susha Cheriyedath, M.Sc.Nov 27 2024

In a recent article published in the journal AgriEngineering, researchers introduced a novel approach to enhancing safety in agricultural storage facilities. The study explores the use of carbon dioxide (CO₂) gas sensors as early warning devices for spontaneous combustion (SC), a major hazard in the storage of agricultural products.

The research outlines a systematic testing protocol for evaluating gas sensors under controlled conditions. By linking CO₂ emissions to microbial activity, the study aims to develop reliable solutions for detecting the early signs of SC and preventing potential disasters.

Understanding Spontaneous Combustion

Spontaneous combustion in stored agricultural products arises primarily from microbial processes and heat buildup. As these processes intensify, they can lead to dangerous temperature escalations. While traditional fire detection methods rely on temperature sensors, these systems often fall short in large-scale storage due to structural constraints and potential failures caused by the weight of stored materials.

This study identifies CO₂ as a key indicator of microbial activity and SC risk. By monitoring CO₂ levels, researchers hope to address limitations in existing detection systems and provide a more effective safety mechanism.

Innovative Testing with a Micro-Incubator Protocol

In this study, the researchers employed a micro-incubator protocol to evaluate the performance of CO₂ gas sensors under carefully controlled conditions. The experimental setup replicated a cottonseed storage environment, with a particular focus on varying moisture levels and temperature changes, to simulate real-world scenarios.

The goal was to measure CO₂ production rates in cottonseeds at different moisture levels, comparing samples with low moisture content (less than 12 %) to those with higher moisture levels (around 25 %). This comparison allowed the researchers to understand how moisture influences microbial activity and the resulting CO₂ emissions.

The sensors used in the experiments were assessed for their operational limits, including temperature thresholds and accuracy. The study revealed that the sensors functioned effectively within a temperature range of 50 to 60 degrees Celsius. The researchers also addressed potential confounding factors, such as water vapor pressure and the presence of other gases, ensuring that these variables did not distort the CO₂ readings.

To validate the sensors’ performance, the researchers conducted a side-by-side comparison. Three sensors were placed in separate outer tanks within a closed box filled with CO₂ gas. This setup ensured uniform gas diffusion, exposing all sensors to identical conditions. This provided robust data on the sensors’ ability to detect and respond to changes in CO₂ levels, a crucial factor in determining their potential as early warning systems for spontaneous combustion.

Results and Discussion

The experiments revealed a clear link between moisture content and CO₂ production in cottonseeds. Higher moisture levels corresponded to significantly increased CO₂ emissions, confirming that microbial activity is more pronounced in wetter conditions. This finding emphasizes the importance of monitoring moisture levels alongside CO₂ emissions to effectively evaluate the risk of SC.

The gas sensors demonstrated reliable performance, with a detection range that extended to CO₂ levels of up to 20,000 ppm under controlled conditions. However, the researchers cautioned that sensor readings are influenced by environmental factors such as temperature and pressure, which must be accounted for through careful calibration and data correction. This ensures accurate and meaningful CO₂ monitoring in real-world scenarios.

The study’s discussion highlights the broader implications of these findings for fire prevention in agricultural storage facilities. Integrating CO₂ sensors into monitoring systems provides a proactive way to detect early signs of SC, enabling timely interventions before dangerous conditions develop. The authors suggest that further refinements in sensor technology and calibration methods are needed to enhance the accuracy and reliability of CO₂ measurements in practical applications.

Conclusion

This study presents compelling evidence for the use of CO₂ gas sensors as a practical solution for early warning detection of SC in agricultural storage. By establishing a strong correlation between CO₂ emissions and microbial activity, the research provides valuable insights into the underlying dynamics of SC.

The micro-incubator protocol developed for testing the sensors offers a robust and systematic approach, paving the way for advancements in fire detection technology. The findings underscore the critical role of continuous monitoring of both CO₂ levels and moisture content in mitigating SC risks.

As agricultural practices continue to evolve, integrating innovative solutions like CO₂ monitoring systems will be essential for safeguarding valuable stored commodities and ensuring the safety of storage facilities.

Journal Reference

Pelletier M.G., McIntyre J.S., et al. (2024). Micro-Incubator Protocol for Testing a CO₂ Sensor for Early Warning of Spontaneous Combustion. AgriEngineering, 6, 4294-4307. DOI: 10.3390/agriengineering6040242, https://www.mdpi.com/2624-7402/6/4/242