Thermodynamic Multi-Gas Odor Grain Analyzer
A device for simultaneous measurement of concentrations of multiple gases in the air within or above stored grain. The combined data forms a unique “odor profile”, allowing for real-time detection of storage violations and early prevention of grain spoilage.
Which Gases Signal Grain Spoilage
- Decay, mold, and anaerobic processes:
- Methane (CH₄): produced during anaerobic fermentation (a sign of poor ventilation)
- Hydrogen sulfide (H₂S): indicates decomposition of organic matter and presence of anaerobic bacteria
- Ammonia (NH₃): signals protein breakdown or urea decomposition
- Carbon dioxide (CO₂): increases with active respiration by microorganisms or insects
- Bioactivity and dry matter loss:
- CO₂: a key indicator of metabolic activity in grain and microflora
- Hydrogen (H₂): byproduct of fermentation
- NH₃: again, indicates biochemical degradation of proteins
- Rodent presence (rats, mice):
- Direct gaseous metabolites are hard to isolate, but:
- Urine odor (including NH₃ and amino acids)
- Volatile Organic Compounds (VOCs): from feces and pheromones
- Specific odor patterns, which can be recognized by a trained AI model based on VOC traces
Key Monitoring Directions
✅ Spoilage, mold, and anaerobic activity:
Increased levels of CH₄, H₂S, NH₃, and CO₂ indicate decomposition processes, mold growth, and ventilation failure.
✅ Bioactivity and weight loss:
Rising CO₂ and H₂ levels signal intensified metabolic activity of grain, microbes, and pests, leading to mass loss and quality decline.
✅ Rodent detection:
Although rodent-specific gases are hard to isolate, urine odor (NH₃ and amino acids) and secondary VOCs from feces and pheromones create identifiable odor profiles. These VOC templates can be detected early by an AI-based analyzer.
Key Indicator Gases and Their Monitoring Significance
| Gas | Source / Signal | Monitoring Significance |
| Methane (CH₄) | Anaerobic fermentation | Indicator of poor ventilation, decay |
| Hydrogen sulfide (H₂S) | Organic decomposition, anaerobic bacteria | Early signal of spoilage |
| Ammonia (NH₃) | Protein breakdown, urea decomposition | Indicates biochemical degradation |
| Carbon dioxide (CO₂) | Respiration of microorganisms and insects | Key metabolic activity indicator |
| Hydrogen (H₂) | Fermentation byproduct | Marker of biological activity |
✅ Advantages of the Approach
- Comprehensive grain condition evaluation via multi-gas detection
- Early diagnosis of storage violations and biological threats
- Integration with AI to automatically interpret VOC profiles and trigger alerts
Three Scientifically Justified Monitoring Directions
| Problem Area | Gas Markers | Scientific Basis |
| Spoilage & Anaerobiosis | CH₄, H₂S, NH₃ | Fermentation processes, microbial growth |
| Respiration & Microflora | CO₂, H₂, NH₃ | Grain respiration, mold development |
| Rodents | VOCs, NH₃, odor patterns | Urine, feces, metabolic byproducts |