Preliminary Emission Air Quality & TEQ Analysis

2026-02-15

Stack Gas Quality – Thermal Treatment Process (SGS Method)

This note summarizes three emission air quality analysis reports obtained from stack gas sampling during controlled thermal treatment operation. The purpose of this document is to provide a technical overview of emission characteristics, combustion stability, and preliminary Dioxin/Furan (TEQ) performance under real operating conditions.

1. Combustion and Process Conditions

Measured parameters indicate a stable excess-air oxidation regime:

• Stack temperature: approx. 260–277 °C
• Oxygen (O₂): ~11–12.5 %
• Gas flow rate: approx. 4,300 Nm³/hr
• Opacity: 0.0

The relatively high residual oxygen level suggests lean combustion conditions with sufficient air supply. The absence of visible opacity implies low soot formation and effective oxidation during thermal treatment.

2. Acid Gases and Conventional Pollutants

Key measured results (SGS stack sampling):

• NOx: ~16 ppm (well below reference limit)
• SO₂: Not detected
• HCl: ~13 ppm
• HF: ~0.94 ppm
• Total Suspended Particulates (TSP): ~4.4 mg/Nm³

All measured values remained significantly below reference emission standards. The low particulate concentration and zero opacity indicate minimal incomplete combustion products.

3. Heavy Metals

Measured heavy metals were either not detected or present only in trace quantities:

• Mercury (Hg): Not detected
• Cadmium (Cd): ~0.002 mg/Nm³
• Lead (Pb): ~0.057 mg/Nm³

These values suggest limited volatilization of metal contaminants during the test condition.

4. Dioxins and Furans (Preliminary TEQ Results)

Dioxin/Furan analysis using TEQ conversion produced the following preliminary result:

Total Dioxins/Furans (TEQ): ~0.00229 ng-TEQ/Nm³

Reference emission guideline shown in the report: 0.5 ng-TEQ/Nm³ (waste incinerator standard).

The measured TEQ value is substantially lower than the referenced limit under the sampling condition.

Congener distribution indicates that higher-chlorinated species dominated the mass fraction, while TEQ-weighted toxic congeners remained very low. This pattern is typically associated with stable high-temperature oxidation and reduced re-formation during cooling.

5. Technical Interpretation

Across the three analysis reports, the combined emission profile suggests:

• Stable excess-air thermal oxidation
• Extremely low particulate formation
• Low acid gas emissions
• Ultra-low preliminary TEQ levels without indication of secondary flue-gas treatment in the test description

These results should be interpreted as preliminary stack gas performance data under specific operating conditions. Waste composition, residence time, and long-term operational variability were not evaluated within this single sampling event.

6. Limitations

• Sampling was conducted at a specific time and operating state.
• Results do not represent regulatory certification or continuous monitoring data.
• Additional testing under varied feedstock and operating conditions is recommended for comprehensive evaluation.

Summary

The emission air quality data set indicates a controlled thermal treatment regime characterized by clean oxidation behavior, low particulate emissions, and very low preliminary TEQ values. The findings support further technical evaluation while emphasizing the importance of contextual interpretation and operational limitations.

Combustion State

Stable excess-air oxidation behavior indicated by sustained CO₂ formation, low particulate levels, and zero visible opacity during continuous operation.

Temperature Stress

Moderated thermal profile suggested by low NOx levels, implying controlled peak flame temperatures rather than aggressive high-temperature combustion.

Toxicity Indicators

Preliminary ultra-low TEQ and controlled acid-gas measurements observed under field-based stack testing conditions.