An increase in residual methane is often the first sign of incomplete reaction. Simply adjusting the air-to-gas ratio may mask the problem without addressing its cause.
Insufficient temperature
If the retort or catalytic bed does not reach the required temperature, methane conversion falls. Check the heating system, thermocouples, temperature uniformity and heat losses.
Degraded catalyst
Loss of catalytic activity slows the reactions. The change may be gradual and accompanied by higher gas consumption and increased soot formation.
Excessive flow rate
Demand above the generator’s actual capacity reduces residence time in the catalytic zone and can increase residual methane.
Sampling errors
Condensation, dirty tubing or unrepresentative samples can distort the measurement. Validate the analysis system before making adjustments to the generator.
Recommended checks
- Actual retort temperature
- Actual flow rate
- Pressure differential
- Catalyst condition
- Comparison with a second analyser