For coal-fired power plants, PS 12B sorbent traps remain the preferred mercury compliance strategy. They are trusted, cost-effective, relatively simple to operate, and well suited for units that cycle, shut down, restart, or experience changing operating conditions.
With some coal units seeing increased operation or delayed retirements, plants may be placing renewed attention on mercury-control performance. For facilities already using sorbent traps, the question is not whether to replace a successful compliance program.
The better question is:
How can a plant gain better mercury visibility between trap results without adding the cost and complexity of a full PS 12A mercury CEMS?
Compliance Data Is Not Process Feedback
Sorbent traps provide the data needed for compliance reporting by measuring average mercury emissions over the collection period. However, they do not show how mercury responds in the moment to fuel changes, load changes, activated carbon injection adjustments, FGD additive changes, startups, shutdowns, or process upsets.
That delay can make mercury-control optimization difficult. By the time trap results are available, the operating condition that caused the change may already be gone.
A Practical Hybrid Strategy
The Ohio Lumex 915J is designed to complement PS 12B programs by providing process mercury monitoring and operational visibility between trap collection periods.
This gives plants a middle path: keep sorbent traps for compliance, while adding mercury control feedback for day-to-day operations.
What the 915J Helps Plants Understand
Process mercury monitoring can help facilities:
- Observe mercury trends as operating conditions change
- Evaluate fuel and load impacts
- Assess activated carbon injection performance
- Optimize reagent use
- Detect unexpected mercury increases earlier
- Investigate process upsets
- Improve confidence between trap results
More Data, Not More Complexity
A full PS 12A mercury CEMS can provide continuous compliance data, but it also brings higher capital cost, additional maintenance requirements, more staff training, and greater system complexity.
| Strategy | Compliance | Operational Visibility | Complexity | Relative Cost |
| PS 12B sorbent traps only | High | Low | Low | Low |
| PS 12B + 915J | High | High | Moderate | Moderate |
| PS 12A mercury CEMS | High | High | High | High |
The 915J offers a practical way to add supplemental mercury monitoring without replacing PS 12B sorbent traps or taking on the burden of a full compliance CEMS. Contact Ohio Lumex to discuss whether continuous mercury monitoring could provide valuable insight for your facility.
