Extending SCR Catalyst Life While Transforming NH₃ Monitoring Reliability
A chemical plant in South Texas relied on ammonia (NH₃) monitoring to support emissions control and optimize the performance of its Selective Catalytic Reduction (SCR) system.
The plant’s existing analytical method had become a significant operational challenge, resulting in frequent analyzer failures, extensive maintenance, and rising operating costs. In addition to the maintenance burden, inconsistent NH₃ monitoring made it more difficult to optimize the SCR catalyst beds and maximize their service life.
The customer needed a more reliable analytical solution that could improve measurement performance while meeting stringent site validation and emissions requirements.
Challenges
The existing NH₃ monitoring system required near-daily maintenance, creating a substantial burden for plant personnel.
The situation presented several challenges:
- Frequent analyzer failures and maintenance
- Increasing operating and maintenance costs
- Difficulty maintaining consistent NH₃ monitoring
- Reduced ability to optimize SCR catalyst performance
- Demanding site validation requirements
- Difficult analyzer alignment due to the installation configuration
- Frequent technician access to a 250-foot stack
- The need to maintain compliance with PS-18 emissions requirements
A conventional replacement installation would not have addressed all of these challenges. The analyzer’s alignment and accessibility also created the potential for continued maintenance issues.
Solutions
Pan Tech engineered and implemented a new NH₃ monitoring solution utilizing Tunable Diode Laser (TDL) technology and Neo Monitors’ Ultra software.
Rather than simply replacing the existing analyzer, Pan Tech designed the installation around the customer’s specific application and site requirements.
Engineered for Installation and Maintenance
A typical installation could have introduced alignment challenges and made it difficult to meet the site’s validation standards. Pan Tech developed a customized installation approach designed to minimize alignment faults while simplifying future maintenance.
Custom valves were incorporated into the system, allowing the analyzer to be removed for service without requiring a process shutdown.
This provided the plant with a more maintainable analytical system while minimizing disruption to ongoing operations.
Improved NH₃ Measurement
The combination of TDL technology and Neo Monitors’ Ultra software provided improved measurement capabilities in the plant’s high-moisture application.
The system’s enhanced speciation capabilities allowed operators to better distinguish and monitor the NH₃ concentration profile, including identifying a higher NH₃ peak that could not be effectively observed with the previous analytical method.
This improved visibility gave the plant greater control over its SCR process and enabled more effective catalyst optimization.
Compliance & Safety Improvements
The new monitoring solution provided benefits beyond analyzer reliability.
Improved Emissions Compliance
More reliable NH₃ monitoring helped the facility maintain compliance with PS-18 emissions requirements, reducing the risk of regulatory violations and associated fines.
Reduced Technician Exposure
The dramatic reduction in maintenance frequency also created an important safety benefit.
Previously, technicians were required to access a 250-foot stack on a weekly basis to address analyzer maintenance issues. By replacing a near-daily maintenance problem with a system that operated reliably for more than 14 months, the project significantly reduced the need for personnel to perform routine work at height.
The Results
The transformation in analyzer reliability was substantial.
The site went from near-daily maintenance to more than 14 months of continuous NH₃ monitoring—and counting.
The improved monitoring capability also allowed the plant to better optimize its SCR catalyst beds, contributing to an estimated five-plus-year increase in catalyst life.
The combination of reduced maintenance, improved SCR optimization, and avoided regulatory costs resulted in a solution that paid for itself in less than 12 months.
Results at a Glance
| Challenge | Result |
| Near-daily analyzer maintenance | 14+ months of continuous operation |
| Frequent analyzer failures | Dramatically improved reliability |
| SCR catalyst optimization | 5+ year increase in catalyst life |
| Difficult analyzer alignment | Engineered installation to reduce alignment faults |
| Process shutdown required for service | Custom valves enabled analyzer removal without shutdown |
| High-moisture measurement challenges | Improved NH₃ speciation and peak detection |
| PS-18 emissions requirements | Improved compliance and reduced risk of fines |
| Weekly access to 250′ stack | Significantly reduced technician exposure |
| Project economics | Solution paid for itself in <12 months |
Customer Impact
What began as a persistent analyzer reliability problem became an opportunity to improve the plant’s entire approach to NH₃ monitoring and SCR optimization.
By combining advanced TDL technology with application-specific engineering, Pan Tech delivered more than a replacement analyzer. The solution provided greater measurement visibility, dramatically reduced maintenance, improved emissions compliance, enhanced personnel safety, and extended the life of the customer’s SCR catalyst beds.
The result was a more reliable monitoring system that delivered measurable operational and financial value—and paid for itself in less than a year.