SCR Management Services

Evonik Steag provides a fully integrated SCR management program with individual services being performed only on an as-needed basis tailored to the needs of the customer’s SCR system.  This perpetual cycle of SCR management has also been used for successfully managing our own SCR systems during the past 20 years.  What services needed to be provided at what point in time is decided in close cooperation with the SCR operator in order to optimize the operation of each individual SCR reactor, improve the SCR system’s performance, reliability and availability, as well as extending the life of the catalyst for the ultimate purpose of reducing O&M costs and minimizing investment.
                          

Our services are offered in a menu-type program and the plant operator will be advised on what services to select for each unit that best suits this individual unit’s needs and budget considerations.

SCR Reactor Inspection and Catalyst Sampling
An important part of SCR management is reactor inspection to identify any issues that impact the efficient operation of the reactor and catalyst testing services to determine the activity level of the installed catalyst.

Evonik Steag highly recommends that at least once a year the reactor be inspected and that at least one catalyst sample from each layer be taken, tested and analyzed for deactivation and DeNOx potential tracking purposes.  We also recommend additional SCR reactor inspections be done at any time when an individual SCR reactor is accessible whether it is due to a scheduled or a forced outage.

Especially during the first years of SCR operation, more frequent than annual inspections and catalyst sampling has been proven to be very advantageous.  As a historyis developed, inspection and catalyst testing can be reduced to a long-term frequency of once per year. 
 

SCR reactor inspection should include at a minimum:

• Inspection of SCR reactor and all associated equipment
• Inspection of the reactor insulation and lagging
• Inspection of all catalyst layers in each reactor including modules and seals
• Soot blowers and/or sonic horns
• Reactor support structure
• Catalyst sampling (at least one sample per layer)
• Inspection of the flue gas guide vane system upstream of the SCR reactor
• Evaluation of possible fly ash deposits
• Inspection of the gas inlet distribution system and rectifier
• Inspection of the flue gas and economizer bypasses including bypass dampers and expansion joints
• Inspection of the AIG system, particularly the nozzles and tuning valves
• Inspection of key ancillary equipment, e.g., the fixed installed sampling grid downstream of the last catalyst layer, seal air system including dampers and   expansion joints, etc.