Refinery Boilers NOx Reduction
NEC evaluated and helped the refinery implement several NOx reduction options including:
- FCC COB combustion improvements
- FCC COB SNCR Process Design and Technology Selection
- Combustion Turbine HRSG SCR Process Design and Technology Selection
- Coker COB LNB Process Design and Technology Selection
- Boilers steam injection Process Design
- Ammonia system modifications
- Boilers Induced Flue Gas Recirculation (IFGR)
NEC offered the following proposed solutions:
After evaluating numerous refinery combustion sources, past studies under various ownership, operational, and emissions information, Norton Engineering developed a summary of potential options with capital and operational cost estimates. Numerous options were considered and discussed with refinery engineering and management. Among the most intriguing and beneficial options introduced by NEC, was to implement Induced Flue Gas Recirculation (IFGR) at two of the refinery boilers. IFGR is the practice of recirculating and mixing flue gas with fresh combustion air at the FD fan. NOx reduction with IFGR installed on both boilers was predicted to be reduce NOx by approximately 30% (~55-70 TPY) at maximum rate.
IFGR is commonly practiced in the power industry but rarely implemented in refineries. Due diligence was performed by the client and NEC to visit a refinery boiler system with IFGR installed in Baton Rouge to obtain information and answer questions to satisfy concerns from the client’s rotating equipment, operations, and maintenance groups.
NEC produced a Process Design Specification (PDS) with performance estimates for emission reduction under varying boiler loads and preliminary engineering. Following the process design, NEC provided additional support with vendor coordination and bid evaluations, mechanical system design and 3D modeling, PHA participation, multi-discipline detailed engineering, fabrication drawings, project management and startup assistance for the project. FD and ID fan capacity assessments were performed, working with the client to collect accurate plant data to confirm viability and reliability of the fans with IFGR. NEC provided Operator training and startup and tuning support for the new system, which resulted in NOx reductions of almost 40% over baseline.