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EnginEEring and construction 2011corporate profile: Kti

SCR Retrofits of FCC UnitsKTi focuses on quality project execution

KTI Corporation has a successful track record for retrofit of Fluid Catalytic Cracking Units (FCCUs) with Selective Catalytic Reduction (SCR) emission reduction systems. As the primary money maker in refinery operations, the FCCU is considered to be one of the most important secondary conversion processing units in modern petroleum refineries. FCCUs are also primary sources of NOx, SO2, CO and Particu-late Matter (PM), thereby requiring effective emission reduction strategies to ensure compliance with environmental regulations.

Of available options to mitigate FCCU emissions, an SCR is the most effective and commonly applied technology for reducing NOx. Given that FCCUs generate more NOx than any other refinery combustion process, they are the primary focus of any overall plant NOx reduction strategy. As a continuous process operation, FCCUs must operate with minimal downtime and disruption. Hence, the importance of executing a FCCU SCR retrofit project on time and on budget while achieving target emission reductions. Missing schedule by one day, or failing to meet emission targets consistently, can be extremely costly to the refinery operator.

Quality solutions begin with detailed planning. There is a simple rule of thumb—the more detailed the plan; the higher quality the engineered solution. Successful retrofit projects are predicated on detailed up-front planning, application of highly qualified expertise and proven methods, and rigorous quality control of which SCR retrofits are no exception. It is the client’s responsibility to define the overall emission reduction objective, and together with an experienced engineering contractor, to define the project scope, cost, and schedule in execution of a successful FCCU SCR retrofit project.

Once an engineering firm, such as KTI, is engaged to design an SCR system, they will begin to evaluate the design parameters necessary for successful imple-mentation and post install operation and maintenance. A few engineering design considerations for an FCCU SCR retrofit include:•  Size catalyst pitch and volume appropriately for anticipated normal and 

upset operating conditions,•  Achieve required uniformity of flow and ammonia concentration to meet NOx 

and ammonia slippage specifications,•  Design the SCR reactor housing for construction and maintenance friendly 

access and ensure the structural support can withstand the potential weight of large quantities of fine particles carried over from the FCCU reactor, and•  Consider the need for a design that incorporates standby reactor capacity in 

the event that a problem occurs with the primary catalyst bed.

Be on the lookout for common project execution issues. With experience in thousands of new capital and retrofit projects, KTI has faced and successfully overcome just about every retrofit project execution challenge imaginable. For an FCCU SCR retrofit, the primary execution challenges include:•  Clearly document, articulate and manage project objectives,•  Engage qualified suppliers of specialized components early in the project 

to assure that design solutions are compatible and overall schedule objectives are achieved,

•  Validate fabrication QA (KTI uses in-house inspectors) to ensure that the SCR system components (ammonia skid, distribution grid, mixers, turning/distribution devices and maintenance/handling provisions) function as intended,•  Protection of the most critical component—the catalyst—to ensure proper 

handling during transport, storage, installation and commissioning leading up to successful start up of the unit, and•  Stay focused on Health, Safety and Environment during the entire project 

execution cycle.

Contact information

11720 Katy Freeway, Suite 110Houston, TX 77079Phone: 281.249.2400Fax: 281.249.2328Email: sales@kticorp.comWebsite: www.kticorp.com

Dual SCR Reactor

Article copyright © 2011 by Gulf Publishing Company. All rights reserved. Not to be distributed in electronic or printed form, or posted on a Website, without express written permission of copyright holder.