A Tracerco Diagnostics™ FCCU study allows refiners to identify operational and mechanical issues while the Fluid Catalytic Cracking Unit is still online. The use of Tracerco’s sophisticated scanning and tracer technologies allows refiners to improve productivity, maximise throughput, and plan any maintenance effectively. The insight provided from the study will lead to greater unit efficiency and higher profitability across the units run cycle. In this blog post we will discuss the top three questions we are asked with regard to a Tracerco Diagnostics™ FCCU study. 

1. What information will a Tracerco Diagnostics™ FCCU study provide me with? 

Tracerco has performed hundreds of FCCU studies worldwide to help diagnose operating problems and improve the performance of all major components of FCC units. These technologies are used to measure the velocity, distribution and residence time of the catalyst or vapour phase through any part of the system as well as density profiles within vessels. This includes testing to determine the efficiency of riser termination devices, cyclones or distribution devices. Each project is performed online and customised to provide the information needed to optimise or troubleshoot your specific process.

2. What preparation is needed before a study can be performed?

In general, most work is performed without any preparation to the vessels. A Tracerco engineer will need access to the top of the vessel or above the section to be studied, but that is usually available by existing platforms. The detection systems are portable but may require additional support such as scaffold if the work scope is large enough and platforms are not readily available. Current drawings, showing the orientation of internals, is needed prior to ensure the appropriate detector or scanline locations are selected to get the best possible evaluation of the process conditions 

3. What information will the Tracerco Diagnostics™ FCCU study results provide?

After a Tracerco Diagnostics™ FCCU study has been completed the lead crew member will leave a preliminary report with the customer before the project completion. A formal report will be provided soon afterwards. A few of the results the study provides on FCC equipment include:

• Reactor - Tracer distribution studies of the reactor cyclones are used to determine vapour residence time, relative amounts of vapour or catalyst traffic entering the primary reactor cyclone, and detection of vapour carry under to the diplegs as well as catalyst carry over through the cyclones. A Tru-Scan™ provides a density profile of bed level and effectiveness of catalyst disengagement.

• Reactor Riser - Tracer flow studies provides information on the velocities and distribution of the lift steam, feed, and catalyst allowing for flow adjustments to increase efficiency to get the best conversion rate possible. A Tru-Scan™ can identify the size of the expansion zone providing details on unit efficiency. ThruVision™ generates a cross-sectional density profile that can determine the flow distribution of the catalyst, identify flow inefficiencies such as catalyst maldistribution, and determine if a nozzle is plugged or fouled.

• Stripping Section - Tracer techniques yield information about steam/catalyst distribution, mean residence times, and damage or plugging in steam rings. A Tru-Scan™ of the spent catalyst stripper will identify blockages and damage to internals.

• Regenerator - A detailed analysis of maldistribution from the air grid to the primary cyclone inlets is achieved by using vapour or catalyst tracer injections to track the flow distribution, superficial velocities, and mean residence times. A Tru-Scan™ identifies problem cyclones, the evenness of the dilute phase catalyst levels (which can indicate air maldistribution), and high catalyst levels in diplegs.

• Spent & Regenerated Catalyst Standpipe - Tru-Scan™ results characterise catalyst flow, identify blockages, bubble formation, and study the effects of fluffing steam that might influence the catalyst flow regime. Tracer studies will also identify areas of de-fluidization and backward vapour flow.

You can learn more about how a Tracerco Diagnostics™ FCCU study can enable you to make the right decision by downloading the full list of the questions and answers, or by watching our FCCU animation.