In-Situ FCCU Process Optimization Mapping
Fluid Catalytic Cracking Units (FCCUs) are vital to refinery production across the globe. Since the first FCCUs were put into operation in the 1950s, considerable upgrades have become available as have more stringent environmental control regulations, such as EU Directive 2015/2193. Existing units may be upgraded, replaced, or even decommissioned due to environmental regulations or operating costs.
Continuous FCCU operation over time can produce unexplained or increased catalyst loss, reduction in FCCU efficiency, or unforeseen complications with downstream pollution control devices, such as expander blade wear or exceeding stack opacity limits. Third Stage Separator (TSS) or Fourth Stage Separator (FSS) cyclone hoppers can be analyzed to determine composition of the emitted particulate matter. Compositional analysis will show the presence of catalyst but can also reveal critical safety components, such as excessive refractory material.
In-situ particulate matter tests along the TSS, FSS or additional FCCU sampling points provide the refinery with an option to measure process conditions in lieu of modeled or calculated values including, but not limited to, volumetric flow rate (Nm3/hr), particulate concentration (mg/Nm3) and emission rates (kg/hr). This profile is developed on site to map mass and flow balance across the FCCU or determine cyclone efficiency. Testing across key FCCU points can be completed at multiple throughput settings to optimize FCCU operation and improve operational best practices. Post-test particle sizing and compositional analysis samples may lead to further process improvement by studying cyclone effectiveness.
Each FCCU is unique and requires a tailored approach to safely collect quality measurements for FCCU optimization. This presentation will outline these challenges and highlight previous fieldwork examples as reference.