State-of-the-Art Review of Fluid Catalytic Cracking (FCC) Catalyst Regeneration Intensification Technologies

Abstract

Fluid catalytic cracking (FCC) is the workhorse of modern crude oil refinery. Its regenerator plays a critical role in optimizing the overall profitability by efficiently restoring the catalyst activity and enhancing the heat balance in the riser reactor. Improvement in the device metallurgy and process operations have enabled industrial regenerators to operate at high temperatures with better a coke burning rate and longer operating cycle. Today, the carbon content of regenerated catalyst has drastically reduced to less than 0.1 wt.%. However, the unit is still plagued with operational complexities and insufficient understanding of the underlying dynamic, multiscale intricacies. Recent process-intensification strategies provide insights into regenerator performance improvement potentials. In this review, the importance of the uniform distribution of spent catalysts through structural modification and operational manipulations of the catalyst distributor is discussed. The knowledge of the role of baffles in enhancing excellent gas–solid interaction has been increasing, but skepticism due to its complex hydrodynamic effects on gas–solid flows fends off operators from its application, a critical evaluation of its implication in the regenerators is covered. The understanding of the contribution of air/steam distributor design and feed gas injection techniques for even contact with spent catalyst leading to the improvement in FCC performance is also investigated. The reliability of FCC components is a big concern, as unplanned shutdown and enormous economic losses are being witnessed due to device failure. To this end, mitigation approaches to damaging afterburn and high-temperature erosion problems with respect to process control and geometric adjustment in the bed, freeboard, cyclone separators and collection ducts are explored. Emission limits for fluid catalytic cracking unit (FCCU) and products are consistently ratcheting downward; the commingled turnkey solutions to reducing pollutants generation are also reviewed.

Ab Initio Group Additive Values for Thermodynamic Carbenium Ion Property Prediction

“…Rotational modes with barrier heights above 50 kJ/mol were not considered as a hindered rotor but approximated as a harmonic oscillator. The reduced moment of inertia calculated at the I (2,3) level together with the Fourier series expression of the hindrance potential, as defined by East and Radom, 57 are used for the construction of the Schrodinger equation for onedimensional internal rotation. The eigenvalues of the solution determine the partition function as a function of temperature.…”

“…The structured aluminosilicates are predominantly applied as acidic, shape-selective catalysts to steer product yields and increase the reaction activity. Their use within the petrochemical industry is widespread, ranging from fluid catalytic cracking and hydrocracking to the reforming of specific assays. , The development of suitable zeolites will also play a crucial role in the shift from fossil carbon sources to more sustainable sources such as biomass or plastic waste. Initially, fossil streams will be blended with sustainable hydrocarbon streams in conventional processes to facilitate a gradual shift to a fossil-free chemical industry.…”

A comprehensive study of product distributions and coke deposition during catalytic cracking of vacuum gas oil over hierarchical zeolites

“…The fluidized bed hydrocarbon catalytic cracking process (FCC) is considered the most important process within the refinery to convert heavy cuts into light and valuable ones. This process constantly undergoes different modifications and improvements in terms of its technology and the catalyst to increase its efficiency and meet the specific demands of each refinery [ 1 ]. The feed used in FCC reactors is usually known as vacuum gas oil (VGO), characterized by having average boiling points of approximately 450 °C, which fall in the C20–C50 range, and the catalysts used in these units are composed of Y zeolite, which is supported on a matrix with different characteristics, active or inactive, and a binder [ [2] , [3] , [4] ].…”

Analysis of the Process Parameter in Fluid Catalytic Cracking Unit for a Refining and Petrochemical Company in Nigeria

“…The dense bed, however, is somewhat stable since the heat of combustion is released by regeneration. This is as a result of the high catalyst storage and holdup, which absorb the heat of combustion released as they are regenerated, also the dense bed is unsusceptible to post-combustion, which affects plenums, cyclones and flue gas up in exit ducts [15]. As a result, extremely high heat in the dense bed are evenly distributed and ducked.…”