Experimental analysis of volatile liquid injection into a fluidized bed

Motlagh, A.H. Ahmadi; Grace, John R.; Briens, Cédric; Berruti, Franco; Farkhondehkavaki, Masoumeh; Hamidi, Majid

doi:10.1016/j.partic.2016.11.003

Cited by 12 publications

(5 citation statements)

References 28 publications

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“…Because of a high degree of turbulence, large thermal gradients and high flow inhomogeneity in the vaporisation section, it makes it the most complex region to model in the entirety of the riser reactor [199]. Studies have also shown that the diameters of the atomised feed [200,201], the nozzle and particle wetting characteristics of particles [202][203][204][205] also play crucial roles in feed vaporisation, proving the complexity of the vaporisation section to modelling. However, according to plant data from Ali et al [199], the entirety of the vaporisation process only occurs in 0.1 s, corresponding to only about 3% of the residence time of catalyst in the riser.…”

Section: Feed Vaporisationmentioning

confidence: 99%

A Review of Modelling of the FCC Unit–Part I: The Riser

et al. 2022

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Heavy petroleum industries, including the fluid catalytic cracking (FCC) unit, are useful for producing fuels but they are among some of the biggest contributors to global greenhouse gas (GHG) emissions. The recent global push for mitigation efforts against climate change has resulted in increased legislation that affects the operations and future of these industries. In terms of the FCC unit, on the riser side, more legislation is pushing towards them switching from petroleum-driven energy sources to more renewable sources such as solar and wind, which threatens the profitability of the unit. On the regenerator side, there is more legislation aimed at reducing emissions of GHGs from such units. As a result, it is more important than ever to develop models that are accurate and reliable, that will help optimise the unit for maximisation of profits under new regulations and changing trends, and that predict emissions of various GHGs to keep up with new reporting guidelines. This article, split over two parts, reviews traditional modelling methodologies used in modelling and simulation of the FCC unit. In Part I, hydrodynamics and kinetics of the riser are discussed in terms of experimental data and modelling approaches. A brief review of the FCC feed is undertaken in terms of characterisations and cracking reaction chemistry, and how these factors have affected modelling approaches. A brief overview of how vaporisation and catalyst deactivation are addressed in the FCC modelling literature is also undertaken. Modelling of constitutive parts that are important to the FCC riser unit such as gas-solid cyclones, disengaging and stripping vessels, is also considered. This review then identifies areas where current models for the riser can be improved for the future. In Part II, a similar review is presented for the FCC regenerator system.

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Section: Feed Vaporisationmentioning

confidence: 99%

A Review of Modelling of the FCC Unit–Part I: The Riser

et al. 2022

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“…For example, Zhu et al examined the effects of cohesion on the spout–annulus interface and particle velocity profiles in distinct zones. Ahmadi Motlagh et al conducted liquid injection experiments in a lab-scale fluidized bed and explained the relationship between superficial gas velocity and liquid distribution pattern. The agglomeration of particles in a conical spouted bed was investigated using multiple experimental means and detected by different signals .…”

Section: Introductionmentioning

confidence: 99%

Experimental Study and DEM Numerical Simulation of Dry/Wet Particle Flow Behaviors in a Spouted Bed

Tang

Ren

et al. 2019

Ind. Eng. Chem. Res.

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In this study, wet particle flow behaviors were investigated in a spouted bed using numerical simulations and experiments. Effects of liquid contents and viscosities were investigated. For the experiment, instantaneous particle distribution and particle velocity distributions were explored. Liquid content and viscosity affected flow pattern together. Keeping increasing liquid content and viscosity, the flow pattern displayed flow instabilities, and the gas channel became curved. Numerical simulation results of time-averaged particle velocities agreed well with the experimental data. The regime map of domination forces is shown. Drag force has little effect on particle flow behaviors with liquid viscosity exceeding 10 mPa·s, and contact and liquid bridge forces were almost 50–50. Furthermore, effects of liquid content and viscosity on particle granular temperature and velocity were explored. The experimental and numerical simulation results might provide theoretical guidance for reactor design and further investigation on particle flow behaviors with cohesive liquid.

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“…Manufactured agglomerates of coke and bitumen were introduced in a fluid coker pilot plant; agglomerate breakup occurred more quickly when the fluidization gas velocity was increased, when the liquid content of the agglomerates was reduced, and when the reactor temperature was increased . Experiments with experimental models at lower temperatures confirmed these results. ,− Agglomerates containing highly viscous liquid are more stable, ,,, and although preheated coker feedstocks have a viscosity of around 2 mPa s, the liquid viscosity increases rapidly as the reaction proceeds, volatile products vaporize, and residual liquid polymerizes. , Wettability of the bed solids by the liquid is an essential factor: agglomerates with poorly wettable solids are less stable , and do not grow as quickly through the capture of dry bed particles; , in fluid cokers, coke particles are nearly perfectly wettable by the injected liquid. , Larger monosize particles make less stable agglomerates, and if particles within an agglomerate have a wide size distribution, then the small particles in the interstitial spaces act as a bridge for the wetting phase, making the agglomerate stronger. ,, Agglomerates of porous particles are less stable, because their pores absorb some of the liquid, reducing the amount of binding liquid on the particle surface; , coke from flexicokers is more porous than coke from fluid cokers and should form less stable agglomerates. In fluidized beds, agglomerates can be broken up by the shear forces associated with gas bubbles. , Larger agglomerates break up more easily .…”

Section: Reactormentioning

confidence: 77%

“…166,167 Larger monosize particles make less stable agglomerates, 159 and if particles within an agglomerate have a wide size distribution, then the small particles in the interstitial spaces act as a bridge for the wetting phase, making the agglomerate stronger. 159,171,172 Agglomerates of porous particles are less stable, because their pores absorb some of the liquid, reducing the amount of binding liquid on the particle surface; 152,173 coke from flexicokers is more porous than coke from fluid cokers 174 and should form less stable agglomerates.…”

Section: Alternative Feedstocksmentioning

confidence: 99%

Review of Research Related to Fluid Cokers

Briens

McMillan

2021

Energy Fuels

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Fluid coking is a thermal conversion process that uses a conventional two-vessel circulating fluidized bed to convert heavy hydrocarbon feeds to lighter products. The technology was developed in the 1950s and since then has been used commercially around the world to upgrade heavy oils from various sources. Research work has been summarized related to all aspects of the fluid coking process, including reaction fundamentals, bed hydrodynamics, liquid distribution and jet–bed interaction, mixing of solid particles and agglomerates, mixing of vapors, control of the particle size, cleaning of the vapor stream in the scrubber, cleaning of the cold coke in the stripper, process monitoring, coke transfer lines, and the burner. The fluid coking process involves complex interactions between fluidized bed hydrodynamics, liquid feed injection, and reaction kinetics, and research tools that can take into account all of these interacting variables are requited to test methods to optimize the process. Fluid cokers can process many different types of feeds, and future applications may include blending and co-processing a variety of feedstocks ranging from waste plastics, pyrolytic bio-oil, and off-spec vegetable oils with heavy oil. The findings from this summary are also relevant for other applications that inject liquid into fluidized beds, such as the fluid catalytic cracking process, olefin polymerization cooled by liquid injection, granulators, and coaters.

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Experimental analysis of volatile liquid injection into a fluidized bed

Cited by 12 publications

References 28 publications

A Review of Modelling of the FCC Unit–Part I: The Riser

A Review of Modelling of the FCC Unit–Part I: The Riser

Experimental Study and DEM Numerical Simulation of Dry/Wet Particle Flow Behaviors in a Spouted Bed

Review of Research Related to Fluid Cokers

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