Session Chair:
- Ray Cocco, Particulate Solid Research, Inc.
Schedule:
| PRESENTATION | SPEAKER |
| Focus of Some Scale-Up issues for Gas-Solid Flows with Group B Particles | Benjamin Amblard, IFP New Energies |
| Building a Bridge Between the Particle Scale and the Bulk Scale Properties | Kerry Johanson, Materials Flow Solutions |
| Modeling for Formulation Development, Scale-up and Control of Agglomeration Processes | Paul Mort, Procter & Gamble |
Focus of Some Scale-Up issues for Gas-Solid Flows with Group B Particles
Benjamin Amblard, IFP New Energies
Chemical Looping Combustion is an oxy-combustion like technology where oxygen-carrying particles are used to supply oxygen for combustion. The process uses dense group B metal oxide as an oxygen carrier to transfer oxygen from an air reactor to a fuel reactor in a circulating fluidized bed. Process development and scale-up issues require good understanding of particle flow. This paper discusses two important aspects that were investigated in detail. The first one deals with riser flow. Experiments were conducted in a large cold flow model with two monodispersed group B solids having similar density and size, but different shape factors (sand and glass beads). For a given condition, pressure drop in the riser roughly decreases by 50% with the spherical particles. This work, therefore suggests that particle sphericity has a strong impact on the riser hydrodynamic that is not presently accounted by models. The second aspect relates to attrition. Existing knowledge of attrition is mostly based on FCC background using standard tests such as PSRI Jet-Cup apparatus. For group B powders, we found useful to define a new attrition index and also to evaluate with CFD the jet cup internal circulation rate of CLC particles compared to FCC particles.
Building a Bridge Between the Particle Scale and the Bulk Scale Properties
Kerry Johanson, Materials Flow Solutions
Understanding agglomeration or attrition of a collection of particles bound together requires an understanding of the key binding forces between particles, particle scale mechanical properties, tomography of particles, particle shape, particle size distribution, and the interaction of all adjacent particles. There are dozens of potential variables that could be investigated to determine their effect on key bulk scale property effects. Not all of these properties have a primary effect on bulk scale properties. The question is where to put the resources to be able to link the particle scale world to the bulk world. This presentation will demonstrate that, of all the bulk scale properties, the most critical one to understand is the concept of unconfined yield strength, and which particle scale properties have primary influence on unconfined yield strength. When viewed from the particle scale, strength is a mechanistic property. We will present a combined theoretical and experimental procedure for determining the primary cause of strength, the magnitude of each cause, and how these causes might interact based on easily measured particle scale parameters.
Modeling for Formulation Development, Scale-up and Control of Agglomeration Processes
Paul Mort, Procter & Gamble
Modeling can be used to aid in developing agglomerate-based product formulations and production processes. Addressing multiple objectives in the development process can be done using a set of complementary models, each with a distinct and [relatively] simple objective function. Models include formulation, process control, scale-up of unit operations and system integration. This presentation will cover some examples of useful modeling as applied to agglomerate process development.