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14/09/2011
Scaleup of O-carrier production for Chemical Looping Combustion by spray drying
Jasper Van Noyen, Frans Snijkers, Ivo Thijs, Jan Deckx
14/09/2011 2© 2011, VITO NV
Outline
» Introduction» Spray drying principles and equipment» Spray drying of oxygen carriers in 7FP Innocuous
» Results» Batches» Scale up» Particle morphology and physical properties
» Conclusions
14/09/2011 3© 2011, VITO NV
IntroductionSpray drying principles and equipment
» Continuous production of dry powder, granules or agglomeratesfrom slurry or liquid by rapidlydrying with hot drying medium (mostly air)
» One step, continuous» Capacities from labscale up to
over 100ton/h» Mostly spherical granules are
obtained» E.g. pharma, food, catalyst
preparation, ceramic industry…
Suspension preparation
Spray drying
Classification
Calcining
(Reactive) Sintering
Raw materials
14/09/2011 4© 2011, VITO NV
Spray dryer Niro SD-6.3-N
» Critical parameters» Inlet T» Outlet T» Viscosity slurry» Surface tension» Solid content» Feed temperature» Volatility solvent» Nozzle type» Calcination and sintering
(rate, t, T)
IntroductionSpray drying principles and equipment
After www.niro.com
14/09/2011 5© 2011, VITO NV
Model calculation for VITO unit
14/09/2011 6© 2011, VITO NV
Primary → granulated powder
14/09/2011 7© 2011, VITO NV
Particle morphology
K. Masters, Spray Drying Handbook 4th ed. 1985
14/09/2011 8© 2011, VITO NV
Particle morphology
heat
Moisture release (evaporation)
14/09/2011 9© 2011, VITO NV
» Innovative development of scale up ready particle preparation routes
» e.g. 120 kW unit TUVienna
The ideal oxygen carrier particle:» High activity through high and
accessible surface area» High selectivity» Resistance to poisoning » Structural integrity, for good
multicycle -performance and long service life
» Cost, including environmental and safety costs.
After Oil & Gas Science and Technology (2011) 66, 2: 161-172
IntroductionSpray drying of oxygen carriers in Innocuous
14/09/2011 10© 2011, VITO NV
Role of VITO
» Full processing of OC batches by spray drying (batch size up to 1000 kilo)
» Flexible for » composition» size range » mechanical strength
» Materials characterization» Physico-chemical eg. size distribution, porosity, …» Mechanical eg. crushing strength
14/09/2011 11© 2011, VITO NV
Outline
» Introduction» Spray drying principles and equipment» Spray drying of oxygen carriers in Innocuous
» Results» Batches» Scale up» Particle morphology and physical properties
» Conclusions
14/09/2011 12© 2011, VITO NV
BatchesSEM images of particles (1kg batches)
» E.g. Ni based O-carriers from previous projects (CLC Gas power)» Ni-compounds of different suppliers tested» ~no difference with freeze granulated particle in CLC-operation» NiAl2O4 can be considered as an inert support material since no α-Al2O3-
phase was detected after sintering.
14/09/2011 13© 2011, VITO NV
After reactivity testing
Batchescharacterization and reactivity testing
» OC based on Vogler Brown grade, Umicoreand OMG HSA grade NiO showed a high reactivity but a too low crushing strength (<1 N)
» The sphericity was maintained during the reactivity analysis
» Increasing sintering time increases apparent density and crushing strength
» Oxygen carriers sintered for a longer time displayed a higher gas yield early in reduction and hence a lower fraction of unreacted CH4
» Gas yield and fraction of unreacted methane were practically identical, thus no unexpected difficulties should be expected during scale-up in particle production.
14/09/2011 14© 2011, VITO NV
Mechanical testing of spray dried samples: comparison of methods
» Instron measurement visualizes the crushing behaviour (force vs. displacement)
» Importance of reliable test in view of attriation behaviour and particlelifetime
14/09/2011 15© 2011, VITO NV
Mechanical testing of spray dried samples: conclusions
» Effect of sintering:» increased strength for higher sintering temperatures (as expected); » non-linear, exponential increase of strength with sintering temperature
» Effect of fraction (100-200 vs. 180 -200 µm): no clear effect observed
» Effect of crushing speed (‘cross head speed’) 0.5 – 2.0mm/min: highercross head speed gives slightly lower strengths
» Instron test bench allows for accurate measurements, over the wholerange of particle strengths
» Comparison attrition tests vs mechanical properties under investigation
14/09/2011 16© 2011, VITO NV
Outline
» Introduction» Spray drying principles and equipment» Spray drying of oxygen carriers in Innocuous
» Results» Batches» Scale up» Particle morphology and physical properties
» Conclusions
14/09/2011 17© 2011, VITO NV
Conclusions
» Spray drying is a well established industrial methods for production of dry solid particles in large quantities.
» Catalyst particles were spray dried at VITO and characterized and tested in CLC GP project partners laboratories and fluidized bed reactors
» Particles show similar behavior as freeze granulated particles, although shape is somewhat different» Strength» Particle size» Defluidization» Agglomeration» Fuel conversion
» Ni-free materials were spray dried, the experience of Chalmers, CSIC, and VITO with oxygen carrier preparation, using freeze granulation, spray drying and impregnation techniques, will form the basis of development of scale up ready processes.
14/09/2011 18© 2011, VITO NV
Acknowledgements
» EC project FP7 Innocuous for financial support
» Previous project: EC project FP6 CLC Gas Power
» Chalmers University of Technology, TUVienna, CSIC
» Raymond Kemps, Myrjam Mertens, Willy Hendrix, Annemie De Wilde
14/09/2011 19© 2011, VITO NV
Backup slides
14/09/2011 20© 2011, VITO NV
Particle morphology
K. Masters, 2002