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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

http://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)

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» 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


» 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

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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


» 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

scaleup of o-carrier production for chemical looping ... · pdf filescaleup of o-carrier...

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