1. Multi-Scale Sustainable Reaction Engineering Multi-Scale, Sustainable Reaction Engineering A New Departmental Initiative J. S. Dennis Department of Chemical Engineering, University of Cambridge

2. Multi-Scale Sustainable Reaction Engineering Future Industrial Competitiveness manufacturing across wide range of scales manufacturing across wide range of scales micro- to macro- scale no pre-conceptions about “economy of scale” sustainability of processes sustainability of processes fewer by-products, higher selectivity, high purity, less waste etc. much improved exergetic efficiency to reduce CO 2 footprint flexibility of operation from small to large scale flexibility of operation from small to large scale rapid start-up and shut-down integration of chemical reaction and separation modelling and prediction modelling and prediction rapid design, rapid diagnosis of problems… Reaction engineering has been neglected in recent years in many leading Universities worldwide but it remains a continuing strength for the Department, underpinned by many new developments

3. Multi-Scale Sustainable Reaction Engineering Illustration by Current/ Future Research Reactor and Reaction Efficiency Sustainable Energy Generation Transport Biofuels Modelling

4. Multi-Scale Sustainable Reaction Engineering Reactor and Reaction Efficiency

5. Multi-Scale Sustainable Reaction Engineering MR Multi-scale Application Thiele modulus,  1 10 –3 10 3 Effectiveness factor,  (catalyst performance) 1 10 –6 10 –9 10 –3 10 3 10 6 10 9 10 12 10 15 STA- 2 DAF- 4 Co AlPOCH Spectroscopy Pulsed Field Gradient (PFG) spectroscopy MRI + spectroscopy PFG L. Gladden, M. Johns et al.

6. Multi-Scale Sustainable Reaction Engineering Trickle Bed - Product Invention trickle flow regime pulsing flow regime transition regime gas velocity constant at 112.4 mm/s liquid velocity = 1.4 mm/s8.4 mm/s13.3 mm/s Hydrodynamic transition from trickle to pulsing flow occurs via local flow instabilities Catalyst shape can be selected to improve process operation – product launch Velocity on superficial basis liquid in liquid out gas out gas in

7. Multi-Scale Sustainable Reaction Engineering Heterogeneity in Chemical Conversion and Hydrodynamics A B C 10%54%X A B C -0.050.1 v z (mm/s) Feed flowrate = 0.025 ml/min

8. Multi-Scale Sustainable Reaction Engineering Oscillatory Flow Mixing (OFM) M. Mackley A Departmental Invention (M. Mackley) Process advantages Controlled mixing & shear Near plug flow Enhanced heat and mass transfer Homogeneous particles suspension Multi phase mixing Reaction Engineering application Continuous flow Higher selectivity & less waste Higher quality of products Linear scale-up Lower operational costs Unbaffled tube tube BaffledtubeParticleSuspension

9. Multi-Scale Sustainable Reaction Engineering Application of OFM Large-scale reactors “Meso-scale” reactors Continuous Crystallisation Biodiesel production Hydrogenation Polymerisation/Nano-particles Pharma. continuous flow screening Bioprocessing Continuous oscillatory flow meso-reactor. Nitech Solutions Ltd, Scotland Polymer Fluids Group Cambridge

10. Multi-Scale Sustainable Reaction Engineering Innovation Through Electrochemistry Rapid Prototyping using Micro & Nanofabrication 1mm 2mm A. Fisher Microfluidic & microelectrode devices devices continuous analysis continuous analysis integrated miniature sensors integrated miniature sensors study of reactions at interfaces study of reactions at interfaces (+ MRI) (+ MRI) controlled formation of metallic controlled formation of metallic nanoparticles nanoparticles

11. Multi-Scale Sustainable Reaction Engineering Chemical Co-Generation Fisher, Gladden, Dennis The exergetic efficiency of most catalytic reactions is poor since they are conducted far from equilibrium; there can also be significant irreversibility in subsequent heat transfer. So, conduct them in a "fuel cell" arrangement..... e.g. nitric acid production, sulphuric acid production......

12. Multi-Scale Sustainable Reaction Engineering Sustainable Energy Generation

13. Multi-Scale Sustainable Reaction Engineering The challenge is to find a sorbent which The challenge is to find a sorbent which can be reused many times. can be reused many times. Natural limestone (mainly CaCO 3 ) degrades. Natural limestone (mainly CaCO 3 ) degrades. How can it be improved, based on a fundamental How can it be improved, based on a fundamental understanding of the reactions involved? Synthetic sorbents? understanding of the reactions involved? Synthetic sorbents? ZECA – Generation of H 2 from Coal (Imperial/Cambridge) Gasifier Reformer Calciner 4 H 2 Fuel Cell Air CaCO 3 CaO C(s) Work Shift Reactor CO + 3H 2 + H 2 O CH 4 2H 2 2H 2 O CO 2 2H 2 O J. Dennis, S. Scott

14. Multi-Scale Sustainable Reaction Engineering CO + H 2 O CO 2 + H 2 CO 2 + CaO  CaCO 3 * * The percentage completion of this reaction * The percentage completion of this reaction (g CO 2 /g sorbent) is the carrying capacity of the solid (g CO 2 /g sorbent) is the carrying capacity of the solid sorbent. sorbent. KEY REACTIONS Calcination CaCO 3  CaO + CO 2 Carbonation Watergas Shift Separation of H 2 and CO 2 Regeneration of sorbent: CO 2 to storage

15. Multi-Scale Sustainable Reaction Engineering HA-85-850 Number of cycles RESULTS - NOVEL SORBENTS CO 2 Uptake, g CO 2 /g sorbent New sorbent - capacity loss much less. Capacity increases with [CO 2 ] Micropore volume increases with [CO2] Natural sorbent - uptake degrades with no. of cycles of sorption & regeneration. Insensitive to [CO 2 ] Micropore volume continuously decreases Pacciani, Müller, Davidson, Dennis & Hayhurst, A.I.Ch.E.J., paper accepted, July 2008

16. Multi-Scale Sustainable Reaction Engineering SIMPLE MODEL: REACTION IN PARTICLE Macropore volume Micropore (BJH) volume Grain (~ 200 nm) Sorbent Particle (~ 3 mm) (~ 3 mm) Micropore (5 – 100 nm) Micropores fill up with CaCO 3 when reaction largely stops

17. Multi-Scale Sustainable Reaction Engineering STEM HAADF TOMOGRAPHY - Nanoengineering A grain from our synthetic sorbent showing pores in 5 - 50 nm range Collaboration with Prof. Paul Midgeley, Materials Science e.g. Midgley, P.A., Science, 309, 2195 (2005)

18. Multi-Scale Sustainable Reaction Engineering CHEMICAL LOOPING COMBUSTION CH 4 N 2, O 2 Fuel reactor Regenerator Me MeO Air CO 2, H 2 O Fuel Reactor: CH 4 + 4/y Me x O y → 4x/y Me + CO 2 + 2H 2 O Regenerator: 4x/y Me + 2 O 2 → 4/y Me x O y Overall: CH 4 + 2O 2 → CO 2 + 2H 2 O The exergetic efficiency of a plant using chemical looping combustion would be comparable with a conventional IGCC plant Departmental Research: Combining in situ gasification of SOLID fuels with CuO based oxygen carrier for clean coal utilisation J. Dennis, S. Scott

19. Multi-Scale Sustainable Reaction Engineering Suitable for range of scales for H 2 production H 2 production uncoupled from syngas production:  flexibility in fuels being gasified  provides H 2 free of CO x Upgrades low grade syngas to high grade H 2. Pure stream of CO 2 for sequestration Tars are destroyed High Purity Hydrogen from Biomass via Iron Oxide Looping Dennis & Scott (2006). A.I.Ch.E.J., 52, 3325-3328. EPSRC Grant EP/F027435/1.

20. Multi-Scale Sustainable Reaction Engineering Transport Biofuels

21. Multi-Scale Sustainable Reaction Engineering Biomass Conversion to Fuel - Issues Options (i) gasification/GTL (ii) hydrolysis/fermentation Need for profitability at range of scales Feedstock logistics/local pre-processing defines scale of processing plant Objectives set/managed by process modelling LCA, cost modelling, exergy analysis, water use, logistics… “Food vs. Fuel” – algae?

22. Multi-Scale Sustainable Reaction Engineering Biodiesel Pilot Plant - New Process Continuous Pressure 6 bar Temperature ~60 C Production 30 l/h Frequency ~ 4 Hz Product meets BS EN14214 Consistent quality V. small footprint Economic at intermediate scale Reactor Section M. Mackley, R. Skelton

23. Multi-Scale Sustainable Reaction Engineering Algal Biofuels Issues Intensification Energy in < energy out Downstream extraction Possibly the biggest bioreactors ever built Scale-up on surface area Integration with biological science critical. Dennis, Scott, Mackley

24. Multi-Scale Sustainable Reaction Engineering Modelling to Investigate Scale-Up

25. Multi-Scale Sustainable Reaction Engineering THEORY AND EXPERIMENT in CFBC SCALE-UP Observations inside a fluidised bed using Magnetic Resonance Prediction from our recently developed computer code Müller, Dennis, et al. (2006). Phys. Rev. Letters, 96, 15404-1 to 15404-4. Circulating Fluid. Beds (CUED/CanMET/TU Hamburg) oxyfuel firing: modelling of particle motion/reaction Müller, Dennis, Gladden et al. (2007). ICMF 2007, Leipzig Dennis, S. Scott, D. Scott, L. Gladden et al.

26. Multi-Scale Sustainable Reaction Engineering Outlook new senior-level research appointment to area new senior-level research appointment to area strong support from industry partners, e.g. Johnson Matthey, Shell strong support from industry partners, e.g. Johnson Matthey, Shell joint working on projects (exchange of personnel, industry – Dept.) joint working on projects (exchange of personnel, industry – Dept.) projects with Universities having key complementary skills (e.g. Imperial College, Queen’s University Belfast, Ohio State University, TU Hamburg ….) projects with Universities having key complementary skills (e.g. Imperial College, Queen’s University Belfast, Ohio State University, TU Hamburg ….) LOTS TO DO..!!