Pratik Desai AMIChemE AMInstP GradEI Professor William B S - - PowerPoint PPT Presentation
Hot Microbubble Injection in Thin Liquid Layers for Ammonia Water Separations Pratik Desai AMIChemE AMInstP GradEI Professor William B S Zimmerman BSc PhD Problem Description S Ammonia in Leachate is an environmental hazard - Lowering
S Ammonia in Leachate is an environmental hazard - Lowering
Ecotoxicity - Requires High Cost for Ammonia Removal! EQS = 0.39 mg/l, landfill conc. = 50-3000 mg/l
S Ammonia Production (Haber-Bosch) is energy intensive -High
Pressure , Low Temperature
S 2 % of world’s energy used for ammonia production , 0.5% used for
remediation. Ammonia used for several products – fertilisers, adjuvants, fuels, explosives, high value chemicals
Tackle problem in two steps Design new microbubble unit operation – Microbubble Stripping Lower leachate ecotoxicity by ammonia recovery & try to sell ammonia either as a pure product or upgrade it and sell it as a more valuable chemical via Desai-Zimmerman MMARP
Increase in publication on ammonia removal from landfill leachate. Source: Scopus
S Processing Time designated as Indicator (Efficiency as well) S Variables decided – Benchmarking to be performed once
results are obtained
Microbubbles (Mb) > 1µm <1000 µm >HX & MX for smaller bubbles ( >> SA/V ratio) Microbubble Generation - requires surface energy
No-moving part bi-stable diverter valve – Several benefits
Steady Flow Bubble Formation Oscillatory Bubble Formation
Temperature gradient (Ethanol-Water) Concentration gradient (Ammonia-Water)
identification of operational parameters
Ammonia -Water used for identifying operational parameters Selected as main performance together with efficiency – Shorter the processing time, greater is the throughput possibility!
S Factorial Design of Experiment
Runs determined by the interaction between the different effects and therefore lot more information obtained from the same set of data obtained differently!
FC PC TI FI TI
AIR INLET FLUIDIC OSCILLATOR DIFFUSER BLEED VALVES ELECTRIC HEATER MICROBUBBLE GENERATION (HXRig)TI TI TC TI
S Sintered Steel Sparger –
S Inexpensive S Bespoke design based on calculations S Material Selection – Sintered SS – Durable , easy
to manufacture, possibility to make it really thin – 100 m μ
S Low pressure drop- 20 mbar – Calculations from
Holdich et al ,2006 – maintained by larger orifice – 100-150 m , greater porosity & thinner sparger μ
S Very effective separation observed for Ammonia Water! S Operational conditions identified for leachate
Removal at pH < 9 still achieved. NH3 + H2O NH4+ + OH- ↔ Bubbles are vapourising water and driving equilibrium towards ammonia generation
S KD is on the 101 magnitude. S Srinath and Loehr (1974) report KD on the 10-3
magnitude; Smith and Arab (1988) between 10-3 and 10-2.
Ammonia Removal in Leachate ?
YES!
Cheung et al. (1997) Cheung et al. (1997) Cheung et al. (1997) Kabdasli et al. (2000) Marttinen et al. (2002) Marttinen et al. (2002) Silva et al. (2004) Collivignarelli et al. (1998) 20 40 60 80 100 0.1 1 10 100 1000 Stripping efficiency (%) Processing time (h) Stripping Adsorption Chemical precipitation Oxidation
15,000 times for some ammonia rich liquors!
Pratik D Desai Professor William B J Zimmerman
Microbubble Mediated Ammonia Recovery Processes
Leachate
Ammonia Removal, COD/BOD Reduction, Heavy Metal Ion Densi ication and Increase in Optical Transparency Removal of Heavy Metal Ions & Need for BOD/ COD, Lipid Production
Micro lotationSeparation of MAC & Recovery of Metals, Sewering the remnant off.
Flue Gas enriched using FO mineral carbonation/ Ammonia Mb Intervention 1 – Preprocessing Mb Intervention 2 – Increased Growth Rate Mb Intervention 4 – Algal flotation and separation Ammonia converted to other products –
by WBJZ and PD – High Value product
Cat
running)
conversion – Patent pending – work proceeding from IIKE 1 and IIKE 2 Mb Intervention 3 – Microbubble condenser Lipid rich MACs to be used for energy recovery Biomass used for AD – Energy plus CHP – Energy Catalyst
We can make Carbamate at RT and Atm P without catalyst. 50% Ratio but tuneable – Carbamate and Carbonate. 70% conversion per pass.
+ NH3 (aq) Optimise to select for mono- di- tri-ethanolamines Scheme 2 O H2N OH HN OH 2 N OH 3 O HO + NH3 (aq) HO NH2 OH High value chiral intermediates
R1 O R2 O + NH3 (aq) N H R2 R1 Stable aromatic products Relatively poor aqueous solubility Scheme 1
S CO2 injection can cause 110% (unoptimised) increase in
production rate for biogas ( untreated wet foodwaste)
S We can sustainably recover ammonia from ammonia rich
liquor.
S We can generate tuneable salts of carbamate and carbonate
at RT/AtmP and this is exothermic and this can sequester CO2
S Combining these concepts together, we have a sweetening
process and a reduced CAPEX ,increased payback AD with process integration
S Hot microbubbles can achieve up to 97% efficiency in 30
minutes for a broad range of concentrations – up to 25% greater and in 98% less time than industry
S Cold microbubbles yield a MTC 1000 times greater than
conventional stripping. 3000 times for hot microbubbles and 15000 times for certain liquors
S Adding alkali increased efficiency by up to 105 % BUT…
Stripping at pH> 9.0 can be achieved with hot microbubbles
S Microbubbles can influence chemical equilibria to generate and
strip ammonia
S Hot microbubble mediated ammonia recovery – in talks
with large waste management company
S Microbial algal consortia – 1. IIKE award for PoC , NERC
award for pilot scale, 2.Grantham Scholar supervision
S Tunable salts of Ammonium Carbonate/Carbamate – 50%
generation of each salt , 70% conversion per pass for POC. Pilot scale- Energy Catalyst
S Working on larger scale implementation of MMARP-
‘Waste Factory’ led by me.