U DAY B. P AL D EPARTMENT OF M ECHANICAL E NGINEERING D IVISION OF M ATERIALS S CIENCE AND E NGINEERING B OSTON U NIVERSITY Clean Energy Week: University Research Briefing Day NOVEMBER 11, 2009 Green Technology Research at Boston University

2 Green Processing Research at BU Waste to Energy Conversion Current BU Team: Pal and Gopalan  Problems with solid waste  10 lb per person/day of SW (US)  170 million tons/yr is landfilled  Energy value 6.4 MJ/lb of SW BU Technology (SOM Electrolyzer) Meet up to 5-10 % of US annual energy consumption Solve waste disposal problem Reduce carbon foot print Production of High Purity H 2 Expensive $120/kg Based on fossil fuel/electrical energy Net negative environmental impact BU Technology (SOM Electrolyzer) Less Expensive Does not use fossil fuel (more energy efficient) Facilitate hydrogen economy Ideal for Potential Start-ups Teaming with Municipalities and Large Companies Potential Internal Collaborators: ITEC and SMG Funding Sources: DOE, NSF, and VCs

MTTC Sponsored Green Processing Research at BU Waste In Liquid Metal Anode Syn–Gas Out Solid Oxide Membrane O 2- Porous Cermet Cathode Steam In Pure H 2 Out V DC V DC Combustion/ Gas Turbine Combustion/ Gas Turbine Fuel Cell

ADVANTAGES : SOLID OXIDE MEMBRANE (SOM) ELECTROLYZER - Electrochemical conversion of H 2 O(g) High purity H 2 - Efficient way of converting energy value in waste

SOM Feedstock Candidates Wood/Lumber Plastics Food Bio-mass Oil Animal Carcasses Biological Wastes Cardboard Chemicals Coal Methane Natural Gas Any hydrocarbon source!

Experimental Liquid Metal + Waste Ni-YSZ Cathode tube YSZ coating Waste In H 2 O ( Entry) Syn Gas (Exit) Pure H 2 exit Refractory separator Iron Crucible

Specifications Anode StructureTubular COE No of Anodes13 Total active anode length (cm)515 Active Anode Area(cm 2 ) Crucible ID (cm) Active Cathode Area (cm 2 ) Current Density1 A/cm 2 Hydrogen Production Rate 225 ml/min675 ml/min SOM Reactor for Lab Scale Production of Hydrogen

Green Processing of Energy Intensive Metals (Si, Ti, Mg, Ta, and Al) Current BU Team: Pal and Powell BU Technology (SOM Electrolyzer) Oxide feed (little or no feed preparation) Lower dissociation potential Higher efficiency Environmentally friendly – Oxygen evolution at the anode Existing Electrolytic Process Chloride feed preparation Higher dissociation potential Lower efficiency Environmentally Hazardous – Chlorine and its byproducts form at the anode Potential External Collaborators: MIT, WPI, Primary Metals Industries, DOE Labs Potential Internal Collaborators: ENG (BME and ME) Funding Sources: DOE, ARPA-E, VCs

DOE/NSF/Industry Sponsored Research Schematic of the BU Electrolyzer for Green Processing of Metals DC Solid-Oxide Oxygen Ion Conducting Membrane(YSZ) ‏ Anode O 2– (melt)  O 2– (YSZ) Ionic Melt with Dissolved MeO Me 2+ (melt) + 2e –  Me ‏ Cathode V O2–O2– O2–O2– O 2-  ½ O 2 (g) + 2e

Experimental SOM Reactor Stainless Steel construction Single Tubular YSZ membrane Separate chamber for Electrolysis and Condenser 15 g/hr of Mg at 1 Amp/cm 2 10 w% MgO in 55.5 w% MgF 2 - CaF 2 at 1150 o C Argon used as carrier and diluent for Magnesium vapor

Setup 1 cm 3 cm

Potentiodynamic Sweep at C MgO Dissociation

SOM Electrolysis of MgO Potentiostatic Hold at 4.0 Volts MgO concentration is decreasing 1150 o C

SOM Electrolysis of MgO Condensed Magnesium

SOM Design with Three Tube Arrangement (0.5-1 Kg/day) Mg(g) + Ar Ar MgO Feed Tubular YSZ COE Anode Hydrogen Inlet Tube & Anode connection Argon Bubbling Tube Reactor Condenser Cathode Connection

Top and Side Views of the Possible Scale-up Version of the SOM Electrolytic Cell Steel Cathode SOM Anode Mg Vapor Sujit Das, “Primary Magnesium Production Costs for Automotive Applications,” J. of Metals, 60(11), 2008, p. 63.

SOM Features for Mg Production Cost Effective & Environmentally friendly – Direct reduction of Magnesium oxide – Minimize pre-processing, reduce capital and operating cost High Current Density ( >1 Amp/cm 2 ) – with high applied voltages  Good Scale up Potential Reformation of Natural gas due to high temperature operation Specific Energy consumption of MgO reduction is 10 KWh/Kg

Waste to Hydrogen  60/760,906 (Provisional Converted) SOM Process  09/002,581( Issued)  2,277, Issued  60/699,970 (Provisional Converted)  PCT/US06/ (PCT Entered National Phase)  11/994,806 (Filed) BU: Clean Energy Patent Applications