Development of a 2 kw Direct Methanol Fuel Cell System for Backup Power

Transcription

1 Development of a 2 kw Direct Methanol Fuel Cell System for Backup Power Piero Lunghi Conference, Rom, December 2013 Martin Müller, Nicola Kimiaie, Andreas Glüsen, Detlef Stolten

2 Outline DMFC Backup Power System Methanol or hydrogen DMFC systems in the kw power range DMFC system for backup power Demands Setup System costs / reduction of costs Market situation Technical challenge à lifetime of 10 years Use of commercial available MEAs Identification of operating strategies 21. June 2013 Institute of Energy and Climate Research IEK-3: Electrochemical Process Engineering 2

3 Methanol or Hydrogen Methanol Energy density (4,42 kwh/l) Large range without refueling (1,2 kwh/l) Liquid Fuel Easy refilling Easy handling As biofuel available Closed CO 2 -loop specific energy content [kwh/l] H 300 bar 200 bar 300 bar H2 cylinder bundles CH 3 OH 300 bar H2 Methanol Institute of Energy and Climate Research IEK-3: Electrochemical Process Engineering 3

4 DMFC Systems in kw Range More than ten years of progress DMFC systems Research & Development Topics n MEA composi?on and manufacturing n Electrochemical characteriza?on n Durability tes?ng n Stack development and manufacturing n System development and tes?ng Horizontal order picker system à Durability 3000 h and now > 20,000 h 2014 Backup power system à Cost compe==ve à Durability 10 a 2 W 50 W monopolar stack design 500 W 650 W 2003 Systems to demonstrate feasibility à Gold coated Ti collector plates bipolar stack design 2005 First integrated system à Bipolar plates from expanded graphite 2007 Horizontal order picker system à Automated stack manufacturing 2006 Improved system à Modified control strategy 1996: development of cells : stack development : system development : light trac=on : industrial applica=ons Institute of Energy and Climate Research IEK-3: Electrochemical Process Engineering 4

5 Goals for Developing DMFC Backup Power Costs per kwh el (~ 10,000 /kw) Power 1 kw- System power Low maintenance Range 24 h Dynamically load (> h opera?on) Power [W] Time [h] Simplifica?on of system Use of commercial MEAs Scale up Size of tank Standby opera=on Demands Backup Power Supply Costs per kwh el Comparable with H 2 - System Power 1-3 kw Low maintenance (Remote Control) Range 72 h Sta?c load (Life?me 10 a) h opera?on Power [W]? Time [h] Institute of Energy and Climate Research IEK-3: Electrochemical Process Engineering 5

6 Setup and Technical Data of a DMFC Backup Power System Heat, H 2 O, CO 2 P el System Power Lifespan Integra?on Simplifica?on & cost reduc?on Water autonomous Methanol 2 kw 10 a Electric board (19 ) Remote control No CVM Stack Nominal Power 2.4 kw Number of cells Cell area MEAs No CH 3 OH sensor Up to 35 C ambient temp. Range 72 h (>70 l) cm² Commercial available Institute of Energy and Climate Research IEK-3: Electrochemical Process Engineering 6

7 Specific Production Costs of DMFC Systems for Backup Power in the kw Range Institute of Energy and Climate Research IEK-3: Electrochemical Process Engineering 7

8 Backup Power for Telecom. Remote Stations Market Situation and Competition Mobile networks Worldwide growth of the number of master sta?ons Growth of the energy supply with diesel engines Decrease of the local power consump?on (1.7 kw à 1.1 kw) Number of sta?ons [Mio.] Sta?ons worldwide Diesel generators Share of diesel generators [%] Year Source: IEEE Communica,ons Magazine, 08/2011 Asia and Africa: decentralized infrastructure in telecommunica?on sta?ons India: Ofen electricity blackouts of more than h a day [Bhar? Infratel] Trend of the marked: Combina?on of FC with regenera?ve energy sources (Photovoltaic, Wind) à ~500 opera?ng hours per year [GSMA, Frost & Sullivan] Institute of Energy and Climate Research IEK-3: Electrochemical Process Engineering 8

9 Backup Power for Telecom. Remote Stations Market Situation and Competition Civil service radio (TETRA) Germany à ~4.500 sta?ons Denmark à ~500 sta?ons Addi?onal countries Boundary condi?ons 72 hours availability in case of electrical black out Available backup power systems Fuel costs Scaling Maintenance Energy density Emissions Diesel generator H 2 - fuel cell DMFC Institute of Energy and Climate Research IEK-3: Electrochemical Process Engineering 9

10 Technical Challenge: 10 Years Lifetime 10 Years in use à 87,600 h in use ~ 5,000 h in regular opera=on Degrada=on in opera?on: < 10 µv/h 0.1 A/cm²; 70 C ~ 80,000 h in standby Degrada=on during stand s?ll: < 1 µv/h 0.1 A/cm²; 70 C à What is the best standby strategy? Power [W] Time [h] Institute of Energy and Climate Research IEK-3: Electrochemical Process Engineering 10

11 20,000 h Durability Test of DMFC Fork Lift System Average cell voltage [mv] Degradation rates: till 580 h after 580 h Power [W] Time [h] à Water autonomous operation up to 35 C ambient temperature à Over all efficiency 29 % Operation time [h] Institute of Energy and Climate Research IEK-3: Electrochemical Process Engineering 11

12 Performance and Durability Tests of Commercial MEAs in Continuous Operation (single cell) Cell Voltage [V] Aim: Degrada=on rate in opera=on < 10 µv/h 0.1 A/cm²; 70 C 0,8 0,7 0,6 0,5 0,4 0,3 0,2 0,1 0,0 MEA JM MEA SC MEA EC MEA LC MEA IR Johnson Matthey Solvicore Elcomax Linecoater Jülich 0 0,05 0,1 0,15 0,2 0,25 0,3 Current density [A/cm²] IRD Degradation from 500 h to 1500 h 70 C, 0.1A/cm² Cell area: 18 cm² MEA Degrada=on rate Institute of Energy and Climate Research IEK-3: Electrochemical Process Engineering 12 JM LC EC SC IR 9 µv/h 13 µv/h 0 µv/h 1 µv/h

13 Durability in Standby Mode: Study of the Operating Conditions and their Influence on Degradation Aim: Degradation rate during stand still < 1 µv/h 0.1 A/cm²; 70 C Standby modes: Water anode / air cathode Dry (air) anode / air cathode Anode methanol and water / cathode closed Institute of Energy and Climate Research IEK-3: Electrochemical Process Engineering 13

14 Durability During Standby Short Stack Tests (wet anode / air at the cathode) Boundary conditions: 70 C 0.1A/cm² 5 cell stack Cell area: 315 cm² à 6 µv/h Institute of Energy and Climate Research IEK-3: Electrochemical Process Engineering 14

15 Durability During Standby Short Stack Tests (dry anode / dry cathode) Boundary conditions: 70 C 0.1A/cm² 5 cell stack Cell area: 315 cm² à 7 µv/h Institute of Energy and Climate Research IEK-3: Electrochemical Process Engineering 15

16 Durability during standby - Short stack tests (methanol/water supply anode / cathode clothed) Boundary conditions: 70 C 0.1A/cm² 5 cell stack Cell area: 315 cm² à 1.5 µv/h Institute of Energy and Climate Research IEK-3: Electrochemical Process Engineering 16

17 Additional Alternative Standby Strategies Single Cell Tests Cell Voltage [V] 0,8 0,7 0,6 0,5 0,4 0,3 0,2 0,1 0,0 After Start- up and 500h operation After 2500h Standstill dry After Start- up and 500h operation After 2500h Standstill filled and closed After Start- up and 500h operation After 2500h Standstill filled with water After Start- up and 500h operation After 2500h Sandstill Anode fed with methanol, cathode closed After Start- up and 500h operation After 2500h Standstill anode fed with methanol, cathode open After Start- up and 500h operation 0 0,05 0,1 0,15 0,2 0,25 0,3 Current density [A/cm²] Best Durability during stand- s?ll, Anode fed con?nuously with methanol and water Stands=ll procedure Filled and closed Dried with Nitrogen Filled with water Degradation during standby 2500 h with different conditions 70 C, 0,1 A/cm²) MEA Type JM Anode fed, cathode closed Anode closed, cathode open Degrada=on rate 6.4 µv/h 4.8 µv/h 2 µv/h 1.2 µv/h 6.4 µv/h Institute of Energy and Climate Research IEK-3: Electrochemical Process Engineering 17

18 Conclusions Economical DMFC is a cost competitive technique for backup power Commercial MEAs with low degradation rates are available Procedure for stack treatment in standby was identified Single cell à 1.2 µv/h (stand still) Short stack à 1.5 µv/h (stand still) à < 9 µv/h (in operation) Outlook Deeper knowledge of effects in standby mode is necessary Increasing of efficiency and power density Use of technical methanol Institute of Energy and Climate Research IEK-3: Electrochemical Process Engineering 18

19 Direct Methanol Fuel Cell (DMFC) Compact Systems for Light Traction and UPS MEA Development Stack Development Systems Development MEA production center Analy?cs & Diagnos?cs Stack production center R&D Challenges Cost reduction CO 2 emissions Hybridization Water autonomy Systems efficiency Prototype development