Power to Gas - state of the art and perspectives

Transcription

1 DVGW Research Center at Engler-Bunte-Institut of Karlsruhe Institute of Technology (KIT) Power to Gas - state of the art and perspectives Frank Graf MARCOGAZ General Assembly: Workshop new developments Prague

2 1. Background 2. Power to gas technologies 3. Challenges for Power to Gas 4. Conclusion 2

3 PtG technology the (missing) link between electricity and gas grid Power grid Gas grid Coal CO/CO 2 natural gas nuclear Renewables methanation electrolysis H 2 CH 4 biogas power plants SNG CHP mobility industry 3

4 Drivers for PtG Power generation Chemical storage of surplus energy Balancing services Transport of electrical energy via gas grid Chemical industry H 2 as feed stock for chemical products deployment of H 2 -distribution infrastructure Mobility Generation of renewable fuels for transport sector (CNG, LNG, H 2 ) deployment of infrastructure for alternative fuels (EC directive in 2 nd half of 2014) 4

5 Gas industry related Power to gas activities Pilot and demonstration projects H 2 generation and injection (e.g. E.ON, Falkenhagen; Thüga, Frankfurt) SNG generation and injection (e.g. Audi e-gas, Werlte) testing of new technologies (e.g. biological methanation) Power to gas platforms and networks North Sea Power to Gas Platform ( Dena Strategieplattform Power to Gas ( Mediterranean Power to Gas Platform Feasibility of H 2 injection HIPS project (GERG): gathering available knowledge and experiences HIPS-NET (DBI/GERG): network aiming for an European understanding on H 2 -limits SUN STORAGE (RAG): Evaluation of H 2 underground storage 5

6 Power to gas projects in Germany 6

7 1. Background 2. Power to gas technologies 3. Challenges for Power to Gas 4. Conclusion 7

8 H 2 O electrolysis State of the art alkaline electrolysers are commerically available PEM electrolysis systems will be available in near future in MW range HT electrolysis is still in research phase several pilot and demonstrations plants are in operation Source: ITM Power H 2 generation costs are not yet competitive Source: Hydrogenics Source: Siemens 8

9 Catalytic and biological methanation Fundamentals CO 2 methanation CO 2 (g) + 4 H 2 (g) CH 4 (g) + 2 H 2 O(g) CO 2 (g) + 4 H 2 (g) CH 4 (g) + 2 H 2 O(l) Δ R H = -165 kj/mol Δ R H = -253 kj/mol CO methanation CO(g) + 3 H 2 (g) CH 4 (g) + H 2 O(g) Δ R H = -206 kj/mol watergas shift reaction CO(g) + H 2 O(g) CO 2 (g) + H 2 (g) Δ R H = -41 kj/mol Operation parameters p in bar T in C catalyst nickel microorganisms 9

10 Catalytic methanation State of the art In the th various processes and concepts were developed for coal based SNG generation (large scale) New SNG plants are planned in China Fixed bed reactor concepts are well established technology fluidized bed, honeycomb and 3 phase reactors are alternatives During the last 15 years methanation was examined in context with biomass gasification (medium size plants), e.g. Gobi Gas project) first demonstration plant coupling PtG and biomethane production started operation this year (Audi E-Gas project) Great Plains (USA); production: 4, m³/d SNG 10

11 Biological methanation State of the art Fundamentals are investigated for decades wide range of input gases is feasible (CO rich gases, flue gas, biogas etc.) Challenging is the mass transfer of hydrogen to the microorganisms First pilot and demonstration plants are in planning and operation phase renewable power electrolyser H 2 in situ digester biomass digester SNG renewable power electrolyser biomass digester a) H 2 CH 4 reactor SNG separate reactor CO 2 or CO rich gases b) 11

12 1. Background 2. Power to gas technologies 3. Challenges for Power to Gas 4. Conclusion 12

13 What are the challenges for PtG? H 2 integration into the natural gas infrastructure need for suitable carbon source (CO or CO 2 ) methanation processes have to be flexible, robust and simple advanced process integration is obligatory to increase overall efficiency Production costs have to be lowered significantly R&D and demonstration are necessary Business cases have to be created 13

14 Challenges for the injection of H 2 H 2 limitations in the natural gas infrastructure pore storage CNG tanks gas turbines/compressors capacity restrictions for H 2 injection interoperability and billing aspects Competition with pure hydrogen usage H 2 mobility H 2 for industrial usage 14

15 Possible CO/CO 2 sources for PtCH 4 small: biogas plants medium: BM-gasification large: industry (NH 3 etc.) 500 m³/h CO m³/h H 2 ( 10 MW el ) product gas (bio methane + SNG): m³/h CH 4 11 MW (chem.) m³/h CO m³/h CO m³/h H 2 (8 100 m³/h from electrolysis) product gas: m³/h CH 4 50 MW (chem.) m³/h CO m³/h H 2 ( 600 MW el ) NH 3 -Plant: CO 2 is by-product product gas: m³/h CH MW (chem.) suitable carbon sources are available

16 Efficiency of PtG-Processes 16

17 Process integration PtG - biomethane Electrolyser (P el = 10 MW) Methanation biomass Digester Desulphurization CO 2 removal P th = 650 KW 1) Drying digestate energy efficiency > 80 % Injection (16 bar) DVGW Project PtG concepts 1) To steam turbine 17

18 KIC project DemoSNG (I) Power to Gas + Gasification honeycomb methanation Consortium DVGW-EBI KIT KTH Cortus Gas Natural Fenosa Objectives Design and installation of bench scale methanation unit (capacity: 10 m³/h) tests at Cortus gasification plant Combined CO/CO 2 methanation in PtG mode 18

19 KIC project DemoSNG (II) Cortus Woodroll Gasifier Methanation module 19

20 Economic evaluation of PtCH 4 CM biogas with H 2 BM biogas with H 2 BM biogas II with H 2 BM CO 2 with H 2 CM gasification with H 2 CM biogas without H 2 BM biogas without H 2 BM biogas II without H 2 BM CO 2 without H 2 CM gasification without H 2 specific SNG production costs in Ct/kWh (HHV) full load hours: electricity price: methanation capacity in MW, (HHV SNG) BM: Biological methanation CM: Catalytic methanation 3000 h/a 5 Ct/kWh DVGW Project PtG concepts ; Techno-economic evaluation of biological methanation 20

21 1. Background 2. Power to gas technologies 3. Challenges for Power to Gas 4. Conclusion 21

22 Conclusion Power-to-Gas is a promising option for the injection and usage of renewable gases H 2 and SNG route should be pursued coupling with biomass related processes increases area-related methane yield by CO 2 methanation Process integration enables high energy efficiency and further benefits for coupled processes Generation cost are not competitive, advances in the manufacturing of electrolysis offers relevant potential for cost reduction Costs for methanation process are much lower than for electrolysis Further experiences have to be gathered in pilot and demonstration plants Transport sector could be the main driver 22

23 Let s go forward together! Dr.-Ing. Dipl.-Wirt.-Ing. Frank Graf Tel.: 0721 / [email protected] 23