Power-to-gas process with high temperature electrolysis and CO2 methanation

Transcription

1 Power-to-gas process with high temperature electrolysis and CO2 methanation Myriam De Saint Jean, Pierre Baurens, Chakib Bouallou To cite this version: Myriam De Saint Jean, Pierre Baurens, Chakib Bouallou. Power-to-gas process with high temperature electrolysis and CO2 methanation. IRES: International Renewable Energy Storage Conference and Exhibition, Nov 2013, Berlin, Germany. pp.session E1. <cea > HAL Id: cea Submitted on 13 Mar 2014 HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

2 POWER-TO-GAS PROCESS WITH HIGH TEMPERATURE ELECTROLYSIS AND CO 2 METHANATION IRES 2013 Session E1 Myriam De Saint Jean 1,2 Pierre Baurens 1 Chakib Bouallou 2 1 LTH LITEN CEA & 2 MINES ParisTech Contact : myriam.desaintjean@cea.fr NOVEMBER 19 th 2013 Myriam De Saint Jean IRES 2013 Power-to-SNG process with HTSE and methanation PAGE 1

3 CONTENTS 1. Energy background 2. Power-to-Substitute Natural Gas process with high temperature steam electrolysis and CO 2 methanation 1. Power-to-SNG : architecture studied 2. High temperature steam electrolysis Presentation Modelling 3. CO 2 methanation Presentation Modelling 4. Full power-to-sng process 3. Results and conclusion 1. Parametric study results 2. Conclusion 2

4 ENERGY BACKGROUND Myriam De Saint Jean IRES 2013 Power-to-SNG process with HTSE and methanation PAGE 3

5 Energy background POWER-TO-SNG : A SOLUTION FOR ELECTRICITY STORAGE High consumption periods Excess electric production Transportation of energy from production areas to consumption areas Substitute Natural Gas (methane) Source : Spetch et al

6 Energy background A LINK BETWEEN TWO NETWORKS Gas-to-heat Electrical Network Irregular production Excess Production = Consumption Distribution and storing Natural gas network Gas-to-mobility Gas-to-chemistry Gas-to-power Electric ressource Unstorable Irregular production Network congestion Final user Avantages PtSNG and GtP Use of existing natural gas network Mid or long term storage Transportation Production of electricity Connection of the 2 netwoks 5

7 POWER-TO-SNG PROCESS WITH HIGH TEMPERATURE STEAM ELECTROLYSIS AND CO 2 METHANATION Myriam De Saint Jean IRES 2013 Power-to-SNG process with HTSE and methanation PAGE 6

8 Power-to-SNG : HSTE + CO 2 methanation Architecture STUDIED POWER-TO-SNG PROCESS ARCHITECTURE Thermal integration HTSE STORING Methanation Wobbe index W = HHV ρ HT Fuel Cell Recycling CO 2, H 2 O and H 2 NG type H NG type L HHV (kwh/nm 3 ) 10,7 12,8 9,5 10,5 W (kwh/nm 3 ) 13,4 15,7 11,8 13 Composition (% vol ) CO < 2, CO 2 < 3, H 2 < 6 (mg/nm 3 ) H 2 O < 55 Thermal integration Steam reforming RECOVERY 7

9 Power-to-SNG : HSTE + CO 2 methanation HTSE Presentation HIGH TEMPERATURE STEAM ELECTROLYSIS e - e - H 2 O H 2 H 2 O + 2e - H 2 + O 2- O 2- O 2-1/2 O 2 + 2e - Cathode Solid Oxide Electrolyte Anode HTSE avantages High temperature : H decrease Irreversibility decrease High efficiency Reversible (SOEC /SOFC techno) Thermal behaviours : Exo, auto et endothermal Reactants : H 2 O and / or CO 2 : co-electrolysis O 2 H 2 O (g) H 2 + ½ O 2 T = 1073 K HTSE current limitations R&D Cost Long-term degradation of performances Source : Graves et al

10 Power-to-SNG : HSTE + CO 2 methanation HTSE Modelling SIMULATION : HTSE MODELLING AND VALIDATION To determine P elec and N cell for a incoming flow Experimental and phenomenological laws. n cath, cell = -0,829 SC + 83,2 with air sweep. n cath, cell = -0,727 SC + 81,8 with O 2 sweep SOEC technology U op = U tn and SC : fixed values Molar and energy balances : P elec Electrochemical modelling : exp. law Determination of N cell (and j) Correction with pressure and stack effects R eq = (U op U Nernst )/j Pressure effect and stack effect R eq = R eq, P P -0,09 R eq, Stack = (R eq,cell + 0,034) N cell Ω.cm² for P [1;10 bar]. Experimental data and interpolated law linking n cath,cell and SC for T = 1073 K, P = 1 bar, U op = U tn, H 2 / H 2 O = 10 / 90, on cells referenced C 941, C 944, D 261, E 15 et E 16. Modelling : Calculation of j and N cell with errors up to 40% cell dispersion effect 9

11 Power-to-SNG : HSTE + CO 2 methanation CO 2 methanation Presentation CO 2 METHANATION Sabatier reaction CO H 2 CH H 2 O RWGS reaction CO 2 + H 2 H 2 O + CO CO methanation CO + 3 H 2 CH 4 + H 2 O Carbon craking CO H 2 C (s) + 2 H 2 O Catalysed reaction Favorable operating conditions for CH 4 production : P et T Avantages of CO 2 methanation No CO at moderate T High CH 4 selectivity Exothermal reaction High conversion yield Existing catalysts Equilibrum at P = 15 bar for H 2 /CO 2 = 4 Current limitations of CO 2 methanation Poor literature on kinetic laws Not a lot of experiemental data published, preference given to syngas (CO + H 2 ) methanation 10

12 Power-to-SNG : HSTE + CO 2 methanation CO 2 methanation Modelling SIMULATION : METHANATION MODELLING 2n n PH 2OP /RT n 4n CH4 r mol.s. m = e PCO P 2 H - 2 K n éq (T) T² T -3 K eq(t) = exp lnt T Plug-flow reactor with fixed-bed catalyst and boundary conditions Pressure (bar) n Kinetic law from literature (Cat Ru) [Lunde 1974, Ohya 1997] 1D plug-flow reactor modelling Kinetic law (cat Ru) Pressure 16 bar Adiabatic behaviour Inlet temperature = 573 K Outlet temperature < 973 K Simulation and experimentation agreement for n = 0.5 (P = 2 bar ) for P exp [3.4 ; 7] Higher P, lower gap between simulation and experimentation, n used 11

13 Power-to-SNG : HSTE + CO 2 methanation Full process SIMULATION : PERIMETER AND HYPOTHESES η AC / DC = 0.92 ΔP hexch = 0.2 bar ΔT hexch = K H 2 /H 2 O HTSE = 1 / 9 H 2 /CO 2 meth = 1 / 4 Cold unit (273 K) EER elec = 1.73 Electric heaters η =

14 Power-to-SNG : HSTE + CO 2 methanation Full process O 2 H 2 O 293 K 100 bar 293 K 1 bar Electric heater 314 K SOEC Reactor R K 17,1 bar H 2 production 573 K 16 bar 740 K 573 K H 2 O SNG H 2 CO 2 O 2 CO / H 2 TEG MEA 345 K 12,8 bar CO 2 Absorber H 2 O 300 K Absorber 12,6 bar O K 18 bar SNG 293 K 4 bar CO 2 Reactor R1 Reactor R3 836 K 573 K 642 K 13,4 bar 293 K CH 4 production Purification H 2 O n HHV SNG SNG SNG SNG η= P + P + P + P elec, HTSE elec, mech elec, hot elec, cold n HHV η = P elec, HTSE = 0. 13

15 SIMULATION RESULTS & CONCLUSION Myriam De Saint Jean IRES 2013 Power-to-SNG process with HTSE and methanation PAGE 14

16 Results and conclusion SIMULATION : PARAMETRIC STUDY Parametric study results U op = U tn, SC = 75%, H 2 /CO 2 = 4, P meth = 16 bar, T HTSE = 1073 K Reference case : P CO2 = 100 bar P SNG = 4 bar P HTSE = 17 bar H gas Sensitivity : P CO2 = 5 bar P SNG = 16 and 80 bar P HTSE = 2.5 bar B gas Electricity consumption except HTSE Ref P SNG = 16 P SNG = 80 P CO2 = 5 L gas P HTSE = 2.5 Ref Ref P SNG = 16 P SNG = PP CO2 CO2 = = 5 5 gaz L gas B P EVHT P HTSE = 2,5 = 2.5 P mech P hot P cold P HTSE Injection on H or L gas network : no influence on energy efficiency η Kind of network (transportation or distribution): high influence on η CO 2 origine (separation or storage) : high influence on η P HTSE : very high influence on η : loss of 7.4 pts (9.6%) regarding ref. case η HP 77% η LP 70% 15

17 Results and conclusion CONCLUSION Conclusion HTSE modelling for sizing with experimental law Kinetic law and modelling of methanation Adequation between modelling results and experimental data Adequation between simulation results and observed performances Production of SNG matching with the specifications Two gas qualities (H and L) are achievable Scale-up of methanation stage Purification of produced SNG Higher efficiency if The process is operated at high pressure CO 2 from industrial storage is used 16

18 POWER-TO-GAS PROCESS WITH HIGH TEMPERATURE ELECTROLYSIS AND METHANATION IRES 2013 PAGE 17 Myriam De Saint Jean IRES 2013 Power-to-SNG process with HTSE and methanation Commissariat à l énergie atomique et aux énergies alternatives Centre de Grenoble GRENOBLE Cedex 09 Etablissement public à caractère industriel et commercial RCS Paris B Direction de la Recherche Technologique Liten