水素製造システム（第 3回） まとめ

1 1 Kyushu University UI project Kyudai Taro,2007 CO2 2 Kyushu University UI project Kyudai Taro,2007 40% 20% 40%3 1. 2. Kyushu University UI project Kyudai Taro,2007 No CO2emission ! Kyushu University UI project Kyudai Taro,2007 5 Kyushu University UI project Kyudai Taro,2007 6 Well CO i,ii,iii ( 2005 2007) TankWheel ( 1 2 % ) LPG 50% ( 1 4 % ) ( 2 1 % ) ( - ) ( - ) ( 3 % ) FCV III LH IIICO2CO2CO2 CCSCCSK yushu University UI project Kyudai Taro,2007 CH4+H2O CO+3H2H2+ H2O 7 Kyushu University UI project Kyudai Taro,2007 8 Kyushu University UI project Kyudai Taro,2007 9 G= H T S= U P V T S G<0 G>0 H2(g)+ (g) H2O(l); 298 = kJ/molH2O(l) H2(g)+ (g).

2 298 = Kyushu University UI project Kyudai Taro,2007 Steam reforming of methaneCH4+H2O CO+3H210 GT<700: positiveT>700: negative Reaction takes place when T>700. H Always positive=endothermic: Heat is necessary. 3 Kyushu University UI project Kyudai Taro,2007 Shift reactionCO+H2O CO2+H211 G Negative at low temperatures. Slightly exothermic 3 12 MRF (Pd )H2H2H2CO2CH4 COCH4H2O CH4+ H2O CO + 3H2 (CH4) CO + H2O CO2+ H2 3 Kyushu University UI project Kyudai Taro,2007 13 H+H2O2 Cathode2H++2e-=H2 AnodeH2O=2H++1/2O2+2e-TotalH2O=1/2O2+H2e lectronDC powersourceKyushu University UI project Kyudai Taro,2007 Why water electrolysis takes place?14 Mixture of hydrogen and oxygenH2O2 CatalystWater: H2O?

3 Kyushu University UI project Kyudai Taro,2007 3 1502004006008001000-1000100200300 rHo rGo rGo, rHo (kJ/mol) (oC)(b) 0~1000oC H2O (g, l) H2 (g) +1/2O2 (g)010002000300040005000-1000100200300 rHo rGo rGo, rHo (kJ/mol) (oC)(a) 0~5000oC H2O (g, l) H2 (g) +1/2O2 (g)H2O H2+ 4100 C 4100 C Kyushu University UI project Kyudai Taro,2007 16 Water splitting reaction: G > 0 (uphill)H2O H2+1/2O2 Water electrolysis :H2O 1/2O2+2H++2e-& 2H++2e- H2 Electric potentialAnodecathodeTwo necessities:ElectrolyteElectrodeElectrol yteKyushu University UI project Kyudai Taro,2007 17 = , , = + ln = + ln +ZiF Kyushu University UI project Kyudai Taro,2007 H2+1/2O2=H2O H2O 1/2O2+2H++2e- 18 19 H2 (p(H2,I)), AnodeII|HIII+ IV|CVathode, O2 (p(O2,VI)) H2p(H2,I)O2p(O2,VI)H+IIIIIIVVV 20 OCV)222)III,H()I,H(ln22)e(2)H(2)H()II()I II( apFRTFoooAB )VIO,H()VI,O()IV,H(ln22)OH()O(2/1)e(2)H( 2)IV()V(22/12222ppaFRTF ooooBC B(IV) B(III) 0 )VIO,H()VI,O()I,H(ln22)OH()O(2/1)H()II() V(22/122222pppFRTFoooAC )VIO,H()VI,O()I,H(ln22)

4 OH(22/1222pppFRTFGof Kyushu University UI project Kyudai Taro,2007 21 Polymer electrolyte water electrolysisAlkaline water electrolysisHigh-temperature steam electrolysisOverviewElectrolyte: NafionElectrode: Pt supported on active carbonElectrolyte: KOH solution, conventional methodElectrolyte: zirconiaWorking at 800 900 CEfficiency(HHV)70 80%@1 2A/cm273 @1A/cm2 CostHigh cost of polymer electrolyte and platinum electrodeDurabilityProblematicCorrosive due to concKOH due to high-temp operationApplicability to pressurization of hydrogenLow strength of polymer electrolytepossibledifficultEnergyeffici ency liquid water electrolysissteam electrolysis 600 C H2O H2+ kJ/mol( V) kJ/mol kJ/mol kJ/mol V(Efficiency)= ( +h)(Efficiency)= ( + +h) GheatT S GVapoli-zationheatheatT ShH2O H2+ kJ/mol( V)LHV Confidential22 Kyushu University UI project Kyudai Taro,2007 3 23 PEFC SOEC) SOFC polymer)

5 200 400 600 800 1000 , j/A cm-2 , V/ VKyushu University UI project Kyudai Taro,200724 Photochemicalwatersplitting H2O,CO2n(CH2O),O2 CO2H2OH2+ Photosynthesis Kyushu University UI project Kyudai Taro,2007 Photochemicalwatersplitting 25+ Kyushu University UI project Kyudai Taro,2007 3 26 Kyushu University UI project Kyudai Taro,2007 3 27 Conductionband Valenceband BandgapKyushu University UI project Kyudai Taro,2007 3 28 E=h/ Kyushu University UI project Kyudai Taro.

6 2007 3 29p n V VlowVhigh Kyushu University UI project Kyudai Taro,2007 Photochemicalwatersplitting 30+ VlowVhighKyushu University UI project Kyudai Taro,2007 600 C-1000 C 3 31 950 C 00-650 C Kyushu University UI project Kyudai Taro,2007 3 32H2O H2+ (1)(1) (2)+(3) H2O X H2+XO(2)XO X O2(3) H2O X H2X+O2(2) H2X X H2(3) X (2) (3) Kyushu University UI project Kyudai Taro,2007 3 33H2O X H2+XO(2)XO X O2(3) rH(H2O) rG(H2O) rH(2) rG(2) rG(3) rH(3)THTLTHTL rH(H2O)= rH(2)+ rH(3) rG(H2O)= rG(2)+ rG(3)X XOH2OH2,O2QH=n rH(2)QL=n rH(3) Kyushu University UI project Kyudai Taro,2007UT-3 3 34 ATOMICA University UI project Kyudai Taro,2007 Thermochemical water splittingIodine-sulfur process (IS process)35 , KL(2010 ) KL(1999 ) , , , KL KL(2010 ) ( ) ( ) , KL(2010 ) 20%30% 37 H2 , H2 CH4 70% B:10t/d dry base H2: % 60% B:10t/d dry base PSAH2:60% 17Nm3/h H2) wet base CaO H2 CH4 1kg/h , ( ) PSAH2:10% ,CH4.

7 45% PSACH4:60%,CO2:40% :50t/d(wet base) PSAH2 CH4 ( )NEDO PSACH4 E 40 67 B:10t/d dry base PSAH2 CH4 PSAH2:10% ,CH4:50% PSA , Et-OH,BDF 38 P 900 C PSA 39 ProcessB: ProcessA: 10 58m3/h100 /m3-CH4 58m3/h54 /m3-CH4 200m3/h123 /m3-H2 200m3/h110 /m3-H2 10 Process A 13 /m3-H2 424 /m3-CH4 379 /m3-CH4 2,303 10km 40 /m3-CH45.

8 198 60km 90 /m3-CH4 40 41 FCEV LNG LNG NGNGLNG FCFC -142H2 FCEVFC FC LNG LNG FC NGNGNGLNG FCFCFCFCFCFCFCFCFC -243 H2 FCEVFC FC LNG LNG FC NGNGNGLNG FCFCFCFCFCFCFCFC FC CO CO CO FCFCFCFC -3CO 44 CO2 CO2 46 Kyushu University UI project Kyudai Taro,2007 3 4748 JRCM Source: Chiyoda Corporation 60% 51 (2) projectSIP Energy Carrier by Japanese Cabinet54 2030 CO2 2050 A4 3 5 2 8 5 54 3