Biomass Hybrid Concept and Its High Temperature Blanket

Transcription

1 Japan-US Workshop on Fusion Power Plants and Related Advanced Technologies Biomass Hybrid Concept and Its High Temperature Blanket Feb. 22, 2011 NIFS, Gifu, Japan S. Konishi, K.Ibano,E.Yamakawa, K.Oyama T. Shibata and Y. Yamamoto Kyoto University

2 Introduction Background Fusion energy MUST respond to immediate expectation for global environmental and energy problem. Fusion technology is far from maturity as energy plant. Fusion needs an ENGINEERING machine -to be immediately constructed with current technology -to be possible to show the net energy output by fusion Objectives to propose a possible next step option to be immediately start, to be justified as an option in carbon-free energy systems, and to provide engineering maturity for fusion technology.

3 Expected Fusion Role (if possible) Environmental Not only carbon-free, but reduces carbon dioxide emission to replace fire powered stations is needed, not to compete with fission or renwerables. Providing substute fuels are more important than electricity Electricity systems Renewables (solar, wind) will increase, and large stations are required to stabilize the grid. Dispersed power (battery, fuel cells) will increase. Large starting power and unit capacity are not welcome. Fusion must find its time and place

4 Fuel Production Energy Balance Fusion Energy (Heat,900 ) Biomass (1kg) + H 2 O H 2,CO cellulose:(c 6 H 10 O 5 ) n/6 + n/6h 2 O nh 2 + nco 136n [kj] lignin: (CH 1.4 O 0.3 )n + 0.7nH 2 O 1.4nH 2 + nco 136n[kJ] 8.2MJ endothermic 24.2MJ Shift Reaction Fischer-Tropsch reaction CO + H 2 O H 2 + CO [kj] Synthetic oil (Diesel) hydrogen Waste heat Carbon Neutral 2H 2 + CO -CH H 2 O Waste /usable [kj] 15.6MJ Substitute of OIL (0.5 litter)

5 Fusion Energy Balance Plasma Heating Energy P cd Fusion Energy Multiplication Q Blanket Output Net plant energy output Generation Efficiency η ~0.33 Conversion Efficiency η 2.0~2.7 Large Q (>20) needed for DEMO because of poor generation efficiency. If fusion plant is used for fuel production, only a fraction is regarded to be converted to electricity for plasma heating.

6 Fusion heat Energy Conversion efficiency water electricity Thermal cycle Loss (40~70%) Electrolysis Loss hydrogen water Fusion heat IS process hydrogen Biomass (with enthalpy) Chemical cycle Loss(50%) Fusion heat gasification Hydrogen+CO Chemical cycle Loss(400C) FT oil

7 Biomass Hybrid Concept Electricity generation Q=20, η e =0.33 DEMO Net 6P f High Plasma Q not required Driven and pulsed operation is acceptable GNOME Break-even Q=1,η=1 ITER -0.6 Negative power T(kev) biofuel Q=5, η f =2.7 Net 8P f High output temperature is required for gasification efficiency is required High temperature blanket To be developed.

8 Fusion-biomass hybrid reactor for fuel production Neutron wall load Blanket for Biomass process Small Major radius R p =5.2m High temp. extraction IHX 900 o C Biomass Gasification reactor P n ~1MW/m 2 Pb-17Li blanket with SiC cooling panel Hydrogen Fuel High η

9 Tokamak Parameters

10 Radial build CS 150 TF 60 BLK Shield 60 SOL Plasma BLK 340 SOL 80 Shield Shield 210 TF 60 Neutron flux average 0.7 MW/m 2 (max 1.4 MW/m 2 ) Neutron fluence (< 0.1MeV) to the CS reaches n/m 2 a reaches in 40 years No vacuum vessel. Cryostat is regarded as boundary.

11 Plasma ANSYS Ver.10.0 He at fl SiC Panel F82 H Plasma ux Heat flux Blanket Structure ( V He =65m/s ) L i90 構造材冷却パネル P0 380 (F82H) (SiC f /SiC) 900 ] 35MW/m b 3 [ RAFM SiC Heat LiPb flux Temperature [ ] He :8MPa, 300 o C, MW/ m 3 LiPb-RAFM blanket with SiC cooling panel Actively cooled SiC panel to control heat transfer isolate outer RAFM vessel structure obtain high temperature LiPb for heat F82H He F82H SiC He SiC 40m/s 80 m/s 60 m/s 40 m/s Tmax 550 LiPb 1000 position[cm] 1000 o C ANSYS Ver LiP 900

12 SiC/SiC cooling panel Blanket parameters Heat flux to the FW 0.2 MW/m 2 Neutron flux from the plasma 0.5 MW/m 2 Boundary temperature at the LiPb/SiC interface He temperature at F82H channel He temperature at SiC channel Heat transfer coefficient of He coolant at F82H channel Heat transfer coefficient of He coolant at SiC channel 1000 o C 350 o C 850 o C W m -2 K W m -2 K -1 Thermal conductivity of F82H 33.3 W m -1 K -1 Thermal conductivity of SiC 20 W m -1 K -1 SiC cooling panel Actively cooled SiC panel to control heat transfer isolate outer RAFM vessel structure obtain high temperature LiPb for heat

13 複雑形状の接合 Fabrication R&D for SiC cooling panels

14 LiPb circulated >900 C Loop operated >900 C Only in the test vessel SiC module ヒーティングコイル アルミナ管 IHX heat transfer from LiPb to He Installed in 900 C vessel

15 Expansion tank EMP Dump tank LiPb/He dual coolant loop heater SiC tube T Test economizer 9 0 T T section2 700 P 0 cooler T IHX module T heater Test vessel T T Test T Test section3 section1 Primary loop Secondary loop P F T F MS BZr ~200 Gas Chromatograph G C hygro meter G C

16 Heat transfer in SiC/LiPb module

17 Concept of the biomass reactor Assumed biamass:6mton/year (cellulose 70%,lignin 30%) biomass Reaction heat(kj) Reaction time(s) steam cellulose rignin Fusion reactor 10m Liquid metal 900 Liquid metal path Reactor tube:29500 Gas product Concept of the reactor Diameter:~3.5m Biomass/product path path

18 Hybrid Fusion power plant Hydrogen Liquid fuel H 2 9.0kg/s Gas separator Shift reactor 300 CO + H 2 O H 2 + CO 2 water 25kg/s CO 2 :90kg/s CH 4 :1.5kg/s Heat exchange reactor biomass 63kg/s Preheat No thermal cycle used. water 28kg/s No waste heat Discarded. Fusion reactor:500mw With High Temperature Blanket residue 10kg/s gas H 2 CO CO 2 CH 4 5.3kg/s 39kg/s 29kg/s 1.5kg/s

19 Gasification of Cellulose >95% carbon was converted to C1 gases and H2. This conversion efficiency is practical level. Conversion[%] CH 4 CO 2 CO H Conversionfor H2 mol[%] Temperature[ ] High temperature blanket is being developed. (However, pressure and steady-state requirements are not.)

20 Tritium Balance in plant Net TBR 1.05 LiPb Pb m 3 /s m 3 /s biomass Plasma Consumption 4.5E-04 n Blanket Generation 4.7E-04 HEX IHX Permeation 2.3E-8 Reactor Permeation 2.5E-10 Stock Stock 2.3E-05 [mol/s] T3-OS14 Yamamoto Recovery 4.7E-04 T Recovered tritium Tritium Recovery System 1 IHX permeability, tritium confinement of Entire power plant needs maturity and Demonstration for social understanding. - Recovery 2.3E-08 Tritium Recovery System 2 Environmental release T3-PS2.4 Shibata

21 IHX LiPbBlanket Tritium Recovery Process at 500 o C Vac. T 2 M M t = 1 Φ=4mm n= exp[ n π D t n π ] r Vacuum Sieve Tray Φ=4.6 m H = 1.2m M M t = 1 j= 0 depth= D 8 (2 j + 1) 2 (2 j + 1) 2 exp[ π 2 4 l Recovery ratio 45% 2 2 π D t] reruirement Inventory control Tritium in hydrogen product 2mm 30mm M(t ) [mol] :gas release M D t r 0 l [mol] :dissolved tas [m 2 s -1 ] [s] [m] [m] :diffusion coefficient :time :radius of the droplet :depth

22 Fusion-biomass hybrid as carbon recycle External Energy Source (FUSION) Large amount of biomass is discarded - burnable garbage - agricultural byproduct - woods - (plastics) Combustion Conversion to Fuel Reduction of fossil consumption Landfill replacing fossil reduces CO 2 emission use CO 2 emission (regarded as neutral)

23 Tritium concentration in product hydrogen (Bq/m 3 ) Tritium Recovery Process Tritium permeability through IHX [mol Pa -1/2 s -1 m -1 ] Regulation for HTO 35% assumed Tritium recovery ratio[-] Natural background SiC fiber -Recovery ratio determined from the contamination of product. -Requirement is a function of permeability through IHX Target recovery ratio >35% in the LiPb stream

24 Yearly change of tritium concentration Tutorial course Atmosphere HTO Cocentration (Bq/m3) Change on the tritium concentration in the atmosphere during prolonged operation is analyzed. Emission rate: 1.35x10 14 Bq/year 100 1st year 2ndyear 10 4th year 10th year 20th year 40th year 60th year 80th year 100th year Distance from fusion plant (km, -West, +East) Atmosphere HTO concentration (Bq/m 3 ) Atmosphere HTO concentration (Bq/m 3 ) Atmosphere HTO concentration after 100 years operation Operatinf time (year) 5.7 km west 100 km west Tritium concentration increase for about 60 years on land. Tritium concentration on the sea surface is low and dose not show accumulation Operatinf time (year)

25 Tutorial course Accumulation in the environment Annual emission accumulates in the environment Emission rate: 1.35x10 14 Bq/year Operating time:80years 10years Atmosphere HTO conc. (Bq/m 3 ) Atmosphere HTO conc. (Bq/m 3 ) 1.0E E E E E E E E-04 Considerably increases for 20 years Still negligible from dose, but easy to detect. - If 100 plants operated 100 years? Operating time (year) km west Operating time (year) km west

26 Future Energy Systems Fusion Fuel (H 2 / CO) FC Load following power FIRE Solar cell Fuel Cells Large scale grid DC Microgrid Battery NUCLEAR (h) Electricity will be powered by Carbon-free sources Day peak will be supplied by Battery and fuel cells.

27 Electrical Energy [MWh] Indirectly supplied by fusion Large-scale Day power generation Charge of NaS Fusion start-up SOFC Fission, Hydro Fusion and grid Time [h] Office Only for start up ~ 400 MW Office Only night, for NaS Fusion reactor (2 GW) 2.9 GL/day H 2 16 GL/day Fusion will be started by night sources DC Microgrid Large scale grid DC Microgrid 6.7 GL/day 10 4 Microgrid AC DC DC Microgrid Transport etc. 6.5 GL/day

28 Fusion Energy Development CDA88-90 ITER EDA Const..Oper.. ITER(2010) Plan B of Fusion Smaller than ITER follows ITER construction Oil product Demo before m TBM Competition to demonstrate Fusion power JA DEMO Targetted to 2050 comercial electricity demonstration possible 2038 EU fast DEMO Bio Hybrid

29 Fusion as biomass hybrid Fusion biomass hybrid may demonstrate fusion energy earlier than pure fusion electricity. small power generation has better market chance. cost requirements for the product (hydrogen, oil) may be easier (eventually. Depends on oil price and carbon tax) Low Q plasma can generate net energy product realistic target with current plasma technology earlier requirements for plasma, divertor and first wall smaller plant of R=~5m scale smaller device, smaller cost and project risk and tritium needs High temperature blanket/divertor are realistic challenge SiC-LiPb blanket being developed. Biomass-hydrogen conversion in bench scale test.

30 Strategic consideration Fusion plays minor, but inevitable contribution Serves as heat source for fuel production processes Fusion can improve in temperature by blanket development. There is few High temperature carbon-free heat Fusion has less limitation in resource, site, environment, and nuclear proliferation concern than fission. suitable for deployment in developing countries. fuel application provides fusion a better chance. Eventually larger market than electricity Global demands for fuel and its supply capability. Fuel production does not require stable steady state. Blanket and energy plants can be developed independently. Possibly slower demand change than electricity. Fits the entire carbon-free energy systems better.

31 Conclusion Fuel production from biomass has larger market. Substituting Oil contributes CO 2 reduction Biomass-Fusion Hybrid will give a good chance for technology maturity of fusion power, and more attractive feature as energy Hybrid Device smaller than ITER and will not have to wait for ITER success. Applicable for ICF, stellarator and other confinements. Fusion can respond to global environment and resource problem in the near future!