The potential of water-gas shift membrane reactors for CtX and flexible poly-generation processes

Transcription

1 The potential of water-gas shift membrane reactors for CtX and flexible poly-generation processes 7 th International Freiberg/Inner Mongolia Conference on IGCC & XtL Technologies, Coal Conversion and Syngas 9 June 15, Inner Mongolia, China Alexander Buttler, Hartmut Spliethoff Institute for Energy Systems, Technical Universtiy of Munich

2 Structure Transition of the German Energy System Actual challenge of volatile renewable feed-in Future demand of flexible power plants and resulting requirements The potential of IGCC poly-generation plants in a changing energy system Water-gas shift membrane reactor Theory Flexible poly-generation concept Modelling and analysis Modelling appraoch and boundary conditions Concept evaluation th international Freiberg/Inner Mongolia Conference on IGCC&XtL Technologies, Alexander Buttler 2

3 Power [GW] Transformation of the German energy system Installed capacity of wind and PV 16 Solar Wind Offshore Wind Onshore Peak net load Installed Wind and PV power will exceed peak load next year 3

4 Power [GW] Titel Actual challenge of volatile renewable feed-in Impact of wind and PV on the residual load 9 Biomass, hydro Wind+PV Load Res2 Res1 9 82,5 87, 85,8 81,2,9 83, ,2 72,9 76,3 39,2 39,1 38,7 19,5,5 18,2 Load Max Res1 Max Res2 Max Load Min Res1 Min Res2 Min hours per year 11,6 12,5 1, Strong lowering of minimal residual load Little decrease of residual peak load 4

5 Day-Ahead Spot market price [ /MWh] Actual challenge of volatile renewable feed-in Inflexibilities of the conventional power plants - negative electricity prices Net power [GW] 7 6 nuclear Lignite Hard coal Gas Oil 79,9 21,4 1, Data 14 ø 32,6 /MWh Min. -65 /MWh Max. 88 /MWh 5 4 3,9 19,6 23,6 3, Residual load [GW] 1 Jan. März March Mai May July Juli Sept. Nov. 12,1 Max 9,2 7,5 Min Source: Own illustrations based on eex.com and eex-transparency.com Minimum net output of conventional power plants lies far above minimum residual load 5

6 The potential of IGCC poly-generation plants in a changing energy system Base load demand (nuclear power phaseout) Medium load demand Peak load demand and energy storage CCPP Gasifier island Gas cleaning Synthesis unit Electrolysis unit Power Production Synfuel Production 1% % IGCC allows a very flexible adaption to the future requirements 6

7 Water-gas shift membrane reactor Theory Hydrogen flux across the membrane: With P Permeability δ...membrane thickness T Temperature p H2 partial pressure A M Membrane area Large scale concept Source: Melin (4) Feed Membrane tubes 7

8 Water-gas shift membrane reactor Concept and advantages of a flexible WGS--poly-generation plant BC steam MeOH/SNG BC Base Case (Water quench, Rectisol) Membrane Reactor (Gas quench, hot gas clean up) GF WGS AGR CCPP CO 2 to pipeline GF HGCU steam WGS- MeOH/SNG CCPP CO 2 to pipeline Advantages of -concept: + Low steam demand for CO-shift + Reduced gas temperature cycling + variable split of gas streams with adjusted composition for gas turbine or synthesis plant 8

9 Retentate Water-gas shift membrane reactor Detailed poly-generation concept Clean gas Splitter for adjustment of optimal gas composition for synthesis plant Permeate steam Number of WGS- for synfuel plant N SYN H 2 H 2 H 2 To synfuel plant H 2, CO, CO 2 ; SN=opt. For MeOH: n Sweep n C = Y n C,H2 +Y X n C,H2 SN+Y X n C,CO + M 1 n C,H2 With C Clean gas Y H 2 -yield X CO-conversion SN stochiometric number.(=h 2 /CO=2.5) Sweep gas Expansion in turbine H 2... H 2 Catalytic combustion CO 2 to pipeline O 2 For given syngas composition n Sweep n C : MeOH:.43 SNG:.3 (SN= n H2 n CO2 n CO n CO 2 = 3) N 2 from ASU H 2 Number of WGS- for CCPP N CCPP To gas turbine (N 2 +H 2 ) Variable product ratio: synthesis product/electricity ~ N syn /N CCPP 9

10 Modeling approach and boundary conditions Gasifier Island and Gas Cleaning Combined Cycle Power Plant Ebsilon Professional Membrane Reactor All models validated with industrial data [Kunze(12), Buttler(13)] 1

11 Main boundary conditions Gasifier island Entrained flow gasifier with syngas cooler Fuel Input: 1 MW th Hard Coal Temperature/Pressure: 14 C/4 bar Carbon Conversion: 98.5 % Cryogenic ASU:.273 kwh/kg O 2 Rectisol power demand:.4-.6 kwh/kg CO2 CO 2 pressure: 11 bar Combined Cycle Power Block Fuel Gas LHV: kj/kg Gas turbine: TIT 13 C/ /.5-1 load 3-pressure HRSG: 13/4/5 bar Membrane reactor Pd/Cu H 2 O/CO 1.6 H 2 -yield 94 % CO-conversion 98 % Synthesis plants SNG: 3-stage adiabatic fixed bed process 6/45/3 C, /.5-1 load MeOH: LPMEOH isothermal 25 C, 5 bar 11

12 MW Efficiency Concept evaluation SNG WGS--poly-generation-process 7 6 Net power SNG production (LHV) Poly-generation % 6% BC Base Case (Water quench, Rectisol) Membrane Reactor (Gas quench, hot gas clean up) % 4% 3% BC-SNG IGCC Base Case IGCC configuration, gas composition adjusted for SNG-synthesis plant *values referred to gas turbine load or synthesis plant load respectively % 1 1% BC IGCC BC-SNG IGCC IGCC CO 2 -sequ.: 91.6% 69.1% >98% IGCC-1% SNG-%* IGCC-5% SNG-6%* SNG BC SNG % Electric power must-run of 88 GW ( SNG) Reduced SNG-production compared to base case 12

13 MW Efficiency Concept evaluation Methanol WGS--poly-generation-process Net power MeOH production (LHV) Poly-generation % 6% 5% 4% BC Base Case (Water quench, Rectisol) Membrane Reactor (Gas quench, hot gas clean up) *values referred to gas turbine load or synthesis plant load respectively 3 3% % 1 1% BC IGCC IGCC IGCC-1% CO 2 -sequ.: 91.6% 69.1% >98% MeOH-%* IGCC-5% MeOH-6%* MeOH BC MeOH % Electric power must-run of 3 GW ( MeOH) Slightly increased MeOH-production compared to base case 13

14 Summary IGCC concept allows flexible adaption to future requirements in a changing energy system WGS membrane reactor has the potential to improve the Efficiency (about 4 %-points) Flexibility (production of several product gas streams with different gas composition) MeOH is identified as a better option compared to SNG Higher sweep gas stream (lower membrane area) Lower electric power must-run High value follow-up products (MtG, Methanol-to-Propylene) Outlook: Economic evaluation Sensitivity analysis of the membrane area 14

15 The potential of water-gas shift membrane reactors for CtX and flexible poly-generation processes Thank you for your attentation! 7 th International Freiberg/Inner Mongolia Conference on IGCC & XtL Technologies, Coal Conversion and Syngas 9 June 15, Inner Mongolia, China Dipl.-Ing. Alexander Buttler Institute for Energy Systems, Technical University of Munich Alexander.buttler@tum.de

16 percentage % Transformation of the German energy system Time schedule of the energy concept of the German government 1 Goals Energy Concept , PEV Primary relativ energy zu 8 consumption compared to 8 THG relativ zu 199 Bruttostromverbrauch relativ zu 8 Gross electricity consumption compared to 8 Greenhous gas emissions compared to 199 EE-Anteil am BSV Share of renewable energy generation on GEC 16

17 Day-Ahead Spot market price [ /MWh] Number of hours [-] Actual challenge of volatile renewable feed-in Negative electricity prices Data 14 ø 32,6 /MWh Min. -65 /MWh Max. 88 /MWh Residual load [GW] price = price < Source: own calculations based on eex.com Phelix day-ahead spot market price 17