Polygeneration systems for the provision of SNG, power and heat

Transcription

1 Deutsches BiomasseForschungsZentrum German Biomass Research Centre International Freiberg Conference on IGCC & XtL Technologies Polygeneration systems for the provision of SNG, power and heat Stefan Rönsch Dresden, 4 th May 2010 Deutsches BiomasseForschungsZentrum gemeinnützige GmbH, Torgauer Str. 116, D Leipzig,

2 Agenda 1. Introduction 2. Reference concept analysis 3. Analysis of polygeneration approaches 4. Conclusions 2

3 Characteristics of Bio-SNG (Bio Synthetic Natural Gas): Bio-SNG is a combustable gas mixture produced from solid biofuels and containing approx. 95% (vol.) methane. Characterised by the same combustion behaviour as natural gas Can be fed into the natural gas grid Helps to reduce anthropogenic GHG-emissions Gasification: C 4.2 H 6 O ,4 H 2 O 2.2 CO H CO 2 Biomass Rawgas Methanation: CO + 3 H 2 CH 4 + H 2 O Clean gas Biomethane 1 Introduction Bio-SNG 3

4 1 Introduction Bio-SNG production and polygeneration Biomass Harvesting, collecting Conditioning, transport, storage Procedure: Reference concept analysis Reference concept adaption for polygeneration Analysis of polygeneration approaches Biomass supply Biomass gasification Raw gas cleaning Methanation/Synthesis Raw SNG upgrading conversion Biomass conversion Power generation Secondary energy carrier SNG Power Secondary energy carrier Secondary energy carrier 4

5 2 Reference concept analysis Reference concept definition Reference concept with (Drying) Air allothermal fluidised-twin-bed gasification based on the Recycle gas Tars RME Filter cake (Filter, RME washing, active carbon bed, ZnO bed) Steam Air Condensate RME technology at the plant site Güssing Fuel input power: 50 MW (dry) CO 2 H 2 (Fluidised-bed methanation) Steam Electrical power supply by the grid (Amine washing, drying, H 2 - membrane separation) Condensate 5

6 2 Reference concept analysis Exergy balancing Mass and exergy balancing as basis for reference concept analysis 6

7 2 Reference concept analysis Exergetic, economic and environmental analysis Fractions exergy (%) Fractions of different cost positions (%) 54.1 MW Fractions of GHG-emissions (%) 100 Fraction electrical power 9.2 ct/kwh SNG 30.1 g Bio-SNG GHG-emissions Fraction RME CO2-equ /MJ SNG Fraction capital related costs Fraction fuel Fraction SNG Fraction heat Bio-SNG production costs Fraction emissions power Fraction biomass costs demand Fraction emissions Fraction consumption related construction/pull costs down plant Fraction emissions biomass Fraction operation related supply costs Fraction electrical power costs Fraction of further costs Fraction revenues heat Technical analysis: 0 Efficiency calculation (Mass and energy balancing, Simulation) Economic analysis: Bio-SNG production cost calculation (Annuity method) Environmental analysis: GHG-emission calculation (Allocation method) Fraction emissions RME Fraction emissions nitrogen Fraction emissions methane slip Fraction of further emissions 7

8 3 Analysis of polygeneration approaches Reference concept adaption for polygeneration Raw gas Process extensions for polygeneration: exchanger P-199 Gasifier Gas engine + Steam turbine Gas engine + ORC module Gas turbine + Steam turbine Gas turbine + ORC module Bedmaterial Bedmaterial + char Precoatmaterial Riser Filter RME Dust, tar, char Oil washer Part 1 RME, tar Blower H 2 O Blower Raw gas Electrical power Gas engine Flue gas treater exchanger CO 2 Amine washer Electrical power Gas turbine Flue gas treater exchanger Chimney Flue gas Recuperator H 2 - membrane Glycol dryer H 2 O SNG exchanger Dryer Steam Air H 2 O exchanger Filter Ash Blower Electrical power Chimney Flue gas exchanger Recuperator H2 O Compressor 3 ZnO bed H 2 exchanger Steam H 2 O Synthesis reactor Wood chips Steam cycle/ ORC modul Oil washer Part 2 Compressor 1 / 2 exchanger Active carbon bed 8

9 3 Analysis of polygeneration approaches Exergetic comparison of polygeneration approaches Exergetic efficiency (%) Exergetic efficiency of the reference process: 63.0% Maximal exergetic efficiency of 64.5% is reached with steam cycle for power production REFERENCE PROCESS ENGINE + ENGINE + TURBINE + TURBINE + Gas conversion with a gas engine or gas turbine is not promising 9

10 3 Analysis of polygeneration approaches Economic comparison of polygeneration approaches Bio-SNG production costs ( /kwhsng) 0,16 0,14 0,12 0,10 0,08 0, REFERENCE PROCESS ENGINE + ENGINE TURBINE + TURBINE + Bio-SNG production costs of the reference process: 9.20 ct/kwh SNG Minimal Bio-SNG production costs of 9.08 ct/kwh SNG are reached with steam cycle for power production Gas conversion with a gas engine or gas turbine is not promising 10

11 3 Analysis of polygeneration approaches Environmental comparison of polygeneration approaches Bio-SNG GHG-emissions (g CO2-equ/MJSNG) REFERENCE PROCESS ENGINE ENGINE TURBINE TURBINE + Bio-SNG GHGemissions of the reference process: 30.1 g CO2-equ /MJ SNG Minimal Bio-SNG GHGemissions of 27.8 g CO2-equ /MJ SNG are reached with steam cycle for power production Gas conversion with a gas engine or gas turbine is not promising 11

12 3 Analysis of polygeneration approaches Flexible electricity price (EEX 2009) 7500 h/a heat sale: 4000 h/a heat sale: 0 h/a heat sale: Required hours of electricity price per year (h/a) Required hours of electricity price per year (h/a) Required hours of electricity price per year (h/a) Electricity price (ct/kwh el el )) Electricity price (ct/kwh el ) Electricity price (ct/kwh el ) SNG price: 1 ct/kwh SNG price: 2 ct/kwh SNG price: 3 ct/kwh SNG price: 9 ct/kwh Hours electricity price per year (EEX) Annual operating hours 12

13 4 Conclusions Reference concept analysis shows an exergetic efficiency of 63%, Bio-SNG production costs of 9.2 ct/kwh SNG and Bio-SNG GHG-emissions of 30.1 g CO2-Äqu /MJ SNG. With polygeneration approaches are exergetic, economic and environmental process improvements possible: Gas conversion for power and heat provision is not reasonable to increase the exergetic, economic and environmental competiveness of the Bio-SNG production. Conversion of process heat for heat and power provision is reasonable. If process heat is converted in a steam cycle to provide power and heat, the exergetic efficiency can be increased by 1.5%, the Bio-SNG production costs can be decreased by 0.12 ct/kwh SNG and the Bio-SNG GHGemissions can be reduced by 2.3 g CO2-Äqu /MJ SNG. 13

14 Thank you for your attention. Deutsches Biomasse Forschungszentrum gemeinnützige GmbH Torgauer Straße 116 D Leipzig Tel./Fax. +49(0) / -133 Dipl.-Ing. Stefan Rönsch Tel. +49(0)341 / stefan.roensch@dbfz.de Prof. Dr.-Ing. Martin Kaltschmitt Tel. +49(0)341 / mk@dbfz.de 14