Biomass Gasification to 2 nd Generation Biofuels Status Review and R&D activities at VTT

Transcription

1 Biomass Gasification to 2 nd Generation Biofuels Status Review and R&D activities at VTT Solander Symposium Piteå, Sweden Esa Kurkela VTT, Finland

2 2 Alternative Routes to 2 nd generation Bio-Fuels TRANSFORMATION THROUGH INTERMEDIATES (SUGARS) BIOCHEMICAL CONVERSION Biochemical routes to ethanol Hydrotreated vegetable oils Pyrolysis followed by bio-oil upgrading Gasification followed by gas cleaning and conditioning Different final products from syngas: FT-diesel, Methanol, DME, gasoline, H 2, CH 4 Electric or hybrid cars with renewable electricity REDUCTION TO BUILDING BLOCKS (CO, H 2 ) THERMO- CHEMICAL CONVERSION

3 3 Production and Conversion of Biomass-Derived Synthesis Gas Main Steps in Overall Process Biomass Filtration Tar removal Scrubbing CO shift, H 2 S removal CO 2 removal MP Steam Off-gas HP Steam DRYING GASIFICATION REFORMING INITIAL GAS CLEANING FINAL GAS CLEANING AND CONDITIONING SYNTHESIS/ UPGRADING Heat Steam + O 2 Steam Main Product Typical pressures: 1-30 bar 30 bar bar Focus of R&D efforts and industrial demonstrations Special technology for biomass Commercially available technology: experiences from coal, oil and natural gas processing

4 4 Production of Biomass-Derived Synthesis Gas Initial step - two main approaches Main technical challenge: prehandling, feeding of biomass Biomass BIOMASS PRE- TREATMENT Dry Pulver or Pyrolysis oil GASIFIER 1300 ºC + Raw synthesis gas to cooling, clean-up and conditioning Typically: oxygen-blown entrained-flow gasifier Main technical challenge: reforming of gas Biomass GASIFIER e.g. 850 ºC REFORMER 900 ºC catalytic Raw synthesis gas to cooling, clean-up and conditioning Typically: fluidised-bed gasifier, either oxygen-blown or indirectly heated

5 5 Oxygen-Blown Entrained-Flow Gasifiers Large-scale, high-pressure Commercially available for coal and heavy oil Gasification temperature C No tars in raw gas Feedstock size < 0.1 mm Not applicable as such to solid biomass; main problem: feeding examples of solutions: prior pyrolysis on site (Choren Carbo-V ) prior pyrolysis elsewhere (FZK-ITC concept) torrefaction followed by pelletisation and grinding special fuel: black liquor (Chemrec) FEEDSTOCK SLAG OXYGEN & STEAM GAS

6 6 Fluidised-Bed Gasifiers Atmospheric or intermediate pressure Feedstock size < mm Gas temperature C Commercially available in power and heat applications O 2 -blown direct heating or steam gasification with indirect heating GAS CIRCULATING FLUIDISED BED (CFB) Fluidising velocity 3-10 m/s Higher output/diameter Reactive feedstocks BUBBLING FLUIDISED BED (BFB) Fluidising velocity 1-3 m/s Long residence time FEEDSTOCK AIR ASH Applicable to biomass, technologies for synthesis-gas applications in demonstration phase

7 7 Peat from MoDo steam dryer HTW gasifier Steam SYNGAS FROM PEAT AND WOOD HTW-PLANT AT OULU KEMIRA AMMONIA PLANT, 120 MW fuel, (operation in ) Peat crush moisture 15 % 10bar C Waste heat boiler Benzene from naphthalene extraction Benzene scrubber Gas to amisol scrubber 1500 k mol/h 29 bar Steam Oxygen Recycle gas Water scrubber To naphthalene extraction Improvements to the process: Dust Sludge separation HTW gasifier replaced by CFB - fuel flexibility, high availability - operation at lower temperature Ash Pressurised steam/o 2 -blown gasifier Technology was successfully demonstrated in late 1980 s with peat and lignite (Oulu, Berrenrath) Single gasifier train MW feasible New gas cooler design - not sensitive to fouling Hot filtration instead of wet scrubbing of particulates Reforming of hydrocarbons - elimination of tar problem - higher syngas yield - higher H2/CO ratio

8 8 Gasification and Gas Cleaning Process - Developed and tested at VTT on 1 MW scale -Demonstrated in the 12 MW industrial plant by NSE Biofuels at Varkaus NEW INNOVATIVE TECHNOLOGY FUEL-FLEXIBLE FLUID-BED GASIFICATION STEAM/OXYGEN PRESSURISED GAS CLEANING TAR & METHANE REFORMING FILTRATION DIRTY SHIFT ULTRA CLEANUP FT-DIESEL CH 3 OH HYDROGEN SNG GASOLINE JET FUEL GASIFIER TARGETS NO ASH-RELATED PROBLEMS SIMPLE DESIGN AND HIGH RELIABILITY HIGH C-CONVERSION TO GAS+TARS LOW OXYGEN CONSUMPTION GAS CLEANING TARGETS COMPLETE TAR DECOMPOSITION 60-80% METHANE REFORMING H 2 /CO RATIO SUITABLE TO FT-SYNTHESIS

9 9 NSE Biofuels JV company owned by Neste Oil and Stora Enso From: V.Jokela, NSE presentation at IEA gasification seminar, Piteå, 2011

10 10 From: Sami Kokki, Foster Wheeler

11 11 From: V.Jokela, NSE presentation at IEA gasification seminar, Piteå, 2011

12 12 From: K.Salo, Andritz Carbona presentation at IEA gasification seminar, Piteå, 2011

13 13 Syngas Route to Biofuels Integrated Concept Paper or pulp Process steam & power power plant Pulp and paper mill Energy to drying Gasification and gas treatment fuel gas + steam MW Forestry residues, mill residues, straw, energy crops, urban biowaste Biomass handling and drying MW bark, forestry residues, other biomass steam & oxygen synthesis -gas Synthesis & upgrading MW Hydrocarbon fuels (FT) or methanol, DME, SNG, H 2, etc.

14 14 Biorefinery BTL Demonstration Plans in Finland Three consortiums are presently planning second-generation BTL biorefineries in Finland The planned capacities are ton/a of diesel EU s NER300 funding has been applied - decisions expected at the end of 2012 Overall investment costs in order of million? Several sites have been investigated by companies Very large-scale is needed to achieve positive economics? First plants will be more expensive than mature technology?

15 15 Biomass-to-Syngas R&D at VTT NEXTUCG: Industrial development project funded by NSE Biofuels (Neste Oil and Stora Enso), co-operation with Foster Wheeler Resulted in NER300 proposal large FT-production unit PRODUCTION OF SNG OR H2 FROM BIOMASS Evaluation of process alternatives less capital intensive and suitable to smaller size that BtL plants Pre-competitive R&D on gasification and gas cleaning US-CO-OPERATION PROJECT ON EVALUATION OF GASIFICATION-BASED SYSTEMS Ilkka Hannula as visiting scientist at Princeton University Co-utilisation of biomass and coal for liquids and electricity and combinations of biotechnical and thermochemical routes Evaluation of US development projects Aspen modelling of selected concepts and technologies NORDSYNGAS: Nordic University co-operation: Luleå, Piteå, Sinteff, VTT Fundamental aspects of pressurised gasification System studies related to integrated plants to pulp and paper industries GASIFICATION REACTIVITY Fundamental research with Åbo Akademi and Jyväskylä University Funded by Finnish Akademy

16 16 Reactivity and ash sintering behavior of biomass set limits for gasifier operation conditions Large differences between different biomasses: fate of inorganic species during gasification => inherent catalysis for H 2 O and CO 2 gasification Effect of pressure on reactivity different than in coal gasification R&D topics in this field Thermobalance tests with new biomass samples Fundamental R&D with universities & modeling of char gasification

17 17 Possible ways to improve the synthesis gas route - preliminary plans for new R&D in Optimised high-pressure steam-oxygen gasification process aiming to improved fuel-to-syngas conversion efficiency and to wider feedstock basis (above 200 MW scale) Indirectly heated or air-blown gasification processes for smaller size range ( MW) Simplified final gas cleaning to replace Rectisol Syntheses/catalysts with less stringent gas purity requirements compared with present processes - Higher inert concentration (N 2 ) - Lower requirements for CO 2 removal - Higher tolerance for sulphur Co-production of fuels, heat and electricity integration to forest industries and district heating

18 18 Process Scheme for Production of SNG Oxygen plant Oxygen Steam: 0.44 kg/ kg of dry biomass HP Steam Large steam feed lowers thermal efficiency HP Steam LP Steam Moist feedstock Dryer Gasifier Reforming HT Shift Heat Combustor HP Steam Scrubbercooler Minimal reforming of CH 4 Steam: 1.15 kg/ kg of dry biomass Regenerative Absorber I Regenerative Absorber I LP Steam Methanator I LP Steam CW H 2 O Methanator II Main SNG synthesis reaction: CO + 3H 2 From: McKeough & Kurkela, 2007 SNG 96 % CH 4 50 bar CH 4 + H 2 O Recycle loop lowers thermal efficiency

19 19 Woody biomass based gasification process development for hydrogen or SNG production (VETAANI) Tekes/Biorefine project Total budget 1,5 M, TEKES 60 %, VTT 30 %, companies 10 % (GASUM, HELEN, Metso, NesteOil, HVK, Outotec) Applications: SNG, suitable for pipeline distribution Bio-Hydrogen or hydrogen-methane gas mixture, e.g.for refineries Clean fuel gas for SOFC power plants or NG based IGCC Clean medium-btu gas for industrial process kilns R&D methods System studies using Aspen Plus modeling tools Selective tar reformer and hot filtration R&D Indirectly heated gasification and reforming Overall process optimization: Higher efficiency and/or lower costs

20 20 Targets for catalytic reforming and shift conversion in SNG applications VTT s Vetaani project Complete conversion of tars and C 2 -hydrocarbon gases Low conversion of CH 4 As high benzene conversion as possible Shift conversion before gas cooling in order to minimize steam consumption 100% 80% 60% 40% 20% Conversions achieved in first test at VTT s reformer C2Hy Tar Benzene Methane Followed by oil scrubbing of benzene & residual tars replacement of Rectisol by cheaper desulphurisation and CO 2 removal? 0% Clean wood - low sulphur Wood residues

21 21 Pyrolysis to Liquid Biofuels Potential for lower investment costs than in systems based on gasification and synthesis FEEDSTOCK PREPARATION Additional Hydrogen PRODUCTS Gasoline Diesel Jet fuel PYROLYSIS BIO-OIL STABILIZATION AND UPGRADING FUEL SYNTHESIS Catalytic upgrading Distillation Product quality Oxygen content Production technology ready for industrial demonstration Reduce oxygen content Reduce acid number Remove char&ash R&D on-going - not yet industrial reality BY- PRODUCTS Light Hydrocarbons+ Chemicals?

22 The Biofuel Chain can be Integrated to Existing Industries Refinery products FCC Wood PYRO Boiler Bio oil Pyrolysiss HDO Chemicals Helsinki, 3 September 2009 Y.Solantausta

23 23 CONCLUSIONS biomass gasification to synfuels First semi-industrial gasification plants have been successfully operated (e.g. Chemrec, NSE) Several large-scale projects are in design phase - financial challenges in 500 M projects Smaller demo units in continuous production could be an alternative pathway New alternatives would also be needed for smaller size range ( ktoe/a) pyrolysis-based concepts indirect steam gasification simpler gas cleaning hydrogen to refineries once-through synthesis with co-production of electricity and heat Thank you for your attention. esa.kurkela@vtt.fi 20 years too early? Peat-ammonia plant HTW gasifier, 120 MW Oulu, Finland 1990