Fast Pyrolysis as Pretreatment for Further Upgrading of Biomass

Transcription

1 Fast Pyrolysis as Pretreatment for Further Upgrading of Biomass Gasification 2010 Feedstock, Pretreatment and Bed Material October, Gothenburg, Sweden Anja Oasmaa, Kai Sipilä, Yrjö Solantausta VTT Technical Research Centre of Finland

2 2 FAST PYROLYSIS OF BIOMASS Rapid (1-2 s) thermal (about 500 C) degradation of biomass under inert atmosphere into bio-oil, gases, and char Yield of main product from fast pyrolysis, liquid phase organics, is defined based on dry ash-free feed Yield wt% based on dry feed CHAR 60 GAS WATER 40 PYRWAT ORG Liquid organic product 20 0 PINE BIO-OIL

3 3 Yield wt% based on dry ash free feed. PYROLYSIS OIL YIELDS VTT/PDU Water 40 Organic 20 0 Pine Eucalyptus Forest residue Straw Grass Water Organic Highest organic yields (50-60 wt-%) from wood Most homogenous and stable oil from wood

4 4 CHEMICAL COMPOSITION OF BIOMASS PYROLYSIS OIL 4 6 wt-% carboxylic acids wt-% aldehydes, ketones, furans, pyrans, monomeric phenols, etc wt-% carbohydrates, sugars wt-% water wt-% pyrolytic lignin, etractives, solids (incl. ash), polymerisation products Chemical composition determines physical properties

5 5 PROPERTIES OF PYROLYSIS OILS First set of fuel grade - Fast pyrolysis liquid Biofuels in ASTM D7544 burner fuel standard Property Test Method Specification Units Gross Heat of Combustion D min MJ/kg Water Content E max mass % Pyrolysis Solids Content Annex A1 2.5 max mass % Kinematic Viscosity at 40 oc D445A 125 max mm2/s Density at 20 oc D kg/dm3 Sulfur Content D max mass % Ash Content D max mass % ph E70-07 Report Flash Point D93 Procedure B 45 min oc Pour Point D97-9 max oc One fuel grade having below 0.5 wt-% solids (< 0.05 % ash) under discussion Water content about 25 wt-% Acidic, ph 2-3, acetic (4 wt-%) and formic (1 wt-%) acids LHV MJ/kg Viscosity between that of light and heavy fuel oils High ignition temperature Flash point C Density kg/l Not distillable, unstable when heated Oasmaa, Anja; Elliott, D.C.; & Müller, S Quality Control in Fast Pyrolysis Bio-Oil Production and Use. Environmental Progress & Sustainable Energy, vol. 28, 3, ss

6 6 PYROLYSIS OIL PRODUCTION Pilots above 200 kg/h Host organisation Country Technology kg/h Applications Status Agri-Therm/ University of Western Ontario Canada Fluid bed 420 Fuel Operational BTG Netherlands Rotating cone Fuel and chemicals Operational 2012 BTG/Genting Malaysia Rotating cone Fuel Dormant KIT/Lurgi Germany Twin screw Fuel Operational 2011 Metso Finland Integrated fluid bed 300 Fuel Operational Pytec Germany Ablative 500 Fuel Operational Red Arrow/Ensyn 6 plants USA Circulating transported bed Up to Fuel and chemical Operational Virginia Tech USA Fluid bed 250 Fuel Operational Ensyn, KIT, BTG, and Metso have consortiums for commercialization

7 7 PYROLYSIS OIL MARKETS IN EUROPE The European P & P industry has a potential to build up to 50 pyrolyzers integrated to fluidised bed boilers, which means pyrolysis oil production of 11 TWh/a The major challenge is to develop and demonstrate technical and economical feasibility of the concept and the availability of woody biomass at competitive price Pulp and paper mills in Europe Calculated maximum production of pyrolysis oil within next 20 years in Europe 11 TWh / year (about 1 Mtoe/a) Feasibility and market potential of pyrolysis oils in the european pulp & paper industry. Esa Sipilä et al., 15th European Biomass Conference European market study for bio-oil (pyrolysis oil), Doug Bradley, IEA Bioenergy Task 40 - Biotrade, Dec 15, 2006

8 8 METSO - UPM - Fortum Metso, UPM, Fortum and VTT have developed an integrated biomass-based bio-oil production concept to provide an alternative to fossil fuel oil A 2 MW th fuel fast pyrolysis unit has been integrated with Metso s 4 MW th circulating fluidized bed boiler, located at Metso s R&D Center in Tampere Proof-of-concept has been done: More than 80 tons of bio-oil have been produced from sawdust and forest residues High availability, reliable process Bio-oil utilization has been proven: More than 20 tons of bio-oil has been used to replace heavy fuel oil at district heating boiler in Masala, Finland More than 50 MWh of district heating has been done by utilizing bio-oil Demonstration plant is being planned

9 9 ADVANTAGES Liquid versus solid fuel Decoupling of biomass handling and use Pyrolysis oil may be produced near biomass resources and transported to centralized processing units The volumetric energy density is increased by roughly five times compared to bulk biomass Easier feeding in pressurized systems From bulky biomass solids, a homogenous liquid is produced Decrease of harmfull elements in the feed Pyrolysis is an ash separation process - the minerals and metals are concentrated in the char Costs case specific Capital cost increase due to economics of scale in small pyrolysis plants Capital cost reduction due to lower costs in feeding, from absence of alkali metals causing slagging and solids causing erosion Efficiency loss due to additional processing step

10 10 BIOLIQ BY KIT AND LURGI Entrained flow gasifier based on the MPG (multi-purpose gasifier), 5 MW th, 1 t/h bioliqsyncrude High-temperature (>1200 C) gasification of pyrolysis oil char slurry yield a clean synthesis gas (CH4 < vol % 0.5) and full carbon conversion Decoupling of the evaporation, primary pyrolysis oil conversion, and gas conditioning is beneficial for the overall energetic efficiency and allows the separate optimization of the processes Costs per tonne slurry 140 (1 t slurry = 0.5 t mineral oil), diesel from oil ~ 0.45 /kg, synfuel ~ 0.9 /kg E. Dinjus, KIT, 2010

11 11 ADVANTAGES Liquid versus solid fuel Decoupling of biomass handling and use Pyrolysis oil may be produced near biomass resources and transported to centralized processing units The volumetric energy density is increased by roughly five times compared to bulk biomass Easier feeding in pressurized systems From bulky biomass solids, a homogenous liquid is produced Decrease of harmfull elements in the feed Pyrolysis is an ash separation process - the minerals and metals are concentrated in the char Costs case specific Capital cost increase due to economics of scale in small pyrolysis plants Capital cost reduction due to lower costs in feeding, from absence of alkali metals causing slagging and solids causing erosion Efficiency loss due to additional processing step

12 12 BTG Some herbaceous fuels could also be effectively pyrolysed, since they have low bulk density and are difficult to shred

13 13 ADVANTAGES Liquid versus solid fuel Decoupling of biomass handling and use Pyrolysis oil may be produced near biomass resources and transported to centralized processing units The volumetric energy density is increased by roughly five times compared to bulk biomass Easier feeding in pressurized systems From bulky biomass solids, a homogenous liquid is produced Decrease of harmfull elements in the feed Pyrolysis is an ash separation process - the minerals and metals are concentrated in the char Costs case specific Capital cost increase due to economics of scale in small pyrolysis plants Capital cost reduction due to lower costs in feeding, from absence of alkali metals causing slagging and solids causing erosion Efficiency loss due to additional processing step

14 14 DECREASE IN ASH AND HARMFULL ELEMENTS IN PYROLYSIS Potassium (K), Chlorine (Cl), and Sulphur (S) K, ppm Cl, ppm S, ppm Forest residue Feedstock Oil Wheat straw Feedstock Oil VTT results More than 90% of total ash removed in pyrolysis - Up to 95% decrease in K - Up to 90% decrease in Cl - Up to 80% decrease in S Less ash sintering and melting Less corrosion and fouling

15 15 ADVANTAGES Liquid versus solid fuel Decoupling of biomass handling and use Pyrolysis oil may be produced near biomass resources and transported to centralized processing units The volumetric energy density is increased by roughly five times compared to bulk biomass Easier feeding in pressurized systems From bulky biomass solids, a homogenous liquid is produced Decrease of harmfull elements in the feed Pyrolysis is an ash separation process - the minerals and metals are concentrated in the char Costs case specific Capital cost increase due to economics of scale in small pyrolysis plants Capital cost reduction due to lower costs in feeding, from absence of alkali metals causing slagging and solids causing erosion Efficiency loss due to additional processing step

16 16 SUMMARY Pyrolysis oil as a feed may be advantageous in pressurized entrained flow gasifiers where liquid feed means easier feeding In pyrolysis significant reduction in ash and harmfull elements is accomplished which means less ash sintering, ash melting, corrosion and fouling Pyrolysis oil demonstration plants under way Economics and efficiency have to be assessed case by case

17 17 Thank you! Acknowledgements Matti Reinikainen, Pekka Simell, Antero Moilanen, VTT