thermal pretreatment of biomass/torrefaction - jaap kiel
DESCRIPTION
Presentation given at Biomass Gasification EuropeTRANSCRIPT
www.ecn.nl
Torrefaction – an enabler for biomass gasification
Biomass Gasifica0on Europe 2014 Jaap Kiel Alkmaar, the Netherlands 2 October, 2014
Biomass – major challenge
• Enable decoupling of biomass produc0on and use – Place – Time
– Scale • By conver0ng biomass into high-‐quality bioenergy carriers (solid, liquid or gas), that: - BeOer fit in (exis0ng) logis0c infrastructures - Allow efficient, reliable and cost effec0ve conversion into electricity and heat, transport fuels and chemicals
Solve biomass related problems at the source
Torrefaction for upgrading biomass
• Process parameters – Temperature: 240-‐320 °C – Absence of oxygen
Tenacious and fibrous LHV = 9 - 12 MJ/kg Hydrophilic Biodegradable Heterogeneous
Torrefaction
Friable and less fibrous LHV = 18 - 24 MJ/kg Hydrophobic Preserved Homogeneous
Pelletisation
Bulk density = 650-800 kg/m3
Bulk energy density = 12 - 19 GJ/m3
Torrefied biomass properties in perspective Wood chips Wood pellets Torrefied wood
pellets Charcoal Coal
Moisture content (wt%) 30 – 55 7 – 10 1 – 5 1 – 5 10 – 15 Calorific value (LHV, MJ/kg) 7 – 12 15 – 17 18 – 24 30 – 32 23 – 28 VolaCle maEer (wt% db) 75 – 85 75 – 85 55 – 80 10 – 12 15 – 30 Fixed carbon (wt% db) 16 – 25 16 – 25 20 – 40 85 – 87 50 – 55 Bulk density (kg/l) 0.20 – 0.30 0.55 – 0.65 0.65 – 0.80 0.18 – 0.24 0.80 – 0.85 Vol. energy density (GJ/m3) 1.4 – 3.6 8 – 11 12 – 19 5.4 – 7.7 18 – 24 Hygroscopic properCes Hydrophilic Hydrophilic (Moderately)
Hydrophobic Hydrophobic Hydrophobic
Biological degradaCon Fast Moderate Slow None None Milling requirements Special Special Standard Standard Standard Product consistency Limited High High High High Transport cost High Medium Low Medium Low
sources: ECN (table, fig.1, 3), Pixelio (fig. 2, 5), ofi (fig. 4)
Abbrevia0ons: db = dry basis LHV =Lower Hea0ng Value
The added value of torrefaction
• Torrefac0on (+ densifica0on) enables energy-‐efficient (>90%) upgrading of biomass into commodity solid biofuels with favourable proper0es in view of logis0cs and end-‐use
• Favourable proper0es include high energy density, beOer water resistance, slower biodegrada0on, good grindability, good “flowability”, homogenised material proper0es
• Therefore, cost savings in handling and transport, advanced trading schemes (futures) possible, capex savings at end-‐user (e.g. outside storage, direct co-‐milling and co-‐feeding), higher co-‐firing percentages and enabling technology for gasifica8on-‐based biofuels and biochemicals produc8on
• Applicable to a wide range of lignocellulosic biomass feedstock, even mixed waste streams
Sdr. Stenderup demo plant
Simplified single line flow sheet; capacity 1 t/hr biomass input (db)
Sdr. Stenderup demo plant Capacity 1 t/hr biomass input (db)
• The demo plant has been operated successfully in a range of up to 500 hour trials, yielding good quality product
• Currently, the demo plant is operated on demand, e.g. to produce product for test firings
• Andritz is in the process of discussing commercial-‐scale systems
• Andritz is pleased to discuss your requirements
Status
Ready for commercial market introduction
Torrefaction Ready for commercial market introduction
• Torrefac0on technology in demonstra0on phase with >10 demo-‐units and first (semi-‐)commercial units in opera0on (e.g., Torr-‐Coal)
• Successful co-‐firing trials, e.g.: – Amer 9 (Essent, end of 2013)
– 2300 tonne Topell pellets – 5-‐25% co-‐milling – 1-‐4% co-‐firing
– Studstrup 3 (DONG, March 2014) – 200 tonne Andritz pellets – Dedicated mill – 33% co-‐firing
– Helsingin Energia Hanasaaren (March 2014) – 140 tonne Torr-‐Coal pellets – 14% co-‐firing
9
Product quality optimisation Biomass
Torrefac0on
Validated and op0mised solid biofuel
Densifica0on
Logis0cs tes0ng
End-‐use tes0ng
• Pilot, demo and first commercial plants produce tonne-‐scale batches allowing representa0ve logis0cs and end-‐use performance tes0ng by industry
• Product quality op0misa0on requires a systema0c, itera0ve approach (2 itera0ve loops)
• For this purpose, European torrefac0on developers, combus0on and gasifica0on technology providers and end-‐users have joined forces in the EU-‐FP7 project SECTOR
• + NL project Pretreatment, with involvement of Topell Energy, Torr Coal, Biolake, Essent, NUON, GdF Suez, TU Delm, U Twente, ECN
This project has received funding from the European Union’s Seventh Programme for research, technological development and demonstration under grant agreement n° 282826
The SECTOR project
§ Collaborative project: SECTOR
§ Project start: 01.01.2012
§ Duration: 42 months
§ Total budget: 10 Mio. Euro
§ Participants: 21 from 9 EU-countries
§ Coordinator: DBFZ
www.sector-project.eu
Alkmaar, October 2, 2014
This project has received funding from the European Union’s Seventh Programme for research, technological development and demonstration under grant agreement n° 282826
Torrefaction technologies
Produc0on with available demo plant Con0nuous opera0on
Produc0on of 100-‐200 tonnes Specific feedstock
Produc0on with available pilot scale faciliCes Typical test runs 50-‐100 hours
Typical produc0on per test few tonnes 3-‐6 different feedstocks
Moving bed* (ECN) pilot
Rotary drum / Auger (Umeå University)
pilot
Rotary drum (CENER) pilot
Toroidal (Topell Energy)
demo
Different technologies
Alkmaar, October 2, 2014
* And the resulting Andritz/ECN technology, successfully demonstrated in Denmark at a scale of 1 ton/h
This project has received funding from the European Union’s Seventh Programme for research, technological development and demonstration under grant agreement n° 282826
Densification: Pilot-scale tests (CENER)
Image © Andritz © Image from Andritz
Date Durability Pine Date Durability Straw
October 2012
88.8 February 2013
84.2
January 2013
92.3 September
2013 94.3
June 2013
94.7 October 2013
96.6
November 2013
95.7 November
2013 97.6
Optimised parameters: • Particle size of feedstock • Moisture content of feedstock • Torrefaction degree of feedstock • Die diameter/length ratio • Die rotation speed
Alkmaar, October 2, 2014
This project has received funding from the European Union’s Seventh Programme for research, technological development and demonstration under grant agreement n° 282826
Logistics: Outdoor storage and handling tests (EON)
Two outdoor storage piles built in June 2013
Flat-topped pile � Model the formation of piles after compaction
(though no compaction occurred) � 3 tonnes � 2.34 x 2.36 x 1.5 m3
Peaked-topped pile � Model the formation of piles after it has been
delivered � 4 tonnes � 2.34 x 2.36 x 1.5 m3
© EON © EON
Alkmaar, October 2, 2014
This project has received funding from the European Union’s Seventh Programme for research, technological development and demonstration under grant agreement n° 282826
Logistics: Outdoor storage and handling tests (EON)
§ Pellet durability as function of time
60
65
70
75
80
85
90
95
100
105
0 10 20 30 40 50 60 70 80
Durability (%
)
Time (Days) Peak Middle Flat Middle Peak Surface Flat Surface
Alkmaar, October 2, 2014
This project has received funding from the European Union’s Seventh Programme for research, technological development and demonstration under grant agreement n° 282826
End use: (Co-)gasification in EF gasifiers (Vattenfall)
NUON/Vattenfall Buggenum IGCC Plant: • 253 MWe power plant, entered service in 1993 as a
coal gasification demonstration plant, closed in 2013
• Hard coal as main fuel with continuous co-gasification of saw dust up to 15 wt%
• Trial (outside SECTOR, but results brought in): • 1200 tonnes of torrefied fuel co-‐gasified with hard
coal in a 24 hours trial • Mixing rate ~70% on energy basis
Main observations during the trial: • No big technical challenges during conveying, sluicing and milling of torrefied pellets/coal
blend • Estimated to be possible to achieve 90% of the plant nominal capacity without major
modifications in the fuel feeding system • Higher heating value in the pellets connected to better milling properties but less
advantageous dust formation behaviour
Alkmaar, October 2, 2014
ECN torrefaction R&D services In support of product quality assessment and optimisation
• Lab-‐to-‐pilot scale torrefac0on tests
• Extensive physico-‐chemical characterisa0on
• Full logis0cs, storage and end-‐use performance tes0ng: – Logis0cs and storage tes0ng (e.g., durability, hydrophobicity, biodegrada0on, leachability) – Safety assessment (e.g., self hea0ng, explosivity) – Determina0on of milling, pneuma0c feeding and gasifica0on/combus0on characteris0cs
Milling (pulverisation) Milling characteristics similar to coal
-
500
1,000
1,500
2,000
2,500
3,000
3,500
4,000
4,500
5,000
- 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
Power consumption (kJ/kg)
dpv (volume-based mean particle size, mm)
wood chips A
beneficiated/densified wood chips A
beneficiated/densified wood shavings B
beneficiated/densified corn stover C
PRB coal
Source: CEATI SOIG 0530 B/C project
Pneumatic feeding Importance of particle morphology and density
Coal
Raw Spruce Torrefied spruce chips Torrefied spruce pellets
• Fresh wood par0cles fluffy upon milling • Torrefied chips par0cles s0ll needle-‐shaped but not fluffy • Torrefied and pelle0sed par0cles much more
“spherical” (and closer to coal) • Also: density torrefied/pelle0sed wood much larger (not
shown)
Pneumatic feeding Importance of particle morphology and density
0
5
10
15
20
25
0 0.002 0.004 0.006 0.008 0.01 0.012
Pressure drop P 2-‐P
1 (m
bar)
Mass rate (kg/s)
Coal
Spruce 260°C
Poplar 265°C
Spruce 280°C
• All materials milled with similar power consump0on
• Milled pellets, mean par0cle size 200-‐350 μm
• Ambient air as carrier gas • Ground fresh wood does not
flow at all • Milled torrefied pellets flow
well • Flow proper0es dependent on
feedstock, less on torrefac0on temperature
Reactivity Conversion kinetics comparable to coal
0
10
20
30
40
50
60
70
80
90
100
0 500 1000 1500 2000 2500
conversion (% d.a.f.)
residence time [ms]
PRB coal (75-‐200 µm) PRB coal (53-‐75 µm)
woodchips A (300-‐1000 µm) woodchips A (75-‐300 µm)beneficiated/densified woodchips A (300-‐1000 µm) beneficiated/densified woodchips A (75-‐300 µm)
beneficiated/densified woodchips B (300-‐1000 µm) beneficiated/densified woodchips B (75-‐300 µm)
• Lab-‐scale comb./gas. simulator – Tflame/furnace = 1450/1300 °C – [O2]final= 3.8 % vol dry – (shallow) burner staging (~200 ms)
• Reac0vity: – large impact of milling
– (75-‐300 µm) fresh wood > PRB coal (53-‐75 µm) – (75-‐300 µm) beneficiated wood ~ PRB coal (75-‐200 µm) – (300-‐1000 µm) kine0cs significantly lower (fresh and upgraded) – deeply-‐torrefied/pyrolysed B material: reac0vity very low (at the applied condi0ons)
Source: CEATI SOIG 0530 B/C project
Torrefaction and gasification • Torrefac0on has significant advantages in the logis0cs chain (wide range of biomass/
waste feedstock converted into high-‐quality solid bioenergy carriers)
• Torrefac0on is a technical enabler for (dry feed) entrained-‐flow gasifica0on: – Grindability
– Par0cle shape and density
– Energy density and reac0vity
• Torrefac0on may be a technical facilitator for other gasifica0on processes: – Increased reliability/availability due to more consistent feedstock quality
– Posi0ve impact on gasifica0on process (e.g. less (problema0c) tars)
• Torrefac0on may be an economic/financial enabler for gasifica0on projects: – Torrefied biomass as supplementary strategic buffer:
– to increase feedstock supply flexibility / lower cost
– to improve bankability of gasifica0on projects
Thank you for your attention!
23
Production at ECN of tonne-scale test batches for industrial trials
Special thanks to: • Colleagues at ECN, Andritz and partners in the SECTOR
project • NL Min. of Economic Affairs, Andritz, EUDP partners,
SECTOR partners and EU for providing financial support
For more informa0on, please contact: Jaap Kiel Programme Development Manager Biomass T +31 88 515 45 90 P.O. Box 1, 1755 ZG PETTEN F +31 88 515 84 88 The Netherlands [email protected] www.ecn.nl
The research in the SECTOR project has received funding from the European Union Seventh Framework Programme (FP7/2007-‐2013) under grant agreement n° 282826