SECTOR Production of solid sustainable

energy carriers from biomass by means of torrefaction

J.H.A. Kiel

R.W.R. Zwart

J. Witt

D. Thrän

M. Wojcik

M. English

Presented at the International Workshop on Biomass Torrefaction for Energy, Albi, France, May 10-11, 2012

ECN-L--12-027 May 2012

www.ecn.nl

SECTOR Production of solid sustainable energy carriers

from biomass by means of torrefaction

International Workshop on Biomass Torrefaction for Energy

Jaap Kiel, Robin Zwart, Janet Witt, Daniela Thrän, Magdalena Wojcik and Martin English

Albi, France May 10th, 2012

Presentation overview

• Background & drivers

• Status torrefaction technology and product quality

• SECTOR- Project

– Facts

– Scope

– Objectives

– Torrefaction technologies considered

– Structure

• Summary

2

Biomass – a difficult energy source

• In view of:

– Logistics (handling, transport and feeding)

– End-use (combustion, gasification, chemical processing)

• Difficult properties are:

Low energy density (LHVar = 10-17 MJ/kg)

Hydrophilic

Vulnerable to biodegradation

Tenacious and fibrous (grinding difficult)

Poor “flowability”

Heterogeneous

3

Bioenergy – major challenge

• Enable decoupling of biomass production and use

– Place

– Time

– Scale

• By converting biomass in high-quality bioenergy carriers (solid, liquid or gas), that:

Better fit in (existing) logistic infrastructures

Allow efficient, reliable and cost effective conversion into electricity and heat,

transport fuels and chemicals

Solve biomass related problems at the source

4

Torrefaction for upgrading biomass

• Process parameters

– Temperature: 200-300 °C

– Absence of oxygen

Tenacious and fibrous

LHV = 7 – 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

5

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

Volatile matter (wt% db) 75 – 84 75 – 84 55 – 65 10 – 12 15 – 30

Fixed carbon (wt% db) 16 – 25 16 – 25 22 – 35 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 properties Hydrophilic Hydrophilic (Moderately)

Hydrophobic

Hydrophobic Hydrophobic

Biological degradation 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)

Abbreviations: db = dry basis LVH =Lower Heating Value

6

The added value of torrefaction

Torrefaction (+ densification) enables energy-efficient (>90%) upgrading of biomass into commodity solid biofuels with favourable properties in view of logistics and end-use

Favourable properties include high energy density, better water resistance, slower biodegradation, good grindability, good “flowability”, homogenised material properties

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 gasification-based biofuels and biochemicals production

Applicable to a wide range of lignocellulosic biomass feedstock, even mixed waste streams

7

Torrefaction technology

Many technology developers (>50) due to strong market pull

Often application of reactor technology proven for other applications (drying, pyrolysis, combustion)

Good process control is essential for good performance and product quality control (temperature, residence time, mixing, condensables in torrefaction gas)

High energy efficiency is crucial in view of overall cost and sustainability; overall energy efficiency is strongly dependent on heat integration design

In general: torrefaction technology in demonstration phase with >10 demo-units and first commercial units in operation and under construction

8

Torrefaction technology – many

reactor concepts considered

Rotary drum reactor Multiple hearth furnace Moving bed reactor Screw conveyor reactor

Torbed reactor Oscillating belt reactor TurboDryer Microwave reactor 9

Densification

• Focus on pelletisation, but briquetting considered as well

• Good quality pellets can be produced without additional binder

• But: – Pelletisation performance strongly dependent on biomass

feedstock

– Case-by-case tuning of the pelletisation conditions (e.g., die type) required

– Good control of torrefaction conditions is essential

– Without binder, window for tuning product quality to logistics and end-use requirements may be small

– Special attention to safety issues (e.g., self heating, dust explosions)

10

Product quality optimisation

• Pilot, demo and first commercial plants produce kg-tonne scale batches allowing representative logistics and end-use performance testing by industry

• Many coal-fired power plants want to be early adaptors and show interest in conducting co-firing trials (e.g., RWE, Vattenfall)

• Product quality optimisation requires a systematic iterative approach (2 iterative loops)

• For this purpose, European torrefaction developers, combustion and gasification technology providers and end-users have joined forces in the EU-FP7 project proposal SECTOR

Biomass

Torrefaction

Validated and optimised solid biofuel

Densification

Logistics testing

End-use testing

11

SECTOR Production of Solid Sustainable Energy Carriers from

Biomass by means of Torrefaction

• Collaborative project: SECTOR • Project start: 01.01.2012 • Duration: 42 months • Total budget: 10 MEuro • Participants: 21 from 9 EU-countries (+ industrial advisory group) • Coordinator: DBFZ (supported by ECN, ofi)

12

SECTOR participants

Kick-off meeting at ECN (14-15 February 2012)

13

Proof-of-concept

•Experimentally based process

designs

•Technology identification

•Knowledge base

•Experimental infrastructure

•Economic evaluations full-scale

(study about 30%)

•Set-up pilot phase development

Torrefaction and densification

technology roadmap

Prototype development

(pilot-scale evaluation)

•Pilot plants / prototype technology

•Demo technical feasibility

•Process & product characterization

(design)

•Economic evaluations full-scale

(preliminary ca. 20%)

•Business plan(s) (technical demo)

Technical demonstration

•Demonstration plants

•Technical optimization

•Product applications (logistics &

end-use)

•Economic evaluations full-scale

(definite ca. <10%)

•Business plan(s) (commercial

operation)

Commercial role out

•Commercial plants

•Quality control and assurance

(product)

•Best practice for sustainability

•Product standardisation

•Purchase agreements (from

energy & chemical sector)

2004 2006 2008 2010 2012 2014

Woody

biomass

Time

Capacity 5-10 kg/h 30-200 kg/h 60-200 kton/a 20-50 kton/a

Proof-of-

principle

Prototype

(pilot-scale)

Commercial

role out

Technical

demonstration

Proof-of-

concept

Proof-of-

principle Proof-of-concept

Prototype

(pilot-scale)

Commercial

role out

2002

Proof-of-

principle

Technical

demonstration

2016 2018

Non-woody

biomass residues

14

SECTOR objectives

• Support the market introduction of torrefaction-based bioenergy carriers as a sustainable commodity solid fuel

• Further development of torrefaction-based technologies (up to pilot-plant scale and beyond)

• Development of specific production recipes, validated through extensive lab-to-industrial-scale logistics and end-use performance testing

• Development and standardisation of dedicated analysis and testing methods for assessment of transport, storage, handling logistics and end-use performance

• Assessment of the role of torrefaction-based solid bioenergy carriers in the bioenergy value chains and their contribution to the development of the bioenergy market in Europe

• Full sustainability assessment of the major torrefaction-based biomass-to-end-use value chains

• Dissemination of project results to industry and into international forums (e.g. CEN/ISO, IEA and sustainability round tables)

15

Torrefaction (reactor) technologies

• Different biomass feedstocks may require different reactor technologies

• Technical feasibility and market potential of the various torrefaction (reactor) technologies with different process conditions (pressure, temperature, etc.) still uncertain

• SECTOR is centred around four torrefaction technology options

Reactor technology European Technology developers & suppliers

Rotary drum CDS (UK), Torr-Coal (NL), Umea/BioEndev (SE), ACB (AT), BIO3D

(FR), Atmosclear (CH), CENER (ES)

Multiple hearth furnace CMI-NESA (BE)

Screw reactor Biolake (NL), FoxCoal (NL)

Torbed reactor Topell (NL)

Moving bed reactor ECN/Andritz (NL), Thermya (FR), Bühler (CH)

Belt reactor Stramproy Green (NL)

Fluidised bed reactor VTT (FI) 16

Torrefaction (reactor) technologies

Production with available demo plant Continuous operation

Production of 100-200 tons Specific feedstock

Production with available pilot scale facilities Typical test runs 50-100 hours

Typical production per test few tons 3-6 different feedstocks

Moving bed (ECN) pilot

Rotary drum (Umeå University)

pilot

Rotary drum (CENER)

pilot

Torbed (Topell) demo

17

Logistics, handling and end-use

Sto

rag

e S

hip

men

t

Ha

nd

lin

g

Gri

nd

ing

& f

eed

ing

Pel

let

bo

iler

C

o-f

irin

g

(Co

-)g

asi

fica

tio

n

source: Vattenfall

source: Vattenfall source: Vattenfall source: Vattenfall

Source: Loesche Source: BIOS Source: Pedersen Group

Logistics and handling of torrefied

material

Disadvantages / Challenges

• Dust and dirtyness at handling and transport

• Safety issues must be assessed

• Self ignition and spontaneous combustion occurs at 150-170°C

• Explosion hazards increase compared to conventional biomass but probably not in comparison with coal

• Compacting (pellets / briquettes) is more difficult

• Additional fuel properties (e.g. degree of torrefaction, grindability, hydrophobic nature, resistance against biodegradation) and sustainability criteria must be defined ISO work

Advantages

• Increased feedstock basis

• High energy density of torrefied products effective transport

• Reduced water retention force (hydrophobicity)

• Slower biodegradation potential

• Better grindability due to embrittlement

• Decreased costs for handling, storage and transport

• Biomass torrefaction can create new markets and trade flows as a commodity fuel ( product standards are needed)

19

Safety issues self-heating (chemical oxidation of torrefied wood chips)

Thermometer Smoke in

24 Minutes

Fire in

32 Minutes

ECN 2008-03

Stramproy Green

2012-02

End of production run on

Wednesday

Fire on

Saturday 20

SECTOR project structure

21

Summary

• Torrefaction potentially allows cost-effective production of commodity solid biofuels from a wide range of biomass/waste feedstock with a high energy efficiency (>90%) allowing a decoupling of biomass production and use

• Torrefaction development is in the pilot/demo-phase, with >10 demo initiatives underway in Europe; strong market pull for torrefaction plants and torrefaction pellets

• Main characteristics of torrefaction are known, but performance testing still is in an early phase, which holds even more for iterative optimisation of production recipes for torrefied biomass pellets

• SECTOR aims at reducing the time-to-market of torrefaction technology by:

– Development of optimised torrefaction + densification production recipes, validated through extensive lab-to-industrial-scale logistics and end-use performance testing

– Development and standardisation of dedicated analysis and testing methods

– Full sustainability assessment of major torrefaction-based biomass value chains

– Dissemination of project results to create sufficient confidence level at industrial stakeholders and initiate standardisation and certification

22

Thank you for your attention!

This presentation was prepared in close co-operation with:

For more information, please contact:

Jaap Kiel Programme Development Manager Biomass & Energy Efficiency T +31 88 515 45 90 P.O. Box 1, 1755 ZG PETTEN F +31 88 515 84 88 The Netherlands kiel@ecn.nl www.ecn.nl

The research leading to these results has received funding from the European Union Seventh Framework

Programme (FP7/2007-2013) under grant agreement n° 282826.