The “NEXT GENERATION” project: valorizationalternatives for char from small scale gasification systems in South-Tyrol

D. Bassoa, S. Vakalisb, F. Patuzzia, A. Gasparellaa, W. Tirlerc, S. Dal Saviod, A. Rizzoe, D. Chiaramontie, M. Baratieria

a Free University of Bozen-Bolzano, Faculty of Science and Technology, Italyb National Technical University of Athens, Greecec Eco Research, Bolzano, Italyd IDM Südtirol – Alto Adige, Bolzano, Italye RECORD Consortium, Firenze, Italy

5th International Conference on Sustainable Solid Waste Management

Athens, 21–24 June 2017

Introduction

BACKGROUND

Introduction

Area: 7400 km2

Population: 511750 ab.

~42% forest

CHP since 1993

The South Tyrol region

Introduction

SMALL SCALE GASIFICATION PLANTS

Data of small-scale biomass gasification units installed capacity by manufacturers:

Europe ~ 920; Germany ~ 435*, Italy ~ 120-150; South Tyrol ~ 43

*Source: workshop “Small scale gasification for CHP” – Innsbruck - 3rd, May 2017

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Europe Germany Italy SouthTyrol

Capacity of plants in Germany

Total capacity of plants

Number of plants in Germany

Total number of plants

Num

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of p

lant

s

2015 – Authorized gasification plants 46

GASIFICATION IN SOUTH-TYROL

580.000 m3

WOODY BIOMASS

450.000 m3

> 70CHP plants

> 40µGasification plants

724 GWhth

57 GWhel

84 GWhth

42 GWhel

2000 ton/y CHARother domestic or

industrial plants

50%

50%

(UNIBZ, GAST project 2014)

Introduction

PROJECTS

Introduction

GAST PROJECT (2013-16)

NEXT PROJECT (2016-17)

WOOD-UP PROJECT (2017-2019)

The GAST project (2013-16)

“Experiences in biomass Gasification in South Tyrol: energy and environmental assessment”

Small scale gasification plants authorized in South Tyrol in the last years

2012201320142015

Project partners

Funded by: Autonomous Province of Bolzano

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Agnion Technologies GmbH

Burkhardt GmbH

Entrade

Future Green Srl

GTS Syngas Srl

Hans Gräbner

Holzenergie Wegscheid GmbH

Kuntschar EnergieerzeugungGmbH

Pyrox GmbH

Repotec GmbH

Spanner Re² GmbH

Stadtwärke Rosenheim

Syncraft Engineering GmbH

Urbas Maschinenfabrik GmbH

Xylogas & EAF

THERMAL POWER ELECTRICAL POWER (kW)

FACTS & FIGURES

Technology PlaceAgnion Technologies GmbH OraBurkhardt GmbH OraBurkhardt GmbH SinigoBurkhardt GmbH Campo di TrensBurkhardt GmbH Campo di TrensBurkhardt GmbH S. GenesioEntrade TerlanoFuture Green Srl LagundoHans Gräbner Campo TuresHolzenergie Wegscheid GmbH Rio di PusteriaKuntschar Energieerzeugung GmbH BraiesKuntschar Energieerzeugung GmbH Senale San FeliceKuntschar Energieerzeugung GmbH Rio PusteriaPyrox GmbH LasaRepotec GmbH MallesSpanner Re² GmbH Badia (S. Cassiano)Spanner Re² GmbH Castelrotto (Siusi)Spanner Re² GmbH RiffianoSpanner Re² GmbH S. CandidoSpanner Re² GmbH S. CandidoSpanner Re² GmbH S. CandidoSpanner Re² GmbH S. Leonardo i.P.Spanner Re² GmbH Campo di TrensSpanner Re² GmbH Chiusa (Latzfons)Spanner Re² GmbH GlorenzaSpanner Re² GmbH Naz SciavesSpanner Re² GmbH Naz SciavesSpanner Re² GmbH RacinesSpanner Re² GmbH Rio Pusteria (Spinga)Spanner Re² GmbH S. Martino i.B.Spanner Re² GmbH SarentinoSpanner Re² GmbH ValdaoraSpanner Re² GmbH VeranoSpanner Re² GmbH DobbiacoSpanner Re² GmbH MallesSpanner Re² GmbH RacinesSpanner Re² GmbH VandoiesSpanner Re² GmbH Lagundo (Aschbach)Spanner Re² GmbH LaimburgSpanner Re² GmbH n.p.Stadtwärke Rosenheim BressanoneSyncraft Engineering GmbH VersciacoUrbas Maschinenfabrik GmbH  VallesUrbas Maschinenfabrik GmbH  CastelbelloUrbas Maschinenfabrik GmbH  MallesXylogas & EAF Val di Vizze

GASIFIER FILTER HEAT EXCHANGER

INTERNAL COMBUSTION

ENGINE

The GAST project

Analyzed parameters

- Feedstock and gasification products (gas, char e tar) characteristics - Mass fluxes- Energy fluxes

Pel

Pth

- water/oil cooling

- flue gases cooling

Pth

- gas cooling

Char

Biomass

GasTar

Introduction Methods ConclusionsResults

Investigated plant typologiesTechnology A B C (D)

Fuel wood chips pellet wood chips wood chips

Feeding from the top from the bottom from the top from the top

Nominal power

45 kWel / 120 kWth

180-190 kWel / 220-240 kWth

100-150 kWel / 200-250 kWth

300 kWel /600 kWth

Reactor downdraft rising co-current downdraft downdraft

Gas cleaning dry, on the cold gas dry, on the hot gas dry, on the hot gas dry, on the hot gas

Engine turbo-compressedOtto cycle dual-fuel Diesel cycle modified Diesel cycle modified Diesel cycle

Peculiarity

The (already quite dry) biomass is first dried in a separated vessel and then transported to the main reactor

• The biomass feeding from the bottom creates a vortex above the combustion zone

• The engine is co-fed with colza oil for theauto-ignition

The wet wood chips are dried in a external drier suiting the excess of heat

The wet wood chips are dried in a external drier suiting the excess of heat

Introduction Methods ConclusionsResults

Applied methodologies

Mass fluxes

- Woody biomass flow rate- Gasifying agent (air) flow rate- Producer gas flow rate- Char flow rate

Input biomass weighted and manually fed to the reactor…

… or inverse strategies applied(e.g. maximum level of the storage used as reference)

Introduction Methods ConclusionsResults

Applied methodologies

Mass fluxes

- Woody biomass flow rate- Gasifying agent (air) flow rate- Producer gas flow rate- Char flow rate

Determined by means of the velocity in a known dimensions tube connected to the air inlet. Velocity measured by means of a Pitot tube.

Air inlet

known dimensions tube

Pitot tube

flexible connection

Introduction Methods ConclusionsResults

Applied methodologies

Mass fluxes

- Woody biomass flow rate- Gasifying agent (air) flow rate- Producer gas flow rate- Char flow rate

Determined once measured the gas composition and the input air flow rate, assuming negligible the nitrogen content in the fuel.

2Ngas air

xV = V

0.21

Introduction Methods ConclusionsResults

Applied methodologies

Mass fluxes

- Woody biomass flow rate- Gasifying agent (air) flow rate- Producer gas flow rate- Char flow rate

Determined collecting the char during the whole monitoring period.

All the parameters have been monitored for a continuous steady operation period of at least 5-6 hours.

Introduction Methods ConclusionsResults

Applied methodologies

Energy fluxes

- Energy related to the input fuel- Energy related to the producer gas- Produced electrical and thermal energy

Determined on the basis of the biomass flow rate and of its Lower Heating Value (LHV), measured by means of calorimetric bomb.

comb comb combP =m LHV

Introduction Methods ConclusionsResults

Applied methodologies

Energy fluxes

- Energy related to the input fuel- Energy related to the producer gas- Produced electrical and thermal energy

Producer gas LHV calculated on the basis of its composition, measured by means of a portable gas chromatography system.

gas gas gasP =m LHV

Introduction Methods ConclusionsResults

Applied methodologies

Energy fluxes

- Energy related to the input fuel- Energy related to the producer gas- Produced electrical and thermal energy

Electrical power measured by means of power analyser and/or integrated meter ofthe plant.

Thermal power estimated from:- Medium flow rate (ultrasonic meter)- Supply and return temperature

(thermocouples type k)

Introduction Methods ConclusionsResults

Applied methodologies

By-products characterization

- Liquid: tar- Solid: char

Tar in the producer gas sampled and analyzed according to UNI CEN TS 15439(bubbling in isopropanol)

Introduction Methods ConclusionsResults

Applied methodologies

By-products characterization

- Liquid: tar- Solid: char

Introduction Methods ConclusionsResults

Char toxicity assessed by means of germination tests - cress seeds (Lepidium sativum L.), treated

with char extracts and - incubated for 24 hours at 25 °C (UNI 10780)

GI = NGSsample x MRLsample/ (NGScontrol x MRLcontrol)

GI: germination indexNGS: number of germinated seedsMRL: mean root length of seedlings mm

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ηel,lorda ηel,netta ηth ηtot

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ienc

y[-

]Tecnologia A Tecnologia B Tecnologia C

Efficiencies

TOTel,gross th el,net

Introduction Methods ConclusionsResults

Technology A Technology B Technology C

Tar in the producer gas

Technology A B C (D)

Gravimetric tar (mg/Nm³) 650-750 200-300 150-250 150-250

Suggested limit value for ICE: ≈ 100 mg/Nm³

Introduction Methods ConclusionsResults

Introduction Methods ConclusionsResults

Tar in the producer gas

The GAST project

Main results

- Quite reliable operation of commercial small scale CHPs (< 200 kWel)- the plants ensure 7000 h/year of operation- similar overall efficiencies for the compared technologies (≈ 70%)- high electrical efficiency (20-30 %)

- but…- high quality feedstock (water content < 10 %)- tar content higher than the limit suggested in the scientific

literature (frequent engine maintenance required)- char as to be disposed off (it is a cost for the plant manager)

The NEXT GENERATION project (2016-17)

“Novel EXTension of biomass poly-GENERATIONto small scale gasification systems in South-Tyrol”

Project partners

Funded by: Autonomous Province of Bolzano

Possible utilization pathways (literature)

energy production (co-firing in power plants)

soil improver

adsorbent

catalyst support (FT-synthesis)

tar cracking applications

char

Energy production: co-firing

Technology Ash C H N S O HHV LHV

(%) (%) (%) (%) (%) (%) (MJ/kg) (MJ/kg)

A 13.34 78.97 0.68 0.20 0.31 6.50 25.53 25.38

B 19.40 66.96 0.18 0.16 0.63 12.67 18.11 18.07

C 5.47 80.23 0.49 0.23 0.28 13.29 26.74 26.53

D 4.63 89.33 0.54 0.21 0.28 9.59 30.92 30.73

E 25.15 69.05 0.15 0.12 0.28 5.24 22.87 22.84

F 16.03 69.49 0.20 0.46 0.33 13.49 24.17 23.99

Next steps: - preparation of pellets (blended char + wood)- co-firing in small-scale boilers

Introduction Methods ConclusionsResults

Adsorption

- Large surface area (200-2000 m2/g)- Micro- and meso-pore distribution compatible with the

molecular dimensions of the adsorbates- Surface chemistry that does not inhibit the adsorption

mechanism.

Scarce data available on surface area of chars

from actual gasification plants

Activated Carbons

Amorphous carbonaceous materials- High carbon content (85-95 %)- High surface area (500-2000 m2/g)- Microporous structure (pore volume: 0.20-0.60 cm3/g)- High degree of surface reactivity

ACs demand in 2018: 2.1 million tons

Cheap precursors are needed

ACs are ideal for adsorption

Mechanism of formation of ACs and char

ACs from biomass

Char from gasificationz

Gas

Tar

Carbonization(Pyrolysis) ActivationLignocellulosic

biomassACs

Pyrolysis GasificationLignocellulosicbiomass

Char

ACs for adsorption applications are synthetized on purpose to adsorb a specific adsorbateand their properties are carefully tuned through controlled carbonization and activation.

Chars from gasification are not developed to be adsorbents. Their properties have to becritically evaluated before choosing the most suitable adsorbate for its utilization.

Introduction Methods ConclusionsResults

Literature reviewFeedstock Technology Gasifying

agentT (°C) SBET

(m2/g)Ref.

poplar fluidized bed 90%H2O/10%N2 750 621 [1]10%CO2/90%N2 750 435

920 687dealcoholized grape marc entrained flow air 1200 60 [2]

steam 1200 35coal 60%/pine 40% fluidized bed steam/air

(ER=0.2)850 127 [3]

soft wood chips bubbling fluidized bed steam 850 489 [4]soft wood pellets 1581switchgrass fluidized bed air (ER=0.28) 700-800 20.8 [5]red cedar air (ER=0.25) 60.8wheat straw two stage gasifier steam 1000-1200 75 [6]pine wood chips 1027sieved pine wood chips 426switchgrass bubbling fluidized bed air/N2 760 31.4 [7]corn stover 730 23.9pine wood fluidized bed steam 800 603 [8]

steam/air 800-850 411-147Activated carbons from biomassAC - Coconut shell 1700 [9]AC – Apricot stones 359.40AC – Macadamia nut-shell 844

References[1] Klinghoffer NB et al. Ind Eng Chem Res

2012;51:13113–22.[2] Hernández JJ et al. J Clean Prod

2016:1–11.[3] Galhetas M et al. Waste Manag

2012;32:769–79.[4] Lundberg L et al. Fuel Process Technol

2016;144:323–33.[5] Qian K et al. Energies 2013;6:3972–86.[6] Hansen V et al. Biomass and Bioenergy

2015;72:300–8.[7] Brewer CE et al. Environ Prog Sustain

Energy 2009;28:386–96.[8] Franco C et al. Bioresource Technology

2003;88:27–32.[9] Ioannidou O et al. Renew Sustain Energy

Rev 2007;11:1966–2005.

Introduction Methods ConclusionsResults

Literature review

[10] Kilpimaa et al. J Ind Eng Chem2015;21:1354–64.

[11] Runtti H et al. J Water Process Eng2014;4:12–24.

[12] Galhetas M et al. J Colloid Interface Sci2014;433:94–103.

[13] Maneerung T et al. Bioresour Technol2016;200:350–9.

References

Application Feedstock Gasification Activation Ref.

conditions * SBET (m2/g) agent T (°C) SBET

(m2/g)

Nitrate and phosphate removal

Fe(II), Cu(II) , Ni(II) ions removal

spruce, pine

downdraft gasifier, air, 1000 °C

52 CO2 600 -800 152 - 590 [10,11]

CO 600 - 800 126 - 135N2 600 - 800 145 - 160ZnCl2 - 285HCl - 194H2SO4 - 157KOH - 117HNO3 - 259

Acetaminophen and caffeine adsorption

pine fluidized bed, air, 850 °C

101 K2CO3 700 - 800 570 - 1509 [12]

Rhodamine B removal

mesquite wood chips

Downdraft, air, -

172 CO2 700 - 800 485 - 737 [13]Steam 700 - 800 - 900 538 - 737 - 776N2 700 - 800 - 900 178 - 280 - 287

* technology, gasification agent, process temperature

biomass gasification char used as ACs for adsorption applications

Char samples – preliminary results

BET surface analysis

Scenarios

- Given the char properties, find the best application (downstream) e.g., dual stage gasifier seems the most promising

technology for adsorption applications- Integrate the existing technologies with activation

stages, optimizing the process in order to obtain a valuable (by-)product

The WOOD-UP project (2016-2019)

“Optimization of WOOD gasification chain in South Tyrol to prodUce bio-energy and other high-value green Products to

enhance soil fertility and mitigate climate change”

Project partners

Funded by:

Question mark- Can char from gasification

be used in an effective way as soil amendment?

LEGISLATIVE BACKGROUND

G.U. n. 186, 12.08.2015: «Biochar as soil improver»

S3 Priorities (Province of Bolzano), Energy and Environment: «Improve the renewable energy production from woody

biomass»

physical and chemical properties of char and its exploitation as soil conditioner

1- analyses of:- PCDD/PCDF 2,3,7,8- WHO-PCB (Dioxin-like) and PCB total- PAH- Heavy metals- Preliminary germination tests

Identification of the technologies that can produce char suitable as soil improver

physical and chemical properties of char and its exploitation as soil conditioner

1- analyses

Technology H/C Cr Cd Zn PAH PCB

(mol/mol)

E 0.104 (0.7) 9.45 (0.5) 1.814 (1.5) 396.11 (500)

D 0.031 (0.7) 0.71 (0.5) 1.856 (1.5) 215.69 (500) 263 (6) 19.5 (0.5)

B 0.074 (0.7) 1.13 (0.5) 6.433 (1.5) 511.06 (500)

F 0.073 (0.7) 2.78 (0.5) 0.224 (1.5) 66.26 (500) 85.6 (6) 0.4 (0.5)

G 0.034 (0.7) 15.47 (0.5) 0.229 (1.5) 570.27 (500) 441.2 (6) 107.8 (0.5)

Preliminary results

physical and chemical properties of char and its exploitation as soil conditioner

2- germination tests

Char toxicity assessed by means of germination tests - cress seeds (Lepidium sativum L.), treated

with char extracts and - incubated for 24 hours at 25 °C (UNI 10780)

GI = NGSsample x MRLsample/ (NGScontrol x MRLcontrol)

GI: germination indexNGS: number of germinated seedsMRL: mean root length of seedlings mm

physical and chemical properties of char and its exploitation as soil conditioner

2- germination testsPreliminary results

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physical and chemical properties of char and its exploitation as soil conditioner

2- germination testsPreliminary results

Technology Germination index [%]

D 73±2B 80±2F 88±3G 50±1

Comparison between gasification chars and

char produced under controlled conditions in lab

Correlation between char properties and

process conditions/technology

• chemical-physical characteristics

• type of technology

• operational conditions of the plant

Pathways to improve polygeneration

   Temperature [°C]900700500

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Char properties Vs process conditions

(char produced in controlled conditions in lab)

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Char properties Vs process conditions

(char produced in controlled conditions in lab)

TIMELINE

10/2016 10/2017 10/2018 10/2019

NEXT project

WOOD‐UP project

The authors want to thank the Autonomous Province of Bolzano, ProvinciaAutonoma di Bolzano – Alto Adige, Ripartizione Diritto allo studio,

Università e ricerca scientifica for the financial support to the NEXT GENERATION project:

“Novel EXTension of biomass poly-GENERATION to small scale gasification systems in South-Tyrol”

CUP B56J16000780003, contract: 20/34 03/11/2016.

THANKS FOR YOUR ATTENTION!marco.baratieri@unibz.it