SllSmall scalebiomassgasifi tiification– Challengesand opportunities?€¦ · ·...

S ll l bi ifi tiSmall‐scale biomass gasification –Challenges and opportunities?

Kari PieniniemiPhil.Lic. (Chem)

Challenges and opportunities?

Phil.Lic. (Chem)Centria Univeristy of Applied Sciences

Ylivieska

Content of presentationp• Climate Change is a Global Challenge • Renewable Energy is the answer• Biomass gasificationg

– Small‐scale biomass gasification• Gasification Strengths and WeaknessesGasification Strengths and Weaknesses

– Technical barriers • Centria Pilot R&D Gasifier• Centria Pilot R&D Gasifier12.11.2013 2Kokkola Material Weeks

Climate Change is a Global Challenge g gCO2 is the primary greenhouse gasHuman activities, such as the burning of fossil fuels release large amounts of carbon to the atmosphererelease large amounts of carbon to the atmosphere

"20‐20‐20" targets, set three key objectives for 2020:d h

Renewable energy (RES) is the answer

• A 20% reduction in EU greenhouse gas emissions from 1990 levels;

• Raising the share of EU energy consumption produced from renewable resources to 20%;

IPCC. 2007. IPCC Fourth Assessment Report. Working Group I Report The Physical Science Basis. Summary for Policy Makers, s. 3.

produced from renewable resources to 20%;• A 20% improvement in the EU's energy efficiency.On 27 March 2013, the European Commission adopted a Green Paper on "A 2030 framework for

Energy Roadmap 2050 to low carbon economy in 2050• RES in energy consumption 75 % in 2050• RES in electricity consumption reaching 97 %higher energy efficiency and shares of renewables are

12.11.2013 3

climate and energy policies".http://ec.europa.eu/energy/green_paper_2030_en.htm

necessary to meet the CO2 targets in 2050

Energy roadmap 2050 (COM(2011) 885 final of 15 December 2011)

Kokkola Material Weeks

Renewable Energy is the answergyRenewablesRenewables BioenergyBioenergy

GAS; 21%

OIL; 35%77 %50 EJ

87 % 43 EJ

Re‐newables;

13 %

Nuclear; 6%COAL; 25%

50 EJ

COAL; 25%

8%

15%

Other renewables

4%9%

Municipal & Industrial WasteAgricultural Crops & By‐productsWood BiomassWorld Primary Energy mixture

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Other renewablesHydropowerBioenergy

100 % = 500 EJ (eksajoule = 1018J)


Renewable Energy is the answergy

• Recognize cost gap between renewable andF th R&D it

For policy makesBut there are Challenges ….

• R&D to reduce energy unit costs• Realistic perception of resource availabilityS t i bl d ti d l d b

Recognize cost gap between renewable and fossil fuels

• resulting market failure requires policy measures

For the R&D community

• Sustainable production and closed carbon cycle

Overall • higher cost cannot be compensated by public Message to consumers

20% Renewables means 2/3 Bioenergy

Finally..

g p y psubsidies

• In a level playing field industry will take over

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“The stone age did not end for the lack of stones and the oil age will end long before the world runs out of oil”

y

Sheiikh Zaki Yamani former Saudi Arabia Oil ministerKokkola Material Weeks

Renewable Energy is the answergyBIOENERGY AND BIOFUELS are an opportunity for the FinnishForest Industry*

1G FirstFirstGeneration

HIGHBIO2

2G SecondGeneration

HIGHBIO2

www.chydenius.fi/en/natural‐sciences/research/highbio2

12.11.2013 6* Hans Sohlström, Vice President UPM‐ Kymmene Corporation, Finland presentation in 18th European Biomass Conference 2010 Lyon France

Generation


Biomass utilization technologiesTechnology/Process State‐of the Art Main Challenges

Commercial available, low efficiency Feedstock variability, feedstockCombustion

Commercial available, low efficiency at small scale

Feedstock variability, feedstock contamination, combustion stability

Gasification Demonstration scale, Earlyi li ti t

Cost reduction, gas qualityGasification commercialisation stage, g q y

Anaerobic digestionCommercial status but high costs, low efficiency and low yield

Scale‐up, cost reduction and use of mixed wastes

Processes to bio‐diesel

Proven technology, high cost and low yield

Cost reduction and continuous production

Fermentation to bio‐ethanol

Commercial status, high cost, low yield

Cost reduction, higher yield

12.11.2013 7Kokkola Material Weeks

Biomass gasificationgBiomass gasification is a promising, energy‐efficient technology for renewable energy generation

Gasification: Thermal conversion of biomass into a low calorific to medium‐ calorific value combustible gas

Producer gas: The mixture of gases produced by thegeneration Producer gas: The mixture of gases produced by the gasification of biomass at relatively low temperatures (700 to 1000 °C)

• can be burned in a boiler for heat production, orp ,• in an internal combustion (IC) gas engine for combined heat and electricity (CHP)

Synthesis gas (Syngas):Synthesis gas (Syngas): • Mainly carbon monoxide (CO) and hydrogen (H2)• Can be transferred to synthetic natural gas (SNG) orsynthetic diesel (Fischer‐Tropsch synthesis) or use as a feedstock in production of green chemicals

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feedstock in production of green chemicals• Gasification in higher temperatures• Cleaning of the producer gas


Biomass gasificationGasification stage gas composition: Carbon monoxide (CO), hydrogen (H2), methane (CH4) light hydrocarbons water vapour (H2O)

gGasification is one stage in the thermal biomassconversion process*

(CH4) light hydrocarbons , water vapour (H2O), carbon dioxide (CO2), nitrogen (N2), tar vapor, and ash particles

Tar content 100 /N 3 i d ft ifi

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*H.A.M. Knoef (Ed,.) (2005) Handbook Biomass Gasification, . ISBN 90‐810068‐1‐9, p. 13

• 100 g/Nm3 in an updraft gasifier, • 10 g/Nm3 in a fluidized bed gasifier and • 1g/Nm3 in a downdraft gasifier. (Neeft, 1999)


Small‐scale biomass gasificationg• Small‐scale CHP (combined heat and power) units for heat and electricity production

Downdraft gasification is ideal for small scale CHP production up to about 1 MWth

Product gas or synthesis gas can be used in

units for heat and electricity production• Production of biofuels and chemicals

Small‐scale* CHP electrical power < 100 kW Mi l CHP l t i it < 15 kW

There are about 50 commercial gasification plant manufacturers in Europe, USA and in Canada from

Micro‐scale CHP electric capacity < 15 kWe

which • 75% were fixed‐bed downdraft type, • 20% fluidized‐bed systems, • 2.5% fixed bed updraft type, and • 2.5% were of various other designs

12.11.2013 10*Dong L., Liu H. and Riffat S. 2009. Development of small‐scale and micro‐scale biomass‐fuelled CHP systems –A literature review. 2009, pp. 2119–2126


Small‐scale biomass gasificationMarkets for small scale CHP1. Biomass CHP Power Plants

g

Small scale CHP has growing markets in Europe and other OECD countries

E i t i i d t i ( t l t t ) h t d t2. Carbon‐free Gas for IndustryEnergy‐intensive industries (metals, cement etc.) has a strong needs to diversify fuel consumption and reduce energy costs & CO2 emissions (Climate Change)3. Decentralized Power

Remote areas are affected by high‐increasing prices of fossil fuel for power production based on diesel generators

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power production based on diesel generators


Small‐scale biomass gasificationg


Small‐Scale Biomass Gasification, XYLOWATT

A Success Story*Small Scale Biomass Gasification, XYLOWATT

XYLOWATT (www.xylowatt.com)• Biomass gasification CHP manufacturer and turnkey

id f B l iprovider from Belgium• aims to be a strong international actor in the small‐scale Woodgas CHP (0,1—10 MWe)

• LHV 5,4 MJ/Nm3, /• High quality syngas (< 10 mg/Nm3 tar, < 10 °C, water free)

Fully automated plant—High efficiency with syngas use in IC engine (75% total efficiency, 25% net electrical efficiency)

— Flexibility for the operation (100% woodgas or 100% NG)— Fully automatic instantaneous power regulation totally

1 950 MWh/yr of electricity 3 900 MWh/yr of heat

S 1644 CO T /

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Fully automatic, instantaneous power regulation, totally remote controlled

Saves 1644 CO2 Tons/yr Uses 600 odt/yr of wood

*Handbook Biomass Gasification (2012) H.A.M. Knoef (Ed,.), Chapter 2 Success stories on biomass gasification p 20. ISBN 978‐90‐819385‐0‐1Kokkola Material Weeks

Kempele Ecovillage since 2009, Volter Oy

A Success StoryKempele Ecovillage since 2009, Volter Oy

The electricity and heat for the ten houses in KempeleEcovillage are produced by a CHP‐plant in the village using V lt ' d ifi ti t h l One liter of oil can be replace

by 2 kg of dry wood

Volter's wood gasification technology

Wood gas is fed to IC engineconnected to generator to produce electricity

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http://www.volter.fi/etusivu


Gasification Strengths and WeaknessesGasification and direct combustion have a number of general strengths and weaknesses

Strengths Weaknesses

g

Gasification

Lower NOx, CO, and particulate emissionsPotential for more efficient conversion process when generating powerVirtual elimination of water needs if

Technology is in the development and demonstration phaseNeed fuel with rather low size distributiond i t t t

generating power without a steam turbineand moisture content

Proven, simple, lower‐cost technologyGreater NOx, CO, and particulate emissions

Direct Combustion

Equipment is widely available, complete with warrantiesFuel flexibility in moisture and size People comfortable with technology

Inefficient conversion process whengenerating power alone—some advanced designs are improving efficiencyRequires water if generating power with aPeople comfortable with technology Requires water if generating power with a steam turbine


Gasification Strengths and WeaknessesgPotential Health, Safety and Environmental aspects of gasification plants*Health, safety and environmental (HSE) issues are found an important barrier to the market uptake of biomass gasification technology

Risk assessment in biomass gasification is becoming

Guideline for Safe and Eco‐friendly BiomassGasification

increasingly important all over the world

Gasification

http://www.gasification‐guide.eu/

*H.A.M. Knoef (Ed.) Handbook Biomass Gasification 2nd Ed.

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(2012) . ISBN 978‐90‐819385‐0‐1, p. 374 ‐ 432


Gasification Strengths and WeaknessesgProducer gas properties regarding to HSE aspects

Typical characteristics of producer gas compared to other gases

Small‐scale biomass gasifiers operate normally with air as a gasification agent => gas composition differs largely from other gases

Parameter Producer gas

Biogas Natural gas

CO (vol %) 12‐20 <1 <0.5( l )

p ff g y f glike biogas or natural gas

• desired products: permanent gas (H2, CO, CH CO N ) and ashes with low remaining

H2 (vol %) 15‐35 <1 <0.5CH4 (vol%) 1‐5 50‐75 90‐99CO2 (vol %) 10‐15 20‐50 <1N (vol%) 40 50 <1 <1CH4, CO2, N2) and ashes with low remaining

carbon content• undesired products: particulate matter, dust, soot, inorganic (alkali metals), H2S,

N2 (vol%) 40‐50 <1 <1Heating value MJ/Nm3 4.8‐6.4 18‐26 35Explosion range (vol%) 5‐59 3‐14 4.5‐15Air to gas ratio 1.1‐1.5 5‐7.5 10

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2COS, NH3, HCN, HCl and organic pollutants(tars or PAH compounds)

g


Gasification Strengths and WeaknessesgExplosion levels and combustion pressure

The following analysis comes from a two‐stage gasification plant.

Gas composition 1st stage 2nd stage

f g y f g g f pThe first stage is evaporation and pyrolysis of wood chips by indirect heating. The second stage is pyrolysis of gases by direct heating with combustion products.

Gas composition 1st stage 2nd stageTar components 0.04 mole/mole 0.02 mole/moleMole weight 24.3 kg/kmol 22.3 kg/kmolStoichiometric combustion air mole air/ mole gas

3.00 mole air/ mole gas

1.59 mole air/ mole gasmole air/ mole gas gas LEL 0.104 0.12UEL 0.395 0.62Deflagration pressure at 15°C 6.6 barg 6.1 bargFlame temperature at 15°C 1695 °C 1575 °C

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Flame temperature at 15 C 1695 C 1575 CDeflagration pressure at 500 °C 3.4 barg 2.5 bargFlame temperature at 500°C 2480 °C 1820 °C


Gasification Strengths and WeaknessesgGuideline for Safe and Eco‐friendly Biomass GasificationRiskAnalyzer computer program

The Guideline is intended to be a training tool and a resource for workers and employers to safely design, fabricate, construct, operate and maintain small‐scale biomass gasification facilities (up to about 1 MWe)

http://www.gasification‐guide.eu/


Gasification Tehnical BarriersTars in producer gas is the largest single problem that has to be overcome in order to commercialize gasification processes

In Large Scale: “Two of the most important operational barriers for both the BFBG and CFBG are the risk for defluidisation and the presence of tar in the product gas ”

Most important way to avoiding condensation is to maintain the gas above the tar dew point (~ 400 °C)

In Energy Production

gas.

In Production of fuels and chemicals from the syngasAs soon as the temperature of the

Internal combustion (IC) engines and synthesis applications require cooling of the gas before use

requirements on product gas purification are very high to prevent poisoning of the catalysts.

syngas As soon as the temperature of the producer gas drops below the dew point, tars will form aerosols or directly condense on the inner surfaces of the equipment,

l i i l i d f li f

12.11.2013 20Ref: Stefan Heyne, Truls Liliedahl, Magnus Marklund,(2013) Biomass gasification ‐ a synthesis of technical barriers and current research issues for deployment at large scale (f3 2013:5)

resulting in plugging and fouling of pipes, tubes, and other componentsdownstream the gasifier.


Gasification Technical BarriersTar cleaning

Tar free producer gas can be achieved in many ways.

Physical methods used for removing condensed tar aerosols are same used in removing particles; wetremoving particles; wet scrubbers, electrostatic precipitators, etc.

12.11.2013 21

Thermal and catalytic methods


Gasification Technical BarriersTar cleaningThe occurrence of tars in producer gas is still the single p g glargest problem that has to be overcome beforecommercialize gasification processes for various purposes

There are two main strategies for dealing with the tar once it is present in the producer gas:• removal and use and • in situ conversion

OLGA: Oil Scrubber

Removal and use, OLGA process

OLGA h b d l d b th E R h C t f

The washing and absorption media (“oil”) is fatty acid methyl esters (FAME) produced by the transesterificationof triglycerides from plants (bio‐diesel)

OLGA operates in the temperature range whereOLGA has been developed by the Energy Research Centre of the Netherlands (ECN)

OLGA operates in the temperature range wheretars condense, but water doesn’t (above the dew point of water)


Gasification Technical Barriers


Tar cleaning

Condensation step: • Inlet temperature of the gas can be up to 350 °C•Gas is cooled down by the recirculating oil which washes


•Gas is cooled down by the recirculating oil, which washes out the condensed heavy tars

• Part of the oil/tar mixture is returned to the gasifier•WESP is used to remove droplets of tars and oil from the gas

Light tar absorber:• Absorber temperature is just above the water dew pointStripper:Ab b d t d il f d i t t i h th li ht t t i d ff b h t i• Absorbed tars and oil are fed into a stripper where the light tars are stripped off by hot air

• Regenerated oil (FAME)is fed back to the absorber


Gasification Technical Barriers

In situ conversion C t l ti t f i

Tar cleaningIn situ conversion

tars are converted in the producer gas by some kind of thermal or catalytic process

Catalytic steam reforming

catalyst of metallic nickel (Ni)water is consumed during the reaction

Catalytic tar crackingBasic catalysts, such as dolomite, magnesite, and olivine, must be calcinated into oxides (activation) reforming temperatures of ~850 °C and

steam/carbon ratios 3• high temperature (>700°C) and low pressure (<10 bars)

• tar‐cracking catalysts convert tars into synthesis gas (i e CO CO and H ) but not into the lower

steam/carbon ratios 3nickel‐based catalyst is very sensitive to contaminants, especially sulphur

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gas (i.e., CO, CO2, and H2) but not into the lower hydrocarbons


Gasification Technical BarriersProducer gas contains dust, ash, tars, and other contaminants and needs to be cleaned before use.

Tar dust and ash removal

Candle filtersCandle filters consist of a porous Tar, dust and ash removal

• Cyclones are standard equipment in producer gas t t t

Cyclones

pmetallic or ceramic filter material that allows gases to pass but not the particulates

treatment. • Cyclones generally remove particles from 1 mm down to 5 m in size and work with dry particulates

Candle filters can be operated at temperatures up to 500 °C and can effectively remove particles in the 0.5–100 mm range

Bag filtersBag filters are made of polymeric, ceramic, or natural fibresThey operate like candle filter and are regularly vibrated or b k fl h d t th b ilt filt k

• Cyclones can operate at actual gas temperatures (up to 900–1000 °C) to avoid cooling the gas

• Cyclones can be used in series as multi‐back‐flushed to remove the built‐up filter cake. The maximum operation temperature of a bag filter is approximately 350 °C

cyclone


Gasification Technical BarriersElectrostatic precipitator (ESP)

In a small scale biomass gasification power plant for IC engine tar and ash particles are filtered from the gas

Small- scale biomass CHPTar, dust and ash removal

In an electrostatic precipitator, ash and dust particles receive a negative electric charge when they pass an electrode connected to a high voltage source (10–100 kV DC).

p p ( ) engine tar and ash particles are filtered from the gas stream usingo Cyclone to remove coarse particles o Scrubber for removal of tar, some dust particles and gas cooling

Electrostatic precipitators can be operated at temperatures up to approximately 400 °C. Collected dust must regularly be removed by vibration

Wet electrostatic precipitators (WESP)

cooling o Catalytic tar cracking unitso Course filters made of packed beds of porous materials o Fine filters made from fabric material for removal of very fine particlesWet electrostatic precipitators (WESP)

WESP are also used to remove oil droplets (FAME) released by oil scrubbers used for tar removal

fine particles

Typically producer gas is cooled to about 35 °Co increases density => increase in the engine power output l h l ffi i

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o lowers thermal efficiency o increases need for waste water treatment (harmful e.g. phenols )


Centria Pilot R&D Gasifier

Centria Pilot R&D Gasifier• CENTRIA Gasifier is based on patented EK gasifier (GasEK)

o Downdraft gasifiero IC engine CHPo IC engine CHPo Stirling engine CHP

• Used in HighBio2 research project

P T i f h dPower Tar concentration of the product gas (dry, STP: 0°C, 1 atm)

9 kWe 24 ± 5 mg/Nm3Low tar content

Fuels used in the gasification Solid, air dried wood chips is normally used as a fuel in the gasification process

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in the gasification process• size of the chips 0 to 100 mm and• moisture content can be up to 40 vol‐%

28Kokkola Material Weeks

Centria Pilot R&D Gasifier1. Wood chip storage2. Wood chip screw conveyor3 G ifi3. Gasifier4. Raw gas pipe 5. Scrubbers6. Water tank7 A h b l7. Ash barrel8. Engine 8.4 liter9. Generator 50 kW10. Startup pipe11 E h t i11. Exhaust pipe12. Heat exchanger for exhaust

gas13. Cooler14 H t h Centria Pilot Gasifier is a Small Scale CHP based on wood gasification

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14. Heat exchanger

29

Centria Pilot Gasifier is a Small Scale CHP based on wood gasification


Centria Pilot R&D GasifierStirling engine CHP Gas engine CHP

• Downdraft gasifier and • 8 cylinder 5,4 L gas engine8 cylinder 5,4 L gas engine• Electric power 20 kWe• Thermal power 50 kWth

Solo Stirling‐engine electric power 9 kWe . thermal power 26 kWth ´From left Yrjö

12.11.2013

Muilu and students Kauko Jarva and Mauri Niskanen

30Kokkola Material Weeks

Centria Pilot R&D GasifierEmissions of the IC engine* Emissions of the Stigling engine**

Measured flue gas component

Measured flue gas composition

Concentration (dry, STP 0°C, 1 atm) mg/Nm3

O 0 4 vol%

Measuredflue gascomponent

Measuredflue gascomposition

Concentration(dry, 6% O2, STP 0°C, 1 atm) mg/Nm3

O 4 10 vol% ‐O2 0.4 vol% ‐

CO2 17 vol% ‐

CO 568 ppm 170

SO 8 2

O2 4,10 vol%

CO2 16,6 vol% ‐

CO 9 ppm 10

SO 0 2 0 4SO2 8 ppm 25

NOx 162 ppm 332

*MuiluY.,Pieniniemi K.,Granö U.‐P.&LassiU(2010) ANovelApproachtoBiomassGasificationinaDowndraftGasifier.In:Proceedingsofthe18th E Bi C f d E hibiti 2010 i L ISBN 10 8889407565 ISBN 13 978 8889407561 688 692

SO2 0,2 ppm 0,4

NOx 22,5 ppm 41

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18thEuropeanBiomassConferenceandExhibition,2010inLyon,ISBN‐10:8889407565,ISBN‐13:978‐8889407561pp.688‐692.

**Pieniniemi K.,MuiluY.andUllaLassi(2013)Micro‐CHPBasedonBiomassGasificationinaDowndraftGasifier andStirlingEngine. In:Proceedingsofthe21stEuropeanBiomassConferenceandExhibition,2013inCopenhagen,ISBN:978‐88‐89407‐53‐0,DOI10.5071/21stEUBCE2013‐2CV.3.21.pp.814– 819


Main task of the CENTRIA R&D in HIGHBIO2 research project is to support the local, decentralized small‐scale heat and power production by research and development work in co‐operation with the partner universities Focus of the research in CENTRIA R&D is

o on improving controllability of the gasification process and o on online analysis of the produced syngas and flue gases

Partners and Funding:

3212.11.2013 Kokkola Material Weeks

Conclusion - Future for Small-ScaleConclusion - Future for Small-Scale Biomass Cogeneration

Wood biomass remains the main energy source for widespread biomass powered CHP systems at small and micro‐scaley

Gasification of biomass using a gas engine (or gas turbine) presents interest possibility for small to medium scale co-generation

The Stirling Engine coupled with a gasifier is an interesting option for distributed CHP and should be available very soon

Tars are still the single largest problem that has to be overcome before

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Tars are still the single largest problem that has to be overcome before commercialize gasification processes


Video – Latest development in Biomass Gasification

VTT ‐ Biomass and Waste Gasification, from R&D to industrial success (20.9.2013) (YouTube)

VTT‐ Gasification of Waste technologies (15.05.2013) (YouTube)


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