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# Biomass Fast Pyrolysis Dr. Christopher M. Saffron Department of Biosystems and Agricultural Engineering Department of Biosystems and Agricultural Engineering Department of Forestry Michigan Agri-Energy Conference March 30 th , 2009 

# Overview • What is pyrolysis? • Technology • Pyrolysis metrics • Upgrading • Distributed processing • Industrial activity

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# What is pyrolysis? • Heat addition to biomass in the absence of oxygen to temperatures ranging from 400°C to 1000°C • One step in gasification • Products of biomass pyrolysis are a – Solid (char) – Liquid (upon condensation with cooling) – Gas (light hydrocarbons and carbon oxides) 

### • Higher temperatures and l onger residence times favor gas production • Lower temperatures and l onger residence times favor char production • Moderate temperatures and short residence times favor liquid production 

# Pyrolysis • Slow pyrolysis

– a k a carbonization a . k . a . carbonization – Used for producing charcoal 

## • Fast pyrolysis – Used for fuel production – High heating rates – Low retention times – Greater liquid, i. e. ‘bio-oil’ yield – Co-products • bio-char • combustible gas http://www.biochar-international.org/

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# Bio-oil

Steele, P.; Ingram, L. Current and Future Products for Pyrolysis Oils. Dept. of Forest Products. Mississippi State University 

### Components of Biomass (Pl ant Cell Wall Polymers) Cellulose: Polymer containing glucose-same sugar as in starch Much more resistant to degradation than starch Hemicellulose: Complex polymers Lignin: Plastic-like polymer; provides structure, but inhibits wall breakdown. Residues can be burned for energy found in cell walls; diverse in sugar composition. 1. Xyloglucan 2. Glucomannan 3. Arabinoxylan 4. Mixed-linkage glucan

Ragauskas et al. (2006) Science 311:484 The path forward for biofuels and biomaterials.

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## Products of cellulose pyrolysis

levoglucosenone cellulose D-glucose
hydroxymethylfurfural
levoglucosan O O

OH OH HO 

## Products of hemicellulose pyrolysis

acetic acid arabinoxylan 1,5-anhydrofuranoses

2-furfural

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## Products of lignin pyrolysis

coniferyl alcohol
p coumaryl alcohol syringol
py ro g allol p - coumaryl alcohol lignin gallic acid guaiacol vanillin py g


# Bio-oil composition • Hundreds to thousands of compounds • Compounds are oxygenated Nt t d d t l b df l – N o ta tre d uce d as pe t ro l eum- ase d f ue l s • Chemical classes identified in bio-oil – Aldehydes – Alcohols – Carbohydrates – Furans – Ketones – Phenolics others – • Bio-oil composition is variable – Interspecies variability – Intraspecies variability – Operational variability

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# Bio-oil production biomass bio-oil

Dryer Grinder Reactor Cyclone Condenser combustible gas char Combustion heat heat

Adapted from Bridgwater, A. V.; Peacocke, G. V. C. Renewable Sustainable Energy Re v . 2000 , 4, 1. gas



# Technology • Reactor configuration

– Fluidized bed – Circulating fluidized bed – Rotating cone – Entrained flow

– Ablative – Auger

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# Bubbling fluidized bed pyrolysis gas

sand biomass char gas & char gas bubble

hot gas

distributor 

# Circulating fluidized bed pyrolysis gas & char char
sand biomass gas char sand gas bubble

hot gas

distributor sand return

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# Rotating cone Biomass & sand Pyrolysis g as heater sand char

sand


# Entrained flow Biomass & gas
Furnace heater

Gas & char

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# Ablation

biomass gas blades pyrolysis gas char heat 

# Auger- or screw-driven reactors
2 N 2 N 2 1 5 6 7 8

10 Gas 3
4 9 M N 2 1 5 6 7 8

10 Gas 3
4 9 M
10 Char Bio-oil Bench-scale screw-conveyor pyrolysis reactor with downstream product recovery to be constructed for use in the MSU Pyrolysis Laboratory. 1. screw motor, 2. feed hopper, 3. feed valve, 4. screw conveyor, 5. pyrolysis reactor, 6. cooler, 7. heat source, 8. cyclone, 9. char collector, 10. bio-oil chiller.

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# Performance metrics • Bio-oil yield

– Li q uid ield 60 - 80% ( w/w y ) 

### • Bio-oil properties – Heating value = 16 – 20 MJ /kg – Viscosity = 40 - 100 cP – Specific gravity = 1.20 – pH = 2.5 – Moisture content 15 – 30% (w/w) 

### Energy requirement • Energy requirement – About 15% of the energy is biomass required to heat the pyrolysis reactor – This energy can be supplied by combusting the non-condensed gas and char 

# Upgrading • Due to oxygen content in bio-oil:

– Lower heating value – Reactive carbonyl and carboxylate functionality lead to polymerization – Organic acids reduce pH and increase corrosiveness 

# • Bio-oil requires upgrading before use as a liquid transportation fuel

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# Upgrading technologies • Catalytic cracking

– M ostwi de l y used p r ocessf o r co nv e rt in g t h e h eavy de y used p ocess o co e t g t e ea y fraction of petroleum into hydrocarbons (e.g. gasoline) 

## • Hydrotreating – More expensive than cracking – Addition of H 2 

### for reduction of bio-oil components – Increase bio-oil heating value U C M Ni M tl t – ses o- o or Ni - o as ca t a l ys t s 

## • Addition of methanol • Emulsification with diesel fuel 

# Distributed processing • Regional Biomass Processing Centers (RBPCs) • Advanced combines • Mobile technology http://www.agri-the rm.com/solution.html

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# Industrial activity • Dynamotive *

– Biomass py rol sis y • Bio-oil used for power generati on at West Lorne, Ontario – 2.5 MW cogeneration plant • 66,000 dtpy of biomass when fully operational at Guelph, Ontario 

### • Ensyn † – Biomass pyrolysis • Bio-oil used for heat, replacing #2 to #6 heating oil • Stationary power • Use bio-oil as feedstock to existing refineries • Food flavors with Red Arrow Products • Pyrolytic lignin to make phenol-formaldehyde resins for OSB • Extraction of pyrolytic lignin for conversion to BTX chemicals *http://www.dynamotive.com/ † http://www.ensyn.com/ 

# Industrial activity • Riverside Technologies, Inc. * – Pyrolysis of scrap tires • Carbon black for reinforcing rubber • Oil for further refinement • Gas for combustion • Scrap steel from belts in tires 

### • Ecovolve † – Electricity production – Project management, equipment procurement – Carbon negative technology 

### • Agri-Therm^ – Canadian Company converting agricultural residues into bio-oil – Fluidized-bed reactor on a mobile pyrolysis plant * http://www.rtiworldwide.com/products.html † http://www.ecovolve.com/ ^http://www.agri-therm.com/

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# Questions