CoER : Biofuels Department of Microbiology • Faculty of Natural Sciences

UNIVERSITEIT • STELLENBOSCH • UNIVERSITYjou kennisvennoot • your knowledge partner

Next generation technologies for biofuels/bioenergy production in

Southern Africa

Emile van Zyl

Department MicrobiologyUniversity of Stellenbosch

2

1. Value of biofuels to southern Africa

5. Thermochemical technologies for biofuels production

Next generation technologies

3. SANERI Chair of Energy Research : Biofuels

4. Microbial technologies for cellulosic ethanol production

2. Potential for biofuels production in South Africa

6. Integrating biochemical and thermochemical technologies

3

Value of biofuels to southern Africa

Next generation technologies

4

1. Source of foreign exchange savings for oil-deprived countries.

4. Reduction of GHG emissions and combating climate change.

2. Boosting of agriculture /forestry production and additional markets /revenue for farmers / industry.

Benefits of biofuel production in southern Africa:

3. Help generate employment and local economic development opportunities in rural areas.

5. Contribute to political security, make Africa less dependent on oil and create local wealth.

Biofuels value to southern Africa

5

Bioenergy Production Potential in 2050 (Smeets, Faaij, 2004)

Total bioenergy production potential in 2050 based on different agriculture systems [expressed as EJ (1018 J). yr−1; left to right bars – conventional to highly productive agriculture systems].

Future bioenergy potential in Africa

6

Biomass potential of Africa at large

Ratio of the energy content of the biomass on abandoned agriculture lands relative to the current primary energy demand at the country level. The energy content of biomass is assumed to be 20 kJ g−1. Source: Campbell et al. (2008)

7

Potential for biofuels production in South Africa

Next generation technologies

8

South Africa’s potential:Renewable biomass available

1. Residues Agricultural

Maize stover 6.7 Mt/a (118 PJ/a)Sugar cane bagasse 3.3 Mt/a (58 PJ/a)Wheat straw 1.6 Mt/a (28 PJ/a)Sunflower stalks 0.6 Mt/a (11 PJ/a)Agricultural subtotal 12.3 Mt/a (214 PJ/a)

Forest industryLeft in forest 4.0 Mt/a (69 PJ/a)Saw mill residue 0.9 Mt/a (16 PJ/a)Paper & board mill sludge 0.1 Mt/a (2 PJ/a)Forest industry subtotal 5.0 Mt/a (87 PJ/a)

2. Energy crops From 10% of available land 67 Mt/a (1 171 PJ/a)

(Marrison and Larson, 1996)3. Invasive plant species 8.7 Mt (151 PJ)

Total, annual basis 93 Mt/a (1 622 PJ/a)Lynd et al. 2003. Plant Biomass Conversion to Fuels and Commodity Chemicals in South Africa: A Third Chapter? South African Journal of Science 99: 499 – 507.

9

maize stover

Lignocellulose sources

bagasse wheat straw

paper sludgewood chips

Which bioenergy crops?

Sugar cane(100+ t/ hect?)

Grain sorghum Sweet sorghum

– two harvests?

Invasive plantsHarvesting red grass 10

CoER : Biofuels Department of Microbiology • Faculty of Natural Sciences

UNIVERSITEIT • STELLENBOSCH • UNIVERSITYjou kennisvennoot • your knowledge partner

Chair of Energy Research: Biofuels and other clean alternative fuels

Emile van Zyl Johann Gorgens, Marinda Bloom & Hansie

Knoetze[Stellenbosch University]

&Harro von Blottnitz

[University Cape Town]

11

12

CoER : Biofuels (members)

Microbiology

Chem EngProc Eng

13

Cellulosics biofuels production value chain:

1. The CoER : Biofuels positions itself in the conversion technologies, but acknowledges the importance of establishing the whole value chain.

Technologies for Cellulose Conversion

PrimaryBiomass Production

Biomass Transport

Biomass PrimaryProcessing

Biomass Conversion to Biofuels and By-products

Product Distribution& Marketing

14

Lignocellulose composition

Sugarcane bagasseLignin28%

Arabinan2%

Xylan25%

Cellulose46%

Hexoses(fermentable) Pentoses

(fermentable)

Non-fermentablesugars

high energy aromatics

Technologies for Cellulose Conversion

15

Microbial Technologies for Cellulosic Ethanol Production

Next generation technologies

16

Ethanol production from sugar

Spentyeast

CrashingSugar

extraction

Sugarcane\Sugarbeet

Sweetsorghum

Fuelblending

Alcoholrecovery

Distillation & dehydration

Storagetank

Yeast

Fermentation

Technologies for Ethanol Production

SugarStorage

tank

17

Ethanol production from cellulosics

Spentmaterial

Pre-treatment

ChippingGrinding

Agric Res Woody MaterialGrasses

Water

mixingtank

Steam explosion

~200ºC

Cellulases

Fuelblending

Saccharification

Alcoholrecovery

Distillation & dehydration

Storagetank

Yeast

Fermentation

Technologies for Ethanol Production

18

Pretreatment for Ethanol Production

CelluloseLignin

Hemicellulose

Amorphous Region

Crystalline Region

Pretreatment

Pretreatment - produces an enzyme accessible substrate

Ladisch, 2006

19

Enzymes required for CBP

ComponentGlucan 41.6Xylan 15.9Galactan 0.7Mannan 2.2Arabinan 0.8Acetic acid 5Extractives 1.4Lignin 25.6Ash 0.5Total 93.7

Hemicellulose

Partially hydrolyzed during feedstock pretreatment

Cellulose

Cellobiohydrolases

Endo-glucanase

β-glucosidase

Endo-xylanase

α-glucuronidase

β-xylosidaseAcetyl xylan esterase

α-arabinofuransidase

Endo-mannanaseβ-manosidaseetc.

Glucose

XyloseManoseArabinoseGalactose

20

Enzyme system development

T. reesei secretome

• CBHs are the major constituent of the T. reesei cellulase system

• Second most important species are the EGs

• Broad diversity of enzymes contributes to highly active system

21

Consolidated BioProcessing (CBP)

OO

O

O

O

Glu Man Gal

Xyl Ara

Ethanol + CO2

P TYFG

Glycosyl

Hydrolases

Technologies for Cellulose Conversion

22

[REF] [EG1]

[SFI] [CEL5]

Den Haan, R., S.H. Rose, L.R. Lynd, and W.H. Van Zyl. 2007. Hydrolysis and fermentation of amorphous cellulose by recombinant Saccharomyces cerevisiae. Met. Eng. 9: 87–94.

Growth on amorphous cellulose (PASC)

Technologies for Cellulose Conversion

23

Mascoma CorporationTechnical facilities, Lebanon, NH, USA

(www.mascoma.com)

Leading Investment, Unprecedented Focus on CBPTechnical Focus: Overcoming the biomass recalcitrance barrier and enabling

the emergence of a cellulosic biofuels industry via pioneering CBP technology integrated with advanced pretreatment

Three Platforms

1. T. saccharolyticum, thermophilic bacterium able to use non-glucose sugars2. C. thermocellum, thermophilic cellulolytic bacterium3. Yeast engineered to utilize cellulose and ferment glucose and xylose

Partners in Mascoma’s CBP Organism Development Effort

• Dartmouth College, USA

• University of Stellenbosch, ZA

• VTT, Finland • BioEnergy Science Center, USA

• Department of Energy, USA

Multiple chances to succeed near-term & long-term24

25

Screen CBH1 for high level expression

Enzyme activity:

• 48 hour Avicel hydrolysis

• Best enzyme x13 greater than starting point

Enzyme Production:

• 94 mg/L CBH1• ± 2.5% of

Total cell protein in minimal medium

+ - + - + - + - + 57 94 29 37 mg/L secreted CBHI

97 66

45

30 EndoH

0

1

2

3

4

5

6

7

8

% A

vic

el

Hyd

roly

sis

0

10

20

30

40

50

0

10

20

30

40

50

Pro

tein

Exp

ressio

n (

mg

/g D

CW

)

CBH2 expressed

(Reinikainenet al., 1992)

March2007

March2008

Oct.2008

Mascoma Cellulolytic Yeast

26

Cellulase expression Time-line

Dec.2008

Cellulase expression in Mascoma Yeast (robust C5/C6 fermenting)

Improved CBH1; ~400X ↑

Improved CBH2;

~1500X ↑

Improved host and culture conditions; ~2500X ↑

27

Background strain

Appearance at 120 hrs.

CBP strain

0

10

20

30

40

50

60

0 50 100

Eth

an

ol con

cen

trati

on

, g

/L

Time (hours)

CBP + 1 mg Xylanase

Background +BGL + Xylanase

Background + Cellulase + BGL + Xylanase

Mascoma CBP technology on 18% w/w paper sludge

Enzyme Reduction on Paper Sludge

Enzyme Reduction on Hardwood

Equivalent performance with 2.5-fold less added enzyme

Further reduction likely

Mascoma CBP Strain (robust C5/C6 fermenting yeast) + 22% w/w unwashed Pretreated Hardwood

Fermentation Time (hours)

0

10

20

30

40

0 20 40 60 80 100 120 140 160

Eth

ano

l (g

/L)

28

50

60

Improved CBP Yeast + 0.4X commercial cellulases

CBP Yeast + 0.4X commercial cellulases

Non-CBP Yeast + 1X commercial cellulases

Rome, NY Pilot & Demonstration Plant

January 2008

November 2008

29

30

Thermochemical Technologies for Biofuel Production

Next generation technologies

31

3. Gasification is taking place at higher temperatures for longer in the presence of O2, which yields syngas for Fischer-Tropsch synthesis (SASOL).

Lignocellulose thermo-chemical processes

2. Fast Pyrolysis involves the heating of biomass for few seconds to about 500°C in the absence of O2, followed by rapid cooling. The result is the formation of primarily,bio-oil from condensation of vapours during rapid cooling, biogas and solids called char.

Conversion TechnologiesThermochemical technologies for Cellulose

1. Combustion involves the burning of biomass in the presence of O2 with the harvesting of the released energy as primarily heat, or generating steam.

32

Application of Thermochemical Processes

• Stellenbosch focuses for time been on fast and vacuum pyrolysis.

• Decentralised or mobile pyrolysis units could substantially reduces transportation costs

• Transportation-grade biofuels can be produced :• Bio-oil is a crude product that requires (expensive)

upgrading• Biochar and/or bio-oil can be gasified either as the

sole feedstock or in a mixture with coal• Production of electricity and/or heating from bio-

oils, char and heating gas could be considered for premium markets

Vacuum pyrolysis: • small batch lab unit (±100 g) (15kPa abs and Temp

300-450°C) – operational since 2002.• In SANERI project with Dr J Klaasen from UWC looked

at kraalbos and renosterbos.• Looked at some pioneer/intruder plants, sewage

sludge and bagasse.• Yields typically 25-35% char, 25-35% bio-oil.

Fast Pyrolysis: • Commissioning small bench-scale set-up.• Looking at bagasse, corn cobs and Eucalyptis.• Fast Pyrolysis: < 10% char (high in ash), mostly bio-

oil.

Current status on Thermochemical Processes

33

34

Intergrating biochemicaland thermochemical technologies

Next generation technologies

35

BiologicalProcessing

• Pretreatment• Fermentation• Separation

Non-BiologicalProcessing• Gasification• Fast pyrolysis• Power generation• Synthesis & separation

Biomass Biorefinery Concept

Steam

Process Power

Ethanol

CellulosicBiomass

Biologically-derivedChemicals (potentially several)

Thermochemically-derivedChemicals(potentially several)

Animal feed

Exported Power/BiofuelsResidues

Technologies for Cellulose Conversion

Other fermentation products

36

*Coproducts may include industrial or ag. chemicals, sweeteners, neutraceuticals…

Biofuel Feedstock & Product Options

Starch-rich (grains)• (e.g.) maize/sorghum

Ethanol & CO2

Animal feed, Lignin-rich residuesCo-products*

Oil Seeds• soya beans • canola/ sun flower

Biodiesel

Glycerin, (co-products)

Animal feed, Lignin-rich residues

CellulosicResidues• stover, bagasse

Energy Crops • grasses• intruder plants

• paper sludge

Ethanol & CO2

Co-products*, feeds Lignin-rich residues

Process energy (Electricity &/or Bio-oil/Char)

Sugar-rich• sugar cane• sweet sorghum

Ethanol & CO2

Lignin-rich residuesCo-products*

Evolution towards Cellulose Conversion

Tota

l

Energ

y

crops

Burn

ed

gra

sses

37

South Africa’s potential:Biofuels production

Maize to Ethanol = 430 L/ton Biomass to ethanol = 280 L/tonBiomass to liquid (BtL) = 570 L/tonBiomass to upgraded bio-oils = 310 L/ton

BtL (50%)

0

5000

10000

15000

20000

25000

30000

DieselEthanol

Petrol

Volu

mes in

ML

Maiz

e

Fore

st

bio

wast

e

Invasi

ve

pla

nts

Subto

tal

Curr

fuel

Str

ate

gy

targ

et

Agri

cult

bio

wast

e

Upgraded bio-oil (70% of residue)(70% of residue)

38

Future for Africa??

39

Shaunita RoseRiaan den Haan

Acknowledgements

Danie la GrangeRonél van Rooyen

John McBride Lee Lynd

Marja Ilmen Merja Penttilä

Alan Froehlich Elena Brevnova Erin Wiswall

Haowen Xu Emily Stonehouse Heidi Hau

Mark Mellon Kristen Deleaulte Naomi Thorngren

Deidre Willies Vineet Rajgarhia

Tania de Villiers Maryna SaaymanJohann Görgens