This document provides an overview of cassava's potential as a food crop and feedstock for biofuels. It discusses cassava's advantages, including its tolerance to poor environmental conditions, ability to be planted and harvested year-round, high carbohydrate content, and potential for high root productivity. Well-developed technology exists for ethanol production from cassava, such as a simultaneous saccharification and fermentation process and single-step uncooked liquefaction. Cassava has benefits as a biofuel feedstock compared to molasses, including a higher fermentable to non-fermentable solids ratio and lower ash content, which allows for more efficient ethanol fermentation.

2. Overview of potential of cassava as a food crop
And as a feedstock for biofuels
Klanarong Sriroth
(aapkrs@ku.ac.th)
Cassava and Starch Technology Rerearch Unit (CSTRU)Cassava and Starch Technology Rerearch Unit (CSTRU)
Kasetsart University, ThailandKasetsart University, Thailand

3. Cassava as a biofuel/bioenergy cropCassava as a biofuel/bioenergy crop

4. Cassava: The best alternativeCassava: The best alternative
Cassava as a biofuel/bioenergy crop

5. Cassava as a biofuel/bioenergy crop
World Productions of cassava (2009)World Productions of cassava (2009)
Production (1,000 t)Production (1,000 t) Area (1,000 ha)Area (1,000 ha) Yield (t/ha)Yield (t/ha)
WorldWorld
-Africa-Africa
-LAC-LAC
-Asia-Asia
--CambodiaCambodia
-China-China
-India-India
-Indonesia-Indonesia
-Laos-Laos
-Malaysia-Malaysia
-Myanmar-Myanmar
-Philippines-Philippines
-Sri Lanka-Sri Lanka
-Thailand-Thailand
-Timor-Leste-Timor-Leste
-Vietnam-Vietnam
240,989240,989
124,615124,615 (51.70%)(51.70%)
34,67734,677 (14.38%)(14.38%)
81,47381,473 (33.80%)(33.80%)
3,4973,497
4,5114,511
9,6239,623
22,03922,039
152152
430430
211211
2,0432,043
277277
30,08830,088
4949
8,5568,556
19,05819,058
12,33212,332
2,6672,667
4,0364,036
157157
270270
280280
1,1751,175
1010
4141
1616
215215
2323
1,3261,326
1212
508508
12.6412.64
10.1010.10
13.0013.00
20.1820.18
22.2722.27
16.6716.67
34.3634.36
18.7418.74
14.7014.70
10.4810.48
12.7812.78
9.469.46
11.6411.64
22.6722.67
4.124.12
16.8116.81
Source : FAOSTAT, Sep 2010.

6. Cassava as a biofuel/bioenergy crop
Genotype Environment Management

7. Cassava as a biofuel/bioenergy crop
Yield of cassava : increase 1 ton/ha (per year)
Productions of cassava in 2009
Yield = 12.64 tons/ha
Area = 19,058,000 ha

8. Cassava as a biofuel/bioenergy crop
Productions increase from 2009Productions increase from 2009
= 259,951,120= 259,951,120 -- 240,989,000240,989,000
== 18,962,12018,962,120 tonstons
Productions of cassava in 2010Productions of cassava in 2010
= 13.64 * 19,058,000= 13.64 * 19,058,000
= 259,951,120 tons= 259,951,120 tons

9. Cassava as a biofuel/bioenergy crop
Advantage as Food CropsAdvantage as Food Crops

10. ““Growth tolerance to poorGrowth tolerance to poor
environmental condition ”environmental condition ”
Advantage as Food Crops

11. Advantage as Food Crops
Root yield (t/ha) of cassava roots of different varieties
Variety Harvest time (months)
10 months 12 months
Without water
stresss
With water
stress
Without water
stress
With water
stress
Rayong 1 24.6 + 1.8 14.9+ 2.7 29.8+ 5.8 24.8+ 2.5
Rayong 5 35.2 + 4.5 17.9 + 1.1 41.8 + 5.1 26.9 + 4.9
Rayong 60 26.8 + 3.6 18.7 + 3.9 34.7 + 7.8 30.6 + 2.9
Rayong 90 26.6 + 1.8 16.7 + 4.4 34.9 + 3.4 26.2 + 7.8
KU50 27.8 + 2.9 18.2 + 0.5 34.9 + 6.3 28.8 + 4.4
CMR 33-57-81 41.9 + 3.9 21.3 + 8.1 51.1 + 7.6 28.8 + 7.2
Source : Santisopasri et al., 2001. Industrial crop and Products., 13, p.115-129.

12. ““All year round planting/harvesting”All year round planting/harvesting”
Advantage as Food Crops

13. ““ Possibility toPossibility to increase root productivity ”increase root productivity ”
Improved varieties + Cost-effective cultivation practices = High productivity
Advantage as Food Crops

14. ““Possibility to increasePossibility to increase
High root productivity”High root productivity”
Advantage as Food Crops

15. High Root ProductivityHigh Root Productivity Thai average = 20 T/ha
World = 11 T/ha
Reported ~ 90 T/ha
Advantage as Food Crops

16. “Continuous development of high
yield-improved varieties”
Advantage as Food Crops

17. Rayong5Rayong5
Rayong90Rayong90
Advantage as Food Crops

18. KU50KU50
Huaybong 60Huaybong 60
Advantage as Food Crops

19. ““Less input in plantingLess input in planting
and harvestingand harvesting””
Advantage as Food Crops

20. HarvestingHarvesting
1 man day = 8 hours = 1.20 ton
Advantage as Food Crops

21. Harvesting IndexHarvesting Index = Root yield= Root yield
(HI)(HI) BiomassBiomass
= 50%= 50%
HarvestingHarvesting
Advantage as Food Crops

22. ““High-quantity/qualityHigh-quantity/quality
carbohydrate source”carbohydrate source”
Advantage as Food Crops

23. Advantage as Food Crops
Cultivars Protein
(% w/w)
Lipid
(% w/w)
Ash
(% w/w)
Phosphorus
(mg/kg)
Rayong 1 0.17 + 0.04 nil 0.10 + 0.02 2.45 + 0.08
Rayong 60 0.15 + 0.02 0.01 0.15 + 0.04 2.20 + 0.14
Rayong 90 0.28 + 0.06 nil 0.08 + 0.01 2.04 + 0.05
KU 50 0.30 + 0.04 0.01 0.15 + 0.02 2.04 + 0.05
Proximate analysis of Cassava starches
Source : Sriroth et al., 1999. Carbohydrate Plymer. 38, p.161-170.

24. ““Simple conversion to dried chips forSimple conversion to dried chips for
effective storage and transportation”effective storage and transportation”
Dried ChipsDried Chips
Advantage as Food Crops

25. Cassava ChipCassava Chip
Cassava ChipCassava Chip
Conversion : 2.25 kg fresh roots / 1 kg chip
(25% starch content) (14% moisture content)
Advantage as Food Crops

26. Advantage as Food Crops

27. Advantage as Food Crops
Modification
Function
Application
Native starch
““Variation of Usage as Food”Variation of Usage as Food”
Source: CSTRU, 2009.

28. Industrial
applications
Confectionery
Pharm
aceuticals
Textile
Paper Noodles
M
eatProducts
Bakery products
SaucesCosmetics
Adhesives &
corrugated board
Dairy products
Packaging
Advantage as Food Crops

29. Cassava as a biofuel/bioenergy crop
Potential as Feedstock for
Fuel

30. Gasohol
is a blend of anhydrous ethanol ‘derived from
agricultural products’ with gasoline !
E10
E20
E85
Advantages of Cassava as Feedstock for FuelAdvantages of Cassava as Feedstock for Fuel

31. Advantages of Cassava as Feedstock for FuelAdvantages of Cassava as Feedstock for Fuel
Sriroth et al,. 2010. The promise of a technology revolution in cassava bioethanol From Thai practice
to the world practice , Fuel. ( Available source:http://www.elsevier.com/locate/fuel )

32. Cassava as a biofuel/bioenergy crop
Advantage of cassava as Feedstock forAdvantage of cassava as Feedstock for
Ethanol fermentation byEthanol fermentation by
Yeast FermentationYeast Fermentation
Source: Sriroth et al,. 2010. Fuel 89, p.1333-1338.
www.praj.com

33. Cassava as a biofuel/bioenergy crop
Advantage in Fermentable to
Non-Fermentable Solids Ratio
(F/N ratio)
CassavaCassava
Fermentable glucose (up to 99%Fermentable glucose (up to 99%))
can be obtained from conventionalcan be obtained from conventional
hydrolysis of cassava starchhydrolysis of cassava starch..

34. MolassesMolasses
Case I : Brix = 85
Total Sugars = 51
Non-fermentable Solids = 85-51 = 34
F/N ratioF/N ratio = 51/34 = 1.50= 51/34 = 1.50
Case II : Brix = 85
Total Sugars = 40
Non-fermentable Solids = 85-40 = 45
F/N ratioF/N ratio = 40/45 = 0.88= 40/45 = 0.88
F/N ratioF/N ratio

35. F/N ratio < 0.9F/N ratio < 0.9
retards fermentation rate by average 15-20%retards fermentation rate by average 15-20%
F/N ratioF/N ratio
(www.praj.com)

36. Ash content > 10%Ash content > 10%
can retard the rate of fermentationcan retard the rate of fermentation
by 5-10%by 5-10%
Ash content
Max = 3.0%
Ash content
10-16%
Advantage of its Low Ash ContentAdvantage of its Low Ash Content
(www.praj.com)

37. Advantage of Absence of Volatile AcidsAdvantage of Absence of Volatile Acids
> 5000 ppm reduce fermention rate by 30-40%
> 7000 ppm reduce fermention rate by 40-50%
Volatile Acids
Cassava chips : None
Molasses : Acetic acid, Formic acid etc.
(www.praj.com)

38. Advantage of no caramelizationAdvantage of no caramelization in cassavain cassava
> 0.40 OD retards fermentation rate by 20-25%> 0.40 OD retards fermentation rate by 20-25%
(Measured as color in OD units(Measured as color in OD units
at 375 nm of 0.1% Solution)at 375 nm of 0.1% Solution)
(www.praj.com)

39. Advantage in waste utilizationAdvantage in waste utilization
Solid wasteSolid waste Liquid wasteLiquid waste

40. Stillage from cassava chips Stillage from molasses
1. COD (mg/L) 40,000-60,000 100,000-150,000
2. BOD (mg/L) 15,000-30,000 40,000-70,000
3. TKN (mg/L) 350-400 1,500-2,000
4. Total Solids (mg/L) 60,000-65,000 100,000-120,000
5. Total Suspended Solid (mg/L) 3,000-20,000 14,000-18,000
6. Total Volatile Solids (mg/L) 20,000-40,000 n.a
7. Total Dissolved Solids (mg/L) 50,000 105,000-300,000
8. pH 3.5-4.3 4.1-4.6
Sriroth et al., 2006.
n.a = not applicable
Waste ManagementWaste Management
Stillage quality from ethanol factories in ThailandStillage quality from ethanol factories in Thailand

41. Cassava as a biofuel/bioenergy crop
““Advantage of Well-developed technologyAdvantage of Well-developed technology
for ethanol production from cassava”for ethanol production from cassava”

42. Cassava as a biofuel/bioenergy crop
Cassava Chips
Milling
α-amylase glucoamylase
yeast
Distillation
&Dehydration
Liquefaction SSF
Simultaneous SaccharificationSimultaneous Saccharification
and Fermentaion processand Fermentaion process

43. Cassava as a biofuel/bioenergy crop
Mass Balance of Ethanol from Cassava Chip
T/D = Ton/Day, TS = Total Solid ,L/D =Liter/day
Fermentation efficiency 90%, Distillation efficiency 98.5%
M i l l i n g
M i x i n g
L i q u e f a c t i o n
S S F
F e r m e n t a t i o n
D i s t i l l a t i o n
M o l e c u l a r S i e v e
D e h y d r a t i o n
F u e l E t h a n o l
C a s s a v a C h i p
C O 2
T h i c k S l o p
F u s e l o i l
S t e a m
W a t e r
- M o i s t u r e 1 5 %
- S t a r c h c o n t e n t 6 5 % ( w e t b a s i s )
3 6 2 . 1 7 T / D
8 5 . 0 0 % T S
1 , 7 9 4 . 4 3 T / D
1 7 . 1 6 % T S
1 , 9 1 4 . 4 3 T / D
1 6 . 0 8 % T S
1 , 7 9 9 . 4 5 T / D
7 . 4 2 % ( w / w ) A l c o h o l
1 2 4 . 5 8 T / D
9 5 % A l c o h o l
0 . 5 0 T / D
1 , 4 9 6 . 8 4 T / D
6 . 5 % T S
1 1 4 . 9 8 T / D
1 1 8 . 3 5 T / D o r
1 5 0 , 0 0 0 L / D
1 , 2 4 8 . 5 0 T / D
1 2 0 T / D
6 . 2 3 T / D
1 7 7 . 5 3 T / D
S p e n t w a s h r e c y c l e
S p e n t w a s h r e c y c l e

44. Cassava as a biofuel/bioenergy crop
Distillation
& Dehydration
Cassava Chips
Milling
Fermentation
yeast
Enzymes
Simultaneous Liquefaction,Simultaneous Liquefaction,
Saccharification andSaccharification and
Fermentation processFermentation process
(SLSF)(SLSF)
UNCOOKED SINGLE-STEPUNCOOKED SINGLE-STEP

45. Cassava as a biofuel/bioenergy crop
SEMs of corn starches treated with granular
starch hydrolyzing enzymes (GSHE)
6 - hr
incubation
12 - hr
incubation
24 - hr
incubation
48 - hr
incubation
CassavaCassava
CornCorn

46. Cassava as a biofuel/bioenergy crop
To increase ethanol concentration
18% (v/v) or 14.6% (w/w)
Increase the total solid/starch content (>30% Total dissolved solid)
by increasing the feedstock to water ratio
VHG (very high gravity) technology in fuel alcohol production

47. Cassava as a biofuel/bioenergy crop
Mash viscosity reduction
by enzyme cocktail
VHG technology development for cassava roots

48. Cassava as a biofuel/bioenergy crop
Ethanol
Fermentation
VHGVHG TechnologyTechnology
DevelopmentDevelopment
Process waterProcess water
9999 TonsTons
MixingMixing
(total solid = 25%)(total solid = 25%)
140 Tons140 Tons
Milling
WaterWater
59 Tons59 Tons
Fresh RootFresh Root
(moisture content =(moisture content =
60-70%)60-70%)
100 Tons100 Tons
CassavaCassava ChipChip
(moisture content = 14%)(moisture content = 14%)
4141 TonsTons
Process water saving
Sun
Drying

49. Pilot scale ethanol plant at ThailandPilot scale ethanol plant at Thailand

50. Pilot scale ethanol plant at ThailandPilot scale ethanol plant at Thailand

51. Filtration Screw Press
Pilot scale ethanol plant at ThailandPilot scale ethanol plant at Thailand

52. Solar CollectorSolar Collector
Pilot scale ethanol plant at ThailandPilot scale ethanol plant at Thailand

53. Technology transfer for ethanol production

54. Distillation Pilot PlantDistillation Pilot Plant

55. On going development
Fermenter
Molecular sieve
Ethanol
90-95%
Cassava Chip / Root
VHG-SLSF process

56. Cassava as a biofuel/bioenergy crop
ConclusionsConclusions
CassavaCassava :: The WINNERThe WINNER for an alternativefor an alternative
food and biofuelfood and biofuel
FoodFood - Improved yield with variation productions- Improved yield with variation productions
FuelFuel – Reduction of energy for– Reduction of energy for
ethanol productionethanol production
(SLSF / VHG)(SLSF / VHG)

57. Cassava as a biofuel/bioenergy crop
THANK YOU
aapkrs@ku.ac.thaapkrs@ku.ac.th
www.cassava.orgwww.cassava.org
www.thailandethanol.comwww.thailandethanol.com