Direct Conversion of Fresh Cassava Root to Alcohol 4. European Bioethanol Technology Meeting, 15-16 April 2008 Gang Duan*, Sophia Xu, Bruce Ruan, Pauline Teunissen and Jay Shetty Wuxi, China; Leiden, The Netherlands; Palo Alto,CA, USA
2 Content Information on Cassava roots and chips Conventional process for ethanol production using chips New process for fresh roots for ethanol Discussion/Q&A
3 Root and Chips/ Cassava and Tapioca http://i76.photobucket.com/albums/j14/biopact/thailand_cassava_ethanol.jpg Cassava: Tapioca: Spanish?
4 Comparison of corn and tapioca -Why Tapioca? Chemical composition of cassava chips and corn grain Composition Content Corn grain* Cassava chips Moisture (% wet basis) 7~23 7~11 Starch (% dry basis) 64~78 75~85 Protein (% dry basis) 8~14 1.5~3 Fat (% dry basis) 3.1~5.7 0.2 Ash (% dry basis) 1.1~3.9 2~4 Crude fiber (% dry basis) 1.8~3.5 3~4 Source:Watson,1984
Gelatinization temperature of cassava starch 5
6 Corn and Cassava ethanol production economics Cassava Corn Crop yield, ton per hectare 25 11 Crop rice, $ per ton 25 81 Crop revenue, $ per hectare 625 900 Sugar yield, kg/metric ton crop 270 675 Sugar yield, ton/hectare 6.8 7.5 Ethanol yield, liters/ton crop 151 379 Ethanol yield, liters/hectare 3785 4207 Substrate cost, $ liter ethanol 0.17 0.21 By-product credit, $liter ethanol -0.017-0.063 Processing cost, $liter ethanol 0.21 0.16 Ethanol production cost, $/liter 0.36 0.31 Ethanol revenue@$0.60/liter, $/hectare 1363 1311
7 Current Process for ethanol using chips 1. Cassava Chips 2. Milling/Grinding 3. Liquefaction (80-100, 1-2hr, ph5.6) 4. SSF (60, ph 4.2) 5. Fermentation (30-36, 48-66hr) 6. Filtration & Distillation Ethanol Why not from fresh root?
8 Composition of Cassava Root Moisture 70.25 Starch 21.45 Sugars (S/G/F) 5.13 Protein 0.5~2 Fats 0.05 Crude Fiber 0.5~2 Very viscous!! Ash 0.5~2
What is STARGEN TM? 9
STARGEN Process in the direct conversion Cassava root to alcohol 10
Viscosity Comparison STARGEN process vs conventional process Conventional viscosity Conventional temperature STARGEN TM temperature STARGEN TM viscosity *Viscosity / Heating / Cooling 11
12 Pre-treatment with vs without LAMINEX TM SUPER: Viscosity profile of the slurries with and without LAMINEX TM SUPER. The blue line indicated without LAMINEX TM SUPER and the red line was with LAMINEX SUPER, the black line indicated the temperature changing during the whole process. The results indicate that LAMINEX TM SUPER helped to reduce the viscosity of fresh cassava root mash to even lower level.
Fermentation HPLC and Distillation Results 13
14 Corn and Cassava ethanol production economics Cassava Crop yield, ton per hectare 25 Crop rice, $ per ton 25 Crop revenue, $ per hectare 625 Sugar yield, kg/metric ton crop 270 Sugar yield, ton/hectare 6.8 Ethanol yield, liters/ton crop 151 Ethanol yield, liters/hectare 3785 Substrate cost, $ liter ethanol 0.17 By-product credit, $liter ethanol -0.017 Processing cost, $liter ethanol 0.21 Ethanol production cost, $/liter 0.36 Ethanol revenue@$0.60/liter, $/hectare 1363 New varieties with higher starch content Available!
15 Availability of Fresh Roots Cassava has no definite maturation point, the roots could be stored under the ground up to 24 months and 36 months for some varieties, which will allow the processors have enough stock and don t have to change raw material seasonally.
16 Distillation/Foaming Conventional process STARGEN TM Process
17 Conclusions: STARGEN process offers a direct conversion of starch in fresh cassava root into alcohol by eliminating energy intensive conventional hot-cook process. The potential benefits of the STARGEN process are listed below: No need for drying of the root to produce cassava chip; Reduced loss of free fermentable sugars during cooking; Less energy consumed; Higher alcohol yield ; Less water is needed for grinding and processing (Africa).
18 Process for Tapioca Chips to Make Ethanol (LT 75C) OPTIMASH TBG Tapioca Powder Liquefied starch Aq.slurry,20-32% ds, ph 5.5 Spezyme Extra at 0.15 Kgs/MT 75 C for 1~2 hour Decrease Temp to 60 C Decrease ph 4.2 GA L at 1.0 Kg/MT 1 hour or skip by Glucose Syrup Urea 800 ppm Yeast 32 C Yeast Fermentation With advanced liquefying enzyme Spezyme Xtra and thermostable viscosity reducing enzyme Optimash TBG, chip can be pretreated at 75C before fermentation, which leads to increase of ethanol yield.
19 Acknowledgement THANKS Dr Jay Shetty and my team members in Wuxi! Roy Sim Soo Kiang Tok Siam Chemical and CSTRU of Thailand Gerhard Konieczky-Janda