1. Biorefinery Annexed to Typical South African Sugar Mill, Part I: Flowsheet development and simulation
By: Dr. Mohsen A. Mandegari
Research head: Prof. Johann F. Görgens
Department of Process Engineering

2. South African Sugar Industry
Introduction
South African Sugar Industry
It is a diverse industry combining the agricultural activities of sugarcane cultivation with the production of
Raw and Refined Sugar, specialized sugars and
a range of by-products
Approximately one million South Africans already depend indirectly on the Sugar Industry for their livelihoods.
∼ registered small scale-growers in the sugarcane cultivation side.

3. Introduction
Economic Challenges
fluctuating and low global sugar prices,
increasing competition with the global low-cost producers,
increasing in energy prices
aged facilities in their sugar mills and
The Economic Challenges facing the Global Sugar Industry are volatile world trade sugar prices (Fig. below1, March 1985 to March 2015)
Given increasing pressure from 32 26
US$ cents per Pound 20 16 14 12 10 8 6 4 2
2009
2010
2011
2012
2013
2014
2015
sustainability demands
What can one do to Sustainably continue the Industry?
1Commodity Price Indices:

4. Re-Vitalisation of the Sugar Industry
Introduction
Re-Vitalisation of the Sugar Industry
Proposed Strategy 1
The sugar industry has to “re-invent” itself, as a means to ensure long-term economic survival
This re-invention can lead to significant opportunities for being Competitive and Sustainable in the future
job creation & expansion of the community-level impact generation of Additional Revenue
What we propose as a strategy for re-vitalisation of the sugar industry is to annex BIOREFINERIES to existing sugar mills, using low value LIGNOCELLULOSE to co-produce high value chemicals, biofuel, bioenergy . . . 2 3
Valuable Products +
Electricity/Steam

5. Existing Sugar Mills Sugar Cane CHP Electricity & Steam Extraction
Biorefinery
Existing Sugar Mills
Sugar Cane
CHP
Electricity
& Steam
Extraction
Bagasse
Molasses
Clarification
Ethanol
Sugar

6. Sugar Cane Leaves & Tops CHP Electricity & Steam Extraction Bagasse
Biorefinery
Sugar Cane
Leaves
& Tops
CHP
Electricity
& Steam
Extraction
Bagasse
Molasses
Clarification
Ethanol
Sugar

7. BIOREFINERY Sugar Cane Leaves & Tops CHP Electricity & Steam
Extraction
Bagasse
Bagasse & trash are
Rich in Carbohydrate & don’t compete with food/feed demand
Molasses
Clarification
BIOREFINERY
Ethanol
Sugar

8. BIOREFINERY Sugar Cane Leaves & Tops CHP Electricity & Steam
Extraction
Bagasse
Bagasse & trash are
Rich in Carbohydrate & don’t compete with food/feed demand
Molasses
Clarification
BIOREFINERY
Bioenergy
Bioproducts
Ethanol
Sugar

9. tens of thousands of man-years of employments
Biorefinery
Sugar Cane
Leaves
& Tops
CHP
Electricity
& Steam
Extraction
Bagasse
Bagasse & trash are
Rich in Carbohydrate & don’t compete with food/feed demand
Molasses
Clarification
BIOREFINERY
Bioenergy
Bioproducts
Ethanol
Sugar
bulk chemicals
fine chemicals
animal feed
food
biomaterials
fertilizer
pulp & paper
gases
-liquid/gaseous
transport biofuels,
Sugarcane Bagasse(Lignocellulose)
Cellulose → C6 42%
Hemicellulose → C5 25%
Lignin 22%
Ash + Extractive + 11%
electricity
heat
solid fuels
tens of thousands of man-years of employments

10. Baseline of Biorefinery
The varieties of products such as Ethanol, Furfural, Lactic Acid, Butanol, and etc. can be produced by Biorefinery. Bioethanol production can be considered as the baseline of Biorefinery. Ethanol production is simpler than production of any other valuable products, needs less capital and operating cost and more developed.

11. Baseline of Biorefinery
Schematic view of Bioethanol Production.

12. General approach for development of process flow diagram

13. Aspen PlusTM Simulation Development
Simulated Process:
Bioethanol production
Pretreatment (Steam Explosion+SO2)
Simultaneous Saccharification and Co-fermentation (SSCF)
Seed Training
Bioethanol purification and recovery
Evaporation unit
Waste water treatment unit
Combustor, boiler and power generation
Utility

14. Developed Aspen Plus Simulation

15. Developed Aspen Plus Simulation

16. Ethanol Purification and recovery Unit

17. Concise Result Overall Balance Total Feedstock (DM) kg/h 65000
Feedstock to biorefinery (DM)
Pure Ethanol production
16922
Net Power production (to Grid) kW
26200
LPS contingency
42888

18. Energy Demand/Production
Result (Energy)
Energy Demand/Production
Total Heat Demand (kW)
92600
Heat Production (kW)
133600
Total Power Demand (kW)
1300
Power Production (kW)
27500
Distribution of electric power demand (total 1300 kW)

19. Result (Cooling Demand)
Cooling medium kW
ton/h
Cooling Water
42200
4050
Chilled Water
5250
410
Cooling Air
24800
17900
Distribution of cooling demand (total 72.3 MW)

20. Conclusion Ethanol production : 261 kg / ton of DM
Electricity production: 0.4 MW / ton of DM
Cooling demand of the process: 1.1 MW / ton of DM
Total chemical consumption: 27 kg / ton of DM

21. Thank you for your attention!
planned output
Acknowledgement
Thank you for your attention!
any question, comment, ?
Mohsen Ali