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

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. ∼ 25000 registered small scale-growers in the sugarcane cultivation side.

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 30 30 28 25 26 US$ cents per Pound 24 20 22 15 20 18 10 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: www.indexmundi.com 3-1-1985 3-1-1987 3-1-1989 3-1-1991 3-1-1993 3-1-1995 3-1-1997 3-1-1999 3-1-2001 3-1-2003 3-1-2005 3-1-2007 3-1-2009 3-1-2011 3-1-2013 3-1-2015

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

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

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

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

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

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

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.

Baseline of Biorefinery Schematic view of Bioethanol Production.

General approach for development of process flow diagram

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

Developed Aspen Plus Simulation

Developed Aspen Plus Simulation

Ethanol Purification and recovery Unit

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

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)

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)

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

Thank you for your attention! planned output Acknowledgement Thank you for your attention! any question, comment, . . . ? Mohsen Ali Mandegari(mandegari@sun.ac.za)