ADB FINESSE Training Course on Renewable Energy & Energy Efficiency for Poverty Reduction

1. ADB FINESSE Training Course on Renewable Energy & Energy Efficiency for Poverty Reduction 19th – 23rd June 2006 Nairobi, Kenya

2. Module 5:Modern Biomass - Cogeneration Dr. Kassiap Deepchand

3. Large Scale Biomass Energy Options • Biofuels • Ethanol – Zimbabwe, Malawi, Swaziland, Kenya • Bio-diesel – Selected projects with plans for expansion • Biomass gasification – Pilot projects • Direct biomass combustion – Widely used in agro and forest industries • Biogas – Pilot projects • Briquetting – Pilot projects • Cogeneration

4. Sugar Cane Biomass Composition

5. Sugar Processing in a typical Mauritian Sugar Factory

7. Bagasse Characteristics • Fibrous residue leaving the last mill of a milling tandem • Varies from 22 to 36% on cane - average of 30% (depends on fibre % cane, cane cleanliness, harvesting practices) • Moisture content – important factor influencing calorific value • GCV of 19,250 kJ/kg @ 0% moisture and 9950 kJ/kg @ 48% moisture • NCV @ 48% moisture is 7985 kJ/kg • Good milling work ~ 45% moisture & poor milling work ~ 52% • Boiler house design to burn bagasse @ ~ 50 % moisture • Fibre % bagasse ~ moisture % bagasse (cellulose) • 1-2 % sucrose (influence calorific value) • Extraneous matter (higher with mechanical harvesting) • Low bulk density of 130 kg/m3

8. What is Cogeneration? • Simultaneous production of Electricity and Steam (or heat) in a single power plant • It represents a saving when compared to separate generation of electricity and steam (or heat) • Well known examples: -> Chemical industries, District Heating -> Sugar Mills

9. HP Steam C Condenser LP Process Steam Typical Cogeneration Set-Up Factory Uses & Export Boiler T/A BP Bagasse

10. Electricity Typical sugar factory annexed to a cogeneration plant GRID Sugar cane Factory Independent Power Plant (HP steam/ CE turbo alternator) Electricity Low pressure steam Bagasse

14. Investment in Power Plants

15. Power Plant Configurations

16. Energy projects from the Sugar Industry

17. Share ownership of power plants • Firm • Corporate sector 51% • Strategic Partner 27% • SIT (Small planters/workers) 14% • State Investment Corporation 8% • Continous • Corporate sector 80% • SIT 20%

19. Energy Generated by Source for sales (2005)

20. The Future of Bagasse Energy in Mauritius • Avg. export of surplus electricity from bagasse at CTBV is around 110 kWh compared to an average of 60 kWh in other bagasse base power plants in Mauritius • Potential for Mauritius can thus be estimated to be 600 GWh based on • Production of 5.8 million TC/yr • Further centralisation with each mill crushing 800,000 TC/yr • Upgrading of boiler pressure up to 82 bar (similar to CTBV) • Further increase through the use of • Cane field residues (150 GWh) • Emerging technologies – BIG-CC, pyrolysis • Total of 2000 GWh is achievable with the use of coal as complementary fuel

21. Evolution of Electricity Production from the Sugar Industry

22. Bagasse Energy and its Impact on the Energy Sector

23. Environmental Life Cycle Benefits • Cane plant is a very efficient sequestrator of atmospheric carbon • All co-products and waste streams have a value • Bagasse (cane trash) for energy • Filter cake/furnace ash as soil conditioner • Molasses for ethanol and spirits • Vinasse as fertiliser through • - field irrigation or • - composting with filter cake or • - incinerated and spread in fields

24. Environmental Impacts of 300 GWh of Bagasse Electricity ATMOSPHERIC CO2 • Total coal avoided = 200,000 tonnes • Total oil equivalent = 120,000 tonnes • Coal ash avoided = 40,000 tonnes • Carbon dioxide avoided = 300,000 tonnes

25. Positive Environment Impact • Improved thermal efficiency compared to traditional mills => less heat rejected • Limited atmospheric emissions • Particulate <100 mg/Nm3 • SO2: almost non-existent with bagasse and in live with international regulations due to use of low-sulfur coal • NOx: also reduced due to use of spreader-stoker technology

26. Positive Environment Impact • Bagasse: a renewable fuel • Bagasse contributes to a reduction in Greenhouse Gas Emissions • CO2 released by bagasse combustion is absorbed by the ensuing crop => no effect • Increase in cane trash recovery from the fields produces more bagasse, more electricity and reduced methane release (caused by trash decay) • Optimal use of bagasse implies reduced fossil fuel imports

27. Surplus Electricity Yield from cane in Mauritius (2003)

28. The Potential of Bagasse Energy in Africa • Sugar production = 9,612 x103 tonnes • Cane production @ 11% sugar = 87 x106 tonnes • Cogeneration potential • @ 31 bars = 4,300 GWh • @ 44 bars = 6,000 GWh • @ 82 bars = 9,600 GWh

30. Lessons Learnt: Successful Development of Cogeneration • Clearly spelt policy on sugar cane bagasse for cogenerated electricity • Provision for appropriate incentives to induce investment in sugar factory modernization and investment in power plants. • Adopt energy efficiency and conservation measures in cane juice processing for sugar recover to minimize process steam consumption. • Electrification of drive of all prime movers in cane milling. • Target a cane crushing capacity of around 200 TCH to match with one module of 35-40 MW power plant at steam pressure of around 82 bars. A commercially proven technology. • Use coal as complementary fuel for year round power export to grid.

31. Lessons Learnt Successful Development of Co-Generation • Centralization of cane milling to ensure bagasse availability on site rather than saving bagasse in a cluster and transporting it to a central power plant. • A kWh price worked out independently of the utility and the IPP or alternatively inviting request for proposal with set guidelines in a competitive bidding process. • Make provision for participation of small planters and workers in the equity portion of investment. • Negotiate a PPA with details on the obligations of the IPP towards the utility and vice versa, including in particular payment obligations by the utility. • This PPA is used inter alia, in negotiating a loan from the bank. • Concurrently seek all permits including EIA license

32. Concluding Remarks • Bagasse based electricity – high priority in the sugar sector reform in Mauritius as well as significant source of revenue to the industry • The sugar industry power plant exports 39.6 % of the total electricity in 2003 • The success is attributable to the various entrepreneurs operating in an environment with clearly defined Government policy • Bagasse/coal power plant associated with environmental advantages and benefit the sugar industry and the country at large • Can easily be replicated in the sugarcane industry in Africa

33. Thank You