biomass to energy assessment st. kitts & nevis
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Biomass to Energy Assessment St. Kitts & Nevis. Mark Lambrides (OAS/DSD) Kevin de Cuba (OAS/DSD). Pre-conclusions December, 2006. Why does sugar matter?. Shutdown of the sugar industry Unemployment Decreased sources of income Lost benefits of sugar crop (tradition, erosion, tourism) - PowerPoint PPT PresentationTRANSCRIPT
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Biomass to Energy Assessment St. Kitts & Nevis
Mark Lambrides (OAS/DSD)Kevin de Cuba (OAS/DSD)
Pre-conclusions
December, 2006
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Why does sugar matter?Shutdown of the sugar industry
– Unemployment– Decreased sources of income– Lost benefits of sugar crop (tradition, erosion, tourism)
Traditional energy supplies– High cost of diesel import for electricity generation– High cost of transportation fuels– Dependent on external geo-political forces– Negative environmental impacts (local and global)– Increased reliability of electricity supplies
Current waste management– Health impacts– Environmental impacts– Landfill space constraints
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Current state of the sugar industry
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Current state of the energy sectorElectricityCurrent installed capacity: 33.5 MW (2006)
Peak demand: 20 MW
Firm capacity: 19 MW
Demand Growth from 2005-2015: 84.5%
Average electricity price in St. Kitts: 0.17 US$/kWh (2006)*
Average electricity price in USA: 0.08 US$/kWh (2006)*At diesel fuel cost of 1.588 US$/gal, currently diesel fuel cost is 3.37 US$/gal
Imported Fossil Fuel Value Unit
Gasoline
12,614 m3
3,332,619 US gallons
Transportation fuel
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Current state of waste management
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Objectives
• Determine if there is reliable biomass feedstock supply for long term ethanol and/or electricity production
• Highlight commercially viable biomass to energy conversion approaches
• Outline potential strategy for public-private partnership to develop biomass to energy
• Attract commercially proven developers to consider investment approach in SKN
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Methodology of study• Biomass resource assessment • Technology identification and selection• Design of multiple scenarios• Techno-economic analysis• Sensitivity analysis• Results summary• Recommendations – Outline a commercial
development pathway
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What do we know? Sugar cane/ bagasse data (1)
Parameter Value range Unit
Available cultivable area 2,226 – 2,630 ha
Sugar cane yield 60.6 ton/ha
Average length of grow cycle 10-12 months
Weighted average length of crushing / harvesting season
120 days/yr
Variation in length of crushing season 20 days/yr
Sugar cane production 134,750 – 159,250 ton/yr
Bagasse production 25,603 – 30,258 dry ton/yr
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What do we know? Sugar cane/ bagasse data (2)
Parameter Value Unit
Average distance lands to mill ? km
Weight ratio of wet bagasse on wet cane 22 – 30 %
Sugar cane fiber content 18 - 19 %
HHV of sugar cane 17.0 MJ/kg
LHV of bagasse on dry basis (50% moisture) 15.6[1] MJ/kg
HHV of bagasse on dry basis (50% moisture) 18.1[2] MJ/kg
LHV of bagasse on wet basis 7.8[3] MJ/kg
C as fraction of (CxHyOz) 45 - 50 %
H as fraction of (CxHyOz) 5 - 6 %
O as fraction of (CxHyOz) 38 - 45 %
[1] Van Groen, M., “Energy rooted in sugar cubes”, The interaction between energy savings and cogeneration in Indian sugar mills, Utrecht University, 1999[2] Hassuani et al., “Biomass power generation”, Sugar cane bagasse and trash, UNDP Brazil, 2005, page 26 [3] Hassuani et al., “Biomass power generation”, Sugar cane bagasse and trash, UNDP Brazil, 2005
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What do we know? Municipal waste data
Waste category 2004
Weight (tons)Organic fraction (%)
Green waste 1,455 ?
Household 10,390 35 - 45
Land clearing 3,514 ?
Institutional 150 ?
Sludge (Septic tank waste) 1,876 ?
Ship generated waste 6 ?
Total 17,391
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Scenario A – Ethanol (from SKN sugar)
16,921 ton/yr sucrose147,137 ton 8,832,634 L/yr
2,333,582 US Gallon/yr16.8 ton/hr 6393.3752 US Gallon/day
11,624 GJth/yr 24.198998 m3/day27,220 dry ton/yr bagasse 2,943 GJe/yr
4,782 MWh/yr3.21 MWe
17,215 GJe/yr503,576 GJp/yr
51,498 GJth/yr
18.5 GJ/dry ton bagasse 81,120 GJe/yr22,533 MWh/yr
339,177 GJth/yr
2428 2630 ha60.6 60.6 ton/ha
147,137 159,378 ton/yr
2,333,582 2,527,723 US gallons/yr2 3 US$/gallon
Output range
Scenario A
Ethanol production
Land availableYield
Sugar cane
Input range
Sugarcane crusher + Mill
(Step 1)
Fermentation and Destillation
Ethanol prod. Rate =
522 L/ton Sucrose
(Step 2)
Ethanol
Bagasse receipt and storage
Boiler / TurbineHeat rate = 17,9 GJ/MWh
Electricity
Heat
Sugarcane (18-19% fibre)(11-12% sucrose)
Stillage / Fertilizer
CO2
In case of ethanol consumed locally: - Current gasoline consumption: 3.3 mm US gallons/yr- Possibility to blend with gasolineup to 10% (requires 300,000 US gallons)- Would permit a large scale transformation of Vehicle Fleet to consume E-85 or E-100 fuels (up to 2/3 of transportation fuel requirements)
Excess electricity available to grid and excess heat available for additional electric production
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Scenario B – Electricity and Cane Juice
16,921 ton/yr sucrose147,137 ton
817 MWh/yr2,943 GJe/yr
27,220 dry ton/yr bagasse 11,624 GJth/yr
98,335 GJe/yr27,315 MWh/yr
503,576 GJp/yr 3.12 MWe
393,617 GJth/yr
18.5 GJ/dry ton bagasse
2428 2630 ha60.6 60.6 ton/ha
147,137 159,378 ton/yr27,220 29,485 dry ton/yr
16,921 18,328 US gallons/yr3.1 3.4 MWe
Electricity to grid 27,315 29,588 MWh/yr0.15 0.13 US$/kWh
Sugar cane
Output rangeSugarcane juice
Bagasse
Power capacity
Scenario B
Input rangeLand available
Yield
Sugarcane Shredder, Crusher + Mill
Bagasse receipt and storage
Boiler / Turbine (CHP)Heat rate = 17,9 GJ/MWh
Electricity to grid
Heat
Sugarcane (18-19% fibre)(11-12% sucrose)
Electricity
Sugarcane juice
Excess heat
In case of juice exported and electricity consumed locally: - Juice can be exported for further processing to ethanol- Electricity for national grid to support SKED
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Complimentary Alternatives
• Add BMW as feedstock (A & B)
• Import hydrated ethanol from Brazil, create larger facility, feed in imported and local product to produce ethanol
• Manufacture other derivatives
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Critical challenges
• Available land for sugarcane production (currently ~6,000 acres, optimal 10,000 acres)
• State of sugarcane harvesting system
• State of sugar processing system
• SIZE MATTERS….
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What's next: Steps to commercialization
• Remainder of this week - data gathering interviews with stakeholders in St. Kitts and Nevis
• Preparation of preliminary assessment– Final Draft expected by end of January ´07
• Stakeholder review and comment on final draft• Presentation of findings• Initiative to facilitate commercial development
(international tender; short list tender; sole source)
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Bio-Energy Potential St. Kitts