ISSCT Trash utilization at sugarcane mills A path to advanced biomass power generation Suleiman Hassuani suleiman@ctc.com.br 29 June 2009 CTC - CENTRO DE TECNOLOGIA CANAVIEIRA SULEIMAN HASSUANI 1
Energy conversion alternatives BIOCHEMICAL CONVERSION ETANOL BAGASSE COMBUSTION STEAM / EE EE/STEAM GASIFICATION Products for the sugarcane sector Electricity Fuels Etanol, Diesel, DME, Gasoline Fertilizers NH3 FUELS FERTILIZERS NEED OF ADDITIONAL BIOMASS TRASH SULEIMAN HASSUANI 2
How to increase electricity generation 1. Improve energy generation efficiency advanced technologies 2. Increase fuel availability 3. Reduce process steam/energy consumption SULEIMAN HASSUANI 3
Advanced Technologies sugarcane mill integration Gasification - full integration JUICE EXTRACTION Dryer bagasse Gasifier Gas cleaning Gas turbine bagasse gas gas Hot gases generator gas Heat recovery steam generator steam Mill is totally dependent on energy for its processes. Energy production depends on gasification process. System is quite risky for integration at initial stages of technology development and commercialization. EEE Condensing turbo generator Turbo generator steam MILL PROCESS EE SULEIMAN HASSUANI 4
Advanced technologies sugarcane mill integration Pure cogeneration STORAGE JUICE EXTRACTION bagasse Boiler bagasse Increase in energy export is made through high pressure boilers steam Energy export depends on process consumption MILL PROCESS vapor Turbo generator ee Reduction in process consumption decreases energy export Electricity generation only during the season SULEIMAN HASSUANI 5
Advanced technologies sugarcane mill integration Cogeneration & condensing STORAGE JUICE EXTRACTION MILL PROCESS steam bagasse Boiler Turbo generator EE steam bagasse Condensing turbo generator EE The increase in energy export is made through: 1. The use of higher pressure boilers. 2. Reduction of process steam consumption 3. Increase efficiency of mechanical energy generation - electrification 4. Use of condensing steam turbo generators 5. Increase in the consumption of biomass (bagasse) SULEIMAN HASSUANI 6
Advanced technologies sugarcane mill integration Cogeneration & condensing with trash Cleaning station bales STORAGE JUICE EXTRACTION bagasse Boiler steam bagasse + trash The increase in energy export is made through all the previous conditions plus: Use of trash as additional renewable fuel MILL PROCESS steam Turbo generator Condensing turbo generator Possibility to generate electricity year-round EE EEEE SULEIMAN HASSUANI 7
Advanced technologies sugarcane mill integration Gasification with trash Cleaning station bales STORAGE JUICE EXTRACTION bagasse Boiler steam bagasse + trash GASIFICATION MILL PROCESS steam Turbo generator Condensing turbo generator EE EEEE SULEIMAN HASSUANI 8
Advanced technologies sugarcane mill integration Gasification with trash Cleaning station bales STORAGE JUICE EXTRACTION bagasse Boiler steam bagasse + trash Dryer Gasifier bagasse+trash Hot gases generator gas gás Gas cleaning MILL PROCESS steam Turbo generator EE Use of trash will probably be necessary to guarantee: year-round generation & gasification feasibility Gas turbine EEEE gas ee Heat recovery steam generator steam Condensing steam generator SULEIMAN HASSUANI 9
Comparison of technologies Potential of electricity export 300 Especific electricity export (kwh/tc) 250 200 150 100 50 Gasification integrated bagasse+70% trash 15%mc Gasification integrated bagasse+50% trash 45%mc Gasification stand alone bagasse+50% trash 45%mc Bagasse 62 bar + 50% trash 45% mc Bagasse 62 bar 0 500 450 400 350 300 250 Process steam consumption (kg/tc) SULEIMAN HASSUANI 10
Trash potential For each 1 t of cane stalks there is: 140 kg of dry trash (14%) % Dry leaves Green leaves wet 71 24 dry 81 17 Tops 5 2 SULEIMAN HASSUANI 11
First step towards trash accessibility Pre harvest burning elimination impacts Field impacts Increase in harvester losses Reduction in harvester capacity Difficulties in field operations Changes in the ecosystem: herbicide effect, organic matter, soil moisture, etc. Industry impacts Increase in vegetal impurities Increase of soil in the process Reduction in milling capacity Increase in maintenance Process control difficulties SULEIMAN HASSUANI 12
Trash available in the field Conventional unburned harvesting 75 to 80% of the trash stays in the field 20 to 25% of the trash goes to the mill with the cane BAGASSE Cane fiber + trash with the cane SULEIMAN HASSUANI 13
Trash recovery Questions that should be answered How to collect the trash? How much trash should be collected? What is the impact of trash recovery in the field? agronomy and equipment performance. What is the trash cost? What is the necessary industrial process? What is the impact in the industry? What are the gains??? SULEIMAN HASSUANI 14
Saga of trash recovery effort Baler & Hay harvester recovery from the soil Excessive number of equipment Traffic in the field Difficulties in management High humidity if it rains after harvesting Time limitations before cane sprout Excessive soil with trash (5 a 10%) Several maintenance problems. Baler: needs unbailing and trash shredding Hay harvester: no need of shredding but soil is incorporated to trash Low trash moisture content (10 15%) SULEIMAN HASSUANI 15
Saga of trash recovery effort Saga of trash recovery effort Trash recovery from the harvester Operational problems Reduced harvester reliability Need to increase harvester power Reduced harvester performance Difficulties in controlling vegetal impurities in the cane Reduced trash density SULEIMAN HASSUANI 16
Saga of trash recovery effort Harvesting cane and trash Partial Cleaning Objective: Make feasible the best alternative to collect trash and cope with field operations SULEIMAN HASSUANI 17
Saga of trash recovery effort Saga of trash recovery effort Harvesting cane and trash Partial Cleaning REDUCED SPEED Primary extractor Secondary extractor TURNED OFF Topper Crop divider Elevator Knock down roller Finned roller Base cutter Chopper Roller feeding train SULEIMAN HASSUANI 18
Harvesting cane and trash Partial Cleaning Harvesting with reduced fan speed 50% 50% TRASH in the field TRASH with the cane TRASH Leaves separated at the Cleaning Station BAGASSE Cane fiber + leaves and tops not separated SULEIMAN HASSUANI 19
Partial Cleaning Impacts Harvesting with reduced fan speed Losses reduction Fuel consumption reduction Increased performance 50% 50% TRASH in the field TRASH with the cane Agronomic benefits Weed control Erosion control TRASH BAGASSE Truck Leaves load reduction Cane fiber + leaves separated Need of trash at the separation and at tops mill not Cleaning Need to Station process the trash separated SULEIMAN HASSUANI 20
Trash and soil separation from the cane at the industry Cleaning station systems Feeding table separation Between conveyors separation Cane and trash Cane and trash Air stream Air stream Trash and soil capture chamber Trash and soil capture chamber SULEIMAN HASSUANI 21
Trash processing Soil removal and trash shredding ROTARY SCREEN SHREDDER SULEIMAN HASSUANI 22
Trash processing Shredder Shredding by cutting Operates even with high moisture Need of knives sharpening SULEIMAN HASSUANI 23
Trash processing Shredder SULEIMAN HASSUANI 24
Trash as a fuel Characterization of sugarcane trash Heating Value Moisture content (%) Higher heating value (dry) MJ/kg Lower heating value MJ/kg kcal/kg Trash 1 15 17,0 12,9 3.100 Trash 2 35 17,0 9,4 2.250 Bagasse 50 18,0 7,2 1.710 Proximate Analysis* (%) Ash Fixed C Volatile matter Trash 9 16 75 Bagasse 3 14 83 *Dry basis Ultimate Analysis* (%) Trash Bagasse *Dry basis C 48 46 H N O S Cl 6,4 0,6 45 0,1 0,2 5,8 0,4 48 - - SULEIMAN HASSUANI 25
Trash as a fuel Ash fusion Trash high mineral impurities content Temperatures ( o C) Trash Bagasse Beginning of ash deformation 1160 1260 Fluid 1260 1330 Whole trash bale burning in furnace SULEIMAN HASSUANI 26
Trash as a fuel year round generation Biomass storage Traditional bagasse storage systems SULEIMAN HASSUANI 27
Trash as a fuel year round generation Biomass storage With trash - Additional fuel Define generation strategy season or year-round generation Impact on equipment and storage needs Bulk uncovered storage Soil preparation Location Piles form and size Equipment Need of covered storage: 7 days storage?? Trash has to be burnt immediately, mixed to bagasse STORAGE BECOMES A RELEVANT ISSUE SULEIMAN HASSUANI 28
Energy cane Sugarcane high fiber content varieties Increase biomass by cane stalks fiber increase Parameters under study Impact on milling/diffusers capacity Impact on sugar extraction Impact on bagasse quality Impact on energy consumption of equipment Feasibility analysis Fiber optimized range Definition of new contribution margin equation Varieties development SULEIMAN HASSUANI 29
Steps for the generation of considerable amounts EE Conclusions 300 Use high pressure steam boilers (above 65 bar) 250 Use of steam extraction & condensing systems Especific electricity export (kwh/tc) 200 150 100 50 0 500 450 400 350 300 Process steam consumption (kg/tc) 250 Electrification of mechanical power Reduce process steam consumption Use additional biomass: trash and cane fiber increase Use of advanced technologies gasification combined cycle Costs versus gains will define the technologies to be applied SULEIMAN HASSUANI 30
The end THANK YOU! Suleiman Hassuani suleiman@ctc.com.br CTC Centro de Tecnologia Canavieira www.ctc.com.br SULEIMAN HASSUANI 31