Waste to energy

• 1.CM4282 Energy Resources Tutorial Presentation Waste-to-EnergyGroup JFOONG CHUERN YUE DARREN NATASHA E GOUW MING ZHI RAYSTON LEONG YU MIAO YU YUEBO

2. Presentation Outline What is Waste-to-Energy? IncinerationGasification Waste to Fuel Plastic to Fuel 3. Turning non-recyclable waste to a useable form of energy E.g. Electricity, heat or fuels Through combustion, gasification, anaerobic digestion, landfill gas recovery, and pyrolysis http://www.epa.gov/osw/nonhaz/municipal/wte/ Image: http://wastetoenergyinternational.com/wp-content/uploads/2013/03/Promoting-a-clean-future.jpg 4. Incineration Works primarily on the combustion of municipal waste to generate heat for use in electricity generation. Key features: Waste storage and handling Waste feeding Combustion Steam and electricity generation Air pollution control Ash residue handling Combustion Stages: Ignition Drying Moisture is evaporatedCombustionDevolatilization Combustible volatiles are releasedhttp://www.rpi.edu/dept/chem-eng/Biotech-Environ/incinerator.htmlVolatiles are ignited in the presence of oxygenVolatile matter is completely combusted and fixed (Carbon is oxidized to CO2) 5. Incineration Advanced Stoker Systemhttp://www.khi.co.jp/english/kplant/business /environment/g_waste/heat.html 6. Incineration A Rankine Cyclehttp://upload.wikimedia.org/wikipedia/commons/0/00/Rankine_cycle_layout.png 7. Incineration Pros and Cons Advantages Waste volume reduction (95%-96%) Destruction of combustible toxins Destruction of pathogenically contaminated material Energy recoveryhttp://www.rpi.edu/dept/chem-eng/Biotech-Environ/incinerator.htmlDisadvantages Air pollution Ash must be landfilled and may be hazardous High capital and operation cost Wastewater problems 8. Gasificationhttps://www.gasification.org/page_1.asp?a=87 9. Gasification Schematics for a CCGT plant fed by syngashttp://www.killingholme-energy.com/ 10. Waste to Fuel: Biogas Biogas Production Anaerobic digestion of organic matter in airtight digesters Anaerobic digestion in landfillsImage: http://www.mnn.com/green-tech/research-innovations/blogs/landfill-methane-could-power-3-million-homes# Image: http://www.daviddarling.info/encyclopedia/A/AE_anaerobic_digestion.html 11. Waste to Fuel: BiogasImage: http://www.cowpattypatty.com/ 12. Waste to Fuel: Biogas Advantages Efficient way of energy conversion Household and bio-wastes can now be disposed of in a useful manner Provides a non-polluting and renewable source of energy* Significantly lowers the greenhouse effect on the earths atmosphere E.g. removing N2O from manure** Excellent solution for agricultural & livestock waste Disadvantages Less efficient than natural gas as direct fuel (low % purity) Process is not suitable for commercial use largely domestic/rural cooking, etc. 13. Waste to Fuel: Biogas Development History in China First digester (8 m3) was built by Mr Luo Guo Rui ( ) in the 1920s. Biogas was used for family cooking and lighting. In 1950s, the Chinese government started promoting biogas in rural areas to provide energy for farmers. From 2003-2013, rapid development in rural areas. 41.68 million household small digesters (8-12 m3) were built. Increase use of AD in municipal and industrial sectors.Advertisement for Luos biogas in Shen Newspapers, Shanghai 1932.http://www.epa.gov/agstar/documents/conf13/Biogas Production in China - Current Status and Future Development, Dr Xiujin Li.pdf 14. Waste to Fuel: Biogas Current Status (Agricultural and Rural Sector) Household small digesters 41.68 million units, providing clean energy to 160 million people in rural areas. Small-scale biogas plants 24,000 units mainly for small animal farms Medium and large-scale biogas plants3,691 units Biogas plants in animal farms 80,500 units (15 billion m3 p.a. (2012)) http://www.epa.gov/agstar/documents/conf13/Biogas Production in China - Current Status and Future Development, Dr Xiujin Li.pdf 15. Waste to Fuel: Biogas Current Status (Municipal Sector) For sludge 51 units For refuse 10 units For food waste 40 units Current Status (Industrial Sector) 60-80 plants to treat waste waster Largest in Nanyang City, processing waste water from ethanol plant producing 500,000 m3 biogas daily capable of providing energy for http://www.epa.gov/agstar/documents/conf13/Biogas Production in all residents China - Current Status and Future Development, Dr Xiujin Li.pdf 16. Waste to Fuel: Biogas Future Development Biogas potential MSW: 15 billion m3 Industrial: 48 billion m3Agriculture: 289 billion m3 In total: 352 billion m3, if 100% utilized176 billion m3, if 50% utilized (equivalent to current NG consumption)http://www.epa.gov/agstar/documents/conf13/Biogas Production in China - Current Status and Future Development, Dr Xiujin Li.pdf 17. Waste to Fuel: Biomethane Biogas Upgrading Biogas is 65% methane, compared to 98.5-99% fuel grade Also contains other contaminants Inert diluents reduce energy content: CO2, N2 Contaminants: Biologicals, Microbes, Trace Metals Corrosives: Sulfur & H2S, Siloxanes, AmmoniaImage: http://www.bio-methaneregions.at/?q=node/41 18. Waste to Fuel: Biomethane Biogas Upgrading Technologies Water Wash Chemisorption/Physisorption Pressure Swing Adsorption Membrane separationBiomethane Applications Direct power generation Direct gas injection Vehicle use http://www.bcfarmbiogas.ca/files/pdf/Biomethane%20Feasibility%20Study.pdf http://www.apvgn.pt/documentacao/advantages_of_biomethane_as_a_fuel.pdf 19. Waste to Fuel: Biomethane Advantages High CH4 content, effectively Natural Gas Carbon neutral Reduces waste, which would cost energy otherwise Current Developments Biomethane is highly successful in Sweden & Germany zero fuel taxes, financial support for biomethane production, 40% reduced personal income tax for CNG company car 20. Waste to Fuel: SummaryImage: http://www.biogasmax.co.uk/biogas-strategybiofuel-opportunities/from-biogas-tobiomethane-and-biofuel.html 21. Plastic to Fuel ProblemImage via: coastalcare.org Only 8% of waste plastic is recycled in US, 15% in W. Europe and much less in developing countries 227 billion kg of plastic is manufactured annually and 33% is single-use/thrown away Plastic accounts for 4/5 of garbage in the oceans http://www.inspirationgreen.com/plastic-waste-as-fuel.htmlChange in Mindset Plastic should be viewed as an underused resource rather than being landfill destined 22. Plastic to Fuel Case Study: Cynar in the UKhttp://www.youtube.com/watch?v=0SDS58y0hDY#t=149 23. Plastic to Fuelhttp://www.cynarplc.com/images/ProcessFlowDiagram.jpg 24. Plastic to Fuel ProsCons Process (pyrolysis) takes place in vacuum and plastic is melted, not burnt. Hence minimal to no resultant toxins released into the air PVC produces chlorine that will corrode reactor and pollute the environment PETE produces oxygen into the oxygen-deprived chamber The synthetic fuel is low in thereby slowing down the sulfur process (PETE recycles efficiently traditionally, so just Conversion rate of 95% (wt. send PETE to recycling to vol.) centres) PE and PP produces fuel that burns cleanly http://www.inspirationgreen.com/plastic-waste-as-fuel.html 25. Turning non-recyclable waste to a useable form of energy E.g. Electricity, heat or fuels Through combustion, gasification, anaerobic digestion, landfill gas recovery, and pyrolysis http://www.epa.gov/osw/nonhaz/municipal/wte/ Image: http://wastetoenergyinternational.com/wp-content/uploads/2013/03/Promoting-a-clean-future.jpg 26. Questions?