STRUCTURE

• Introduction – A short Introduction (15 words)               
• Body – Explain
  • Waste based energy (60 words)
  • biomass based energy technology for sustainable development(60 words)
• Conclusion – Mention a short conclusion  (15 words)

ANSWER

WASTE-TO-ENERGY (WTE)

• Waste-to-Energy (WtE) or Energy-from-Waste (EfW) is a form of energy recovery and the process of generating energy in the form of electricity and/or heat from the primary treatment of waste, or the processing of waste into a fuel source.
• Most WtE processes generate electricity and/or heat directly through combustion, or produce a combustible fuel commodity, such as methane, methanol, ethanol or synthetic fuels.
• Incineration, the combustion of organic material such as waste with energy recovery, is the most common WtE implementation method.
• All new WtE plants in OECD countries incinerating waste (residual MSW, commercial, industrial or RDF) must meet strict emission standards, including those on nitrogen oxides (NOx), sulphur dioxide (SO2), heavy metals and dioxins. Modern incinerators reduce the volume of the original waste by 95-96 percent, depending upon composition and degree of recovery of materials such as metals from the ash for recycling.
• Incinerators may emit fine particulate, heavy metals, trace dioxin and acid gas, even though these emissions are relatively low from modern incinerators. Other concerns include proper management of residues: toxic fly ash, which must be handled in hazardous waste disposal installation as well as incinerator bottom ash (IBA).

BIOMASS ENERGY

• Biomass is a renewable energy resource derived from plant and animal waste.
• The energy from biomass (biomass conversion) is released on burning or breaking the chemical bonds of organic molecules formed during photosynthesis.
• Biomass fuels can be used directly or they can be transformed into more convenient form and then used.
• Sources of biomass
• By-products from the timber industry, agricultural crops and their byproducts, raw material from the forest, major parts of household waste and wood.
• Solid Biomass fuels: Wood logs and wood pellets, charcoal, agricultural waste (stalks and other plant debris), animal waste (dung), aquatic plants (kelp and water hyacinths) urban waste (paper, cardboard and other combustible materials).
• Conversion to gaseous and liquid biofuels
• Biomass can be converted into alcohol (liquid biofuels) by distillation.
• Liquid Biofuels: Ethanol, Methanol, Gasoho, Biodiesel.
• Gaseous Biofuels: Synthetic natural gas (biogas), Wood gas: Methane – 70% and CO2 – 30%.
• Instead of burning loose biomass directly, it is more practical to compress it into briquettes (compressing them into blocks of a chosen shape) improve its utility and convenience of use.
• Such biomass in the biomass briquettes can be used as fuel in place of coal in traditional furnaces or in a gasifier.
• A gasifier converts solid fuels into a more convenient-to-use gaseous fuel called producer gas.