Biomass energy is a renewable energy source derived from organic materials like plant residues, agricultural waste, and animal manure. It converts biological matter into electricity, heat, or biofuels. As a sustainable alternative to fossil fuels, biomass helps reduce greenhouse gas emissions and supports waste management while promoting energy independence.
About Biomass Energy
- Biomass is renewable organic material that comes from plants and animals. Biomass energy is energy generated or produced by living or once-living organisms.
- Biomass continues to be an important fuel in many countries, especially for cooking and heating in developing countries. The use of biomass fuels for transportation and for electricity generation is increasing in many developed countries as a means of avoiding carbon dioxide emissions from fossil fuel use.
- Biomass contains stored chemical energy from the sun. Plants produce biomass through photosynthesis. Biomass can be burned directly for heat or converted to renewable liquid and gaseous fuels through various processes.
- Biomass sources for energy include:
- Wood and Wood Processing Wastes: firewood, wood pellets, and wood chips, lumber and furniture mill sawdust and waste, and black liquor from pulp and paper mills
- Agricultural Crops and Waste Materials: corn, soybeans, sugar cane, switchgrass, woody plants, and algae, and crop and food processing residues
- Biogenic Materials in Municipal Solid Waste: paper, cotton, and wool products, and food, yard, and wood wastes
- Animal Manure and Human Sewage
Converting Biomass to Energy
Biomass is converted to energy through various processes, including:
Direct Combustion (Burning) to Produce Heat
Direct combustion is the most common method for converting biomass to useful energy. All biomass can be burned directly for heating buildings and water, for industrial process heat, and for generating electricity in steam turbines.
Thermochemical Conversion to produce solid, gaseous, and liquid fuels
Thermochemical conversion of biomass includes pyrolysis and gasification. Both are thermal decomposition processes in which biomass feedstock materials are heated in closed, pressurized vessels called gasifiers at high temperatures.
Chemical Conversion to produce liquid fuels
A chemical conversion process known as trans- esterification is used for converting vegetable oils, animal fats, and greases into fatty acid methyl esters (FAME), which are used to produce biodiesel.
Biological Conversion to produce liquid and gaseous fuels
Biological conversion includes fermentation to convert biomass into ethanol and anaerobic digestion to produce renewable natural gas. Ethanol is used as a vehicle fuel.
Renewable natural gas – also called biogas or biomethane – is produced in anaerobic digesters at sewage treatment plants and at dairy and livestock operations. It also forms in and may be captured from solid waste landfills.
Anaerobic Digestion or Biomethanation
Biomethanation or methanogenesis, is a scientific process whereby anaerobic microorganisms in an anaerobic environment decompose biodegradable matter producing methane-rich biogas and effluent. The three functions that take place sequentially are hydrolysis, acidogenesis, and methanogenesis.
Cogeneration
- Co-generation is producing two forms of energy from one fuel. One of the forms of energy must always be heat and the other may be electricity or mechanical energy. In a conventional power plant, fuel is burnt in a boiler to generate a high-pressure system. The steam is used to drive a turbine to produce electric power. The exhaust steam is generally condensed to water which goes back to the boiler.
- As the low-pressure steam has a large quantum of heat that is lost in the process of condensing, the efficiency of conventional power plants is only around 35%. In a cogeneration plant, the low-pressure exhaust steam coming out of the turbine is not condensed, but used for heating purposes in factories or houses, and thus very high-efficiency levels, in the range of 75%-90%, can be reached.
- Since co-generation can meet both power and heat needs, it has other advantages as well in the form of significant cost savings for the plant and reduction in emissions of pollutants due to reduced fuel consumption.
Significance of Biomass Energy
- Renewable Resource: Utilizes organic waste, ensuring sustainability.
- Carbon Neutral: Reduces greenhouse gas emissions by recycling carbon already in the ecosystem.
- Energy Diversification: Decreases dependence on fossil fuels.
- Waste Management: Converts agricultural, industrial, and household waste into energy.
- Economic Growth: Promotes rural development and job creation in energy production.
- Versatility: Generates electricity, heat, and biofuels for various applications.
Role of Bio-energy in Meeting India’s Energy Demands
- Energy Demand: Bioenergy can help to meet the growing demand for energy within the country, especially in rural areas. Nearly 25% of its primary energy comes from biomass resources and close to 70% of rural population depend on biomass to meet their daily energy needs. Biomass can further help in meeting rural energy demands.
- Climate Change Mitigation: Bioenergy provides important benefits compared to fossil fuels, in particular regarding GHG emissions. Biomass recycles carbon from the air and spares the use of fossil fuels, reducing the additional fossil carbon from the ground into the atmosphere.
- Market Growth: The market for renewable energy systems in rural and urban markets in India is set to grow exponentially. Despite this, bioenergy does not figure in most energy studies and is classified as ‘non-commercial’ energy. Plants like Jatropha, Neem and other wild plants are identified as the potential sources for biodiesel production in India.
- Waste to Energy: Biofuels can augment waste to wealth creation. Being a derivative of renewable biomass resources such as plastic, municipal solid waste, forestry residues, agricultural wastes, surplus food grains etc. it has huge potential to help the country achieve the renewable energy goal of 175 GW.
- Income Generation: Adopting biofuels as an alternative source of energy can significantly improve farmers’ income, generate employment opportunities etc.
- Reduce Imports: India’s energy demands met by imports are about 46.13% of total primary energy consumption. Bioenergy can help in reducing these imports and boost India’s energy security and self-reliance.
| Various Government Efforts in the Field of Bio-mass Energy National Policy on Biofuels: The policy is aimed at taking forward the indicative target of achieving 20% blending of biofuels with fossil-based fuels by 2025. Policy for Biomass and Bagasse Cogeneration: MNRE has further developed a policy for biomass and bagasse cogeneration that will help in meeting India’s energy demands. It includes financial incentives and subsidies, both for biomass projects and sugar mills that use this technology. 10 GW National Target: Ministry of New and Renewable Energy (MNRE) has set the national target is to achieve 10 GW of installed biomass power by 2022. Waste to energy projects: Waste to energy projects are also being set up for generation of energy from urban, industrial and agricultural waste such as vegetable and other market wastes, slaughterhouse waste, agricultural residues and industrial wastes & effluents. Fiscal Incentives: Government gives 10 years Income tax holidays. Concessional customs and excise duty exemption for machinery and components for initial setting up of Biomass power projects. General sales tax exemption is available in certain States. National Biomass Repository: MNRE also plans on creating a ‘National Biomass Repository’ through a nation-wide appraisal program which will help ensure availability of biofuels produced from domestic feedstock. |
National Mission on Use of Biomass in Coal-based Thermal Power Plants
- To address the issue of air pollution due to farm stubble-burning and to reduce carbon footprints of thermal power generation, the Ministry of Power has decided to set up a National Mission on the use of Biomass in coal-based thermal power plants.
- The proposed National Mission on biomass will also contribute to the National Clean Air Programme (NCAP).
- It would further support the energy transition in the country and our targets to move towards cleaner energy sources.
Objectives of The Mission
- To increase the level of co-firing from the present 5% to higher levels to have a larger share of carbon-neutral power generation from the thermal power plants.
- Biomass co-firing stands for adding biomass as a partial substitute fuel in high efficiency coal boilers.
- To take up R&D activity in boiler design to handle the higher amount of silica, alkalis in the biomass pellets.
- To facilitate overcoming the constraints in the supply chain of biomass pellets and agro- residue and its transport up to the power plants.
- To consider regulatory issues in biomass co-firing.
Advantages of Biomass Energy
- Renewable: Derived from organic, naturally replenishing materials.
- Carbon Neutral: Emits only the carbon it absorbed during its lifecycle.
- Waste Reduction: Utilizes agricultural, industrial, and household waste.
- Energy Security: Reduces dependency on fossil fuels.
- Versatile: Produces electricity, heat, and biofuels.
- Economic Benefits: Creates jobs in rural areas and supports local economies.
- Decentralized Production: Allows energy generation closer to consumption points, reducing transmission losses.
Concerns With Biomass Energy
- Land Use: Large-scale biomass production may compete with food production, leading to land and resource shortages.
- Air Pollution: Burning biomass can release particulate matter and other pollutants.
- Deforestation: Unsustainable harvesting of wood can contribute to deforestation.
- Energy Efficiency: Biomass conversion may be less efficient than other energy sources.
- Carbon Emissions: While carbon-neutral in theory, transportation and processing of biomass can contribute to emissions.
- Cost: High infrastructure and processing costs for biomass energy production.
- Impact on Biodiversity: Large plantations for biomass can negatively affect ecosystems and wildlife.
Way Forward
- The way forward for biomass energy involves enhancing technology to improve efficiency and reduce costs, such as developing advanced biogas systems and second-generation biofuels.
- Strengthening policy support, incentivizing research, and promoting sustainable sourcing of biomass are essential. Expanding infrastructure and integrating biomass with other renewable sources can accelerate its role in achieving energy security and combating climate change.
Conclusion
Biomass energy offers a sustainable, renewable alternative to fossil fuels, helping reduce waste and carbon emissions. It provides economic benefits by creating jobs and promoting energy security. With technological advancements, biomass energy can play a crucial role in a cleaner, more sustainable energy future.
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