UNIT-5
Contents as per syllabus:
1. Biomass
1.1. Biomass as a renewable resource
1.2. Availability of biomass and its conversion theory
1.3. Conversion Theory
1.4. Biogas Plants in India
1.5. Short Answer Questions
1.6. University asked Questions
1.7. MCQs
2. Ocean Thermal Energy Conversion (OTEC)
2.1. Introduction
2.2. How Does Ocean Thermal Energy Conversion Create Electrical Energy?
2.3. Ocean Thermal Energy Conversion Advantages and Disadvantages
2.4. Short Answer Questions
2.5. University asked Questions
2.6. MCQs
3. Wave and Tidal Wave
3.1. Introduction
3.2. Wave Energy Plants
3.3. Tidal Energy Plants
3.4. Short Answer Questions
3.5. University asked Questions
3.6. MCQs
4. Waste Recycling Plants
,1. Biomass
1.1 Biomass as a renewable resource
• Biomass is biological organic matter derived from living or recently living organisms.
• Bioenergy is the energy contained (stored) in biomass.
• Biomass is an extremely important energy source, available nearly everywhere.
• Biomass encompasses a large variety of materials, including wood from various sources, agricultural and
industrial residues, and animal and human waste.
• Two forms of biomass Raw: forestry products, grasses, crops, animal manure, and aquatic products
(seaweed) Secondary: materials that undergone significant changes from raw biomass. Paper, cardboard,
cotton, natural rubber products, and used cooking oils.
1.2 Availability of biomass
Available Biomass sources for energy includes:
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, switch grass, 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
1.3 Conversion Theory
Biomass is converted to energy through various processes, including:
Direct combustion (burning) to produce heat
Thermochemical conversion to produce solid, gaseous, and liquid fuels
Chemical conversion to produce liquid fuels
Biological conversion to produce liquid and gaseous fuels
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 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. They mainly differ in the process temperatures and amount of oxygen
present during the conversion process.
Pyrolysis entails heating organic materials to 800–900oF (400–500 oC) in the near complete absence of free
oxygen. Biomass pyrolysis produces fuels such as charcoal, bio-oil, renewable diesel, methane, and
hydrogen.
, Fig.1. Classification of Biomass Feedstock
Hydro treating is used to process bio-oil (produced by fast pyrolysis) with hydrogen under elevated
temperatures and pressures in the presence of a catalyst to produce renewable diesel, renewable gasoline,
and renewable jet fuel.
Gasification entails heating organic materials to 1,400–1700oF (800–900oC) with injections of controlled
amounts of free oxygen and/or steam into the vessel to produce a carbon monoxide and hydrogen rich gas
called synthesis gas or syngas. Syngas can be used as a fuel for diesel engines, for heating, and for generating
electricity in gas turbines. It can also be treated to separate the hydrogen from the gas, and the hydrogen can
be burned or used in fuel cells. The syngas can be further processed to produce liquid fuels using the Fischer–
Tropsch process.
A chemical conversion process known as transesterification is used for converting vegetable oils, animal
fats, and greases into fatty acid methyl esters (FAME), which are used to produce biodiesel.
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. Properly treated
renewable natural gas has the same uses as fossil fuel natural gas.
Researchers are working on ways to improve these methods and to develop other ways to convert and use
more biomass for energy
Contents as per syllabus:
1. Biomass
1.1. Biomass as a renewable resource
1.2. Availability of biomass and its conversion theory
1.3. Conversion Theory
1.4. Biogas Plants in India
1.5. Short Answer Questions
1.6. University asked Questions
1.7. MCQs
2. Ocean Thermal Energy Conversion (OTEC)
2.1. Introduction
2.2. How Does Ocean Thermal Energy Conversion Create Electrical Energy?
2.3. Ocean Thermal Energy Conversion Advantages and Disadvantages
2.4. Short Answer Questions
2.5. University asked Questions
2.6. MCQs
3. Wave and Tidal Wave
3.1. Introduction
3.2. Wave Energy Plants
3.3. Tidal Energy Plants
3.4. Short Answer Questions
3.5. University asked Questions
3.6. MCQs
4. Waste Recycling Plants
,1. Biomass
1.1 Biomass as a renewable resource
• Biomass is biological organic matter derived from living or recently living organisms.
• Bioenergy is the energy contained (stored) in biomass.
• Biomass is an extremely important energy source, available nearly everywhere.
• Biomass encompasses a large variety of materials, including wood from various sources, agricultural and
industrial residues, and animal and human waste.
• Two forms of biomass Raw: forestry products, grasses, crops, animal manure, and aquatic products
(seaweed) Secondary: materials that undergone significant changes from raw biomass. Paper, cardboard,
cotton, natural rubber products, and used cooking oils.
1.2 Availability of biomass
Available Biomass sources for energy includes:
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, switch grass, 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
1.3 Conversion Theory
Biomass is converted to energy through various processes, including:
Direct combustion (burning) to produce heat
Thermochemical conversion to produce solid, gaseous, and liquid fuels
Chemical conversion to produce liquid fuels
Biological conversion to produce liquid and gaseous fuels
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 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. They mainly differ in the process temperatures and amount of oxygen
present during the conversion process.
Pyrolysis entails heating organic materials to 800–900oF (400–500 oC) in the near complete absence of free
oxygen. Biomass pyrolysis produces fuels such as charcoal, bio-oil, renewable diesel, methane, and
hydrogen.
, Fig.1. Classification of Biomass Feedstock
Hydro treating is used to process bio-oil (produced by fast pyrolysis) with hydrogen under elevated
temperatures and pressures in the presence of a catalyst to produce renewable diesel, renewable gasoline,
and renewable jet fuel.
Gasification entails heating organic materials to 1,400–1700oF (800–900oC) with injections of controlled
amounts of free oxygen and/or steam into the vessel to produce a carbon monoxide and hydrogen rich gas
called synthesis gas or syngas. Syngas can be used as a fuel for diesel engines, for heating, and for generating
electricity in gas turbines. It can also be treated to separate the hydrogen from the gas, and the hydrogen can
be burned or used in fuel cells. The syngas can be further processed to produce liquid fuels using the Fischer–
Tropsch process.
A chemical conversion process known as transesterification is used for converting vegetable oils, animal
fats, and greases into fatty acid methyl esters (FAME), which are used to produce biodiesel.
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. Properly treated
renewable natural gas has the same uses as fossil fuel natural gas.
Researchers are working on ways to improve these methods and to develop other ways to convert and use
more biomass for energy
