This document summarizes a paper on the energy aspects of biomass. It discusses how biomass stores solar energy through photosynthesis, which converts solar energy into chemical energy by using carbon dioxide, water, and sunlight to produce carbohydrates and oxygen. Only about 0.1% of the solar energy that reaches Earth is stored through photosynthesis. The paper also examines the energetics and processes of photosynthesis at different time scales, how energy is absorbed and transferred through antenna systems and reaction centers in chloroplasts, and how chemical energy is ultimately stored in biomass through the reduction of carbon dioxide.
Photosynthesis uses light energy to produce chemical energy in the form of carbohydrates. It occurs in two stages: the light-dependent reactions where light energy is captured to produce ATP and NADPH, and the light-independent reactions where carbon dioxide is fixed into carbohydrates using the ATP and NADPH produced previously. Chlorophyll, located in the thylakoid membranes, absorbs mainly blue and red light for photosynthesis while reflecting green light, giving leaves their green appearance. The chemical energy produced during photosynthesis is then used by organisms for growth, development and other life processes.
The document discusses designing artificial photosynthetic systems inspired by natural photosynthesis. It summarizes the key processes in natural photosynthesis including light absorption, charge separation, and using the energy to fix carbon and reduce NADP+. It also discusses challenges in designing artificial solar energy storage systems, including controlling light harvesting and charge separation/transport while avoiding recombination. Perfect light harvesting systems are outlined as having high absorption, long-lived excited states, and catalytic properties while maintaining stability.
This document provides an overview of cellular metabolism and energy transformation. It discusses key topics including:
1) Metabolism transforms matter and energy in living cells through ordered chemical reactions. Metabolic pathways involve series of enzyme-catalyzed steps that either release (catabolism) or consume (anabolism) energy.
2) ATP is the main energy currency molecule in cells. It is regenerated through catabolic pathways and powers cellular work through exergonic hydrolysis reactions that drive endergonic processes.
3) Enzymes are protein catalysts that lower the activation energy of metabolic reactions, speeding up biochemical transformations without being consumed in the process. They confer specificity to reactions by precisely
1. The document outlines a lecture presentation on cellular respiration and fermentation. It discusses the three stages of cellular respiration - glycolysis, the citric acid cycle, and oxidative phosphorylation.
2. Glycolysis breaks down glucose into pyruvate and generates a small amount of ATP. The citric acid cycle then completes the oxidation of pyruvate and generates more ATP.
3. Oxidative phosphorylation, powered by redox reactions, generates the majority of ATP through chemiosmosis and the electron transport chain in the mitochondria. This three-stage process extracts energy from glucose and other organic molecules to produce ATP.
This document provides an overview of chapter 8 from Campbell Biology, 9th edition, which discusses metabolism. It covers several key topics in 3 paragraphs or less:
Metabolism transforms matter and energy according to the laws of thermodynamics through metabolic pathways mediated by enzymes. Catabolic pathways release energy by breaking down molecules, while anabolic pathways use energy to build molecules. ATP powers cellular work by coupling exergonic reactions to endergonic reactions.
Enzymes speed up metabolic reactions by lowering activation energy. Each enzyme has a specific substrate that binds at its active site, orienting the reactants in a way that facilitates the reaction. Environmental factors like temperature and pH can impact an enzyme's activity by influencing its
1) Cellular respiration involves the breakdown of glucose and other organic molecules to extract energy through redox reactions in the form of ATP.
2) Glycolysis breaks down glucose into two pyruvate molecules in the cytoplasm, generating a small amount of ATP through substrate-level phosphorylation.
3) Pyruvate is further oxidized in the mitochondrion, entering the citric acid cycle which completes the oxidation of pyruvate and generates more ATP and electron carriers like NADH and FADH2.
4) Most ATP is produced through oxidative phosphorylation, as electrons from NADH and FADH2 are passed through an electron transport chain which powers ATP synthesis.
Photosynthesis is the process by which plants, algae, and some bacteria use sunlight, water, and carbon dioxide to produce oxygen and energy-rich organic compounds like glucose. It occurs in two stages: in the light-dependent reactions, sunlight is absorbed and used to split water into hydrogen, oxygen, and ATP; in the light-independent reactions, carbon dioxide is fixed into organic compounds like glucose using energy from ATP and hydrogen. Photosynthesis transformed Earth's early reducing atmosphere into an oxygen-rich one and was crucial for the evolution of complex multicellular life. The rate of photosynthesis is affected by factors like temperature, light intensity, and carbon dioxide concentration.
Photosynthesis uses light energy to produce chemical energy in the form of carbohydrates. It occurs in two stages: the light-dependent reactions where light energy is captured to produce ATP and NADPH, and the light-independent reactions where carbon dioxide is fixed into carbohydrates using the ATP and NADPH produced previously. Chlorophyll, located in the thylakoid membranes, absorbs mainly blue and red light for photosynthesis while reflecting green light, giving leaves their green appearance. The chemical energy produced during photosynthesis is then used by organisms for growth, development and other life processes.
The document discusses designing artificial photosynthetic systems inspired by natural photosynthesis. It summarizes the key processes in natural photosynthesis including light absorption, charge separation, and using the energy to fix carbon and reduce NADP+. It also discusses challenges in designing artificial solar energy storage systems, including controlling light harvesting and charge separation/transport while avoiding recombination. Perfect light harvesting systems are outlined as having high absorption, long-lived excited states, and catalytic properties while maintaining stability.
This document provides an overview of cellular metabolism and energy transformation. It discusses key topics including:
1) Metabolism transforms matter and energy in living cells through ordered chemical reactions. Metabolic pathways involve series of enzyme-catalyzed steps that either release (catabolism) or consume (anabolism) energy.
2) ATP is the main energy currency molecule in cells. It is regenerated through catabolic pathways and powers cellular work through exergonic hydrolysis reactions that drive endergonic processes.
3) Enzymes are protein catalysts that lower the activation energy of metabolic reactions, speeding up biochemical transformations without being consumed in the process. They confer specificity to reactions by precisely
1. The document outlines a lecture presentation on cellular respiration and fermentation. It discusses the three stages of cellular respiration - glycolysis, the citric acid cycle, and oxidative phosphorylation.
2. Glycolysis breaks down glucose into pyruvate and generates a small amount of ATP. The citric acid cycle then completes the oxidation of pyruvate and generates more ATP.
3. Oxidative phosphorylation, powered by redox reactions, generates the majority of ATP through chemiosmosis and the electron transport chain in the mitochondria. This three-stage process extracts energy from glucose and other organic molecules to produce ATP.
This document provides an overview of chapter 8 from Campbell Biology, 9th edition, which discusses metabolism. It covers several key topics in 3 paragraphs or less:
Metabolism transforms matter and energy according to the laws of thermodynamics through metabolic pathways mediated by enzymes. Catabolic pathways release energy by breaking down molecules, while anabolic pathways use energy to build molecules. ATP powers cellular work by coupling exergonic reactions to endergonic reactions.
Enzymes speed up metabolic reactions by lowering activation energy. Each enzyme has a specific substrate that binds at its active site, orienting the reactants in a way that facilitates the reaction. Environmental factors like temperature and pH can impact an enzyme's activity by influencing its
1) Cellular respiration involves the breakdown of glucose and other organic molecules to extract energy through redox reactions in the form of ATP.
2) Glycolysis breaks down glucose into two pyruvate molecules in the cytoplasm, generating a small amount of ATP through substrate-level phosphorylation.
3) Pyruvate is further oxidized in the mitochondrion, entering the citric acid cycle which completes the oxidation of pyruvate and generates more ATP and electron carriers like NADH and FADH2.
4) Most ATP is produced through oxidative phosphorylation, as electrons from NADH and FADH2 are passed through an electron transport chain which powers ATP synthesis.
Photosynthesis is the process by which plants, algae, and some bacteria use sunlight, water, and carbon dioxide to produce oxygen and energy-rich organic compounds like glucose. It occurs in two stages: in the light-dependent reactions, sunlight is absorbed and used to split water into hydrogen, oxygen, and ATP; in the light-independent reactions, carbon dioxide is fixed into organic compounds like glucose using energy from ATP and hydrogen. Photosynthesis transformed Earth's early reducing atmosphere into an oxygen-rich one and was crucial for the evolution of complex multicellular life. The rate of photosynthesis is affected by factors like temperature, light intensity, and carbon dioxide concentration.
Photosynthesis is the biological process by which plants, algae, and some bacteria use sunlight, water and carbon dioxide to produce oxygen and energy-rich organic compounds like sugars and starches. It involves two main reactions - the light reaction which uses light energy to split water into hydrogen and oxygen, and the dark reaction where hydrogen is used to convert carbon dioxide into sugars and starches. Certain conditions like visible light, adequate carbon dioxide levels and temperatures between 0-60°C are required for photosynthesis to take place.
Light energy is converted to chemical energy through photosynthesis. In the light-dependent reactions, light is absorbed by chlorophyll in the thylakoid membranes which generates excited electrons. These electrons are used to produce ATP and NADPH. In the light-independent reactions that occur in the chloroplast stroma, CO2 is fixed into carbohydrates using ATP and NADPH produced in the light reactions. The structure of the chloroplast, including the thylakoid membranes, is adapted to efficiently carry out these photosynthetic reactions.
Single-atom catalysts for biomass-derived drop-in chemicalsPawan Kumar
Conversion of biomass to fuel and drop-in chemicals is envisaged to solve the problem of depleting fossil fuel reserves while leveling-off the staggering CO2 concentration. By-passing the natural carbon cycle via the transformation of abundant lignocellulosic biomass into chemicals does not add any extra CO2 to the environment and the net CO2 concentration remains the same. The paradigm shifts from fossil fuel-based chemicals to biomass-derived products will rely on efficient and cost-effective catalysts that can compete with cheap and readily available fossil fuels. Existing transition and noble metal-based nanoparticle catalysts either in the supported or unsupported form are crippling due to poor activity/selectivity, deactivation of catalytically active sites, and the complex composition, recalcitrant nature, and high moisture content of biomass. Single-atom catalysts (SACs) possessing single-atom centers decorated on support have shown great promise in biomass conversion due to their unique geometric configuration, electronic properties, and ensemble effect. In contrast to traditional catalytic systems, SACs encompass the advantages of both heterogeneous and homogeneous catalysts with improved performance and easy recyclability. Because of the availability of each metal center for the reaction and unique geometrical configuration, SACs have displayed exceptional catalytic activity and selectivity (~95% in most cases). In addition, the SACs show increased thermal and chemical stability due to the stabilization of the metal center on the support. The present chapter highlights the various aspects of SACs for efficient and selective biomass conversion into drop-in chemicals.
The document defines photosynthesis as the process by which plants and algae convert light energy to chemical energy to produce sugars. It occurs in chloroplasts through two stages: the light-dependent reactions where light energy is captured to produce ATP and NADPH, and the light-independent reactions where carbon dioxide is fixed into carbohydrates using the ATP and NADPH. The rate of photosynthesis is affected by light intensity, carbon dioxide concentration, and temperature, with an optimum level for each factor.
The document provides information about photosynthesis including:
1. Photosynthesis is the process by which plants, some bacteria, and some protistans use the energy from sunlight to produce sugar.
2. The primary product of photosynthesis is glucose, which is the source of carbohydrates like cellulose, starches, etc. Photosynthesis also produces oxygen, fats, proteins, and water soluble sugars.
3. Photosynthesis takes place in the chloroplasts of plant leaves. The chloroplasts contain chlorophyll and other pigments that absorb sunlight to drive a series of reactions that produce ATP and NADPH.
1) The document discusses light-dependent (photosynthetic) generators of proton potential, specifically focusing on the photosynthetic apparatus of purple bacteria.
2) Photosynthesis in purple bacteria involves a light-dependent cyclic redox chain where absorption of light by bacteriochlorophyll leads to electron transfer across the membrane, generating a proton gradient.
3) Key components of the redox chain include bacteriochlorophyll dimer and monomer, bacteriopheophytin, ubiquinone, cytochromes, and a nonheme iron-sulfur protein that facilitate electron transfer and proton pumping across the membrane.
Photosynthesis is the process by which plants, algae, and some bacteria use sunlight, water and carbon dioxide to produce oxygen and energy in the form of glucose. It takes place in chloroplasts and involves two stages - the light-dependent reactions where energy from sunlight is captured and converted to chemical energy in the form of ATP and NADPH, and the light-independent reactions where carbon dioxide is fixed into organic compounds like glucose using the ATP and NADPH produced in the light reactions. Many environmental factors like temperature, light intensity, water availability and carbon dioxide concentration can affect the rate of photosynthesis.
Sunlight-driven water-splitting using two dimensional carbon based semiconduc...Pawan Kumar
The overwhelming challenge of depleting fossil fuels and anthropogenic carbon emissions has driven research
into alternative clean sources of energy. To achieve the goal of a carbon neutral economy, the harvesting of
sunlight by using photocatalysts to split water into hydrogen and oxygen is an expedient approach to fulfill
the energy demand in a sustainable way along with reducing the emission of greenhouse gases. Even though
the past few decades have witnessed intensive research into inorganic semiconductor photocatalysts, their
quantum efficiencies for hydrogen production from visible photons remain too low for the large scale
deployment of this technology. Visible light absorption and efficient charge separation are two key necessary
conditions for achieving the scalable production of hydrogen from water. Two-dimensional carbon based
nanoscale materials such as graphene oxide, reduced graphene oxide, carbon nitride, modified 2D carbon
frameworks and their composites have emerged as potential photocatalysts due to their astonishing
properties such as superior charge transport, tunable energy levels and bandgaps, visible light absorption,
high surface area, easy processability, quantum confinement effects, and high photocatalytic quantum yields.
The feasibility of structural and chemical modification to optimize visible light absorption and charge
separation makes carbonaceous semiconductors promising candidates to convert solar energy into chemical
energy. In the present review, we have summarized the recent advances in 2D carbonaceous photocatalysts
with respect to physicochemical and photochemical tuning for solar light mediated hydrogen evolution
Photosynthesis is the process by which plants and other organisms use sunlight, water and carbon dioxide to produce oxygen and energy in the form of glucose. Chlorophyll, located in chloroplasts, absorbs sunlight and uses the energy to convert carbon dioxide and water into oxygen and glucose through a two-step process - the light reactions and Calvin cycle. Plants appear green because chlorophyll, the main photosynthetic pigment, absorbs most wavelengths of visible light except green, which it reflects, giving leaves their green color.
Living things need energy from food to survive. Plants are able to produce their own food through photosynthesis, which uses energy from sunlight, carbon dioxide from the air, and water to produce oxygen and sugars. The sugar glucose can then be stored and used as a source of energy in a cell in the form of ATP molecules, which store and release energy through the addition and removal of phosphate groups.
Photosynthesis is the process by which plants, algae, and some bacteria use sunlight, water and carbon dioxide to produce oxygen and energy in the form of glucose. It requires chlorophyll, carbon dioxide, water, light, and nutrients. There are two stages - the light-dependent reactions where light energy is absorbed and converted to chemical energy, and the light-independent reactions where carbohydrates are produced. The main factors that affect the rate of photosynthesis are light, temperature, and carbon dioxide concentration. Photosynthesis is important as it provides food and oxygen, removes carbon dioxide from the air, and ultimately drives the majority of life on Earth.
This document provides an overview of photosynthesis and summarizes key concepts from Chapter 10 of Campbell Biology. It discusses that photosynthesis converts solar energy to chemical energy through two stages - the light reactions and Calvin cycle. The light reactions use energy from sunlight to produce ATP and NADPH, and involve the photosystems PS I and PS II located in chloroplast thylakoids. The Calvin cycle then uses ATP and NADPH to fix carbon from CO2 into sugars.
Unification of ETP & MFC: Sustainable Development, Environmental Safety, & Re...Abdullah Al Moinee
This document summarizes a presentation given at the 58th IEB Convention in Khulna, Bangladesh on March 5, 2018. The presentation proposed unifying an effluent treatment plant (ETP) and microbial fuel cell (MFC) to achieve sustainable development, environmental safety, and renewable energy generation. Experiments showed an MFC can treat wastewater and remove heavy metals while generating electricity. The proposal aims to integrate an MFC system into the collection tank of an ETP to biologically treat effluent and produce electricity simultaneously. This unified system could provide renewable energy while protecting the environment and recovering valuable metals in a cost-effective way.
Photosynthesis uses light energy to produce glucose from carbon dioxide and water. It consists of light-dependent and light-independent reactions. The light-dependent reactions use chlorophyll to absorb light and generate ATP and NADPH through electron transport. The light-independent reactions use ATP and NADPH to fix carbon and produce glucose. Limiting factors like light intensity, temperature, and carbon dioxide concentration can affect the rate of photosynthesis.
This document provides an overview of photosynthesis and cellular respiration. It begins with an introduction to photosynthesis, noting that it occurs in chloroplasts and uses light to synthesize carbohydrates from carbon dioxide and water. It then discusses the light and dark reactions of photosynthesis, including the roles of ATP and NADPH. The document also describes the Calvin cycle and how it fixes carbon into glucose. It concludes with an introduction to cellular respiration and the different types and mechanisms, including glycolysis, the Krebs cycle, and the electron transport chain.
Cell respiration supplies energy for the functions of life through two main types: aerobic respiration which requires oxygen and gives a large yield of ATP, and anaerobic respiration which does not require oxygen but gives a small yield of ATP. ATP produced through cell respiration is immediately available to the cell as an energy source to power various cellular processes.
The document outlines the process of photosynthesis through 6 main topics: plant structure, pigments and absorbance spectrum, light-dependent reactions, Calvin cycle, and photorespiration. It discusses the key organelles and structures involved in photosynthesis in plant leaves like chloroplasts, stomata, and mesophyll tissue. It also explains the light and dark reactions of photosynthesis, including the light-dependent reaction where light energy is captured and the Calvin cycle where carbon is fixed into glucose.
Water can be split into hydrogen and oxygen through various methods including electrolysis, photolysis, and photoelectrochemical water splitting. Water splitting produces hydrogen which can be used as a renewable fuel and reduces greenhouse gas emissions. Recent research has successfully used an artificial compound called Nafion to split water into hydrogen and oxygen through photoelectrochemical water splitting, demonstrating progress toward replicating natural photosynthesis and providing a clean energy source.
Saving for a Rainy Day discusses the benefits of opening a bank account, such as being able to save extra money earned from a part-time job. The document then provides questions about storing energy in the body and using energy stored in ATP. It concludes with an outline of topics in biochemistry including autotrophs, heterotrophs, and how ATP is used to store and release energy through the addition or removal of phosphate groups.
This document provides information about biochemical processes and molecules involved in living organisms. It discusses how molecular biology explains living processes in terms of chemical substances like carbohydrates, lipids, proteins and nucleic acids. It also describes the roles of anabolism in building complex molecules from simpler ones through condensation reactions, and catabolism in breaking down complex molecules into simpler ones through hydrolysis reactions. Key molecules involved in these processes like glucose, fatty acids, and amino acids are illustrated through molecular diagrams.
Photosynthesis is the biological process by which plants, algae, and some bacteria use sunlight, water and carbon dioxide to produce oxygen and energy-rich organic compounds like sugars and starches. It involves two main reactions - the light reaction which uses light energy to split water into hydrogen and oxygen, and the dark reaction where hydrogen is used to convert carbon dioxide into sugars and starches. Certain conditions like visible light, adequate carbon dioxide levels and temperatures between 0-60°C are required for photosynthesis to take place.
Light energy is converted to chemical energy through photosynthesis. In the light-dependent reactions, light is absorbed by chlorophyll in the thylakoid membranes which generates excited electrons. These electrons are used to produce ATP and NADPH. In the light-independent reactions that occur in the chloroplast stroma, CO2 is fixed into carbohydrates using ATP and NADPH produced in the light reactions. The structure of the chloroplast, including the thylakoid membranes, is adapted to efficiently carry out these photosynthetic reactions.
Single-atom catalysts for biomass-derived drop-in chemicalsPawan Kumar
Conversion of biomass to fuel and drop-in chemicals is envisaged to solve the problem of depleting fossil fuel reserves while leveling-off the staggering CO2 concentration. By-passing the natural carbon cycle via the transformation of abundant lignocellulosic biomass into chemicals does not add any extra CO2 to the environment and the net CO2 concentration remains the same. The paradigm shifts from fossil fuel-based chemicals to biomass-derived products will rely on efficient and cost-effective catalysts that can compete with cheap and readily available fossil fuels. Existing transition and noble metal-based nanoparticle catalysts either in the supported or unsupported form are crippling due to poor activity/selectivity, deactivation of catalytically active sites, and the complex composition, recalcitrant nature, and high moisture content of biomass. Single-atom catalysts (SACs) possessing single-atom centers decorated on support have shown great promise in biomass conversion due to their unique geometric configuration, electronic properties, and ensemble effect. In contrast to traditional catalytic systems, SACs encompass the advantages of both heterogeneous and homogeneous catalysts with improved performance and easy recyclability. Because of the availability of each metal center for the reaction and unique geometrical configuration, SACs have displayed exceptional catalytic activity and selectivity (~95% in most cases). In addition, the SACs show increased thermal and chemical stability due to the stabilization of the metal center on the support. The present chapter highlights the various aspects of SACs for efficient and selective biomass conversion into drop-in chemicals.
The document defines photosynthesis as the process by which plants and algae convert light energy to chemical energy to produce sugars. It occurs in chloroplasts through two stages: the light-dependent reactions where light energy is captured to produce ATP and NADPH, and the light-independent reactions where carbon dioxide is fixed into carbohydrates using the ATP and NADPH. The rate of photosynthesis is affected by light intensity, carbon dioxide concentration, and temperature, with an optimum level for each factor.
The document provides information about photosynthesis including:
1. Photosynthesis is the process by which plants, some bacteria, and some protistans use the energy from sunlight to produce sugar.
2. The primary product of photosynthesis is glucose, which is the source of carbohydrates like cellulose, starches, etc. Photosynthesis also produces oxygen, fats, proteins, and water soluble sugars.
3. Photosynthesis takes place in the chloroplasts of plant leaves. The chloroplasts contain chlorophyll and other pigments that absorb sunlight to drive a series of reactions that produce ATP and NADPH.
1) The document discusses light-dependent (photosynthetic) generators of proton potential, specifically focusing on the photosynthetic apparatus of purple bacteria.
2) Photosynthesis in purple bacteria involves a light-dependent cyclic redox chain where absorption of light by bacteriochlorophyll leads to electron transfer across the membrane, generating a proton gradient.
3) Key components of the redox chain include bacteriochlorophyll dimer and monomer, bacteriopheophytin, ubiquinone, cytochromes, and a nonheme iron-sulfur protein that facilitate electron transfer and proton pumping across the membrane.
Photosynthesis is the process by which plants, algae, and some bacteria use sunlight, water and carbon dioxide to produce oxygen and energy in the form of glucose. It takes place in chloroplasts and involves two stages - the light-dependent reactions where energy from sunlight is captured and converted to chemical energy in the form of ATP and NADPH, and the light-independent reactions where carbon dioxide is fixed into organic compounds like glucose using the ATP and NADPH produced in the light reactions. Many environmental factors like temperature, light intensity, water availability and carbon dioxide concentration can affect the rate of photosynthesis.
Sunlight-driven water-splitting using two dimensional carbon based semiconduc...Pawan Kumar
The overwhelming challenge of depleting fossil fuels and anthropogenic carbon emissions has driven research
into alternative clean sources of energy. To achieve the goal of a carbon neutral economy, the harvesting of
sunlight by using photocatalysts to split water into hydrogen and oxygen is an expedient approach to fulfill
the energy demand in a sustainable way along with reducing the emission of greenhouse gases. Even though
the past few decades have witnessed intensive research into inorganic semiconductor photocatalysts, their
quantum efficiencies for hydrogen production from visible photons remain too low for the large scale
deployment of this technology. Visible light absorption and efficient charge separation are two key necessary
conditions for achieving the scalable production of hydrogen from water. Two-dimensional carbon based
nanoscale materials such as graphene oxide, reduced graphene oxide, carbon nitride, modified 2D carbon
frameworks and their composites have emerged as potential photocatalysts due to their astonishing
properties such as superior charge transport, tunable energy levels and bandgaps, visible light absorption,
high surface area, easy processability, quantum confinement effects, and high photocatalytic quantum yields.
The feasibility of structural and chemical modification to optimize visible light absorption and charge
separation makes carbonaceous semiconductors promising candidates to convert solar energy into chemical
energy. In the present review, we have summarized the recent advances in 2D carbonaceous photocatalysts
with respect to physicochemical and photochemical tuning for solar light mediated hydrogen evolution
Photosynthesis is the process by which plants and other organisms use sunlight, water and carbon dioxide to produce oxygen and energy in the form of glucose. Chlorophyll, located in chloroplasts, absorbs sunlight and uses the energy to convert carbon dioxide and water into oxygen and glucose through a two-step process - the light reactions and Calvin cycle. Plants appear green because chlorophyll, the main photosynthetic pigment, absorbs most wavelengths of visible light except green, which it reflects, giving leaves their green color.
Living things need energy from food to survive. Plants are able to produce their own food through photosynthesis, which uses energy from sunlight, carbon dioxide from the air, and water to produce oxygen and sugars. The sugar glucose can then be stored and used as a source of energy in a cell in the form of ATP molecules, which store and release energy through the addition and removal of phosphate groups.
Photosynthesis is the process by which plants, algae, and some bacteria use sunlight, water and carbon dioxide to produce oxygen and energy in the form of glucose. It requires chlorophyll, carbon dioxide, water, light, and nutrients. There are two stages - the light-dependent reactions where light energy is absorbed and converted to chemical energy, and the light-independent reactions where carbohydrates are produced. The main factors that affect the rate of photosynthesis are light, temperature, and carbon dioxide concentration. Photosynthesis is important as it provides food and oxygen, removes carbon dioxide from the air, and ultimately drives the majority of life on Earth.
This document provides an overview of photosynthesis and summarizes key concepts from Chapter 10 of Campbell Biology. It discusses that photosynthesis converts solar energy to chemical energy through two stages - the light reactions and Calvin cycle. The light reactions use energy from sunlight to produce ATP and NADPH, and involve the photosystems PS I and PS II located in chloroplast thylakoids. The Calvin cycle then uses ATP and NADPH to fix carbon from CO2 into sugars.
Unification of ETP & MFC: Sustainable Development, Environmental Safety, & Re...Abdullah Al Moinee
This document summarizes a presentation given at the 58th IEB Convention in Khulna, Bangladesh on March 5, 2018. The presentation proposed unifying an effluent treatment plant (ETP) and microbial fuel cell (MFC) to achieve sustainable development, environmental safety, and renewable energy generation. Experiments showed an MFC can treat wastewater and remove heavy metals while generating electricity. The proposal aims to integrate an MFC system into the collection tank of an ETP to biologically treat effluent and produce electricity simultaneously. This unified system could provide renewable energy while protecting the environment and recovering valuable metals in a cost-effective way.
Photosynthesis uses light energy to produce glucose from carbon dioxide and water. It consists of light-dependent and light-independent reactions. The light-dependent reactions use chlorophyll to absorb light and generate ATP and NADPH through electron transport. The light-independent reactions use ATP and NADPH to fix carbon and produce glucose. Limiting factors like light intensity, temperature, and carbon dioxide concentration can affect the rate of photosynthesis.
This document provides an overview of photosynthesis and cellular respiration. It begins with an introduction to photosynthesis, noting that it occurs in chloroplasts and uses light to synthesize carbohydrates from carbon dioxide and water. It then discusses the light and dark reactions of photosynthesis, including the roles of ATP and NADPH. The document also describes the Calvin cycle and how it fixes carbon into glucose. It concludes with an introduction to cellular respiration and the different types and mechanisms, including glycolysis, the Krebs cycle, and the electron transport chain.
Cell respiration supplies energy for the functions of life through two main types: aerobic respiration which requires oxygen and gives a large yield of ATP, and anaerobic respiration which does not require oxygen but gives a small yield of ATP. ATP produced through cell respiration is immediately available to the cell as an energy source to power various cellular processes.
The document outlines the process of photosynthesis through 6 main topics: plant structure, pigments and absorbance spectrum, light-dependent reactions, Calvin cycle, and photorespiration. It discusses the key organelles and structures involved in photosynthesis in plant leaves like chloroplasts, stomata, and mesophyll tissue. It also explains the light and dark reactions of photosynthesis, including the light-dependent reaction where light energy is captured and the Calvin cycle where carbon is fixed into glucose.
Water can be split into hydrogen and oxygen through various methods including electrolysis, photolysis, and photoelectrochemical water splitting. Water splitting produces hydrogen which can be used as a renewable fuel and reduces greenhouse gas emissions. Recent research has successfully used an artificial compound called Nafion to split water into hydrogen and oxygen through photoelectrochemical water splitting, demonstrating progress toward replicating natural photosynthesis and providing a clean energy source.
Saving for a Rainy Day discusses the benefits of opening a bank account, such as being able to save extra money earned from a part-time job. The document then provides questions about storing energy in the body and using energy stored in ATP. It concludes with an outline of topics in biochemistry including autotrophs, heterotrophs, and how ATP is used to store and release energy through the addition or removal of phosphate groups.
This document provides information about biochemical processes and molecules involved in living organisms. It discusses how molecular biology explains living processes in terms of chemical substances like carbohydrates, lipids, proteins and nucleic acids. It also describes the roles of anabolism in building complex molecules from simpler ones through condensation reactions, and catabolism in breaking down complex molecules into simpler ones through hydrolysis reactions. Key molecules involved in these processes like glucose, fatty acids, and amino acids are illustrated through molecular diagrams.
Este documento describe diferentes tipos de búsquedas que se pueden realizar, incluyendo búsquedas básicas, denotar frases, especificar palabras clave, excluir términos, buscar variantes y enlazar a sitios web específicos. También cubre cómo buscar archivos PDF.
This document discusses a comparative analysis of non-performing assets (NPAs) through rising asset levels conducted by Savio Basimalla at Thane Janata Sahakari Bank. It includes a declaration, certificate of completion, acknowledgements, table of contents, and executive summary describing the structure of the Indian banking sector and issues considered in reviewing and revising the banking structure. Key topics discussed include small banks vs large banks, universal banking models, continuous authorization of new banks, converting urban cooperative banks, bank consolidation, presence of foreign banks in India, and Indian banks' presence overseas.
Este documento discute la importancia de las competencias laborales en la gestión de recursos humanos. Explica que la gestión por competencias ayuda a las personas y organizaciones a alcanzar la excelencia alineando las habilidades de los empleados con las necesidades del negocio. También describe cómo las competencias se definen en términos de comportamientos observables y cómo pueden usarse para la selección de personal y el desarrollo de los empleados. Finalmente, señala que aunque los modelos de competencias pueden adaptarse, no se pueden aplicar direct
Este documento proporciona 7 pasos para insertar un documento Word en un blog: 1) registrarse en SlideShare, 2) iniciar sesión a través de Facebook o registro, 3) hacer clic en "subir" para seleccionar y subir el archivo, 4) completar los metadatos y asegurarse de que sea público, 5) hacer clic en "compartir", 6) copiar el código de inserción, y 7) pegar el código en el HTML del blog.
Este documento discute valores ágeis e reflexões sobre carreira e desenvolvimento pessoal. Apresenta a história da engenharia de software e a evolução para metodologias ágeis, destacando valores como indivíduos e interações, software funcionando, colaboração com o cliente e resposta a mudanças. Reflete sobre competências como colaboração, resiliência e métricas pessoais para navegar em direção a novos destinos na carreira.
This document discusses new features in HTML5 for validating user input data, including new form field types like numbers, dates, URLs and emails; new form elements like <output> and <datalist>; and new attributes for validation like required, min, max, and pattern. It also briefly mentions CSS, APIs, Ajax, and provides some useful links for learning more about HTML5 validation features and standards.
El documento proporciona instrucciones para crear entradas de blog para cada módulo de trabajo. Indica que se debe hacer clic en "añadir entrada de blog" una sola vez y realizar todas las actividades de un módulo en esa entrada, luego crear una nueva entrada para el siguiente módulo. También explica cómo eliminar una entrada existente haciendo clic en el enlace "eliminar".
Characterization of metals machined using EDM.
Machining on materials - SS304, D2 ; EDM Machine - Sparkonix SN25 ; Study on MRR, Hardness, Roughness, Grain Size with Voltage, Current, Lift as working parameters.
This curriculum vitae is for Numan Saeed, who is seeking a challenging position that utilizes his skills and education. He has a two-year bachelor's degree in electronics and diploma in electrical engineering. His professional experience includes over 5 years working for PTCL installing broadband and TV connections and resolving faults. He also has experience as a service engineer repairing cash machines and as an electrical supervisor. His computer skills include Microsoft Office, hardware maintenance, and graphic design software. He is fluent in English, Urdu, and Pashto.
Este documento fornece uma introdução à anatomia humana, definindo-a como a ciência que estuda a constituição e desenvolvimento do organismo humano. Descreve como a anatomia é dividida em macroscópica e microscópica e em sistêmica, regional e clínica. Também define termos importantes como posição anatômica, planos anatômicos, eixos e termos de movimento e fornece uma visão geral da divisão do corpo humano e do esqueleto.
Este documento resume diferentes técnicas de mercadeo orientadas al cliente individual como el marketing one to one, el marketing de atracción y retención de clientes, y el marketing de recomendaciones. Explica que estas técnicas se enfocan en el cliente más que en el producto, aprendiendo sobre las necesidades e insatisfacciones individuales para ofrecer productos personalizados que generen atracción, fidelización y recomendaciones entre los clientes.
El Perú se ubica en la parte central y occidental de América del Sur, con capital en Lima. El país tiene como idiomas oficiales el español y quechua y aymara como cooficiales, y su moneda es el Nuevo Sol. El Perú obtuvo su independencia de España en 1821 y actualmente su constitución vigente data de 1993.
Este documento describe un proyecto para crear un blog turístico sobre Bogotá, Colombia. El blog tiene como objetivo principal proporcionar información concisa sobre los principales sitios turísticos de la ciudad para extranjeros que visitan y luchan con barreras de idioma. El documento justifica la necesidad del blog debido al gran flujo de turistas extranjeros en Bogotá y analiza algunos de los destinos más populares como museos, parques y atracciones que se incluirían en el blog.
The document provides an overview of photosynthesis, including:
1) Photosynthesis uses light energy from the sun to convert carbon dioxide and water into sugars and oxygen through a two-stage process of light-dependent and light-independent reactions.
2) The light reactions convert solar energy to chemical energy stored in ATP and NADPH. The Calvin cycle then uses this chemical energy to fix carbon from carbon dioxide into sugars.
3) Two photosystems, Photosystem I and Photosystem II, work together to drive electron transport and generate a proton gradient used to produce ATP through chemiosmosis.
Cell chemistry and Biosynthesis
catalysis and the use of energy by cells
We now know there is nothing in living organisms that disobeys chemical and physical laws. However, the chemistry of life is indeed of a special kind. First, it is based overwhelmingly on carbon compounds, whose study is therefore known as organic chemistry. Second, cells are 70 percent water, and life depends almost exclusively on chemical reactions that take place in aqueous solution. Third, and most importantly, cell chemistry is enormously complex: even the simplest cell is vastly more complicated in its chemistry than any other chemical system known. Although cells contain a variety of small carbon-containing molecules, most of the carbon atoms in cells are incorporated into enormous polymeric molecules—chains of chemical subunits linked end-to-end. It is the unique properties of these macromolecules that enable cells and organisms to grow and reproduce—as well as to do all the other things that are characteristic of life
Photosynthesis involves multiple light-dependent and light-independent reactions. The light-dependent reactions use pigments like chlorophyll to absorb light energy which is used to power electron transport and generate ATP and NADPH. This occurs through two photosystems that facilitate electron transfer, with photosystem II initiating the process by splitting water. Cytochrome b6f and other proteins mediate electron transfer between the photosystems. The light-independent Calvin cycle then uses ATP and NADPH to fix carbon from CO2 into glucose.
Photosynthesis is the process by which plants use sunlight, carbon dioxide and water to produce oxygen and energy in the form of glucose. It occurs through two stages - the light-dependent reactions where ATP and NADPH are produced, and the light-independent Calvin cycle where glucose is produced. All living organisms ultimately depend on photosynthesis, which takes place primarily in the chloroplasts of plant leaves using the pigments chlorophyll a and b. The rate of photosynthesis is affected by factors like light intensity, carbon dioxide concentration, temperature and water availability.
1. Photosynthesis occurs in leaves through two stages - the light dependent and light independent reactions.
2. In the light dependent reactions, light energy is captured by chloroplasts and used to convert carbon dioxide and water into oxygen and energy carriers (ATP and NADPH).
3. The light independent reactions, known as the Calvin cycle, use the energy from ATP and NADPH to fix carbon from carbon dioxide into sugars.
1. Photosynthesis is the process by which plants use sunlight, carbon dioxide, and water to produce oxygen and energy in the form of sugar.
2. It takes place in chloroplasts, which contain chlorophyll and other pigments to absorb sunlight and drive a series of chemical reactions.
3. Photosynthesis has two stages: the light reactions where sunlight is absorbed and used to produce ATP and NADPH, and the dark reactions where carbon dioxide is fixed into sugars using ATP and NADPH produced in the light reactions.
The document summarizes key concepts about photosynthesis and cellular respiration. Photosynthesis uses sunlight, carbon dioxide, and water to produce oxygen and glucose through two stages - the light reaction and Calvin cycle. Cellular respiration breaks down glucose to release energy through glycolysis, the Krebs cycle in the mitochondria, and the electron transport chain, using oxygen as the final electron acceptor to produce water. Both processes involve the production and consumption of ATP as an energy carrier.
Photosynthesis occurs in chloroplasts and involves two main stages. In the light-dependent reactions, chlorophyll absorbs light energy which splits water molecules into oxygen, protons, and electrons. The Calvin cycle then uses these products to convert carbon dioxide into glucose through chemical reactions, producing oxygen as a byproduct. Photosynthesis is essential as it is how energy from the sun is captured and stored as chemical energy in sugars, the primary food source for most living things.
CELLULAR METABOLISM AND METABOLIC DISORDERS.pptxMurtiKiya
This document discusses cellular metabolism and metabolic disorders. It begins by explaining that cellular metabolism involves enzyme-mediated chemical reactions that allow cells to carry out functions. Metabolism is divided into catabolic and anabolic reactions. The major classes of metabolites are then described. Subsequent sections discuss enzymes and their role in metabolism, including classifications of enzymes and factors that affect enzymatic activity. Cellular respiration and its stages of glycolysis, the Krebs cycle, and the electron transport chain are then outlined. Biosynthesis, photosynthesis, and the organelles and processes involved are also summarized. Risk factors for metabolic disorders and the criteria for a metabolic syndrome diagnosis are presented.
“Microbial Biomass” A Renewable Energy For The FutureAnik Banik
The document discusses microbial biomass and its applications in bioenergy production. It describes how microbial biomass from bacteria, fungi and algae can be used to produce biofuels through various processes like microbial fuel cells and hydrogen production. Microbial fuel cells generate electricity from organic matter by transferring electrons to anode with the help of exoelectrogenic bacteria. Cyanobacteria can also produce hydrogen through nitrogenase enzyme or soluble hydrogenase. The document further discusses biodiesel production from oleaginous fungi which have the ability to accumulate high lipids under stress.
Photosynthesis is the process by which plants, algae, and some bacteria use sunlight, water, and carbon dioxide to produce oxygen and energy in the form of glucose. Chlorophyll in the chloroplasts absorbs light which is used to convert carbon dioxide and water into oxygen and energy-storing molecules like glucose. The byproducts of photosynthesis like oxygen and glucose are essential for other organisms to survive.
1) The document discusses light-dependent (photosynthetic) generators of proton potential, specifically focusing on the photosynthetic apparatus of purple bacteria.
2) Photosynthesis in purple bacteria involves a light-dependent cyclic redox chain where absorption of light by bacteriochlorophyll leads to electron transfer across the membrane, generating a proton gradient.
3) Key components of the redox chain include bacteriochlorophyll dimer and monomer, bacteriopheophytin, ubiquinone, cytochromes, and a nonheme iron-sulfur protein that facilitate electron transfer and proton pumping across the membrane.
The document summarizes key aspects of photosynthesis. It describes that photosynthesis occurs in plants, algae, and certain microorganisms, which use light energy to synthesize organic molecules from carbon dioxide and water. The two main stages are the light reactions, which convert solar energy to chemical energy in ATP and NADPH, and the Calvin cycle, which uses these products to fix carbon into sugars like glucose.
The document discusses biological oxidation and the electron transport chain. It covers topics like the stages of foodstuff oxidation, redox potentials, enzymes and co-enzymes in biological oxidation, high energy compounds, the organization of the electron transport chain, oxidative phosphorylation, and ATP synthesis. It notes that food is broken down and oxidized to generate reducing equivalents like NADH and FADH2, which then enter the electron transport chain to release energy that is used to synthesize ATP through oxidative phosphorylation.
Catalyst Advancements in Microbial Fuel Cells: Pioneering Renewable Energy So...piyushpandey409164
Microbial Fuel Cells (MFCs) harness the power of microorganisms to convert organic matter into electricity while treating wastewater. By utilizing various biomass sources like wood, food waste, and sewage sludge, MFCs offer a sustainable solution for renewable energy production without competing with food sources. Originally conceptualized in 1911 by Potter, MFC technology has evolved, utilizing catalysts like Escherichia coli and Saccharomyces cerevisiae, and electrodes such as platinum. Over time, advancements have led to the elimination of artificial mediators, with bacteria directly transferring electrons to electrodes. MFCs stand as a promising avenue for clean energy generation, aligning with the imperative to mitigate climate change and reduce reliance on fossil fuels.
Photosynthesis is the process by which plants, algae, and some bacteria use sunlight, carbon dioxide, and water to produce oxygen and energy in the form of glucose. It occurs in two stages - the light-dependent reactions and the Calvin cycle. The light-dependent reactions use energy from sunlight to convert water to oxygen and produce ATP and NADPH. The Calvin cycle then uses the ATP and NADPH to fix carbon from carbon dioxide into organic molecules like glucose. Photosynthesis is essential for life as it produces the oxygen and food on which nearly all organisms depend.
Photosynthesis is the process by which plants use sunlight, water and carbon dioxide to produce oxygen and energy in the form of sugar. It takes place in the chloroplasts of plant leaves using the green pigment chlorophyll. Chlorophyll absorbs sunlight which is used to convert water and carbon dioxide into oxygen and glucose through a pair of light-dependent and light-independent reactions. This process provides a crucial source of food for plants and oxygen for animals and is essential for life on Earth.
This document provides an overview of cellular respiration. It discusses three key stages: glycolysis, the citric acid cycle, and the electron transport chain/oxidative phosphorylation. Glycolysis breaks down glucose into pyruvate and occurs in the cytoplasm. The citric acid cycle further breaks down pyruvate in the mitochondrial matrix. During these stages, electrons are transferred to NAD+ to form NADH. The electron transport chain passes the electrons from NADH to oxygen to form water, extracting energy to synthesize ATP through oxidative phosphorylation. In total, respiration generates up to 38 ATP molecules from each glucose molecule.
Intervention Material in Science (PHOTOSYNTHESIS)John Echon
Photosynthesis is a two-stage process where plants, algae, and other organisms capture light energy from the sun and convert it into chemical energy. In the light-dependent reaction, light energy is absorbed by chlorophyll and passed through an electron transport chain to produce ATP and NADPH. Water is split to release oxygen as a byproduct. In the light-independent reaction, ATP and NADPH are used to fix carbon from carbon dioxide into sugars. The overall photosynthesis equation shows carbon dioxide and water being converted into glucose and oxygen using energy from sunlight.
The document discusses photosynthesis and provides an overview of the key processes and structures involved. It explains that photosynthesis uses carbon dioxide, water and sunlight to produce sugars and oxygen. The light-dependent reactions use energy from sunlight to produce ATP and NADPH, using the thylakoid membranes and photosystems in chloroplasts. The light-independent reactions then use the ATP and NADPH to fix carbon and produce sugars.
The document summarizes the potential for wave energy power plants along the coast of Maharashtra, India. It finds that the 720km Maharashtra coast has an average annual wave potential of 5-8 kW/m, and monsoon potential of 15-20 kW/m, totaling around 500MW of potential wave energy. Several suitable sites for plants are identified, such as Vengurla rocks and Malvan rocks, with the highest potential of 8-20 kW/m. While wave energy technology is still developing, oscillating water column converters have shown promise. To exploit this resource, the document proposes inviting private investors to build and operate wave plants by providing land and infrastructure support.
The document analyzes the potential for geothermal power generation in Maharashtra, India. It finds that while Maharashtra has some hot springs with surface temperatures up to 71°C, these temperatures are too low for commercial power production. Deeper drilling would be required to determine if higher temperature reservoirs exist at depths greater than 1 km, but costs are projected to be very high. Based on the geology and absence of volcanic activity, it is unlikely that high temperature hot rocks could be accessed. While direct thermal uses of the low-temperature springs are possible, geothermal power generation in Maharashtra does not appear commercially viable with current technology and known resource temperatures.
This document discusses waste-to-energy projects in India. It provides information on different types of waste like municipal solid waste and industrial waste that can be used to generate energy. Municipal solid waste contains enough organic matter to produce energy through processes like composting and power generation. Power generation is seen as a better option than composting as it has established markets and is less prone to issues like foul smells. Private partnerships are recommended for implementing waste-to-energy plants as they require significant capital investments. Certain industrial wastes from sectors like food processing and distilleries also contain enough organic matter to feasibly produce energy.
Sanitary landfills are a technology for converting municipal solid waste to energy through controlled waste disposal that allows for faster waste decomposition and methane gas collection. Methane gas is collected from the landfill and can be used to generate electricity by powering internal combustion engines or gas turbines. While ordinary landfilling pollutes groundwater and air, sanitary landfills utilize liners and controls to prevent pollution and allow methane to be captured and utilized as an energy source.
Fuel cells were first discovered in 1838 and demonstrated in 1839. Various improvements were made throughout the 1900s leading to their use in NASA space missions starting in the 1960s. Fuel cells work through an electrochemical reaction of hydrogen and oxygen to produce electricity, heat, and water. They have advantages over combustion engines like higher efficiency and lower emissions. There are different types of fuel cells that are distinguished by their electrolyte, including PEM, alkaline, phosphoric acid, molten carbonate, and solid oxide fuel cells. Fuel cells are being developed for applications in transportation, backup power, and portable power and may eventually replace combustion engines and power grids.
1. Proc. Sem. "Biomass Energy" 25th
March, 1989, Kolhapur, India
(Eds.) S. H. Pawar, L. J. Bhosale, A. B. Sabale and S. K. Goel
Published by Shivaji University, Kolhapur, Printed in 1990 (1-19)
THE ENERGY ASPECTS OF BIOMASS
SUDHIR KUMAR and S. H. PAWAR
Biomass Research Centre
Physics Department
Shivaji University, Kolhapur 416 004
ABSTRACT
The concept of biomass as a storage of solar energy has been elaborated.
The role of energy in the formation, propagation and utilization of biomass has
been discussed with special reference to wood energy. Fuel values of different
biomass can be predicted from their basic chemical constitution. The gross, net
and usable heat contents of wood with respect to moisture content has been
defined. Energetics of biomass conversion processes such as drying,
classification, pyrolysis, gasification, liquefaction and combustion are discussed.
It is proposed that field estimation of biomass energy should be carried out with
some precautions to avoid the over or under estimation.
1. INTRODUCTION:
Although using the biomass as energy source had been the age-old
practice, it had drawn little attention of scientists and technologists until recently
when imminent energy crisis was felt strongly all over the world. However,
biomass fuels are more difficult to study than their counterparts are. The
complexity of the subject is due to its highly interdisciplinary nature. The
agronomists, biologists, environmentalists and biomass conversion technologists
all have to work together with the aim of solving the energy crisis through the
biomass route. Fortunately, there is one term common to all; and that is
"energy". It is therefore appropriate to have a closer look into the involvement of
energy in biomass formation, propagation and utilization.
Energy can be defined as the measure of the ability to do work. The
ability can be decided not only by the extent but by the quality also. In common
language, the quality of energy is decided by1
(a) fuels ability to do work, (b)
maximum temperature a fuel can create and (c) flexibility with which it can be
used. Scientifically, the quality is measured by the thermodynamic term
"entropy" the degree of disorder. Lower the entropy higher is the quality of
energy. The priority order of the quality is given as:
Mechanical energy = Electrical energy > Chemical energy > Heat energy
Mechanical energy is completely ordered and heat energy is disordered. Energy
conversion increases the entropy and degrades the fuel quality. Conversion of
high quality to high quality energy is highly efficient process. Heat energy can
also be high quality energy if it is dissipated at very high temperature. Biomass
energy comes in the category of chemical energy. Production of biomass is in
fact the conversion of solar energy into chemical energy through photosynthetic
route.
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2. 2. SOLAR ENERGY AND BIOMASS:
Sunlight is a form of heat energy whose quality is extremely high because
of Sun's high temperature (5760 0
C). We receive only 2.4 x 10-6
% of the total
Sun's radiation. Out of the total radiation incident above our atmosphere, 35% is
reflected, 17.5% absorbed by the atmosphere and cloud and only 47.5% enters
our biosphere level. On an average 3 x 1024
Joules/year solar energy reaches
our earth. Total aquatic and terrestrial biomass production is estimated to be 3 x
1021
Joules/year. Thus, only 0.1% of the incident solar energy is stored
photosynthetically. Of the remaining incident energy 30% is reflected, 49% is
lost as heat of water vaporization to drive the hydrological cycle and 21% as low-
grade heat, which due to differential absorption causes the wind currents. Thus,
solar energy maintains ecological balance on earth besides producing biomass
by the route of photosynthesis.
2.1 THE PHOTOSYNTHETIC PROCESS
Photosynthesis in a green plant is the process in which sunlight is
captured by pigment molecules and, through a sequence of primary and
secondary reaction initiated by the excited chlorophyll reaction centers; it is
transformed into stored chemical energy2
.
The overall reaction is summarized as the transfer of hydrogen atoms
from water to carbon dioxide to form carbohydrate with liberation of oxygen.
Sunlight
n CO2 + n H2O n O2 + (CH2O)n
ChlorophyII
The low energy content molecules CO2 and H2O form an energy rich
molecule carbohydrate with the help of solar energy. The carbohydrate finally
promotes the metabolic and structural functions during the growth of plant.
Apparently, photosynthesis is the root cause of biomass production.
The photosynthetic process occurs in three main steps with different time
domains2,3
.
(1) 10-14
- 10-12
seconds
Initial light absorption by photosynthetic antenna pigments and transfer of
energy to reaction centre pigments.
(2) 10-9
seconds
Photo-oxidation of reaction centre pigments.
(3) 1 second
Chemical transfer of photo excited electrons via enzymes which finally
results in the reduction of carbon-dioxide by water. The pigment molecule is also
regenerated in its ground state within this period.
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3. 2.2 ENERGETICS OF PHOTOSYNTHESIS
Energy in biomass is stored in the form of bond energy. Energy liberated
when two atoms become attached to each other is called bond energy. Higher
the bond energy greater is the energy released during the formation of bond. In
general, energy is stored in a process when weaker bonds are formed at the
expense of strong bonds. Energy storage in photosynthesis occurs by formation
of 0-0 bonds (-58 K.Cal./mole) and by destruction of O-H bonds (-110
K.Cal./mole) and C-O bonds (-95 K.Cal./mole) as shown below (an endothermic
reaction).
CO2 + H2 → O2 + CH2O + 110 K.Cal/mole
O H O H
190 110 92
190
C + O 116 + C O + 110 K.Cal/mole
190 110 92
O H O H
Let us now have a look at the energetics of three different photosynthetic
steps.
(I) In the first step, the light absorption can be maximized by fulfilling the
following two conditions:
a) Largest possible area should be exposed to sunlight.
b) The absorbent should absorb light over wide frequency range of
visible light.
In green plants, photosynthesis is confined to the membranous organelles
called Chloroplasts. The number of chloroplasts varies from 1 to 1000 per
eucaryotic cell depending on the plant type. Nature fulfills both the above-
mentioned conditions by subdividing the chloroplasts into photosynthetic units
each containing about 300 pigment molecules and a single reaction centre.
These pigment molecules (carotenoids, phycoerythrin, phycocyanin and various
chlorophylls) absorb light in wide frequency range of white light (Fig.1). A
pigment molecule after absorbing light, reaches highly energized and unstable
state. It gives out the excitation energy to the host system by coming back to its
ground state. The structure of each photosynthetic unit is like antenna system
i.e. energy funnel. The typical spatial arrangement of these units (Fig.2)
increases the effective surface area. The absorbed solar energy is efficiently
migrated to the reaction centre at the other end of antenna system to carry out
further photo-oxidation.
(II) The second step i.e. photo-oxidation means ejection of electrons from
water molecules to produce H+
ions needed for CO2 reduction. Thus, a
photosynthetic reaction can be considered as an electrochemical oxidation-
reduction reaction:
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4. light
2H2O O2 + 4H+
+ 4e-
Eo = + 0.81 Volts
H H H
Dark
CO2 + 4H+
+ 4e-
O - C - O
H
CH2O + H2O Eo = - 0.40 Volts
Where Eo is the standard electrochemical potential of the given reaction at
normal hydrogen electrode (NHE) scale. This photo-oxidation reaction is carried
out by the involvement of various different intermediate enzymatic reaction
sequences. During this reaction, the biological energy packet ATP (Adenosine
Tri Phosphate) and strong reduction NADPH (Nicotinamide Dinucleotide
Phosphates) are also obtained as byproduct besides the main product H+
. The
universal energy packet ATP is in fact the ester of phosphoric acid.
O O O
AR - O - P - O - P - O - P - OH
OH OH OH
Where AR = Organic base called adenosine. This molecule liberates
energy upon hydrolysis whereas the hydrolysis of ordinary phosphate esters is
slightly endothermic.
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hk
5. ATP + H2O → ADP + Pi + 7.3 K.Cal.
ADP + H2O → AMP + Pi + 7.3 K.Cal.
AMP + H2O → Adenosine + Pi + 3.4 K.Cal.
Where ADP, AMP are adenosine di- and mono-phosphates and Pi =
H3PO4= Phosphoric acid.
The liberated energy is used to drive many biological reactions in dark, as
we shall see in third step.
(III) The third step involves the final reduction of CO2 in dark. Sugar is finally
synthesized from atmospheric CO2 and the light reaction products ATP and
NADPH in the following stoichiometry.
6 CO2 + 18 ATP + 12 NADPH + 12H+
→ C6H12O6 + 18ADP + 12NADP + 18Pi
where NADPH, NADP are reduced and oxidized nicotinamide dinucleotide
phosphates.
Thus, the potential required to drive overall reaction is 1.21 volts. Free
energy change of the photosynthetic reaction is 110 K.Cal. as obtained by the
formula ∆G = nFE, where n = number of electrons involved in the reaction, F =
Faraday constant (96500 Coulombs) and E = potential required to drive the
reaction. On electronic energy scale, volts can be treated as electron volts (eV).
Thus the incident light should have energy at least 1.21 eV to carry out the whole
photosynthetic reaction. It is interesting to observe that even the lowest energy
light (Wavelength = 700 nm) has the energy of 1.76 eV as obtained by the
formula EeV =1235 / λ (nm). This energy is sufficient to carry out the photo-
oxidation even after considering some inherent loss processes.
2.3 FURTHER SYNTHESES
Photosynthetically produced glucose molecules further polymerize in
different fashions to form starch and cellulose molecules. The former is
responsible for metabolic reaction while the latter forms the structure of plants.
The cellulose in wood, cotton, and common plant material with higher percentage
of starch comes in the category of food (can be easily digested). Wood has
higher percentage of cellulose than that in food materials.
The energy packet ATP formed during the basic photosynthetic process is
also responsible for the protein synthesis in plants by the following route.
First Stage: Nitrogen Fixation
Atmospheric nitrogen is converted to ammonia with the help of
nitrogenase enzyme complex.
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6. Nitrogenase
N2 + 6H+
+ 6e-
+ 20 ATP + 12H2 → 2NH3 + 20 ADP + 20 Pi
Second Stage: Amino acid Formation
High concentration of ammonia is toxic for plants. Therefore, ammonia
formed in the first stage is immediately converted to amino acids.
ATP
NH3 → Amino acids.
About 20 types of amino acids are formed.
Third Stage: Protein Formation
All the amino acids formed in the second stage link together to form
protein.
ATP
Amino acids → Protein
3. ENERGY CONTENT OF BIOMASS
Energy content of biomass is the energy stored in per unit mass of its
body, which is released, on combustion. Plants are made of the elements C, H,
O, and N. The ultimate composition after combustion is CO2, H2 and to some
extent NOx. Unlike photosynthetic storage of solar energy (section 2.2) here
energy is released by the formation of stronger bonds O-H (-110 K.Cal./mole). A
representative elemental composition of wood is shown in table4
.
TABLE - I
--------------------------------------------------------------
Elements % of dry weight
--------------------------------------------------------------
Hydrogen (H) - 6.3 - 6.4
Carbon (C) - 50.8 - 52.9
Oxygen (O) - 39.7 - 11.8
Nitrogen (N) - 0.1 - 0.4
Sulphur (S) - Nil - Nil
Ash - 0.9 - 1.0
--------------------------------------------------------------
On an average wood contains 77% volatile matter, 22% fixed carbon and
1% ash. Assuming that fixed carbon is burned on the furnace grate and that the
volatile matters are burned as flame, it is clear that over 60% of the total calorific
value resides in volatiles4
.
3.1 THE CRITERION FOR FUEL
An approximate relation between elemental composition of fuel and
combustibility can be formulated5
. For this purpose, an average reduction level R
is defined as:
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7. NC + 9.5 NH - 0.5 NO
R = ---------------------------------
NC
where NC NH and NO are the number of carbon, hydrogen and oxygen in
the molecule (Nitrogen is considered to be negligible). R is the number of
oxygen molecules needed to burn a compound to CO2 and H2O, divided by
number of carbon atoms present in the molecule. The basis of this formula is
that each C-atom requires one molecule of O2 to be converted to CO2, each H-
atom requires 0.25 molecules of O2 to be converted to H2O and each O-atom
present in the molecule diminishes by one half the number of out side O2 needed
for combustion.
For completely oxidized carbon CO2, R = O and for completely reduced
carbon CH4, R = 2. All other values of R vary between these two extreme values.
It is interesting that for carbohydrate (CH2O), R = 1. Thus the process of
photosynthesis lifts reduction level of carbon from R = O to R = 1. As a result,
about one-half of the maximum possible combustion energy per atom of carbon
is stored.
A general formula for wood material can be given as CNC HNH ONO. As a
general rule, heat of combustion of this molecule is about 110 K. Cal/mole per
carbon per unit R. Thus, we can get a rough estimate of heat of combustion of
the given wood quality. In fact, the actual heat of combustion has been found to
be within ± 1.5% of the calculated one. Also, it is clear that the plants with less
oxygen content will be more useful as fuel.
In alcoholic fermentation of glucose (R=1), some of it is reduced to ethanol
C2H5OH (R=1.5) and another part is oxidized to CO2 (R=O). The net effect is the
release of only 2.1 K.Cal./Mole while the same molecule of glucose releases
(110x1x6 K.Cal.) = 660 K.Cal./mole when oxidized by oxygen to CO2 and H2O
during respiration. It is worth noting here that photosynthesis lifts the reduction
level of carbon from 0 to 1 and respiration brings it back to zero.
3.2 MEASUREMENT OF CALORIFIC VALUE
The calorific value of a biomass can be measured in Bomb Calorimeter
where the matter is burnt in a sealed chamber in an atmosphere of pure oxygen
gas. The routine procedure is described elsewhere 6,7
. We shall discuss the
method here in context with wood.
a) The high moisture content of most wood materials require that the sample
must be oven dried at 80 -110 o
C.
b) Plants have different parts such as wood, bark, leaves, etc. Each of them will
have separate calorific value. The user should select a method for preparing
sample that will not destroy or remove any of the combustible constituents.
Alternatively, the calorific value of each part should be mentioned separately.
c) It is necessary to make several preliminary tests to determine the
approximate maximum allowable moisture content at which sample can be
ignited in Bomb without difficulty.
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8. e) Due to variation in composition, it is difficult to get reproducible results.
Therefore, one should mention the average value, the number of tests and
percentage variation.
Other general precautions for bomb calorimeter used are as follows:
a) The Calorimeter cannot withstand a sample, which liberates more than 41.8
KJ. In general, the use of sample, more than 1.10 gm should be avoided.
b) The bomb should not be overcharged with oxygen.
c) The operator should stand away from the calorimeter at least after 15
seconds of firing the sample inside.
The calorific values of some biomass materials are given in table 8,9
.
TABLE - 2
------------------------------------------------------------------------------
Biomass Calorific Value MJ/Kg.
------------------------------------------------------------------------------
Farm Product
Cow dung - 15.0
Cow dung Cake - 12.6
Groundnut Shell - 18.1
Mustard Stalk - 18.8
Wheat Straw - 17.3
Saw Dust - 19.7
Rice Husk - 14.5
Wood
Acacia auriculiformis - 20.06 - 20.48
A. branchystachya - 17.97 - 18.39
A. Cyclops - 16.72 - 17.55
Callindra Calothyrsus - 18.81 - 19.85
Gliricidia sepium - 19.64 - 20.48
Gmelina arborea - 20.06
Sesbania bispinosa - 17.55 - 18.39
Prosopis juliflora - 17.97 - 18.39
------------------------------------------------------------------------------
3.3 DIFFERENT ENERGY VALUES
Energy values of wood can be expressed in three ways 4
(a) Gross
calorific values, (b) Net calorific value and (c) usable heat content. In all the
cases, moisture content of material plays an important role in combustion. In
combustion practice, wood moisture content is measured on a wet-weight basis
i.e. percentage of total original weight. However, for forest products, dry weight
basis is being used (amount of moisture is given as percentage of dry matter
only). The inter conversion of both the methods are given below:
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9. % M.C. (dry basis)
% M.C (wet basis) = -------------------------------------- x 100
100 + % M.C. (dry basis)
% M.C. (wet basis)
% M.C (wet basis) = -------------------------------------- x 100
100 - % M.C. (wet basis)
3.3.1 GROSS CALORIFIC VALUE
The gross calorific value is a measure of total energy embodied in the unit
weight of fuel. It is known as “higher heating value” also. Experimentally, it is
determined by bomb calorimeter method. In the standard procedures, wood
samples are usually oven dried before calorimetric analysis. Thus, value thus
obtained is called gross anhydrous calorific value. If the wood contains some
moisture also, the gross calorific value at moisture content is given by
Cg = Cga (1-m)
where Cga = anhydrous gross C.V.
Cg = gross C.V.
Thus for moisture content of 30%
Cga = 18.6 MJ/Kg.
Cg = 13.02 MJ/Kg.
3.3.2 NET CALORIFIC VALUE
Even during the combustion of dry matter, water is formed by the reaction
of fuel's hydrogen content with oxygen. In the measurement of Cga the heat
released by the condensation of internal water is also added up in the total value.
In fact, for practical purpose, no such condensation heat release is gained.
Rather some useful heat is wasted in evaporating this water content. The net
calorific value of "lower heating value" takes care of this fact.
Since hydrogen produces 9 times its own weight of water when burned,
the amount of water formed by the combustion of 1 Kg of oven dry wood is
W = 9 x MH Kg
Where MH = % hydrogen in wood
Thus, the net calorific value can be given as:
Cn = Cga - 9 x ∆H x MH
Where H = Latent heat of vaporization of steam 2.44 KJ/Kg.
If the moisture content is in (wet weight basis), the revised formula would
be
Cn = Cga (1-m) - ∆H m + 9 MH (1-m)
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10. For the wood of moisture content 30% and hydrogen 6% the formula can
be generalized as
Cn = 17.28 - 19.72 m MJ/Kg
3.3.3 USABLE HEAT CONTENT
Earlier mentioned heat content values are the standard reference values
and useful from academic point of view. But in practice, it would be more useful
to obtain the actual energy available in the furnace after facing many loss
processes. The main losses are:
1. Further heating the moisture vapor (L1)
2. Heating the gases CO2, N2 (L2)
3. Heating the excess air (L3)
4. Other conventional losses such as radiation, conduction,
convection and humidity of air (L4)
The total loss L = L1 + L2 + L3 + L4
Each of terms can be separately given as:
L1 = SH2O [m + 9 MH (1 - m] (Tf - Ti)
L2 = SN2 + CO2 [(1 - m) (W CO2 + WN2)] (Tf - Ti)
L3 = S Air [(1 - m) (WS x RE)] (Tf - Ti)
L4 = Cg x 0.04.
where SH2O, SN2 + CO2, SAir are the specific heats of H2O, SN2+CO2 in flue gas
and air in the range of temperatures Tf and Ti.
Ti = Temperature of air and fuel entering the furnace.
Tf = Temperature of flue gases
WCO2, WM2 = weights (Kg) of CO2 and N2 in flue gas after burning 1Kg. of
wood with stoichiometric air (6.21 Kg.).
WS = Stoichiometric weight of air required for complete combustion of 1 kg
of wood (6.21 Kg).
RE = Excess air expressed as a decimal of stoichiometric air requirement
(e.g. 0.5, 0.8 times).
m = moisture content (wet weight basis).
The value of L4 is the assumed one, based on general observation.
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11. The final usable heat content or "recoverable heat content" of wood fuel is
given as: Usable heat Content CU = Cn -L1 + L2 + L3 + L4
3.4 THE COMPROMISE ENERGY UNIT
The very basic statement of second law of thermodynamics "Energy can
neither be created nor destroyed, it can only be converted from one form to
another" itself indicates that all forms of energy must have something common
among themselves. As a concept, all of them can be defined as measure of the
ability to do work. As we know that biomass energy can be directly converted
into heat, electricity, oil, light and mechanical energy. Through modern energy
plantation techniques, each of the above mentioned energy forms could be
converted into biomass more or less directly. Rather muscle power is also added
to it. Thus energy is the unifying concept for food, fuel and other stored or
moving energy forms. Unfortunately, severe lack of unity occurs in using the
units of energy such as:
Heat energy Btu, Calories
Electrical energy Kilowatt-hours
Mechanical energy Horsepower-hours, foot pound
Electromagnetic energy ergs
Food energy Calories
Coal energy Metric tonnes equivalents
Oil energy Barrel oil equivalents
Food Crop energy Bushels
Atomic energy TNT equivalents
Fortunately, this complication has been avoided by using a compromise
unit (International system of units) i.e. Joules. 1 Joule = 0.239 Calories =
0.000949 Btu
This unit is now universally used whether one speaks of oil, gasoline,
electricity, food, water, reservoir, wood, cow dung or muscle energy. The
conversion factors are given below:
TABLE - 3
--------------------------------------------------------------------------------------------------------------
To convert from To Multiply by
--------------------------------------------------------------------------------------------------------------
British thermal unit (Btu) kilojoules 1.054
Calories (Cal) Joules 4.19
Ergs (Eg) Joules 1 x 10 -7
Kilowatt hours (KWh) megajoules 3.6
Megajoules (MJ) kilojoules 1000
Gigajoules (GJ) megajoules 1000
Terajoules (TJ) gigajoules 1000
Watts (W) joules/sec 1
Liter petrol megajoules 35
Kilogram oil megajoules 43.2
Barrel oil equivalent gigajoules 6.1
Tonne Coal equivalent gigajoules 29.3
Tonne Coal equivalent barrel oil equivalent 4.8
-----------------------------------------------------------------------------------------------------
4. ENERGETICS OF BIOMASS CONVERSIONS
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12. Wood is used as energy source for heating, mechanical work or for
electricity generation. It can be either used as "firewood" i.e. used for direct
combustion or as fuel-wood i.e. converted into secondary fuels such as producer
gas, alcohol etc. A detail survey of different conversion processes is given
elsewhere 9
. Emphasis will be given here only on the energetics of different
processes in brief.
4.1 DRYING
The process of physical removal of water from wood is called drying.
Drying the biomass is important because it improves its colorific value. The
energy required for drying will vary largely for different system. Generally, 9% of
energy value of wood is lost in reduction the moisture content from 30% to 9%
4.2 DENSIFICATION
Using the loose biomass e.g. bark, sawdust, chips, leaves and shaving is
very inconvenient. That is why they are converted into a uniformly sized fuel by
densification process i.e. compressing the material particle by mechanical
means. Due to uniformity of size, the densified materials can be used in more
efficient way. However, densification is an energy consuming process and
necessitates the use of electrical energy input for size reduction, transportation,
agglomeration and for moisture removal (74.16 - 540 MJ/tonne of fuel).
4.3 PYROLYSIS
Pyrolysis involves thermal decomposition of wood either in absence of air
or in limited air. This process is used either for carbonization i.e. charcoal
production or for gasification i.e. combustible gas production. The energetic
effectiveness of the conversion process can be assessed by the following terms.
Mass of product fuel
Yield (Y) = ---------------------------
Mass of input fuel
Energy content of product fuel
Conversion efficiency (ηc) = --------------------------------------
Energy content of input fuel
Calorific value of product fuel
Calorific value ratio (R) = ---------------------------------------
Calorific value of product fuel
They are correlated by the following formula
ηc = Y x R
4.3.1 CARBONIZATION
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13. The aim of carbonization is to obtain a solid fuel with a predominant
fraction of fixed carbon and distill volatiles by pyrolysis of wood in absence of air.
Thus, it is a total utilization process in which following three products are formed:
a) Charcoal (C.V. 27-33 MJ/Kg)
b) Condensable volatiles known as pyrolytic oil (mainly pyroligneous acid)
with calorific value 27 - 31.5 MJ/Liter.
c) Non-Condensable gases such as CO, N2, H2 CH4, CO2 (C.V. 8.36
MJ/Nm3
).
The overall conversion efficiency of charcoal production process is 10
-30% depending upon the methods and quality of wood.
4.3.2 GASIFICATION
The aim of the gasification process is to generate a gaseous fuel, the
volatiles are vaporized and combusted and fixed part is reduced to CO2 and H2.
Small chips of wood are burned in closed fire chamber (gasifier) with limited air
supply (only 0.2 to 0.4 of stoichiometric requirement of air). The resulting gas
contains CO, H2, tars, vaporized volatiles, CO2, N2, CH4 with calorific value (4.18 -
6.27 MJ/Nm3
).
The efficiency of conversion of wood to cold unclean gas is 85-95%. The
overall efficiency of wood energy to mechanical power conversion is 15%. The
efficiency of conversion of wood energy to thermal energy is 45-50%.
4.4 LIQUEFACTION
The high energy density i.e. energy content per unit volume of liquid fuels
obtained from wood, makes it the most attractive from practical point of view.
Liquid fuel from wood can be used as a substitute for kerosene and gasoline.
The comparative energy density is shown below:
TABLE - 4
------------------------------------------------------------------------------------------------
Parameters Liquid Solid Gas
------------------------------------------------------------------------------------------------
Energy density 16.4-37.62 5.01 - 10.92 0.0083
(Million KJ/m3
)
Energy Density Ratio 25 10 1
------------------------------------------------------------------------------------------------
Liquefaction of wood can be done by following different ways.
4.4.1 HYDROLYSIS
Hydrolysis is the chemical addition of water to cellulose (C6H10O5....) to
convert it to glucose (C6H12O6) which is finally converted to ethyl alcohol
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14. (C2H5OH). Ethyl alcohol is well known as a clean fuel. Hydrolysis is carried out
either (a) by dissolving the cellulosic material in concentrated acid and then
break it to glucose. Glucose is converted into ethyl alcohol after being fermented
by yeast. Following are the data on hydrolysis of wood.
-Yield: 190 liters/tonne of oven dry wood
- Calorific value of ethanol: 23.6 MJ./liter
- Wood to alcohol conversion: 14-23% efficiency.
4.4.3 LIQUEFACTION OF SYNTHESIS GAS
The mixture of gas containing only H2 and CO is called synthesis gas.
Wood is first converted to synthesis gas. Thereafter, the hydrocarbons and
oxygenated aliphatic compounds are obtained by catalytic hydrogenation of CO
according to following reactions:
(Fischer-Tropsch Method)
CO + 2 H2 ------ CH3 OH
9 CO + 19 H2 ----- C9H2O + 9 H2O
Yield - 190 liters/tonne of dry wood
Calorific value (average) = 34.6 MJ/Liter.
4.5 COMBUSTION
The combustion of wood is the direct burning of wood in air. When wood
is exposed to heat at 2500
C, the total combustion occurs in three stages.
a) Drying - (Moisture removal)
b) Pyrolysis - (burning of volatiles)
c) Glowing - (fixed carbon burning)
The efficiency of wood burner depends upon burner design, wood quality
and size of burner. Wood burner efficiency is obtained generally by measuring
the heat utilized in boiling the given quantity of water by the known weight of
wood. The ratio of heat required to boil the given quantity of water and wood
consumption (in joules) for the same period, gives the efficiency of system. In
general, the efficiency of wood stoves vary between 4% to 25%.
5. FIELD ESTIMATION OF BIOMASS ENERGY
Just as wheat grower is interested in grain yield, a biomass energy
technologist would be interested in "energy yield". The concept of energy
plantation itself aims at harvesting energy. For this purpose, one needs to find
out the yield of biomass in the given area. The yield can be determined either
after harvesting or in the uncut plantation itself10-14
. The calorific values of
different tree species vary between 16.72 - 20.48 MJ/Kg (Table-2). Therefore,
one has to take precautions while estimating the energy value of whole field of
energy plantation.
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15. a) Above mentioned calorific values are reported typically for stems of the
wood. However, an energy plant contains also bark, leaves, branches and
root. Each of the parts has different calorific value. The biomass yield
should be estimated separately for each part in the whole field. Total
energy yield should be taken up as the addition of energy values of
different parts.
b) If energy plantation contains only one type of trees, the calculation is
easier. However, when different species are mixed up in a single plot, an
estimation of biomass yield separately for different species is necessary.
Otherwise, there are chances of overestimation or underestimation of
energy yield. For a non-uniform and completely mixed up energy
plantation the general compromise calorific value is taken to be 16.72
MJ/Kg.
ACKNOWLEDGEMENT
The authors feel deeply indebted to Department of Non-Conventional
Energy Sources, New Delhi for starting the Biomass Research Centre in our
campus. Sincere thanks are due to our colleagues Dr. (Mrs.) U. S. Yadav, Dr.
(Mrs.) S. V. Kulkarni and Mr. J. V. Torane for their full cooperation during the
preparation of this article.
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biological solar energy conversion”, Pub. by Van Nostrand Reinhold
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3. M. D .Kamen, In “Primary Processes in Photosynthesis”, Academic Press
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4. C. J. Lyons F. Lunny and H. P .Pollock, Biomass, 8, 283-300 (1985).
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16. 9. O. P. Vimal and M. S. Bhatt, In “Wood Energy Systems” K. L.
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