Preface Energy crises and environmental pollution are the two major challenges before mankind in present context. The growing use of fossil fuels such as coal and oil has resulted in increasing the greenhouse gas emission. To resolve the energy crisis and reduce greenhouse gas emission, the dependency on fossil fuels shall have to be minimized by replacing them with renewable fuels. Biomass is the storage of solar energy in chemical form in plant and animal materials. It is one of commonly used, precious and versatile resources on the earth. It is rich source for feed, fodder, fiber, fuel, and fertilizer. Biomass has been used for energy purposes ever since man discovered fire. The content of book includes all major aspects of biomass production and efficient utilization for energy generation. Most of the information presented in this book reflects a basis to acquire the understanding of the proper utilization of biomass for heat and power generation. In this book, design criteria, present state of art of technology and future perspective of clean energy are illustrated through graphs, figures, tables, flowcharts. equation etc. to make subject more clear and useful. In this book an attempt has been made to bring out the state of art of technology on production and efficient utilization of clean and green fuel from biomass. The book has been divided into ten chapters. Chapter 1 deals with overview of biomass, energy plantation, proximate and ultimate analysis of biomass. Chapter 2 pertains the application of biomass for domestic application which include improved cookstoves and biomass-based water heating system. Chapter 3 brings out the biogas generation from biomass. Biochar production and its applications highlighted in Chapter 4. Chapter 5 deals with pyrolysis process where biomass conversion into liquid fuel is included. Design and development of torrefaction unit presented in Chapter 6. Design of biomass gasifier and its application for thermal energy generation along with practical exposure are presented in Chapter 7. Chapter 8 pertains the production of biodiesel and case study of biodiesel produced using caster seed oil in actual use. Chapter 9 deals with bioethanol production. Densification of loose biomass is presented in chapter 10. It is hoped that this book will be useful as text book and a reference book for students pursuing course in energy studies.

1.1 General The term “biomass” generally refers to renewable organic matter generated by plants through photosynthesis. Materials having organic combustible matter is also referred under biomass.Biomass is an important fuel source in our overall energy scenario. Biomass is produced through chemical storage of solar energy in plants and other organic matter as a result of photosynthesis. During this process conversion of solar energy in sugar and starch, which are energy rich compounds takes place. The chemical reaction of photosynthesis can be written as: 6CO2 + 6H2O + sunlight → C6H12O6 + 6O2 + 636kcal It indicates that the storage of 636 kcal is associated with the transfer of 72 gm carbon into organic matter. Biomass can be directly utilized as fuel or can be converted through different routes into useful forms of fuel. In fact, biomass is a source of five useful agents, which start with ‘F’ like food, fodder, fuel, fiber and fertilizer. Further, biomass has many advantages like. (1) It is widely available (2) Its technology for production and conversion is well understood. (3) It is suitable for small or large applications (4) Its production and utilisation requires only low light intensity and low temperature (5 to 35°C) (5) It incorporates advantage of storage and transportation (6) Comparatively, it is associated with low or negligible pollution.

2.1 Introduction Biomass store solar energy in the chemical form and it is most precious and versatile resources on earth. Biomass, unlike fossil fuels, is a renewable energy resource that is available where the climatic conditions are favorable for plant growth and production1. The term biomass is used for all organic materials which are combustible in nature, mainly plant and animal origin present in land and aquatic environments. Biomass is considered carbon neutral, because the amount of carbon it can release is equivalent to the amount it absorbed during its life time. There is no net increase of carbon to the environment in the long term when combusting the lignocellulosic materials. Therefore, we can say that biomass is a renewable source of energy and can play vital role in responding to concerns over the protection of the environment and the security of energy supply2,3. Biomass energy accounts for about 15% of the world’s primary energy consumption and about 38% of the primary energy consumption in developing countries4. Furthermore, biomass often accounts for more than 90% of the total rural energy supplies in developing countries5. It is the main source to meet out domestic energy in developing countries6. The efficient use of fuel wood is much more eco-friendly than the use of efficient and conventional fuels like kerosene and liquefy petroleum gas (LPG). LPG emits 15 times more CO2 per kg than wood, and kerosene emits nearly 10 times as much. CO2 is the prominent candidate for global. It is commonly assumed that biomass fuel cycles based on renewable in nature and greenhouse-gas (GHG) neutral because the combusted carbon in the form of CO2 is soon taken up by re-growing vegetation7.

3.1 Introduction Nature has a provision for destroying and disposing off wastes and dead plants and animals. This decay or decomposition is carried out by tiny micro-organisms called bacteria. Making of farm-yard manure (FYM) and compost is also through decomposition of organic matter (OM). When a heap of vegetable or animal waste and weeds etc., die or decompose at the bottom of backwater or shallow lagoons, bubbles can be noticed rising to the surface of water. Sometimes these bubbles burn with dancing flame at dusk. This phenomenon has puzzled man for a long time. It was only during the past hundred years that Scientists unlocked this secret as the decomposition process. The gas thus produced was and is still called “Marsh Gas.” The technology of harnessing this gas under artificially created conditions is known as Biogas Technology.

4.1 Introduction Biomass is referred to as an indirect source of solar energy and considered a source of stored chemical energy. Biomass is renewable organic material derived from plants and animals serving as sources of energy. Biomass produced from agricultural sector is big challenges for all over the world due to its improver disposal. Mitigating greenhouse gas emissions and ensuring adequate global food supplies represent two of the last decade’s mostdifficult challenges.Although global food production has benefitted from chemical fertilizers, environmental problems have emerged as a result of their use. Additionally, overuse of fertilizers can result in hardened soil, decreased soil fertility, polluted air and water, and the release of greenhouse gases. There is an urgent need to find an alternative to chemical fertilizers that, ideally, can be sourced in abundant amounts, promotes global food production, enhances CO2 capture , and does not affect soil health or damage the environment1. To sustain agricultural productivity, it is crucial to maintain adequate levels of organic matter in the soil to preserve its physical, chemical, and biological integrity. Biochar, a pyrogenic black carbon, may play an important role in improving soil health, resulting in higher crop yield and absorbing atmospheric carbon dioxide. Biochar is the most auspicious straw management measures and have highest carbon abatement and economic profit2. Biochar is produced by heating biomass at high temperatures (300 – 600 °C) in a closed reactor containing no to partial levels of air. Under these conditions, biomass undergoes thermo-chemical conversion into biochar. Because of its numerous potentials uses in agriculture, energy, and the environment, much attention has been given to biochar in both political and academic areas. Biochar can be used in a variety of applications such as energy production, agriculture, carbon sequestration, waste water treatment, and bio-refinery; additionally, biochar provides an alternative strategy for managing organic waste. These advantages have renewed the interest of agricultural researchers in producing biochar from bio-residues and using the product as a soil amendment.

5.1 Introduction Today, energy distribution and environmental issues have developed into international threats. Demand for alternative fuels increases every day due to rapid population growth, rising living standards, and economical sustainability. With its massive population, India has become the fourth largest energy consumer country in the world after the United States, China, and Russia. Because most nations use fossil fuels to fulfill their energy demands, they create negative impacts on the environment including raising global temperatures, pollution, acid rain, and other effects. As such, the quest for alternative fuels derived from renewable resources has captured significant attention throughout the world1. Biomass as a renewable energy sources is an important asset for achieving economic development is due to the availability of biomass at a low cost, a good conversion efficiency, the addition of jobs, and an increase in the biodiversity2,3. Typically, biomass is composed of cellulose (40-50%), hemicelluloses (25-35%), and lignin (15-30%). Large amount of resources for biomass are available such as woody biomass, crop residues and their by-products, food processing waste, municipal solid waste, aquatic plant etc. In the present context, pyrolysis process has been received a remarkable identity as a potential method for the conversion of any organic biomass into valuable energy rich products due to its simple in operation and also required a reasonable cost for conversion process. Pyrolysis is the thermal decomposition of any organic material at a specific temperature in absence of air/oxygen; the process ends with three resulting products, namely liquid (bio-oil), solid (biochar), and syngases4. Recently, biooil produced through pyrolysis process and further it up grading has been attracted a significant attention due to its major use as biofuel and as a precursor material for making chemicals5. The pyrolysis process also classified in three different types as per its operating conditions; slow, fast and flash pyrolysis.

6.1 Introduction Torrefaction is a thermophilic process of biomass conversion into a solid, friable, homogenous coal-like material, which has better fuel characteristics than the original biomass. Torrefaction involves the heating of biomass material in the absence of air at 250 to 300°C temperature. Torrefaction produces high-grade hydrophobic nature solid biofuels from various streams of woody biomass or agro residues.Torrefied biomass has high energy density then the original biomass which make torrefied biomass as renewable alternate source for power generation in coal power plant. Torrefied biomass being hydrophobic in nature can be stored easily for longer duration with negligible biological degradation. At 250-300°C temperature volatilization has been taking place and around 30% mass of the biomass is reduced as compared to original untorrefied biomass with net energy loss of approximately around 10%.The end product is a predictable, homogeneous, hydrophobic, high value solid biofuel with far higher energy density and calorific value than the original biomass feedstock. During the torrefaction process a combustible gas is released, which can also utilised to provide heat to the process. The process diagram of torrefaction process is shown in Fig. 6.1.

7.1 Introduction Biomass gasification is age old technology originated in 1800 century for lighting and cooking purposes (Sansaniwal et al., 2017). Biomass typically contents biopolymers such as cellulose, hemicellulose and lignin in addition to the presence of average composition of C6H10O5 which depends upon physical characteristics of biomass1. Oxygen is required for combustion of every fuel. For complete combustion of biomass stoichiometric air to fuel ratio required varies from 6:1 to 6.5:1 with CO2 and H2O as end product. Biomass gasification is an efficient and environmentally friendly way to produce energy2. Gasification process is nothing but it is a conversion of solid fuel into gaseous fuel for wide applications. This whole process completed at elevated temperature range of 800-1300 oC with series of chemical reaction that is why it come under thermo chemical conversion3. Thermo chemical processes are most commonly employed for converting biomass into higher heating value fuels4. Major thermal conversion route is include direct combustion to provide heat, liquid fuel and other elements to generate process heat for thermal and electricity generation is summaries in Fig. 7.1.

8.1 Introduction Rising petroleum prices, increasing threat to the environment from exhaust emissions and global warming have generated an intense international interest in developing alternative non-petroleum fuels for engines. The use of vegetable oil in internal combustion engines is not a recent innovation. Rudolf Diesel (18581913), creator of the diesel cycle engines, used peanut vegetable oil to demonstrate its invention in Paris in 1900. In 1912, Diesel said, “The use of vegetable oils as engine fuel may seem negligible today. Nevertheless, such oils may become, in the passing years, as important as oil and coal tar presently.” Nowadays, it is known that oil is a finite resource and that its price tends to increase exponentially, as its reserves have being decreasing1. India ranks sixth in the world in total energy consumption and needs to accelerate the development of the sector to meet its growth aspirations. The country, though rich in coal and abundantly endowed with renewable energy in the form of solar, wind, hydro and bio-energy has very small hydrocarbon reserves (0.4 % of the world’s reserve). India, like many other developing countries, is a net importer of energy, more than 25 percent of primary energy needs being met through imports mainly in the form of crude oil and natural gas. The rising oil import bill has been the focus of serious concerns due to the pressure it has placed on scarce foreign exchange resources and is also largely responsible for energy supply shortages. The sub-optimal consumption of commercial energy adversely affects the productive sectors, which in turn hampers economic growth2.

9.1 Introduction The rapid growth of industrialization and population significantly affect on the demand of ethanol as an alternate fuel. Generally, conventional crops like sugarcane and corn become unable to meet the demand of bioethanol, due to their primary role in food and feed. Therefore, lignocellulosic biomass from agriculture waste is attractive precursor for bioethanol production. Biomass is renewable organic material, abundant and cost effective. Ethanol production from agriculture waste has been projected an economically attractive option for industrial sector. However, sugar and starch derived ethanol have a more theoretical yield as compared to lignocelluloses, theses sources are insufficient for bioethanol production. The major agricultural wastes including rice straw, corn straw, wheat straw and sugarcane bagasse etc. can subsequently used for ethanol production. Rice straw has a highest worldwide potential for bioethanol production (205 giga liter) followed by wheat straw (104 giga liter), corn straw (58.6 giga liter), and finally for sugarcane bagasse (51.3 giga liter)1. A bio fuels is environmentally friendly options for power generation. Most of the fossil fuels are biological in nature. These are plant forms that, typically, remove carbon dioxide from the atmosphere and give up the same amount when burnt. The bio fuels are therefore considered to be “CO2 neutral”, not adding to the carbon dioxide level in the atmosphere. The type of bio fuel used will depend on a number of factor, chief amongst them being the available feedstock and the energy that can be used locally. India import 70% of the oil it uses, and the country has been hard by the increasing price of oil, uncertainty and environmental hazards that are concerned with the consumption of fossil fuels. In this context, bio fuels constitute a suitable alternative source of energy for India. There are two examples of bio fuels are Ethanol and Bio diesel (Renewable Diesel) Ethanol can be made from biomass material containing sugar, starches, or cellulose (starch and cellulose are complex from of sugar)

10.1 Introduction Biomass fuels are a potential source of renewable energy. One of the major barriers to their widespread use is that biomass has a lower energy content than traditional fossils fuels, which means that more fuel is required to get the same amount of energy. When combined — low energy content with low density -the volume of biomass handled increases enormously. Compaction or densification is one way to increase the energy density and overcome handling difficulties. Densification means compaction of loose material or to increase density of loose biomass so that its volumetric efficiency can be increased. Densification essentially involves two parts; the compaction under pressure of loose material to reduce its volume and to agglomerate the material so that the product remains in the compressed state. The resulting solid may be a briquette, a pellet and a cube. It will be briquettes if roughly, it has a diameter greater than 30 mm. Smaller sizes are normally termed pellets though the distinction is arbitrary. The process of producing pellets is also different from the typical briquetting processes. The densified product can be developed in the cubical shapes as well. If the material is compacted with low to moderate pressure (0.2-5 MPa), then the space between particles is reduced. Further, increasing the pressure will, at a certain stage particular to each material, collapse the cell walls of the cellulose constituent, thus approaching the physical, or dry mass and more, density of the material. The pressure required to achieve such high densities are typically 100 MPa plus. This process of compaction is entirely depending on to the pressure exerted on the material and its physical characteristics including its moisture content.