UNIT I Course Material

8/6/2019 UNIT I Course Material

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MEE230 RENEWABLE ENERGY SOURCES L T P C3 0 0 3

Objectives1. To provide students an overview of global energy resources.

2. To introduce students to bio-fuels, hydrogen energy and solar energy.3. To enable the students understand the importance of energy efficiencyand conservation in the context of future energy supply.4. To expose students to future energy systems and energy use scenarioswith a focus on promoting the use of renewable energy resources andtechnologies.

Outcome Student will be able to1. Possess the knowledge of global energy resources2. Use the renewable technologies like solar, biomass, wind, hydrogen etc. to

produce energy.

3. Involve in optimizing and selecting an alternate source of energy.UNIT I BiofuelsBiofuels classification Biomass production for energy forming Energythrough fermentation Pyrolysis Gasification and combustion - Biogas -Aerobic and Anaerobic bio conversion process - Feed stock - Properties ofbio-gas composition - Biogas plant design and operation - Alcoholicfermentation.UNIT II Hydrogen EnergyElectrolytic and thermo chemical hydrogen production Metal hydrides and

storage of hydrogen Hydrogen energy conversion systems hybrid systems Economics and technical feasibility.UNIT III Solar EnergySolar radiation - availability- Measurement and estimation- Isotropic and anisotropic models- Introduction to solar collectors (liquid flat- Plate collector - Airheater and concentrating collector) and thermal storage- Steady state transientanalysis- Photovoltaic solar cell - Hybrid systems - thermal storage- Solar arrayand their characteristics evaluation Solar distillation Solar drying.UNIT IV Ocean Thermal Energy ConversionGeothermal - Wave and Tidal energy - Availability - Geographical distribution

- Power generation using OTEC - Wave and Tidal energy - Scope andeconomics - Geothermal energy - Availability - Limitations.


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UNIT V Wind EnergyWind energy - General considerations - Wind Power plant design Horizontalaxis wind turbine - Vertical axis wind turbine - Rotor selection - Designconsiderations - Number of blades - Blade profile - Power regulation - Yawsystem - Choice of power plant - Wind mapping and selection of location-Cost

analysis and economics of systems utilizing renewable sources of energy.Text book1. David Merick, Richard Marshall, (2001), Energy, Present and Future

Options, Vol. I and II, John Wiley and sons.Reference Books1. Gerald W. Koeppl, (2002), Patnams power from wind, Van Nostrand

Reinhold Co.2. Ritchie J.D., (1999), Source Book for Farm Energy Alternative, McGraw Hill.3. Twidell, J.W. and Weir, A.D., (1999), Renewable Energy Resources, ELBS.4. Koteswara Rao, M. V. R., (2006), Energy Resources-Conventional and Non

Conventional, Second Edition, BS Publications.5. Khan, B. H., (2009), Non-Conventional Energy Resources, Second Edition,

Tata McGraw Hill.6. Chetan Singh Solanki, (2009), Renewable Energy Technologies: A Practical

Guide for Beginners, Second Printing, PHI Learning Private Limited.7. Mukherjee, D. and Chakrabarti, S., (2005), Fundamentals of Renewable

Energy Systems, New Age International (P) Limited8. Chauhan, D.S. and Srivastava, S.K. (2006), Non-Conventional Energy

Resources, New Age International (P) Limited

Mode of Evaluation: Assignment / Quiz / Written Examination.


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UNIT-I

1.0 BIOFUELS Biofuel is defined as solid, liquid or gas fuel derived from relatively

recently dead biological material and is distinguished from fossil

fuels, which are derived from long dead biological material.

Theoretically, biofuels can be produced from any (biological) carbon

source; although, the most common sources are photosynthetic

plants.

Various plants and plant-derived materials are used for biofuel

manufacturing. Globally, biofuels are most commonly used to power

vehicles, heating homes cornstoves and cooking stoves.

Photosynthesis

Photosynthesis uses light energy and carbon dioxide to make

triose phosphates (G3P)

G3P is generally considered the first end-product of

photosynthesis

It can be used as a source of metabolic energy, or combined

and rearranged to form monosaccharide or disaccharide sugars,

such as glucose orsucrose, respectively, which can be transported

to other cells, stored as insoluble polysaccharides such as starch,
http://en.wikipedia.org/wiki/Biologyhttp://en.wikipedia.org/wiki/Photosynthesishttp://en.wikipedia.org/wiki/Planthttp://en.wikipedia.org/wiki/Biofuel#Liquid_fuels_for_transportation%23Liquid_fuels_for_transportationhttp://en.wikipedia.org/wiki/Kitchen_stovehttp://en.wikipedia.org/wiki/Glyceraldehyde_3-phosphatehttp://en.wikipedia.org/wiki/Monosaccharidehttp://en.wikipedia.org/wiki/Disaccharidehttp://en.wikipedia.org/wiki/Glucosehttp://en.wikipedia.org/wiki/Sucrosehttp://en.wikipedia.org/wiki/Polysaccharidehttp://en.wikipedia.org/wiki/Starchhttp://en.wikipedia.org/wiki/Biologyhttp://en.wikipedia.org/wiki/Photosynthesishttp://en.wikipedia.org/wiki/Planthttp://en.wikipedia.org/wiki/Biofuel#Liquid_fuels_for_transportation%23Liquid_fuels_for_transportationhttp://en.wikipedia.org/wiki/Kitchen_stovehttp://en.wikipedia.org/wiki/Glyceraldehyde_3-phosphatehttp://en.wikipedia.org/wiki/Monosaccharidehttp://en.wikipedia.org/wiki/Disaccharidehttp://en.wikipedia.org/wiki/Glucosehttp://en.wikipedia.org/wiki/Sucrosehttp://en.wikipedia.org/wiki/Polysaccharidehttp://en.wikipedia.org/wiki/Starch


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Waste andBiomass

Anaerobic

Digestion

Gasification

CombustionCo-firing

Biogas

Gas

Char

PyrolysisBio-Oil

Steam

Gas

Turbine

GasEngine

SteamTurbine

Fuel Conversion Intermediate Generation Product

Ele

ctric

power

Third generation biofuels

Algae fuel

Fourth generation biofuels

Conversion ofvegoil and biodiesel into gasoline

Liquid Biofuels Bioethanol

Biodiesel Biobutanol

Pure Plant Oil (PPO)

Biokerosene

Pyrolysis oil

Gas Biofuels

Biogas Biopropane

Synthetic natural gas (SNG)

Solid Biofuels

Wood

Manure

Charcoal

Figure 1.1 Overview of waste and biomass conversion

routes for power generation
http://en.wikipedia.org/wiki/Vegoilhttp://en.wikipedia.org/wiki/Biodieselhttp://www.bioenergywiki.net/index.php/Bioethanolhttp://www.bioenergywiki.net/index.php/Biodieselhttp://www.bioenergywiki.net/index.php/Biobutanolhttp://www.bioenergywiki.net/index.php/Pure_Plant_Oilhttp://www.bioenergywiki.net/index.php/PPOhttp://www.bioenergywiki.net/index.php/Biokerosenehttp://www.bioenergywiki.net/index.php/Pyrolysis_oilhttp://www.bioenergywiki.net/index.php/Gas_biofuelshttp://www.bioenergywiki.net/index.php/Biogashttp://www.bioenergywiki.net/index.php/Biopropanehttp://www.bioenergywiki.net/index.php/Synthetic_natural_gashttp://www.bioenergywiki.net/index.php/SNGhttp://www.bioenergywiki.net/index.php/Solid_biofuelshttp://en.wikipedia.org/wiki/Vegoilhttp://en.wikipedia.org/wiki/Biodieselhttp://www.bioenergywiki.net/index.php/Bioethanolhttp://www.bioenergywiki.net/index.php/Biodieselhttp://www.bioenergywiki.net/index.php/Biobutanolhttp://www.bioenergywiki.net/index.php/Pure_Plant_Oilhttp://www.bioenergywiki.net/index.php/PPOhttp://www.bioenergywiki.net/index.php/Biokerosenehttp://www.bioenergywiki.net/index.php/Pyrolysis_oilhttp://www.bioenergywiki.net/index.php/Gas_biofuelshttp://www.bioenergywiki.net/index.php/Biogashttp://www.bioenergywiki.net/index.php/Biopropanehttp://www.bioenergywiki.net/index.php/Synthetic_natural_gashttp://www.bioenergywiki.net/index.php/SNGhttp://www.bioenergywiki.net/index.php/Solid_biofuels


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1.2 BIOGAS

Biogas is produced by the decomposition ofanimal wastes, plant

wastesandhuman wastes

It is produced by digestion, pyrolysis and hydro-gasification

Digestion is a biological process that takes place in the absence

of oxygen and in the presence of an aerobic organisms at ambient

pressures and temperature of35 to 70C The container in which this digestion takes place is called digester

Animal wastes

Cattle dung, urine, goat and poultry droppings, slaughter housewastes, fish wastes, leather and wood wastes, sericulture wastes,

elephant dung, piggery wastes etc.

Agricultural wastes

Aquatic and terrestrial weeds crop residue, stubbles of crops, sugar

can trash, spoiled fodder, bagasse, tobacco wastes, oilcakes fruit

and vegetable processing wastes, press mud, cotton and textile

wastes, spent coffee and tea wastes

Human wastes

Faeces, urine and other wastes emanating from human occupations

Waste of aquatic origin

Marine plants, twigs, algae, water hyacinth and water weeds

Industrial wastes

Sugar factory, tannery, paper etc.


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Table 1.1 Typical Composition of Bio gas

Sl. No. Matter %

1 Methane, CH4 50 75

2 Carbon dioxide, CO2 25 50

3 Nitrogen, N2 0 10

4 Hydrogen, H2 0 15 Hydrogen Sulfide, H2S 0 3

6 Oxygen, O2 0 2

1.2.1 Micro-organisms

Living creatures which are in microscopic in size and are invisible to

unaided eyes

They are called bacteria, fungi, virus etc.

Beneficial bacteria and harmful bacteria

Compost making production ofbiogas, vinegar, etc., are beneficial

Bacteria causing cholera, typhoid, diphtheriaare harmful bacteria

Bacteria can be divided into two groups based on their oxygen

requirement

Bacteria grow in the presence of oxygen is Aerobic

Bacteria grow in the absence of gaseous oxygen is Anaerobic

When organic matter undergoes fermentation through anaerobic

digestion, the gas produced is Biogas

Fermentation:Fermentation is the conversion of a carbohydrate such as

sugarinto an acid or an alcohol. More specifically, fermentation can refer

to the use of yeast to change sugar into alcohol or the use of bacteria to

create lactic acid in certain foods.

1.2.2 Anaerobic Digestion


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Anaerobic digestion is a series of processes in which

microorganisms break down biodegradable material in the absence

ofoxygen

It is widely used to treat wastewater sludges and organic wastes

because it provides volume and mass reduction of the input material

As part of an integrated waste management system, anaerobic

digestion reduces the emission of landfill gas into the atmosphere

Anaerobic digestion is a renewable energy source because the

process produces a methane and carbon dioxide rich biogas suitable

for energy production helping replace fossil fuels

Anaerobic digestion is particularly suited to wet organic material and

is commonly used for effluent and sewage treatment

Anaerobic digestion is a simple process that can greatly reduce the

amount of organic matter which might otherwise be destined to be

landfilled or burnt in an incinerator.

Almost any organic material can be processed with anaerobic

digestion

This includes biodegradable waste materials such as waste paper,

grass clippings, leftover food, sewage and animal waste

Utilizing anaerobic digestion technologies can help to reduce theemission of greenhouse gasses in a number of key ways:

Replacement of fossil fuels

Reducing methane emission from landfills

Displacing industrially-produced chemical fertilizers

Reducing vehicle movements

Reducing electrical grid transportation losses

1.2.3 Types of Anaerobic Digesters
http://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Waste_managementhttp://en.wikipedia.org/wiki/Methanehttp://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Biogashttp://en.wikipedia.org/wiki/Sewagehttp://en.wikipedia.org/wiki/Landfillhttp://en.wikipedia.org/wiki/Incineratorhttp://en.wikipedia.org/wiki/Automobilehttp://en.wikipedia.org/wiki/Electricity_gridhttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Waste_managementhttp://en.wikipedia.org/wiki/Methanehttp://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Biogashttp://en.wikipedia.org/wiki/Sewagehttp://en.wikipedia.org/wiki/Landfillhttp://en.wikipedia.org/wiki/Incineratorhttp://en.wikipedia.org/wiki/Automobilehttp://en.wikipedia.org/wiki/Electricity_grid


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Anaerobic activated sludge process

Anaerobic clarigester

Anaerobic contact process

Anaerobic expanded-bed reactor

Anaerobic filter

Anaerobic fluidized bed

Anaerobic lagoon

Anaerobic migrating blanket reactor

Batch system anaerobic digester

Continuous stirred tank reactor (CSTR)

Expanded granular sludge bed digestion (EGSB)

Hybrid reactor

Imhoff tank

Internal circulation reactor (IC)

One-stage anaerobic digester

Submerged media anaerobic reactor

Two-stage anaerobic digester

Upflow anaerobic sludge blanket digestion (UASB)

Upflow and down-flow anaerobic attached growth


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1.2.4 Site selection for Biogas Plant

Distance: The distance between the plant and the site of gas

consumption should be less in order to achieve economy in

pumping of gas and minimizing gas leakage. For a plant capacity of

2 m3

, the optimum distance is 10 m Minimum gradient: For conveying the gas a minimum gradient

of1% must be made available for the line

Open space: The sun light should fall on the plant as

temperature between 15Cto30C is essential for gas generation atgood rate

Water table: The plant is normally constructed underground for

ease of charging the feed and unloading slurry requires less

labour. In such cases care should be taken to prevent the seepage

of water and plant should not be constructed if the water table is

more than 10 feet.

Seasonal run off: Proper care has to be taken to prevent the

interference of run off water during the monsoon. Intercepting

ditches or bunds may be constructed

Distance from wells: The seepage of fermented slurry may

pollute the well water. Hence a minimum of 15 m should be

maintained from the wells

Space requirements: Sufficient space must be available for day

to day operation and maintenance. As a guideline 10 to 12 m2 area

is needed perm3of the gas.

Availability of water: Plenty of water must be available as the

cow dung slurry with a solid concentration of7% to 9% is used

Source of cow dung / materials for biogas generation: The

distance between the material for biogas generation and the gas


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plant site should be minimum to economize the transportation

cost.


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1.3 DIGESTER DESIGNThe design of a digester is based on two factors:

Based on the amount of waste available and the gas produced

based on the wastes

Based on the needs

Most of the digesters are based on the second objective since it is easy to

adjust the feed available than to have insufficient

1.3.1 Design characteristics based on the size

Raw material availability: The gas production is proportional to the

amount of raw material digested.Type of material: C/N ratio of the raw material should be in the optimum

range for better digestion. If the raw material is an easily digestible one,

the size of the digester can be reduced proportionally.

Size of raw materials: The feed material should be cut into pieces so that

the surface area for the reaction is the maximum. Also, the slurry

produced should flow smoothly. The scum produced should be

minimized.

Heating requirements: If the digester is situated in cold areas, sufficient

heating arrangements should be provided to keep the digestion

temperature within the optimum range. Burying the digester under the

ground helps to minimize the temperature fluctuations of the ambient

around the digester

Mixing requirements: Providing a mechanism of mixing the feed inside

the digester helps to ensure the easy availability of feed to the bacteria for

the reactions. Also it provides proper slurry flow inside the digester and

avoids the formation of scum


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Construction materials available: Use of locally available expertise and

materials close to the site for the construction of a digester reduces the

cost. Fabrication from corrosion resistant materials such as wood,

ferrocement, concrete, brick or stone rather than metal may also reduce

costs by extending equipment life. Larger digesters require propermaintenance also. Removal of inert wastes such as sand and rocks

prevents wear on mechanical parts and extends equipmentlife

1.4 Biogas Technology

Biogas is produced from wet biomass through a biological conversion

process that involves bacterial breakdown of organic matter by micro-

organisms to produce CH4, CO2and H2O.The process is known as anaerobic digestion which proceeds in three

steps.

1. Hydrolysis

2. Acid formation

3. Methane formation

Hydrolysis

Organic waste of animal and plants contains

carbohydrates in the form of cellulose, hemi cellulose and lignin

A group of anaerobic micro-organisms breakdowns

complex organic material into simple and soluble organic

components, primarily acetates

The hydrolysis depends on bacterial concentration,

quality of substrate, pH (between 6 and 7) and temperature (30C to40C) of digester contents

Acid Formation

Decomposed simple organic material is acted upon by acetogenic

bacteria and converted into simple acetic acid


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Methane Formation

Acetic acid so formed becomes the substrate strictly foranaerobic methanogeric bacteria, which ferment acetic acid to CH4

and CO2

Biogas consists ofCH4andCO2traces of other gases asH2, CO,N2, O2and H2S

Gas mixture is saturated with water vapourThe methane content of biogas is about 60% which provides

a high calorific value to find use in cooking, lighting and

power generation

Hydrolysis Phase: (C5H10O5) n + H2O n (C5H12O6) (Glucose)Acid Phase: n (C5H12O6) CH3CH (OH) COOH (Lactic acid)Methane Phase: 4H2 + CO2 2H2O + CH4

CH3CH (OH) COOH +H2O +CO2CH3COOH + CH4(Acetic acid)

Table 1.2 Energy Density (Heating values) of various fuels

Sl. No. Primary Resources Energy Density

1 Coal: Anthracite

Bituminous

Coke

32-34 MJ/kg

26-30 MJ/kg

29 MJ/kg

2 Brown coal: Lignite (old)

Lignite (new)

Peat

16-24 MJ/kg

10-14 MJ/kg

8-9 MJ/kg

3 Crude petroleum

Petrol

Diesel

45 MJ/kg

51-52 MJ/kg

45-46 MJ/kg

4 Natural gas

Methane (85% CH4)

Propane

Hydrogen

50 MJ/kg,(42 MJ/m3)

45 MJ/kg,(38 MJ/m3 )

50 MJ/kg,(45 MJ/m3)

142 MJ/kg, (12 MJ/m3)


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Mixing Pit

Masonarywork

PartitionWall

Slurry

Outlet pipeInlet pipe

SupportPipe

Gas pipeFloatingGas Holder

Outlet tank

Spent slurry

Figure 1.1 Floating Drum Biogas Plant(KVIC Model)


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Slurry

Gas

Digester

GasValve

GasPipe

Loose Cover

Displacementtank

Foundation

100mm

Removableman hole

cover

Spent

Slurry

Inlet

Figure 1.2 Fixed dome biogas plant (Janta model)


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Table 1.3Comparison between fixed and floating dome digesters

Sl. No. Floating Drum Fixed Dome

1 High capital investmentHigh maintenance cost

LowLow (no moving part)

2 Steel gas holder needsreplacement due tocorrosion

No steel gas holder

3 Life span Digester : 30yearsGas holder : 5 to 8 years

Longer life span

4 Drum space cannot be usedfor other purposes

Space can be used for otherpurposes

5 Effect of low temperatureduring winter is more

Less

6 Suitable for dung. Other

organic materials will cloginlet pipe

Can be adapted / modified for

other materials along withdung slurry

7 Gas released at constantpressure

Variable gas pressure maycause slight reduction inappliance efficiency. Gaspressure regulator is a mustfor engine applications

8 Construction is known tomasons but drum fabrication

requires workshop facility

Dome construction is a skilled job & requires thorough

training of masons9 Locating & rectification ofdefects in drum are easy

Difficult

10 Requires less evacuationwork

More

11 In areas of higher watertable, horizontal plants couldbe installed

Construction of plant isdifficult in high water tableareas


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1.5 Factors affecting Anaerobic Digestion

TemperaturepHAvailability of feed materialCarbon-to-nitrogen (C/N) ratioConcentration of feedMixing and Feeding rateToxic materialsAnaerobic conditionRetention time1.5.1 Temperature

Temperature has a significant effect on anaerobic digestion of

organic material

The optimum temperature for Mesophilic flora is 30 - 40 C and

Thermophilic flora is 50 - 60 C

As the temperature increases, the total retention period

decreases and vice-versa

1.5.2 pH

Measure of pH value indicates the concentration of hydrogen ions and

micro organisms are sensitive to pH of the digested slurry

For optimum biogas production, pH can be varied between 6.8 and 7.2

Control on pH should be exercised by adding alkali when it drops below

6.6

1.5.3 Availability of feed material

Steady supply of substrate and continuous operation of the digester

ensures a higher output than intermittent use


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1.5.4 Carbon-to-nitrogen (C/N) ratio

Methanogenic bacteria need carbon and nitrogen for its survival

Carbon is required for energy while nitrogen for building cell

protein

The consumption of carbon is 30 to 35 times faster than that of

nitrogen

A favourable ratio ofC : N can be taken as 30 : 1

1.5.5 Concentration of feed

The anaerobic fermentation of organic matter proceeds best if the

feeding material contains 7-13 % of solid matter

The usual materials fermented in a biogas plant normally contain

higher percentage of solids and they are therefore usually diluted with

water

From experiments, it is found that a 1:1 (by volume) slurry of cow

dung and water, corresponding to a 10-12% of total solids, is effective

for optimum gas production

1.5.6 Mixing

Stirring of slurry inside the digester is desirable to simulate bacterial

action resulting in higher gas production, though it is not always

essential

Continuous feeding of fresh waste into the digester always induces

some movement in the mass of material in the digester, helping to

expose fresh undigested material to the bacteria

Normally, for small size plants, stirring is not provided

1.5.7 Toxic materials

The main toxic elements are : higher concentrations of ammonia,

soluble sulfides, metallic salts of Cu, Zn, Ni, Na, K, Ca, Mg, etc


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The materials in solution can only be toxic to digestion

1.5.8 Anaerobic Conditions

Inside the digester, strict anaerobic condition has to be maintained since

the methane producing bacteria is sensitive to the presence ofO2

1.5.9 Retention Time

It is the average length of time a sample of waste remaining in the

digester

For batch digestion, it is simply the time from the start-up to the

completion of the cycle

For continuous digestion, the HRT (Hydraulic Retention Time) is the

ratio between the volume of the digester contents to the volume of feed(m3 / (m3/day)). The optimum retention time is found to vary between

14 to 60 days


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1.6 BIOMASS

Biomass refers to the mass of biological material produced from

living processes which includes the materials derived from plants as

well as animals

Chemically biomass refers to hydrocarbons containing hydrogen,

carbon and oxygen which can be represented by C6n(H2O)5n

Biomass is a scientific term for living mater, more specifically any

organic matter that has been derived from plants as a result of

phosynthetic conversion process

Biomass is a sustainable resource that it is constantly being formed

by the interaction of air, water, soil and sunlight

Biomass is a renewable energy resource derived from the

carbonaceous waste of various human and natural activities.

The organic materials produced by plants, such as leaves, roots,

seeds, andstalks (stem)

The term biomass is intended to refer to materials that do not

directly go into foods or consumer products but may have alternative

industrial uses.

The total mass of living matter within a given unit of environmental

area. Plant material, vegetation, or agricultural waste used as a fuel

or energy source

Biomass is a complex mixture of organic materials, such as

carbohydrates, fats, and proteins, along with small amounts of

minerals, such as sodium, phosphorus, calcium, and iron. The main

components of plant biomass are carbohydrates (approximately

75%, dry weight) and lignin (approximately 25%), which can vary with

plant type

Common sources of biomass
http://www.answers.com/topic/carbohydratehttp://www.answers.com/topic/phosphorushttp://www.answers.com/topic/carbohydratehttp://www.answers.com/topic/phosphorus


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Woody biomass, Crop residues, Animal waste

agricultural wastes, such as corn stalks, straw, seed hulls,

sugarcane leavings, bagasse, nutshells, and manure from cattle,

poultry, and hogs

wood materials, such as wood or bark, sawdust, timber slash,and mill scrap

municipal waste, such as waste paper and yard clippings

Woody Biomass

This includes biomass in the form of trees; trees from forest, from farms,

commercial plantations etc. The use of woody biomass is mainly for

household and industrial application for making furniture, shelter,agricultural tools etc. Woody biomass also has applications supplying our

energy needs. In rural areas, woody biomass is used as fuel wood for

cooking purposes while in urban areas, characoal-an upgraded form

woody biomass is used for cooking.

Crop Residues

This includes crops and plant residues produced in the field. These are

the residues that remain after taking out seeds from the crops. For

instance, husk, bagasse, cereal straw, nut shells etc. The crop residues

have several applications. It can be used for livestock feeding, as manure

together with animal dung as source of nutrients for soil.

Animal Waste

The animal dung and poultry manure come in this category. Animal waste

is a good source of nutrients and is used as a fertilizer. Animal dung is

also used for cooking either directly by burning or converting it into

biogas, which is then burned to cook food. Thus animals also fulfill our

needs.

1.6.1. Advantages
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It is renewable source Energy storage is an in-built feature of it It is an indigenous source requiring little or noforeign exchange

The pollutant emissions from combustion ofbiomass are usually lower than those from fossil fuels

Commercial use of biomass may avoid or reduce theproblems of waste disposal in other industries, particularly

municipal solid waste in urban centres

The nitrogen rich bio-digested slurry and sludgefrom a biogas plant serves as a very good soil conditioner and

improves the fertility of the soil

Varying capacity can be installed; any capacity canbe operated, even at lower loads, with no seasonality involved

The forestry and agricultural industries that supplyfeed stocks also provide substantial economic development

opportunities in rural areas.

1.7 BIOMASS CONVERSIONS

Physical Method (Briquetting and Pelletization processes)

Direct combustion, such as wood waste and bagasse

(sugarcane refuge)

Thermochemical conversion(gasification and liquefaction)

Biochemical conversion(anaerobic digestion and fermentation)

1.7.1 Pyrolysis

Pyrolysis is the chemical decomposition of a condensed substance

by heating

Pyrolysis of organic materials produces combustible gases,

including carbon monoxide, hydrogen and methane, and other

hydrocarbons
http://en.wikipedia.org/wiki/Chemical_decompositionhttp://en.wikipedia.org/wiki/Condensedhttp://en.wikipedia.org/wiki/Chemical_decompositionhttp://en.wikipedia.org/wiki/Condensed


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1.7.2 Gasification

Gasification is the process of converting solid fuels to gaseous fuel

Gasification is a process that converts carbonaceous materials, such

as coal, petroleum, orbiomass, into carbon monoxide and hydrogen

by reacting the raw material at high temperatures with a controlledamount ofoxygen and/orsteam. The resulting gas mixture is called

synthesis gasorsyngas and is itself a fuel.

1.7.3 Fermentation

In a general sense, fermentation is the conversion of a carbohydrate

such as sugar into an acid or an alcohol

More specifically, fermentation can refer to the use of yeast to

change sugar into alcohol or the use of bacteria to create lactic acid

in certain foods

Fermentation occurs naturally in many different foods given the right

conditions, and humans have intentionally made use of it for many

thousands of years

Sugars are the most common substrate of fermentation, and typical

examples of fermentation products are ethanol, lactic acid, and

hydrogen

Industrial fermentation, the breakdown and re-assembly of

biochemicals for industry, often in aerobic growth conditions

In food science, fermentation may mean:

Fermentation (food), the conversion of carbohydrates into alcohols

or acids under anaerobic conditions used for making certain foods

1.7.4 Alcoholic Fermentation

In brewing, alcoholic fermentation is the conversion of sugar into

carbon dioxide gas (CO2) and ethyl alcohol

This process is carried out by yeast enzymes
http://en.wikipedia.org/wiki/Coalhttp://en.wikipedia.org/wiki/Petroleumhttp://en.wikipedia.org/wiki/Biomasshttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Steamhttp://en.wikipedia.org/wiki/Syngashttp://www.wisegeek.com/why-does-yeast-make-bread-rise.htmhttp://en.wikipedia.org/wiki/Industrial_fermentationhttp://en.wikipedia.org/wiki/Food_sciencehttp://en.wikipedia.org/wiki/Fermentation_(food)http://en.wikipedia.org/wiki/Coalhttp://en.wikipedia.org/wiki/Petroleumhttp://en.wikipedia.org/wiki/Biomasshttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Steamhttp://en.wikipedia.org/wiki/Syngashttp://www.wisegeek.com/why-does-yeast-make-bread-rise.htmhttp://en.wikipedia.org/wiki/Industrial_fermentationhttp://en.wikipedia.org/wiki/Food_sciencehttp://en.wikipedia.org/wiki/Fermentation_(food)


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1.8 Types of Gasifiers

Counter-current fixed bed (Up draft gasifier)

Co-current fixed bed (Down draft gasifier)

Cross-flow gasifier

Fluidized bed gasifier and Entrained flow gasifier

Table 1.4 Typical composition of producer gas

Application of Biomass Gasification Processes

Large scale applications (500 kW and above)

Medium scale applications (30-500 kW)

Small scale applications (7-30 kW)

Micro scale applications (1-7 kW)

Sl.No. Gas %

1 Carbon monoxide 18 22%

2 Hydrogen 13 19%

3 Methane 1 5%

4 Heavier hydrocarbons 0.2 0.4 %

5 carbon dioxide 9 12%

6 Nitrogen 45 55%

7 Water vapour 4%

Hearth Zone(Oxidation Zone)

Reduction Zone

Distillation Zone(Pyrolysis zone)

Drying Zone

Gas

Feed

Grate

Ash Zone

Air

Figure 1.3 Updraft gasifier

200C

400C

600C

950C

1300C
http://en.wikipedia.org/wiki/Fluidized_bedhttp://en.wikipedia.org/wiki/Fluidized_bed


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1.8.1 Updraft Gasifier

In the updraft gasifierthe feed is introduced at the top and theair at the bottom of the unit via a grate

Immediately above the grate the solid char (the residual solidremaining after the release of volatiles) formed higher up the gasifier is

combusted and the temperature reaches about 1000C. Ash falls through the grate at the bottom and the hot gases passupwards and are reduced.

Higher up the gasifier again, the biomass is pyrolysed and in thetop zone, the feed is dried, cooling the gases to around 200300C In the pyrolysis zone, where the volatile compounds arereleased, considerable quantities of tar are formed which condenses


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partly on the biomass higher up and partly leaves the gasifier with the

product gas

The temperature in the gasification zone is controlled by addingsteam to the air used for gasification, or by humidifying the air

Due to the low temperature of the gas leaving the gasifier, theoverall energy efficiency of the process is high but so also is the tar

content of the gas

The filtering effect of the feed helps to produce a gas with a lowparticulate content


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Ash pit

Pyrolysis Zone

Heart Zone(Oxidation Zone)

Air

Biomassfeed

Gas

Grate

Drying Zone

Air

Reduction Zone

Figure 1.4 Downdraft Gasifier

1.8.2 Downdraft Gasifier

In the downdraft gasifier, the feed and the air move in the samedirection. The product gases leave the gasifier after passing through

the hot zone, enabling the partial cracking of the tars formed during

gasification and giving a gas with low tar content

Because the gases leave the gasifier unit at temperatures about9001000C, the overall energy efficiency of a downdraft gasifier is low,due to the high heat content carried over by the hot gas

The tar content of the product gas is lower than for an updraftgasifier but the particulates content of the gas is high


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Drying Zone

Pyrolysis Zone

Reduction Zone

Oxidation Zone

Ash pit

Air Gas

Biomass feed

Grate

Figure 1.5 Cross draft Gasifier


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1.9.3 Cross-flow Gasifier

In a cross-flow gasifier the feed moves downwards while the air isintroduced from the side, the gases being withdrawn from the opposite

side of the unit at the same level

A hot combustion/gasification zone forms around the entrance of theair, with the pyrolysis and drying zones being formed higher up in the

vessel

Ash is removed at the bottom and the temperature of the gas leavingthe unit is about 800900C Gives a low overall energy efficiency for the process and a gas withhigh tar content

1.9 Types of Zone

1.9.1 Pyrolysis zone

Wood pyrolysis is an intricate process that is still not completely understood.

The products depend upon temperature, pressure, residence time and heat

losses. However following general remarks can be made about them. Upto the

temperature of200C only water is driven off. Between 200 and 280C carbondioxide, acetic acid and water are given off. The real pyrolysis, which takes

place between 280 and 500C, produces large quantities of tar and gasescontaining carbon dioxide (Tars can be easily defined as undesirable and

problematic organic products of biomass gasification). Besides light tars, some

methyl alcohol is also formed. Between 500 and 700C the gas production issmall and contains hydrogen. Thus it is easy to see that updraft gasifier will

produce much more tar than downdraft one. In downdraft gasifier the tars have

to go through combustion and reduction zone and are partially broken down.

1.9.2 Combustion zone

The combustible substance of a solid fuel is usually composed of elements

carbon, hydrogen and oxygen. In complete combustion carbon dioxide is

obtained from carbon in fuel and water is obtained from the hydrogen, usually


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as steam. The combustion reaction is exothermic and yields a theoretica

oxidation temperature of1450CThe main reactions, therefore, are:

C + O2 = CO2 (+ 393 MJ/kg mole) (1)

2H2 + O2 = 2H2O (- 242 MJ/kg mole) (2)

1.9.3 Reaction zone

The products of partial combustion (water, carbon dioxide and uncombusted

partially cracked pyrolysis products) now pass through a red-hot charcoal bed

where the following reduction reactions take place.

C + CO2 = 2CO (- 164.9 MJ/kg mole) (3)

C + H2O = CO + H2 (- 122.6 MJ/kg mole) (4)

CO + H2O = CO + H2 (+ 42 MJ/kg mole) (5)

C + 2H2 = CH4 (+ 75 MJ/kg mole) (6)

CO2 + H2 = CO + H2O (- 42.3 MJ/kg mole) (7)

Reactions (3) and (4) are main reduction reactions and being endothermic have

the capability of reducing gas temperature. Consequently the temperatures in

the reduction zone are normally 800-1000C. Lower the reduction zonetemperature (~ 700-800C), lower is the calorific value of gas.

Table 1.5 Biomass gasification chemical reactions

Gasification stage Reaction formula Reaction heat

Stage I:

Oxidation and otherexothermic reactions

C+2

1 O2CO Exothermal

CO+2

1 O2CO2C+O2CO2(C6H10O5)nnCO2+nH2OH2+ 2

1 O2H2OCO+H2OCO2+H2CO+3H2CH4+H2O


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Stage II:

Pyrolysis

(C6H10O5)nCxHz+nCO Endothermic(C6H10O5)nCnHmOy

Stage III:

Gasification(Reduction)

C+H2OCO+H2 EndothermicC+CO22COCO2+H2CO+H2OC+2H2CH4 Exothermic

Table 1.6 Types of Biomass and Properties

Type of Biomass Lower HeatingValue (kJ/kg)

MoistureContent (%)

AshContent(%)

Bagasse 7,700 - 8,000 40 - 60 1.7 - 3.8Coconut shells 18,000 8 4

Coffee husks 16,000 10 0.6

Cotton residues:

stalks

gin trash

16,000

14,000

10 - 20

9

0.1

12

Maize:

cobs

stalks

13,000 - 15,000 10 - 20 2

3 - 7Palm-oil residues:

fruit stems

fibers

shells

debris

5,000

11,000

15,000

15,000

63

40

15

15

5

Rice husk 14,000 9 19

Straw 12,000 10 4.4Wood 8,400 - 17,000 10 - 60 0.25 - 1.7

Peat 9,000 - 15,000 13 - 15 1 20

Charcoal 25,000 - 32,000 1 - 10 0.5 - 6


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1.10 Ethanol Fuel

Ethanol is also known as ethyl alcohol or fermentation alcohol

Ethanol provides a valuable liquid fuel alternative to a transportation

sector

Ethanol is a colorless, clear liquid that looks like water and is

completely miscible with it

It is widely used in medicines, lotions, tonics, colognes, rubbing

compounds, and solvents and also for organic synthesis Ethanol is more volatile than water, flammable, burns with a light blue

flame, and has excellent fuel properties for spark ignition interna

combustion engines

Ethanol has a somewhat sweet flavorwhen diluted with water; a more

pungent, burning taste when concentrated; and an agreeable ether-like

odor

Ethanol is a member of the alcohol family and has the chemica

formula C2H5OH in which C, H, and O refer to carbon, hydrogen, and

oxygen atoms, in that order

1.11 Ethanol production

1. Fermentation ofsugars derived from sugar, starch, or cellulosic materials

2. Reaction ofethylene with water

The formeris favored for production of fuel. The latterhas been used to make

industrial grade ethanol for solvents, cosmetics, medicines, and so on, but

purification of fermentation ethanol is displacing ethylene-derived ethanol for

these applications

1.11.1 Production of ethanol from cellulosic biomass


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Ethanol can be produced from biomass by the hydrolysis and sugar

fermentation processes.

Biomass wastes contain a complex mixture of carbohydrate polymers

from the plant cell walls known as cellulose, hemi cellulose and lignin.

In order to produce sugars from the biomass, the biomass is pre-

treated with acids or enzymes in order to reduce the size of the feedstock

and to open up the plant structure.

The cellulose and the hemi cellulose portions are broken down

(hydrolyzed) by enzymes or dilute acids into sucrose sugar that is then

fermented into ethanol.

The lignin which is also present in the biomass is normally used as a fuel

for the ethanol production plants boilers

1.11.2 Production of ethanol from sugar crops

The hydrolysis process breaks down the cellulosic part of the

biomass or corn into sugar solutions that can then be fermented into

ethanol

Yeast is added to the solution, which is then heated.

The yeast contains an enzyme called invertase, which acts as acatalyst and helps to convert the sucrose sugars into glucose and fructose

The fermentation process takes around three days to complete and is

carried out at a temperature of between 250C and 300C

1.11.3Production of ethanol from starch crops

Corn grain contains about 70% starch, 10 to 11% crude protein, 4.5 to

6.0% oil, 6% hemicellulose, 2 to 3% cellulose, 1% lignin, and 1% ash and isthe dominant choice for current fuel ethanol production by dry or wet

milling operations

In a typical dry mill, grain is milled to a powder, heated with water

addition to about 851C, mixed with alpha-amylase enzyme, held for up to

an hour, heated further to 110 to 1501C to liquefy the starch and reduce


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bacteria levels, cooled back to about 85C, and held with more alpha

amylase for about 1 hour

the stream is cooled further, and glucoamylase enzyme added to

complete conversion to sugars known as dextrose

This overall saccharification operation occurs by the hydrolysis

reaction:

(C6H10O5) n+nH2OnC6H12O6 C6H12O6 is a glucose sugar molecule formed when the alpha bonds

linking n units ofC6H10O5 in long chains of starch are broken and combined

with n molecules of water, H2O

Yeast then ferment glucose to ethanol and carbon dioxide

C6H12O62C2H5OH+2CO2


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The process flow for ethanol production is explained below

A simplified process flow diagram for production of ethanol from cane

sugar, corn, and cellulosic biomass. All have similar fermentation and

ethanol recovery operations but use different approaches to release sugars

and generate different co-products

Sugar can be directly extracted from sugarcane, and the residua

bagasse is used as a boiler fuel to provide much of the energy for the

extraction and ethanol production and recovery operations

In a corn dry mill, corn is ground, and enzymes and heat are added to

hydrolyze starch to sugars for conversion to ethanol, while the oil, protein,

and fiber in corn are recovered after fermentation as an animal feed known

as DDGS (Distillers Dried Grains)

Wet mills first fractionate corn to separate corn oil, corn gluten mea

(CGM), and corn gluten feed (CGF) to capture value for food and anima

feed, and the starch can then be hydrolyzed to sugars for fermentation to

ethanol For cellulosic biomass, heat and acids or enzymes hydrolyze the

hemicellulose and cellulose portions to release sugars that can be

fermented to ethanol


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1.12 Biodiesel

Biodiesel is a non-toxic, biodegradable diesel fuel made from vegetable oils,

animal fats, and used or recycled oils and fats

Biodiesel is made using the process oftransesterification

Biodiesel is produced by chemically reacting a fat oroil with an alcohol, in

the presence of a catalyst (sodium hydroxide)

The product of the reaction is a mixture ofmethyl esters, which are known

as biodiesel and glycerol, which is a high value co-product

Transesterification is the process of using an alcohol (e.g., methanol or

ethanol) in the presence of a catalyst, such as sodium hydroxide or

potassium hydroxide, to chemically break the molecule of the raw

renewable oil into methyl or ethyl esters of the renewable oil with glycerol

as a by-product

Biodiesel can be made from various components such as; vegetable oil,

animal fats, and waste or recycled oils and fats, such as waste fryer oil

Biodiesel is made by mixing methanol and sodium hydroxide to make

sodium methoxide

The sodium methoxide is then mixed with vegetable oil and allowed tosettle

Glycerin forms on the bottom, while the methyl esters (biodiesel) float to

the top

Biodiesel Production

Three Basic Methods to Making Biodiesel

There are three basic methods of biodiesel (methyl ester) production from oils

and fats.

They are;

Base catalyst transesterification of the oil with methanol.

Directed acid catalyzed esterification of the oil with methanol.

Conversion of the oil to fatty acids, and then to methyl esters with

acid catalysis


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Figure 1.7 Process flow for Biodiesel Production

Oil

WashWater

Reactor Separator

AcidulationandFFA

Separation

MethanolRemoval

Neutralizationand

MethanolRemoval

WaterWashing

Dryer

Methanol /water

rectification

FinishedBiodiesel

Methanol&

Catalyst

Acid

Free FattyAcid

Glycerol

(50%)

Acid

Water

Water

MethanolStorage

CrudeGlycerol

(85%)

MethylEsters


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Figure 1. 7 shows the schematic diagram of the processes involved in

biodiesel production from feedstocks containing low levels of free fatty

acids

This includes soybean oil, canola (rapeseed) oil and higher grades of waste

restaurant oils.

First the methanol and the catalyst (sodium hydroxide) are mixed. After the

methanol and catalyst are mixed, they go into a reactor, where the oil is

added to the mix and agitated for approximately one hourat 60C. Glycerin and methyl esters are the two major products created after the

reaction is complete and the excess methanol has been removed from the

mixture

Gravity is used to separate the two products, since they have different

densities

After separation from the glycerol, the methyl esters enters a neutralization

step and then pass through a methanol stripper, usually a vacuum flash

process before water washing

Acid is added to biodiesel to neutralize any residual catalyst and to splitany soap that have formed during the reaction

Soaps will react with acid to form water soluble salts and free fatty acids

The salts will be removed during the water washing step and the free fatty

acids will stay in the biodiesel

The water washing step is intended to remove any remaining catalyst

soaps, salts methanol, or free glycerol from the biodiesel

The glycerol stream leaving the separator is only about 50% glycerol

It contains some of excess methanol and most of the catalyst and soap

In this form, the glycerol has little value and disposal may be difficult

The methanol contents requires glycerol to be treated as hazardous waste


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The first step in refining the glycerol is usually to add acid to split soaps

into free fatty acids and salts

The free fatty acids are not soluble in the glycerol and will rise to the top

where they can be removed and recycled

After acidulation and separation of the free fatty acids, the methanol in the

glycerol is removed by vacuum flash process, or another type of

evaporator

At this point the glycerol should have a purity of approximately 85% and is

typically sold to a glycerol refiner

The methanol that is removed from the methyl ester and glycerol streams

will tend to collect any water that may have entered the process

This water should be removed in a distillation column before the methano

is returned to the process

1.13 Energy Plantations

Cultivation of any type of plants that store enormous amount of solar

energy within and thereby posses high fuel value is termed as Energy

Plantations

Common species of plantations Eucalyptus

Casuarina

Terminalia

Leucaena Sagassum (seaweed)

Water Hyasynth

Acavia


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Example: Design a biogas plant suitable to fulfil the cooking needs of a family of12

members. Estimate daily requirement of biogas, the number of animals required and

size of the digester. Make necessary assumption. Assume

350 litres of biogas is required per day per person for cooking and average

production of dung per animal per day as 10 kg. Also assume average gas

production from dung is about 40 litres/kg of fresh dung; slurry density as 1090kg/m3

and retention period is 50 days.

Step -1: Amount of gas required per day

Number of family members = 12 (adults)(Two children may considered as equivalent to one adult for cooking energy purpose

only)

Considering 350 litres/day/person for cooking

Total amount of gas required = 12 350 = 4200 litres/day(1000 litres of gas is equivalent to 1 m3 of gas)

Step 2: Number of animals required to fulfil daily gas requirement

Amount of gas produced from a kg of fresh dung = 40litres/kg

Total amount of dung required = Total gas required / gas per kg of dung

= 4200/40 = 105kg

Thus in order to have 105 kg of dung, number of cows required

= 105/10 = 10.5 say 11 cows

Step 3: Design of digester and gas holder

In order to make slurry, water should be added to equal amount of dung

Total mass of slurry = dung + water = 105 + 105 = 210 kg

Density of slurry = 1090 kg/m3

Volume of slurry per day = Total mass of slurry / density

= 210/1090 = 0.192m3

Retention period of slurry = 50 days


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Total volume of the digester = per day volume of slurry retention

period

= 0.192 50 = 9.63 m3

As about 90% volume is occupied by the slurry

Therefore required volume of digester = 9.63 / 0.9 = 10.7m3

Dimension of the digester

Depth to diameter ratio should between 1 and 1.3

7.10D3.14

D2

= m3

Thus diameter of digester D = 2.188 m

Depth of the digester H = 2.844 m


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1. A community biogas plant is used for the following needs of a village having 100 adults and 50

children. Cooking needs of the people of the village and five lamps of 100CP used for one hour in the

evening. Assume 350 litres of biogas is required for cooking per person per day; 125 litres of biogas

required for lighting per lamp per hour and average production of dung per animal per day as 10 kg.

Also assume average gas production from dung is about 40 litres/kg of fresh dung; slurry density as

1090kg/m3 and retention period is 50 days. Calculate the size, depth and dome height of the digester

and the number of cows required to feed the plant. Take dome height as 0.25D. and Depth as 1.3D

where D is the diameter of the digester.

Number of family members = 100+25 = 125 members

(Since two children may considered as equivalent to one adult for cooking purpose only)

Step-1:

Gas required for cooking alone = 350 125 = 43,750 litres/day

Gas required for lighting = 125 5 1 = 625 litres/day

Total amount of biogas required = 43,750 + 625 = 44375litres/day

Step-2:

Total amount of dung required = 44375/40 = 1109.375 kg

Number of cows required = 1109.375/10 = 110.93 = 111 say

Total mass of slurry = 1109.375 + 1109.375 = 2218.75kg

Density of slurry = 1090kg/m3

Therefore volume of slurry = 2218.75/1090 = 2.0355m3

Retention period = 50 days = 2.0355 50 = 101.78 m3

As about 90% volume is occupied by the slurry

Therefore required volume of the digester = 101.78/0.9 = 113.08 m3

Step-3:

Dimension of digester

Assume depth to diameter ratio as 1.3D:1.0D

32

m08.113D3.14

D =

Diameter of the digester D = 4.80m

Depth of the digester H = 1.3 4.80 = 6.24 m

Digester dome height Hdome = 0.25 4.80 = 1.2m.


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Fuel derived from organic matter (obtained directly from plants, or indirectly from

agricultural, commercial,domestic, and/orindustrial wastes) instead of from fossil products

See also fossil fuels.

any fuel derived from renewable biological sources, as plants or animal waste; esp., a liquid

fuel for automotive engines made from corn or soybean oil

Biofuels are fuels derived from living plants, animals or their byproducts which are not more

than 20-30 years old. Biofuels contain stored solar energy and are a renewable source

of energy, since the plants can be grown again. Unlike petroproducts, all biofuels are

biodegradable and do not damage the environment when spilled. As demand and prices of

crude oil increase, more countries are encouraging the use of biofuels by offering tax

incentives.

Wood from trees and manure from cattle (cow dung) are the most widely used biofuels used

for cooking and other household applications in poor countries. Biogas for cooking is

derived from industrial and household waste by the anaerobic digestion. Biogas contains

methane. Chemical processes can also be used to produce biogas from industrial waste

Microalgae may be used as an energy source in future, as their yield per acre is the highest

compared to other sources.
http://www.businessdictionary.com/definition/organic.htmlhttp://www.investorwords.com/3712/plant.htmlhttp://www.businessdictionary.com/definition/agricultural.htmlhttp://www.businessdictionary.com/definition/commercial.htmlhttp://www.businessdictionary.com/definition/commercial.htmlhttp://www.businessdictionary.com/definition/domestic.htmlhttp://www.businessdictionary.com/definition/industrial-waste.htmlhttp://www.businessdictionary.com/definition/product.htmlhttp://www.businessdictionary.com/definition/fossil-fuel.htmlhttp://www.businessdictionary.com/definition/organic.htmlhttp://www.investorwords.com/3712/plant.htmlhttp://www.businessdictionary.com/definition/agricultural.htmlhttp://www.businessdictionary.com/definition/commercial.htmlhttp://www.businessdictionary.com/definition/domestic.htmlhttp://www.businessdictionary.com/definition/industrial-waste.htmlhttp://www.businessdictionary.com/definition/product.htmlhttp://www.businessdictionary.com/definition/fossil-fuel.html


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Gas

Ratio compared toDry Air(%) Molecular

Mass- M -

(kg/kmol)

ChemicalSymbol

Boiling Point

Byvolume

Byweight

(K) ( oC)

Oxygen 20.95 23.20 32.00 O2 90.2 -182.95

Nitrogen 78.09 75.47 28.02 N2 77.4 -195.79

CarbonDioxide

0.03 0.046 44.01 CO2 194.7 -78.5

Hydrogen 0.00005 ~ 0 2.02 H2 20.3 -252.87

Argon 0.933 1.28 39.94 Ar 84.2 -186

Neon 0.0018 0.0012 20.18 Ne 27.2 -246

Helium 0.0005 0.00007 4.00 He 4.2 -269

Krypton 0.0001 0.0003 83.8 Kr 119.8 -153.4

Xenon 9 10-6 0.00004 131.29 Xe 165.1 -108.1


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Documents

UNIT I Course Material