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Sources biomass

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Energy sources in rural areas can be supplemented by woody, non-woody agro -residue, and degradable aquatic biomass. Process inputs can give small industries supplying biofuels.

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Sources biomass

  1. 1. BIOENERGY 1. Biomass: sources, characteristics & preparation:  Sources and classification of biomass available for energy production.  Chemical composition and properties of biomass  Energy plantations  Preparation of biomass for fuel applications: Size reduction, Briquetting of loose biomass, Drying, and Storage and handling of biomass. SOURCES: The material of plants and animals is called biomass. Bio-energy is energy derived from biomass. Before the development of technology based on coal, lignite, crude oil and natural gas (fossil fuels) bio-fuels were the sources of heat energy. Woody biomass is product of forestry and trees from different agroforestry activities of smaller intensity. Timber (used for commercial purpose) and fuel wood are obtained from the forests besides minor forest produce. Commercial plantations like rubber and plants/trees that yield hydrocarbon can be a source of byproduct fuel. Agriculture yields by annual harvest a large crop residue biomass part of which can be a source of rural biofuels. Plants that grow in wastelands are also potential energy crops. Nonedible oils from trees are a byproduct liquid fuel. Non -edible vegetable oils can be used as liquid fuels. By trans-esterification reaction between the oil and an alcohol in presence of an alkaline catalyst, esters can be produced that are potential substitute for diesel as engine fuel. 1
  2. 2. Sources of three categories of biomass WOODY NON-WOODY(cultivated) WET ORGANIC WASTE FORESTS FOOD CROPS ANIMAL WASTES WOODLANDS CROP RESIDUES MANURE, SLUDGE PROCESSING RESIDUES MUNICIPAL PLANTATIONS (MULTI- PURPOSE TREES) HYDROCARBON SOLID WASTE NONEDIBLE OIL SEEDS PLANTS WASTE STARCH & SUGAR SOLUTIONS TREES FROM VILLAGE ENERGY CROPS: (SUGAR OTHER INDUSTRIAL COMMON LANDS CANE BAMBOO) EFFLUENTS (B O D) Biomass that is used for producing bio-fuel may be divided into woody, nonwoody and wet organic waste categories. The sources of each are indicated below. Animal manures and wastewaters containing organic putrefiable matter can be treated by anaerobic digestion or biomethanation to produce biogas as a fuel. Starchy and sugar wastewaters can be substrates for fermentation processes that yield ethanol which is a potential liquid fuel. BIOMASS CONVERSION METHODS FOR PRODUCING HEAT OR FUELS: Controlled decomposition of low value biomass to derive its energy content in a useful form is the purpose of the bio-energy programs. Biomass energy conversion may give a mixture of bio-fuel and. by product. Examples are given below. Bio-fuels derived from biomass can be solid, liquid and gas fuels that can be used for combustion in specially designed furnace, kiln and burners. 2
  3. 3. PRIMARY BIOMASS SECONDARY CO-PRODUCT PRODUCT WOOD CHAR (PYROLYSIS) PYROLYSIS OIL WOOD CHAR (GASIFICATION) PRODUCER GAS ANIMAL MANURE BIOGAS (AN. DIGESTION) FERTILIZER Bio-fuel production from primary biomass may utilize thermo-chemical, biochemical and catalytic conversion processes (see following table) Conversion process chosen depends on the properties of the primary biomass available. THERMOCHEMICAL BIOCHEMICAL CATALYTIC CONVERSION PYROLYSIS ANAEROBIC DIGESTION HYDROGENATION GASIFICATION FERMENTATION TRANS-ESTERIFICATION COMBUSTION HYDROLYTIC ENZYMES SYN.GAS PROCESS 3
  4. 4. Forest resources of India: India’s is sustaining 16 % of the world’s population and 15 % of its livestock population on 2.47 % of world’s geographical area and has just 1 % of world’s forests. o Forest area cover (i.e., the area notified as forest) in 1997: 76.52 million hectares, which is 23.28 % of the total geographical area of India. o The aggregate demand for fuelwood for the country in 1996 was 201 million tonnes, i.e., 213.8 kg per capita per year for a population of 940 million. The current sustainable production of fuelwood from forests is 17 million tonnes and from farm forestry and other areas is 98 million tonnes. There is a deficit of 86 million tonnes of fuelwood, which is being removed from the forests as a compulsion. o Forest resource base has tremendous pressure on it and availability is not catching up with demand for firewood. World Environment Day: June 5 o State Forest Departments and Community based organizations have Joint Forest Management Programs to prevent degradation and to regenerate forest areas. Distribution of forest areas in States: o In Andaman & Nicobar area, forests occupy 86.9% of the total geographical area, whereas in Haryana, forests occupy 3.8%. o Arunachal Pradesh, Himachal Pradesh, Manipur, Mizoram, Nagaland and Tripura have over 50% of their land areas under forests while Gujarat, Jammu & Kashmir, Punjab & Rajasthan have less than 10%. The forest in other states range between 10 and 50 % of their land areas and the per capita forest area of India is 0.07 hectares. 4
  5. 5. Causes of deforestation: o Exponential rise in human and livestock population puts increasing demand on land allocation to alternative uses such as agriculture, pastures, human settlements and development activities. o Insufficient availability of commercial fuels in rural areas as well as the lack of purchasing power of the rural poor and urban slum dwellers makes them dependent on firewood and wood char as fuels for cooking. Energy Crisis of Rural and Urban poor in India: o Nearly 75% of the rural population of India is dependent on bio-fuels (firewood, agricultural residues, and cow dung) for meeting 80% of their energy needs. Similarly the urban poor, including the slum dwellers who constitute 25 – 30% of the urban population are heavily dependent on biofuels. This is because of their low purchasing power and limited availability of the commercial fuels-kerosene and LPG. Consequences of inefficient and high consumption of wood biomass for energy: o Destroying biomass resources at a rate faster than that of their regeneration may lead to depletion of forests and desertification. o Forests, which are earth’s largest depository (sink) of carbon dioxide, diminish the green house effect. Growing gap between biomass consumption and regeneration leads to a crisis of sustainability. WOODY BIOMASS USE SHOULD BE A BALANCED & EFFICIENT ONE o TECHNOLOGICAL INNOVATION ON BIOMASS MUST CONCENTRATE ON: IMPROVING ITS PRODUCTION, TRANSFORMATION AND APPLICATIONS FOR ENERGY. 5
  6. 6.   WOOD BIOMASS IS AN ENDANGERED LIFE SUPPORT SYSTEM. IT SHOULD BE UTILISED IN A SUSTAINABLE WAY. TREES / WOOD: Leucaena leucocephala (Subabul) (50 m3/ha/year) Acacia sp Casurina sp Derris indica (Pongam) Eucalyptus sp Sesbania sp Prosopis juliflora Azadiracta indica (Neem) HYDROCARBON PLANTS: Euphorbia group Euphorbia Lathyrus OIL PRODUCING SHRUBS: Euphorbia Tirucali Soyabean Sunflower Groundnut 6
  7. 7. Environmental impact of biomass utilization for energy: In developing countries, trees are often cut down because they are the only source of fuel for the population. This can lead to environmental damage. The habitats of wild animals are destroyed. Soil is eroded because tree roots are no longer present to bind it together. This soil may be washed down into rivers, which then silt up and flood. But the destruction of trees and forests is a worldwide environmental problem with deforestation accounting for 18% of the greenhouse effect today. New trees must replace the ones that are cut down if we are to protect the global climate and the lives of people in the developing countries. Reference: Forests as biomass energy resources in India by B. N. Dwivedi and O. N. Kaul in Biomass Energy Systems, Edited by P.Venkata Ramana and S. N. Srinivas, British Council and T E R I, N. Delhi, 1996. Energy Plantation: Growing trees for their fuel value on ‘Wasteland’ or land that is not usable for agriculture and cash crops is social forestry activity. A plantation that is designed or managed and operated to provide substantial amounts of usable fuel continuously throughout the year at a reasonable cost may be called as ‘energy plantation’ Suitable tree species and land with favorable climate and soil conditions of sufficient area are the minimum resource required. Depending on the type of trees, the tree life cycle, the geometry of leaf bearing branches that determines the surface area facing the sun, the area required for growing number of would be evaluated. Combination of harvest cycles and planting densities that will optimize the harvest of fuel and the operating cost, are worked out. Typical calorie crops include 12000 to 24000 trees per hectare. 7
  8. 8. Raising multipurpose tree species on marginal lands is necessary for making fuel wood available as well as for improving soil condition. Trees for fuel wood plantations are those that are capable of growing in deforested areas with degraded soils, and withstand exposure to wind and drought. Rapid growing legumes that fix atmospheric nitrogen to enrich soil are preferred. Species that can be found in similar ecological zones, and have ability to produce wood of high calorific value that burn without sparks or smoke, besides having other uses in addition to providing fuel are the multipurpose tree species most suited for bioenergy plantations or social forestry programs. AZADIRACTA INDICA (NEEM), LEUCAENA LEUCOCEPHALA (SUBABUL), DERRIS INDICA (PONGAM), AND ACACIA NILOTICA (Babool) are examples of tree species for the above plantations. AGRO-RESIDUES: Agriculture yields by annual harvest a large crop residue biomass part of which can be a source of rural bio-fuels. AGRO-RESIDUE IN INDIA (POTENTIAL AVAILABILITY - 1995-96) MT = Million tons Agro-residue India, MT T.Nadu, MT Wheat Straw 83.3 9.2 Rice Husk 39.8 3.3 Maize Cobs 2.8 Pearl Millet straw 9 0.6 Sugar Cane Bagasse 93.4 Coconut shell 3.4 0.4 Coconut pith 3.4 Groundnut shells 2.6 0.6 Cotton Stalks 27.3 0.8 Jute Stalks 2.7 8
  9. 9. Table: Estimated potential for biomass energy : 1015 J y-1(1015 J y-1 = 320MW) Estimated total potential bio-fuel resources harvested per year for various countries(1978): Source Sudan Brazil India Sweden U.S.A. Animal Manure 93 640 890 18 110 Sugar Cane 660 1000 430 --- 420 Fuelwood 290 3200 420 160 510 Urban Refuse 5 94 320 23 170 Municipal Sewage 2 11 66 1 5 Other --- --- --- ---- 630 Total Potential 1000 4800 2100 200 1800 Present national energy 180 2700 5800 1500 72000 5.5 1.8 0.4 0.13 0.03 consumption Ratio potential to consumption Ref: Vergara, W. and Pimental, D.(1978)’Fuels from biomass’, in Auer, P.,(ed.), Advances in Energy Systems and Technology, vol.1, Academic Press, New York, pp 125-73 9
  10. 10. Estimated quantity of waste generated in India (1999): Waste Quantity Municipal solid Waste 27.4 million tones/year Municipal Liquid Waste 12145 million liters/day (121 Class1 and 2 cities) Distillary (243 nos) 8057 kilolitres/day Press-mud 9 million tones/year Food and Fruit processing waste 4.5 million tones /year Dairy industry Waste 50 to 60 million litres / day 3 (C O D level2 Kg/m ) Paper and Pulp industry Waste 1600m3 waste water/day (300 mills) 52500 m3 waste water/day Tannery (2000 nos) Source:IREDA News, 10(3):11-12, 1999, V.Bhakthavatsalam Properties of Biomass Physical Properties: Moisture Content, Particle Size and Size distribution Bulk Density & Specific gravity Proximate Analysis: Moisture Content Volatile Matter Fixed Carbon Ash or mineral content Chemical composition and heat content: 10
  11. 11. Elemental Analysis: Carbon Hydrogen Oxygen Nitrogen Sulphur Higher Heating Value: Chemical Composition: Total Ash %, Solvent soluble %, Water Soluble %, Lignin %, Cellulose %, Hemi-cellulose % Wet and biodegradable biomass: C O D value & B O D value, Total dissolved solids & Volatile solids BIOMASS PREPARATION FOR FUEL USE: Preliminary treatment of biomass can improve its handling characteristics, increase the volumetric calorific value, and fuel properties for thermo-chemical processing. It can increase ease of transport and storage. Examples: CHIPPING, CHOPPING, DRYING, GRINDING, BRIQUETTING ETC. Fuel wood requires drying in air and chopping for best result in cook stoves. Saw dust requires drying and briquetting to increase its bulk density. Industrial boilers require uniformly smaller sizes of wood for feeding their furnaces. Predrying of biomass to moisture levels of below 20% (oven dry basis) enhances efficiency of combustion in cook stoves and industrial boilers. 11
  12. 12. For production of high or medium pressure steam by using biomass the best choice of equipment is the water tube boiler. It has a large combustion area surrounded by banks of vertical water tubes, which makes it suitable for biomass fuels. Biomass fuels have a high content of volatile matter and lower density and bulk density compared to solid fossil fuels; as a result , biomass fuels need a large space (relatively ) above the fuel bed to prevent flaring volatile material from impinging upon the chamber wall and causing damage to it over a period of time. Shell boilers are unsuitable for biomass fuels because of the restricted diameter of the furnace tube and high risk of damage to the tube wall by flame impingement. Additionally demand for uniform fuel quality and size by shell boilers are relatively stricter. Other types of end use equipment that are suitable for size reduced biomass include cyclone furnaces, fluidized bed systems and the controlled combustion incinerator. Cyclones furnaces are adaptable to use of wood waste s fuel. Briquetting technologies: Reference: ’Biomass feed processing for energy conversion’ P. D. Grover, in Biomass Energy Systems, Ed. P. Venkata Ramana and S. N. Srinivas , T E R I and British Council, N. Delhi(1996) pp 187-192 The proven high pressure technologies presently employed for the briquetting of biomass are by the piston or the ram type press and the screw or the extruder type machines. 12
  13. 13. Both the machines give briquettes with a density of 1-1.2 gm/cc and are suitable as industrial solid fuels. The screw type machines provide briquettes with a concentric hole that gives better combustibility and is a preferred fuel. These briquettes can also be more conveniently deployed in small furnaces and even cook-stoves than solid briquettes generated by a ram press. Biomass densification-A solid(fuel) solution. N.Yuvraj, Dinesh Babu, TERI, New Delhi. TERI Newswire, 1-15 December, 2001, page 3. 13
  14. 14. In India, briquettes are mostly made from groundnut shell, cotton stalk, saw dust, coffee husk, bagasse, mustard stalk and press mud. While the Southern region of India produces briquettes mostly from groundnut shell and saw dust, Western and Northern regions produce bagasse, groundnut shell, cotton stalk, mustard stalk and press mud briquettes. As a recent addition municipal solid waste is also densified for use as fuel in process industries (tea, tobacco, textile, chemical, paper, starch, tyre re-treading, tiles, etc) for thermal applications. Biomass & Bio-energy 14, no5-6, pp 479-488, 1998 ‘A techno-economic evaluation of biomass briquetteing in India’ A.K.Tripathi, P.V.R.Iyer and Tarachand Khandapal (I I T, N.Delhi) tarak@ces.iitd.ernet.in Various types of raw materials used for briquetteing are: ground-nut shells, cotton stalks, bagasse, wood chips, saw dust, and forest residues. Pyrolysed biomass can also be used. Materials can be fine granulated, coarse granulated or stalky. Material may be dry or wet with various moisture content. After a material is dried and crushed the pellets may be formed under pressure with effect of heat, Biomass & Bio-energy 18(3):223-228(2000) ‘Characteristics of some biomass briquettes prepared under modest die pressures’ Chin,O.C and Siddiqui, K.M, Universiti Sains Malaysia,31750,Perak, Malaysia kmust@hotmail.com 14

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