Bioenergy from wood

WOODY BIOMASS FOR ENERGY

COMPARISON OF BIOMASS WITH COAL / OTHER FOSSIL FUELS,

BIO-FUEL SOURCES, CHARACTERISTICS, CLASSIFICATION,

PROPERTIES, CRITERIA FOR CHOOSING TREE SPECIES FOR ENERGY PLANTATIONS , EXAMPLES

Comparison of bio-fuels with fossil fuels

Why bio-fuels?

Current contribution of bio-fuels to primary energy supply

ENVIRONMENT & BIOFUELS: BENIGN, RENEWABLE

• The fossil fuels - coal, oil and natural gas - are simply

ancient biomass. Over millions of years, the earth has

buried ages-old plant material and converted it into

fuels.

• But while fossil fuels contain the same constituents - as

those found in fresh biomass, fossil fuels are not

renewable because they take such a long time to create.

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Reclaim wasteland by growing biomass; Its Use is carbon neutral

• When a plant decays, it returns its chemical

matter into the atmosphere and is part of carbon

cycle. Fossil fuels are carbon locked away deep in

the ground; when they are burned on a large

scale, fossil fuels overload the earth’s atmosphere

with added CO2,SO2, and NOx. Biofuel has lower

sulphur and NOx emissions and can help

rehabilitate degraded lands.

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Energy Services,

Pumping, Lighting,

Cooking, Heating,

↑

↑

Impact on

economy

Electricity,

Fuels,

Cogeneration

↑

Equity

Social Structures

Empowerment

↑

Biomass

Conversion

Systems ↑

Environment

SUSTAINABLE

DEVELOPMENT

BIOMASS

PRODUCTION

Rural economics & environment

• Biomass-energy systems can increase economic

development without contributing to the

greenhouse effect since biomass is not a net

emitter of CO2 to the atmosphere and it is

produced and used on sustainable basis.

• Growing biomass is a rural, labour-intensive

activity, and can, therefore, create jobs in rural

areas and help stem rural-to-urban migration

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Improved natural resource management

• The use of biomass in larger commercial

systems based on sustainable, already

accumulated resources and residues [from

agro-industries] can help improve natural

resource management.

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Land use and cropping patterns

• Growing biomass provides convenient carriers to help promote other rural industries.

• The "multi-uses" approach: how land can best be used for sustainable development, what mixture of land use and cropping patterns will make optimum use of a particular plot to meet multiple objectives of food, fuel, fodder, societal needs etc.

• This requires a full understanding of the complexity of land use.

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Current contribution- biofuels

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• On a global basis, biomass contributes about 14% of the world's energy (55EJ or 25 M barrels oil equivalent). This offsets 1.1 Pg C of net CO2 emissions annually.

• Biomass based energy in developing countries: About 90% in countries such as Nepal, Rwanda, Tanzania and Uganda About 45% in India, 28% in China and Brazil

Current contribution - In European industrial countries / EU /USA:

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•It is 14% in Austria, 20% in Finland and 18% in

Sweden.

•It represents about 4% of the primary energy use

in both the EU and USA.

• In the EU this is equivalent to 2 EJ/year of the

estimated total consumption of 54 EJ. Estimates

show a likely potential in Europe in 2050 of 9.0-

13.5 EJ depending on land areas, yields, and

recoverable residues, representing about 17-30%

of projected total energy

Share of bio-energy in primary energy consumption in India

• In India, the share of bio-energy was estimated at around 36 % to 46 % of the total primary energy consumption in 1991 , and has come down to around 27 % in 1997.

• For cooking, water heating and village industry, use of firewood may have been substituted by LPG, kerosene and diesel. Though availability has improved, now prices are increasing. Improved cook stoves may also improve energy utilization efficiency.

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Rural India & bio-energy

• Before the advent of fossil fuels, energy needs for all activities were met by renewable sources such as solar, biomass, wind, animal and human muscle power.

• It is interesting to note that in rural India, traditional

renewables such as biomass and human and animal energy continue to contribute 80 % of the energy consumption [MNES, 2001].

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Technology Energy services provided

Biogas Cooking

• Heating

Electricity (local pumping, milling, lighting,

and possible distribution via utility grid

Producer

gas

Electricity (local pumping, milling, lighting,

and possible distribution via utility grid)

• Heating

Ethanol /

Bio-diesel

• Vehicle transportation

• Cooking

Boiler +

Steam

turbine

• Electricity (for industrial processing)

• Heating process heat

Biofuel +

Gas turbine

• Electricity (for industrial processing)

• Heating process heat

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Biomass is called "the poor woman’s oil,"

since women (and children) in rural areas

spend time collecting daily fuel wood needs

and suffer the brunt of indoor air pollution

caused by direct combustion of biomass for

cooking and heating.

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Fuel wood Cook stoves & indoor

air pollution:

58 percent of all human exposure to

particulate air pollution is estimated to

occur indoors in rural areas of

developing countries Better cook

stoves reduce this indoor air pollution

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Biomass production: multipurpose

activity

Bioenergy feed stocks can be produced in

conjunction with — food, fodder, fuelwood,

construction materials, artisan materials,

other agricultural crops, etc. Feedstock

production can help restore the environment

on which the poor depend for their

livelihoods:

Growing biomass, a multiple use activity

• Re-vegetating barren land, • protecting watersheds and harvesting

rainwater, • providing habitat for local species, stabilising

slopes or river banks, or • reclaiming waterlogged and salinated soils.

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Present problems in use of bio-fuels

Traditional biomass use is characterized by

• low efficiency of devices, scarcity of fuel-wood, drudgery associated with the devices used,

• environmental degradation (such as forest degradation) and low quality of life.

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Bio-energy activities can provide locally produced energy sources to:

• pump water for drinking and irrigation,

• light homes, schools, and health clinics,

• improve communication and access to

information,

• provide energy for local enterprises, and

• ease pressure on fuel wood resources.

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Biomass Utilization in Industrialized

Countries:

Converted into electricity and

process heat in cogeneration systems

(combined heat and power production)

at industrial sites or at municipal district

heating facilities.

Thus both produces a greater variety of

electricity (a few megawatts at an

average-sized facility) and process

steam to meet the processing needs of

a mill.

Develop: Modern Bio Energy Technologies [BET]

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•Modern ‘B E T’ offer opportunities to

conserve biomass through efficiency

improvements, and for conversion to

electricity and liquid and gaseous fuels.

• Bio-energy technologies based on

sustained biomass supply are carbon

neutral and lead to net CO2 emission

reduction if used to substitute fossil fuels.

IMPROVE PRODUCTIVITY OF BIOMASS SOURCES:

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•Biomass productivity can be improved

with good management, as in many

places now it is low, being much less

than 5 t / ha / year for woody species.

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•Increased productivity is the key to

both providing competitive costs and

•better utilization of available land.

•Advances have included the

identification of fast-growing species,

breeding successes and

•multiple species opportunities.

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•Advances have included from new

physiological knowledge of plant growth

processes, and

• manipulation of plants through

biotechnology applications, which could

raise productivity 5 to 10 times over

natural growth rates in plants or trees.

Sources of biomass

Primary and secondary sources,

Characteristics, categories, properties of biomass based bio-

fuels

Sources of bio-fuels

Primary:

• Forestry-Dense, Open; Social Forestry

• Agriculture, Animal Husbandry, Agroforestry

• Marine

Secondary:

• Industrial process byproducts, effluents,

• Municipal Waste

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Classification of biomass based on physicochemical properties:

• WOODY,

• NON-WOODY (Agro-residues, cultivated),

• WET [AQUEOUS] ORGANIC WASTE

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WOODY BIOMASS

• FORESTS

• PLANTATIONS (MULTI- PURPOSE TREES)

• TREES FROM VILLAGE COMMON LANDS

• HYDROCARBON PLANTS

• TREES BEARING NONEDIBLE OIL SEEDS

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Physical Properties of Solid Bio-fuels for combustion:

• Moisture Content,

• Particle Size and Size distribution

• Bulk Density & Specific gravity

• Higher Heating Value

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Chemical Composition of Solid Bio-fuels for combustion :

• Total Ash %,

• Solvent soluble %,

• Water Soluble %,

• Lignin %,

• Cellulose %,

• Hemi-cellulose %

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Chemical composition

• Wood is grouped as either hardwood or

softwood.

• Softwoods have 40–45% cellulose, 24–37%

hemicellulose and 25–30% lignin.

• Hardwoods contain approximately 40–50%

cellulose and 22–40% hemicellulose.

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Elemental Composition:

• Carbon

• Hydrogen

• Oxygen

• Nitrogen

• Sulphur

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Properties of Wet biomass for biomethanation process:

• C O D value

• B O D value

• Total dissolved solids

• Volatile solids

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Forestry, Energy Plantations and Agro-forestry

Forestry, Agro-forestry, and Energy Plantations

Current practice in India and future possibilities

Forest resource base-India

• 1 % of World's forests on 2.47 % of

world's geographical area.

• Sustaining 16 % of the world's population and 15 % of its livestock population.

• Forests fulfill nearly 40% of the country’s energy needs and 30% of fodder needs. Annual production of fuelwood, fodder and timber is 270MT(mill. tonnes), 280 MT and 12 Mill. cubic metres , respectively. (Plan. Com. 2002). Forest cover is about 20.7% of the area in 2005.

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Rural demand for Fuelwood for cooking

• Use of dung and agricultural waste is

widespread in agriculturally prosperous

regions with fertile soils and controlled

irrigation, such as the Punjab, Haryana, Uttar

Pradesh and northern Bihar, but wood

continues to be the main domestic fuel in less

endowed and poorer regions.

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•Price Changes: Fuelwood prices in India

increased fast between 1970 and 1985.

•But fuelwood prices have since stabilized.

•The rise in fuelwood prices during the period

1989– 97 was slightly less than the rise in the

wholesale price index (WPI).

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Forests

1. Tropical dense evergreen forests

2. Tropical semi-evergreen forests

3. Moist deciduous forests

4. Dry deciduous forests

Causes of tremendous pressure on

Forest resource base

• Exponential rise in human and livestock population

• increasing demand on land allocation to alternative uses such as agriculture, pastures and development activities.

• Insufficient availability, poor purchasing power of people in rural areas for commercial fuels like kerosene & LPG

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The National Forest Policy

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• Achieve a minimum of 33 % of total land

area under forest or tree cover from present

19.2% cover.

•Recognize the requirements of local people

for timber, firewood, fodder and other non-

timber forest produce-- as the first charge on

the forests,

• The need for forest conservation on the

broad principles of sustainability and

people’s participation.

Joint Forest Management system.

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•In total, 15.5 m. hectare of degraded forest

land has natural root stock available, which

may regenerate given proper management

under the JFM

• 9.5 m. hectare is partially degraded with

some natural rootstock, and another 6 m. ha

is highly degraded.

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•These last two categories together

constitute 15.5 m. hectare,

• which requires treatment through

technology-based

• plantation of fuel, fodder and timber

species with

• substantial investment and

technological inputs.

JFM-2:The emphasis will be on:

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• Fuel-wood and fodder plantations to meet

the requirements of rural and urban

populations.

•Plantations of economically important

species (through use of high-yielding

clones) on refractory areas to meet the

growing timber requirement.

• Supplementing the incomes of the tribal

rural poor through management and

development of non-timber forest products.

JFM-3: The emphasis will be on cont…

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• Develop and promoting pasture on suitable

degraded areas.

• Promote development of degraded forests

by adopting, through micro-planning, an

integrated approach on a watershed basis.

JFM-4: The emphasis will be on cont…

• Suitable policy initiatives on rationalization of tree

felling and transit rules, assured buy-back

arrangements between industries and tree

growers, technology extension, and incentives like

easy availability of institutional credit etc.

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Forestry in the New Millennium:

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To sum up, tropical India, with its adequate

sunlight, rainfall, land and labour,

is ideally suitable for tree plantations.

With the enhanced plan outlay for

forestry sector and financial support

from donor agencies, the country will

be able to march ahead towards the target of 33

percent forest cover.

Agro-forestry

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Integrates trees with farming, such as lines

of trees with crops growing between them

(alley cropping), hedgerows, living fences,

windbreaks, pasture trees, woodlots, and

many other farming patterns.

Agro-forestry increases biodiversity,

supports wildlife, provides firewood,

fertilizer, forage, food and more, improves

the soil, improves the water, benefits the

farmers, benefits everyone.

Energy Plantation: Growing trees for their fuel value

• A plantation that is designed or managed and operated to provide substantial amounts of usable fuel continuously throughout the year at a reasonable cost is called an 'energy plantation‘

• ‘Wasteland’-- not usable for agriculture and cash crops, is used for this activity

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Criteria for energy plantation

• Sufficient area of 'Wasteland‘, not usable for agriculture and cash crops, be made available for this social forestry activity

• Tree species favorable to climate and soil conditions

• Combination of harvest cycles and planting densities that will optimize the harvest of fuel and the operating cost--12000 to 24000 trees per hectare.

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Criteria for energy plantation-continued-

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• Multipurpose tree species-fuel wood supply & improve soil condition

• Trees 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

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Criteria for energy plantation-continued-

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• Species that can be found in similar ecological zones

• Produce wood of high calorific value that burn without sparks or smoke

• Have other uses in addition to providing fuel -- multipurpose tree species most suited for bio-energy plantations or social forestry

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Tree species for regions of India

Trees for energy plantations, their selection basis and utility

Indian TREES / WOOD:

• Leucaena leucocephala (Subabul)

• Acacia nilotica

• Casurina sp

• Derris indica (Pongam)

• Eucalyptus sp

• Sesbania sp

• Prosopis juliflora

• Azadiracta indica (Neem)

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HYDROCARBON PLANTS, OIL PRODUCING SHRUBS:

• Hydrocarbon-- Euphorbia group

• & Euphorbia Lathyrus

• OIL Shrubs-- Euphorbia Tirucali

• Soya bean

• Sunflower

• Groundnut

• Jatropha

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• It makes good yields for green manure.

• Leucaena yields fuelwood.

• Leucaena has great potential for carbon sequestration

• Leucaena Fixes Nitrogen.

• Leucaena is a legume, a tree that fixes nitrogen from the air. It is a fast growing nitrogen fixing tree (FGNFT), which can be profitably grown and used by both small and large farmers.

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Leucaena leucocephala

(Subabul)

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Leucaena produces firewood

Can produce furniture

make paper and fibers for rayon-cellophane

make parquet flooring

make living fence posts

make small woodcraft items

make fertilizer

make livestock feed

create shade for plants and banana crops

neem tree (Azadirachta indica)

• Tree used as windbreaks, fuelwood, and silvo-pastoral systems, for dry zones and infertile, rocky, sandy soils. The leaves, bark, wood and fruit of the neem either repel or discourage insect pests; these plant parts are incorporated into traditional soil preparation, grain storage, and animal husbandry practices.

• Neem - based biological pest control (BPC) products have been developed. The neem tree can provide an inexpensive integrated pest management (IPM) resource for farmers, the raw material for small rural enterprises, or the development of neem-based industries.

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JATROPA CURCAS [PHYSIC NUT]

• Jatropha curcas [ physic nut], is unique among biofuels. Jatropha is currently the first choice for biodiesel. Able to tolerate arid climates, rapidly growing, useful for a variety of products,

• Jatropha can yield up to two tons of biodiesel fuel per year per hectare.

• Jatropha requires minimal inputs, stablizes or even reverses desertification, and has use for a variety of products after the biofuel is extracted.

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Jatropha, continued

• What makes Jatropha especially attractive to India is that it is a drought-resistant and can grow in saline, marginal and even otherwise infertile soil, requiring little water and maintenance.

• It is hearty and easy to propagate-- a cutting taken from a plant and simply pushed into the ground will take root. It grows 5 to 10 feet high, and is capable of stabilizing sand dunes, acting as a windbreak and combating desertification.

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Jatropha projects are documented to be

carried out since 1991 with disappointing

results.

However, there is now more experience,

better expertise about the strengths and

weaknesses and success factors in India

available, even though not yet well compiled.

As well, Jatropha efforts have a much better

Government backing now than ten years

ago.

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In M.P., Babul ( Acacia nilotica) is the most

sought after wood species due to its high

calorific value. The next most popular are

Dhaoda ( Anogcisum latifolia) and Satputa

( Dalbergia panniculata). These are

cheaper than Babul but are inferior as fuels.

The ideal girth class is 25 to 45 cm, at

which size the logs can be used straight

away. Logs of larger girth have to be split,

demanding more time and expenditure,

while thinner logs burn too quickly.

Acacia nilotica: babul

• A useful nitrogen fixing tree found wild in the dry areas of tropical Africa and India

• plantations are managed on a 15-20 year rotation for fuelwood and timber.

• calorific value of 4950 kcal/kg, making excellent fuelwood and quality charcoal. It burns slow with little smoke when dry

• The bark of ssp. indica has high levels of tannin (12-20%)

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Pongamia pinnata

• A nitrogen fixing tree for oilseed

• Also called as Derris indica, karanga,

• Produces seeds containing 30-40% oil.

• is a medium sized tree that generally attains a height of about 8 m and a trunk diameter of more than 50 cm

• natural distribution of pongam is along coasts and river banks in India and Burma

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Liquid fuels from biomass

• Liquid fuels for motor vehicles such as ethanol, or

other alcohol and bio-diesel can be made based

on biomass.

• With increases in population and per capita

demand, and depletion of fossil-fuel resources,

the demand for biomass is expected to increase

rapidly in developing countries.

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Reference books

(Biomass is one of the

renewable energy sources)

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1. a) Discuss the terms Agro-forestry and Energy

Plantation.

b) What criteria are used in selecting species of trees

for such programs?

c) Enumerate different agro-residues available in India

and discuss their characteristics as sources of energy

2. a) For solid biomass used for combustion, what is the

significance of Proximate, Ultimate Analysis and Higher

Heating Value?

b) Give typical values for saw dust, bagasse, wood

char and rice husk.

b) Discuss fluidized bed combustion of woody

biomass.

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3. a) Discuss pyrolysis of biomass for (i) char and (ii) liquid

fuel production.

b) Explain down-draft gasifier with gas purification for

producer gas.

4. a). Discuss cogeneration system involving steam-injected

gas turbine as applicable to biomass fuel.

b). Explain combined cycle with inter-cooled steam injected

gas turbine.

c). Discuss case studies on combined cycle cogeneration

systems developed in cane sugar industry