12417638315 Mechanical Engineering Mradul Yadav NITK

7/28/2019 12417638315 Mechanical Engineering Mradul Yadav NITK

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Name: Mradul Yadav Registration No: 12417638315 Branch: Mechanical Engineering

Semester: 6th Semester College: NITK Surathkal

Biomass Energy

Biomass energy and various methods to efficiently use biomass energy and Conversion ofbiomass into pellets for pellets for improved efficiency.

Biomass can be defined as the raw organic material which has stored sunlight energy in the

chemical form via process of photosynthesis. Biomass works on the principle that whenever there

is a carbon, its easy to generate the energy. The best example is grass and wood because grass and

wood are observed to have 50 % carbon. In short, Plant matter created by the process of

photosynthesis which uses solar energy can be termed as biomass. For a plant, leaves act as solar

collector and branches and stem act as battery and thus obtained biomass in the form of chemical

energy. Usually solar energy and wind energy are the main source for all biomass. It can be

obtained from plants, leaves, grass, pig manure, poultry manure, municipal solid waste, kitchen

waste, industrial waste, sugarcane waste, dead body parts of plants and animals, human excrete.

Biomass is considered as environment friendly as it absorbs the carbon dioxide which it releases in

the atmosphere while consuming as fuel. Biomass is an important source of renewable energy and

after the coal, oil and natural gas it is considered as most important fuel. Biomass is responsible for

the generation of biomass energy.

Biomass energy:

Energy obtained from biomass is known as biomass energy. As a result of photosynthesis when

biomass is produced by the plants, energy conversion takes place from the energy from sunlight to

the chemical energy and that combined various atoms to form carbohydrates molecules. Until thedead plants and animals or dead waste does not undergo any decomposition or conversion process,

the energy captured in the dead matters remains.

Hence, when molecules are destroyed by combustion, only part of the chemical energy stored in

biomass is released. Energy can be produced from both plant matter and animal matter except the

plant and animal matter which is generated by geologic processes to create fossil fuels such as oilor coal as they do not come under the category of biomass.
http://teeic.anl.gov/glossary/glossary.cfm#73http://teeic.anl.gov/glossary/glossary.cfmhttp://teeic.anl.gov/glossary/glossary.cfmhttp://teeic.anl.gov/glossary/glossary.cfm#73


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For making available biomass in the usable form as renewable energy source, lot of research is

going on and there are many processes or methods to convert the biomass into usable form. Those

processes may use the biomass directly for various purposes such as heating or can convert intosome other form such as liquid bio-fuel.

To convert Biomass into usable form:

Basically there are four most important conversion processes:

1. Physical method

2. Incineration3. Thermochemical Process

4. Biochemical Process

1. Physical method :Physical methods can be explained as process to convert the biomass into physical form.

i) PelletizationPellets mean small pieces of wood which contains lot of water. In this process,Moisture is removed first by drying the biomass and then the biomass without moisture

undergo the process of pulverization and then finally carried out by the process of

extrusion to convert into toothpaste and then finally it is taken as pulverized wood form

in the cylinder.

ii) BriquettingBriquetting can explain as the crushing of solid fuel which can increase the calorific

value by removing the moisture content from the biomass. This process is used for

mass production. The first step of this process is to get coal and then it undergo

distillation process and finally the gas produced by coal is known as coal gas.

iii)Expelling agro-productsAgro-products can be defined as the products from agriculture such as groundnut oil,

mustard oil. Since, directly use of the oil in not permitted because of the less calorific

value and high initial viscosity thats why agro-products has to be expelled. The main

reason for expelling agro-products to reduce the viscosity of agricultural products (oil)

and this process is known as Trans-esterization.

Biodiesel Production from Biomass:

The production of biodiesel takes place from vegetable oils (commonly used soybeanoil), animal fats, etc. in the presence of catalyst which is usually sodium or potassium

hydroxide and alcohol. Biodiesel fuels can be used in the diesel vehicles directly and

but usually it is mixed in the ratio of 5% to 15 %. Presently there is lot of research

going on the production of biodiesel from the algae which can produce biodiesel 100

times more than normal vegetable or soybean oil.


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iv)Extraction of fuelThis process can be explained as the cutting of plants to obtain the milky latex

produced via process of photosynthesis and which can be used as a fuel. Euphorbia

Lythris is the tree which gives such type of milky latex in a large amount and this latex

can be used as fuel and can be a replacement for petroleum.

2. IncinerationIncineration is one of oldest and most common process to convert biomass into usable

form. This process can be explained as the process which involves direct combustion of

any fuel which will generate heat and that heat can be used for transforming into energy.

This type of energy can be directly used for various purposes like cooking, heating and for

many industrial applications. For example: direct combustion of wood for cooking purpose,

Charcoal as fuel in the steam power plant. Charcoal is nothing but a further product of the

coal. It can also be used for generating electricity.

3. Thermochemical ProcessThermochemical process can be explained as conversion of Thermal energy into chemicalenergy. This is a process which requires heating but not burning. In this process, the

organic matter is heated in the presence of low oxygen to convert the biomass into the raw

form and then convert them into the solid, liquid or gaseous fuel. This gaseous fuel can be

directly used for steam generators and various industrial applications.

i) PyrolysisPyrolysis can be explained as a process of heating of biomass in the absence of oxygen at a

high temperature. This process is basically used for the production of charcoal whichcontains ash (around 3 %) which is generally used in the metallurgical absorption

application. In this process, heating of biomass (say bituminous coal) takes place at 6000 C

which will result in the removal of moisture and it is heated again for the reduction of ashesfrom the coal and finally it decomposes into the solid fuel which is nothing but charcoal.

Here the biggest advantage is that unlike other process , production of carbon dioxide does

not takes place here .


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ii) GasificationGasification is one of the newest methods for electricity generation. Gasification process isused for the production of coal gas. Basically Gasification can be explained as a process

that converts biomass into carbon monoxide, hydrogen and carbon dioxide . The

gasification process takes place at high temperatures around 1000

0

C in the presence ofoxygen and results in the formation of synthetic gas commonly known as syngas which is

more efficient than direct combustion of the original fuel. The advantage of the syngas is

that it can be burned directly to create methanol and it can converted easily into a syntheticfuel.

iii)TorrefactionThe torrefaction process can be explained as the thermo-chemical processing by the use of

heat in the absence of oxygen and moisture at an intermediate temperature of around 250degree and which leads to formation of dark colored solid which is known as bio-coal. This

bio-coal is generally used for heating purpose at homes and it is also very useful forindustries as a fuel as it is having less smoke than many fuels.

4. Biochemical ProcessBiochemical process is the most important process for the conversion of biomass into

usable form. Biochemical process takes place in the presence of the enzymes of bacteria

and other micro-organisms for the decomposition of the biomass. The decomposition of

biomass takes place in the presence of some of common bacteria such as methane

bacterium, methano coccus, methano sarcina, methano genium, methano thermus,

methanobium, methano halobium.

i) Alcohol FermentationAlcohol fermentation takes place in the absence of oxygen and in the presence of catalyst.

This process is acidic in nature with pH ~ 4-5. In this process, the alcohol is produced by

fermentation process of a sugar-rich biomass. The raw materials required for alcohol are

wood, barleys, grapes, wheat, rice and peat root. In alcohol fermentation, first the organic

matter having sufficient amount of starch is taken and which is then heated to convert into

the sugar and fermentation process takes place in the presence of yeast at the temperature

of 32o

C and result in the formation of ethyl alcohol which is then distilled and then

blended with another fuel such as diesel. The purpose of adding ethyl alcohol is to reduce

emissions.

Fermentation Reaction:

C6 H12 O6 (Hexose) ------------> 2C2H5OH (Ethyl alcohol) + 2CO2 (Carbon dioxide)
http://en.wikipedia.org/wiki/Carbon_monoxidehttp://en.wikipedia.org/wiki/Hydrogenhttp://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Hydrogenhttp://en.wikipedia.org/wiki/Carbon_monoxide


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ii) Anaerobic fermentation

Anaerobic fermentation is used for production of gaseous fuels. This process takes place inthe absence of oxygen due to the reason that bacterial growth takes place at faster pace in

the absence of oxygen. Here in this process, the biomass (human, animal and agricultural

waste) undergoes micro-bacterial activity in the absence of oxygen and thus leads to theformation of methane and carbon dioxide and then methane is stored in vessel for further

use as natural gas consists mostly of methane.

Some of above conversion process to convert biomass into usable form are not as efficient as other

process. There it is necessary to take care of efficiency in the present era of advanced technology.

Conversion of Biomass into pellets

Biomass is converted to pellets for improving the efficiency because biomass pellet is solid bio-fuel of high quality. Conventional biomass fuels are having many drawbacks like low energy

density and high moisture content whereas biomass pellets are having properties like high energydensity, low moisture content and homogenous shape and size. Pellets have better definedcomposition, e.g. with respect to moisture content. These properties are even more useful when it

comes to fuel storage and transportation. These properties lead to the increase in efficiency. Not

only efficiency but also these biomass pellets contributes only slightly to aggravate the greenhouseeffect andclimate change, which is largely due to carbon dioxide(CO2) produced by burning fossilfuels.Conclusion:

Today when the non-renewable source is getting depleted, we started looking for alternatives and

the best alternative is generation of energy from biomass. Biomass is not a new name for us as it is

existing since past thousands of years such as people in the ancient era used to cook food byburning the wood. Biomass is a demanding industry now since it is available at very low cost

because of the lot of effective organic waste all around. Basically biomass opens the door to a new

unpolluted and cleaner environment by saving the non-renewable sources of energy getting

exhausted. Biomass also helps to have a cleaner surrounding since it is generated by organic waste.

It is also environmental friendly and helps in maintaining the global climate because Biomass

emits lesser amount of carcinogenic elements in comparison to the fossil fuels. Since past many

years, Fossil fuels have taken place over biomass as the major source of energy, but biomass

energy has a very growing market and there are lot of opportunities for biomass energy as there is

big concern for the environmental and economic issues due to inflation, due to this scientists and

researcher are keep on exploring the alternatives for the non-renewable source of energy such asbiomass. Biomass now days, not only used for cooking and heating purposes but also as a fuel for

the vehicle and for the generation of electricity and for various industrial processes. Biomass

energy can be used for both industrially and domestically purposes and Hence, in this present era

when the world is facing the climate issues and depletion of non-renewable sources, there is a need

of switching over the biomass energy at a much faster rate and there is a need of finding many

other methods for the conversion of biomass into usable form.
http://www.biomassenergy.gr/en/articles/technology/en/articles/technology/biomass/251-significant-biomass-properties-part-1-moisture-contenthttp://www.biomassenergy.gr/en/articles/technology/en/articles/technology/biomass/90-biomass-pellets-as-a-mean-of-encountering-climate-change-threatshttp://www.biomassenergy.gr/en/articles/technology/en/articles/technology/biomass/90-biomass-pellets-as-a-mean-of-encountering-climate-change-threatshttp://www.biomassenergy.gr/en/articles/technology/en/articles/technology/biomass/90-biomass-pellets-as-a-mean-of-encountering-climate-change-threatshttp://www.biomassenergy.gr/en/articles/technology/en/articles/technology/biomass/251-significant-biomass-properties-part-1-moisture-content


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References:

Power Plant Engineering by P K Nag

http://www.centreforenergy.com

http://teeic.anl.gov/(Tribal energy and environment information)

http://www.eesi.org(Environmental and energy study institute)

http://www.crest.org/(Centre for renewable energy and sustainable technology)

http://www.nrel.gov(National renewable energy laboratory)

Name: Mradul Yadav

Registration No: 12417638315

Branch: Mechanical Engineering

Semester: 6th

Semester

College: NITK Surathkal
http://www.centreforenergy.com/http://www.centreforenergy.com/http://teeic.anl.gov/http://teeic.anl.gov/http://www.eesi.org/http://www.eesi.org/http://www.crest.org/http://www.crest.org/http://www.nrel.gov/http://www.nrel.gov/http://www.nrel.gov/http://www.crest.org/http://www.eesi.org/http://teeic.anl.gov/http://www.centreforenergy.com/

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12417638315 Mechanical Engineering Mradul Yadav NITK