This document summarizes information presented on biomass technologies. It discusses what biomass is, densification processes like briquetting, biomass combustion, gasifier technologies including types of gasifiers, biogas technology and types of biogas plants, and fermentation processes for producing ethanol. Key biomass conversion processes covered include solid fuel combustion, digestion, gasification, and fermentation.
HAND TOOLS USED AT ELECTRONICS WORK PRESENTED BY KOUSTAV SARKAR
biomass.pptx
1. Seminar on
Biomass
Presented by,
kale pratik dadaso
Department of Farm Power and Machinery,
Dr. A. S. College of Agril. Engg. and Tech.
M.P.K.V., Rahuri
2. What is biomass.
Densification of biomass.
Biomass combustion technology.
Gasifier technology.
Types of gasifiers.
Biogas technology.
Types of biogas
Fermentation technology.
3. Biomass is any organic material that is
renewable over time.
During the process of photosynthesis plants
use solar energy to convert carbon dioxide and
water into sugar and oxygen.
Biomass absorbs carbon while it grows and
returns it into atomosphere when it is
consumed.
Biomass can be converted into fuels through a
number of different processes including solid
fuel combustion, digestion, gasification, and
fermentation.
4.
5. Densification is the process of converting mass
of particle into compact product of high bulk
density.
Briquetting is one of the compaction
technologies used for the densification of
biomass.
Briquetting process includes collection of raw
material, preparation of raw material,
compaction, cooling and storage.
Briquetting technologies are divided into three
parts, high pressure, medium pressure and low
pressure compaction technology.
6. In high pressure briquetting the pressure
reaches more than 100 MPa. This type of
technology is used to compact the product
having high lignin content and
The temperature rises to 200 – 250°C in this
process which sufficient to fuse the lignin
material which acts as binding material.
In meduim pressure compaction machine
the pressure ranges 5 MPa to 100 MPa and
additional heat is needed to melt the lignin.
The low pressure machine works at the
pressure less than 5 MPa and additional
binding material is needed.
7.
8. The process increases net calorific value of
the product
The fuel is uniform in size and quality.
The product is easy to transport and store.
Helps to solve the problem of residue
disposal.
The process helps to reduce deforestation
by providing substitute fuel for wood.
The process reduces biodegradation of
residue.
9. Biomass combustion is the process which
consist of consecutive homogenous and
heterogenous reaction.
The main process steps are drying,
devolatilization, gasification, char
combustion, and gas-phase oxidation.
Combustion produces following types of
pollutants-
1. Unburnt pollutants such as CO, unburnt
carbon, tar, soot,etc
10. 2. Pollutant from complete combustion like
NO, NO2,CO2,H2O
3. Ash and other conatminants.
11. The process to convert biomass solid raw
material into fuel gas or chemical feedstock
gas (syngas) is called gasification or
thermochemical gasification.
In order to convert solid biomass into
inflammable gas, a substance to promote the
chemical reaction is necessary. This substance
is called the gasification agent, and mainly air
(N2, O2),oxygen (O2), H2O, or CO2 are applied
as an appropriate mixture.
Air (only O2 reacts) and O2 heat by oxidation,
and increased O2 decreases the effective
amount of inflammable gas.
12. Stage 1- Gasification process starts as auto-
thermal heating of the reaction mixture. The
necessary heat for this process is covered by
the initial oxidation exothermic reactions by
combustion of a part of the fuel.
Stage 2- In the second - pyrolysis stage, being
passed through a bed of fuel at high
temperature pyrolyzes combustion gases.
Heavier biomass molecules distillate into
medium weight organic molecules and C02. In
this stage, tar and char are also produced.
13. Stage 3- Initial products of combustion
carbon dioxide (CO2) and (H2O) are
reconverted by reduction reaction to carbon
monoxide (CO), hydrogen (H2) and methane
(CH4).
These are the main combustible
components of producer gas.
15. Design of gasifier depends upon type of
fuel used and whether gasifier is portable or
stationary.
Gasifiers are classified according to how the
air blast introduced in the fuel column.
The fixed bed gasifier has been the
traditional process used for gasification.
The most commonly built gasifiers are as
follows- updraft gasifiers, downdraft
gasifiers, crossdraft gasifiers.
16. • In updraft gasifiers (also known as
counter-current), air enters from below
the grate and flows upwards, whereas
the fuel flows downwards.
• An updraft gasifier has distinctly
defined zones for partial combustion,
reduction, pyrolysis, and drying.
• The gas produced in the reduction
zone leaves the gasifier reactor
together with the products of pyrolysis
from the pyrolysis zone and steam
from the drying zone.
• The resulting combustible producer
gas is rich in hydrocarbons (tars) and,
therefore, has a higher calorific value,
17. • The downdraft (also known as co-current)
gasifier is the most common type of
gasifier.
• In downdraft gasifiers, the pyrolysis zone
is above the combustion zone and the
reduction zone is below the combustion
zone.
• Fuel is fed from the top. The flow of air
and gas is downwards (hence the name)
through the combustion and reduction
zones.
• A downdraft gasifier is so designed that
tar, which is produced in the pyrolysis
zone, travels through the combustion
zone, where it is broken down or burnt. As
a result, the mixture of gases in the exit
stream is relatively clean.
• It produces gas with low tar content, which
is suitable for gas engines.
18. • In a cross-draft gasifier, air enters
from one side of the gasifier
reactor and leaves from the other.
• Cross-draft gasifiers have a few
distinct advantages such as
compact construction and low
cleaning requirements.
• Also, cross-draft gasifiers do not
need a grate; the ash falls to the
bottom and does not come in the
way of normal operation.
19. The gas from the gasifier burns completely;
it is clean, odourless and colourless.
The gasifier is also environment friendly
equipment without any harmful emission.
The producer gas can also be used to
replace diesel (upto 70-75 percent) in
standard diesel engine.
20. Biogas is one of the most widely used alternative
sources for the production of renewable energy.
It is result of decomposition of organic material by
large number of bacteria in absence of oxygen.
This process of breaking down organic material in
absence of oxygen is known as anaerobic digestion.
Biogas has a high calorific value and can be converted
into electricity and heat.
The fermentation remains is called digest, which is a
completely odourless liquid material with high
agronomic value, with improved features compared
to the starting material.
24. Gasholder and digester constructed as
single unit.
The digesters of such plants are completely
underground to maintain a perfect
environment for anaerobic fermentation.
There are main two types of biogas plants
◦ Janata biogas plant.
◦ Deenbandhu biogas plant.
25. • Provision for inlet and
outlet is constructed in the
form of tanks
• Produced gas rises and is
collected inside the dome.
• As pressure increases it
pushes slurry down
subsequently causing rise
in slurry level of tank
• The pressure coming out
of the tank is variable in
nature.
• The volume of gas inside
the tank is equal to the
volume of slurry displaced
in inlet and outlet tank.
26. • It is constructed by joining
two spheres of different
diameters at their bases.
• Slurry is fed through
concrete pipe and digested
slurry is taken out from
tank.
• The outlet of digested
sluury from tank is kept
below the outlet of gas to
avoid the entry of slurry
through gas outlet.
• This type of plant costs 30-
45% less than janata and
KVIC biogas plants.
27. • This plant consist of
digestion pit for digestion
of material and gas holder
tank for collection of gas.
• There is partition wall in
the digester which divides
it into two equal parts.
• Inlet and outlet are
connected by two pipes.
• Gas holder drum is
constructed of mild steel
and it fits into digester
tank like stopper.
• When gas is formed it
floats freely on the slurry
and pressure is always
constant.
28. Initial investment is low.
It is suitable for rural areas.
It can be locally generated and easily
distributed
It helps to improve the sanitary condition
and helps to reduce the pollution.
The byproduct is nitrogen rich manure
which can be used as advantage
Reduces use of traditional fuels which helps
to reduce deforstation.
29. Ethanol is produced from fermentation of
renewable raw material.
Strachy material is first converted into sugar
and then sugars are converted into ethanol.
The starch material is steamed for 1-2 hours at
2-3 atm pressure to gelatinize the starch.
It is then cooled and equal amount of water
and 10%malt is added.
When dextrin is formed the temperature is
gradually raised to 50°C. and dextrin is
converted into maltose and then into dextrose.
30. Yeast is then added and fermentation is
allowed for couple of days
The yeast converts sugar into ethanol and
then ethanol is sent through additional
distillation columns to increase the
concentration of ethanol.
