Bioenergy is renewable energy made available from materials derived from biological sources

1. BIOENERGY & BIOGAS
M.SRIDEVI
II M.SC MICROBIOLOGY
18PY15
AYYA NADAR JANAKI AMMAL COLLEGE
Department of microbiology

2. INTRODUCTION
• Bioenergy is renewable energy made available from materials derived from
biological sources. Biomass is any organic material which has stored sunlight in the
form of chemical energy. As a fuel it may include wood, wood waste, straw, and
other crop residues, manure, sugarcane, and many other by-products from a variety
of agricultural processes.

3. BIOENERGY TYPES
• Traditional: comes mostly from solid biomass sources. i.e. wood, and other biomass
pellets.
•Advanced: requires converting biomass into liquid or gas form in order to produce
electricity, i.e. biogas, liquid biofuel, ethanol, and biodiesel.

4. BIOENERGY CYCLE
Bioenergy needs a continuous carbon cycle between the atmosphere and the earth.
•In this cycle, carbon dioxide is taken from atmosphere in plant processes i.e.
photosynthesis, and converted into biomass. From this process additional co2 is
produced and converted into energy.

5. PRIMARY ENERGY CONVERSION TECHNOLOGIES
• Combustion - direct combustion of biomass is the most common way of converting
biomass to energy - both heat and electricity. Compared to the gasification and
pyrolysis it is the simplest and most developed.
• Gasification - gasification is a high-temperature (1200-1400 Degree Celsius) thermo
chemical conversion process but the process is used for production of gas, instead of
heat.
• Pyrolysis - thermal decomposition occurring in the absence of oxygen. We use
pyrolysis to produce a liquid fuel, bio-oil or pyrolysis oil. It is also called a
biochemical process, as it uses microorganisms to produce bioenergy.

6. BIOMASS
• Biomass is organic matter from plants, microorganism grown on land and water
and their derivatives. The energy obtain from biomass is also called the biomass
energy. It is a renewable energy source. Because organic matter generated
everyday. Coal, petroleum, natural gas are not come in biomass category because
they produce from dead, burried biomass under high pressure and temperature
during several millions of year.

7. TYPES OF BIOMASS
Biomass are classified in three group…..
• 1. Biomass from cultivated like fields, crops, forests etc.
• 2. Biomass derived from wastes like municipal waste, animal dung
etc.
• 3. Biomass converted into liquid fuels.

8. • In first group the biomass is directly converted into energy by burning the biomass,
Second group the biomass is fermented anaerobically to obtain gaseous fuel like bio-
gas.

9. BIOMASS CONVERSION PROCESSES
1. Direct combustion
2. Thermochemical conversion
3. Biochemical conversion
Direct combustion:-
• Combustion is the oldest and most frequently applied process to
extract the energy content from solid biomass. During combustion,
most of the energy is released in form of heat. Different
thermodynamic processes can be used to transform part of this heat
into electric power.

10. Figure: How to produce electricity by direct
combustion.

11. THERMOCHEMICAL CONVERSION
• Thermochemical conversion the process convert the biomass
and its residues to fuel, chemicals and power using
gasification heating of biomass with about one third of
oxygen is necessary for complete combustion produce
mixture of co2 and hydrogen known as syngas. Pyrolysis
heating biomass in absence or produce a liquid pyrolysis oil.
They both are use as fuel.

12. BIOCHEMICAL CONVERSION
• Biochemical conversion by micro-organic biomass to biofuel are
slow process taking place low temperature. The principle conversion
process is fermentation. Fermentation is a process of decomposition
of organic matter by micro-organism.
• Example fermentation, decomposition of sugar to form ethanol and
carbon dioxide by yeast and ethanol forming acetic acid in making
vinegar.

13. Figure: Biochemical conversion

14. BENEFITS FROM BIOENERGY
• Using waste as a source of energy provides a good way to dispose or process it,
producing energy on the way.
• As it is a renewable and abundant resource, waste is a very efficient way to provide
a reliable source of energy.
• Using bioenergy is more environmentally friendly, as its carbon emission balance
is near neutral.
• Setting up a bio energy facility can be a potential source of local employment.
• Bioenergy is one solution to the substitution of oil.
• The by-product of bioenergy production can sometimes be used, for example as a
fertilizer.

15. BIOGAS
• It refers to a mixture of different gases like fuel gas, sewer and in
India known as Gobar gas. Gas produced by the breakdown of
organic matter in the absence of oxygen. Biogas can be produced
from raw materials such as agricultural waste, municipal waste, plant
material, sewage, green waste or food waste. It is a renewable energy
source. Biogas can be produced by anaerobic digestion with
anaerobic bacteria, which digest material inside a closed system.

16. SUBSTRATE
• Plant & animal biomass
• Animal biomass- cattle dung, manure from poultry, goats &
sheep slaughter house & fishery wastes
• Agricultural waste

17. DOME TYPE GAS PLANT
• This type of biogas plant developed by china. In china design it is
usual to provide a main hole cover at the top inlet and outlet are
connected at a mid point of digester. Upper part of digester above
liquid surface provide storage space for biogas. When gas is
produced level of digester liquid drops whereas that in outlet rises
with height difference between the two varying gas pressure. This
difference in height help to regulate gas pressure within digester over
a wide range.

19. MOVEABLE DRUM TYPE PLANT
• This type is also known as floating dome type biogas plants. A
floating-drum plant consists of a cylindrical or dome-shaped digester
and a moving, floating gas-holder, or drum. The gas holder floats
either directly in the fermenting slurry or in a separate water jacket.
The drum in which the biogas collects has an internal and/or external
guide frame that provides stability and keeps the drum upright. If
biogas is produced, the drum moves up, if gas is consumed, the gas
holder sinks back.

20. ADVANTAGES OF BIOGAS PLANTS
• Reduces burden on forests and fossil fuels
• Produces a clean fuel - helps controlling air pollution
• Provides nutrient rich (N & P) manure for plants
• Control water pollution by decomposing sewage , animal dung and
human excreta.

21. CONCLUSION
• Using biomass can be a very efficient way to reduce carbon
emissions in the atmosphere, and is also a good way to have a
sustainable source of energy for our municipalities. By building new
infrastructures and developing new skills, viable plans can be
delivered on.

22. REFERENCE
• https://www.slideshare.net/bhaskarchoubey/bio-energy-48239864
• https://www.slideshare.net/PrachetSokhiya/biogas-57684254
• https://www.slideshare.net/Rachnasinha3/bioenergy-61206088