Download - A Presentation on Bioenergy
-
8/13/2019 A Presentation on Bioenergy
1/30
B Y
A R T H U R D A N I E L D A D Z I E
M O R G A N J E S S E A S A R E
E S T I B A L I Z B O S I O D O R O
A Presentation on Bioenergy
-
8/13/2019 A Presentation on Bioenergy
2/30
Content
IntroductionResources of biomassEnergy Conversion Processesthermal conversionchemical conversion biological or biochemical conversion
BiogasForms of BioenergyEnvironmental and economic impact of bioenergy and biomass
-
8/13/2019 A Presentation on Bioenergy
3/30
introduction
The material of plants and animals, including their wastesand residues, is called biomass. It is organic, carbon-based,material that reacts with oxygen in combustion and naturalmetabolic processes to release heat.Such heat, especially if at very high temperatures, may beused to generate work and electricity. The initial materialmay be transformed by chemical and biological processes toproduce biofuels.
Examples of biofuels include methane gas, liquid ethanol,methyl esters, oils and solid charcoal.The term Bioenergy is sometimes used to cover biomass and biofuels together.
-
8/13/2019 A Presentation on Bioenergy
4/30
Biomass Resources
Forest and mill residues Agricultural crops and waste Wood wastes
Animal wasteLivestock operation residues Aquatic plantsFast growing trees and plants
Municipal and industrial waste
-
8/13/2019 A Presentation on Bioenergy
5/30
Biomass Resources
-
8/13/2019 A Presentation on Bioenergy
6/30
Biomass Conversion Processes
Biomass conversion methods can be classified based on; Conversion Technologies and The End products.
Conversion Technologies can be said to be through eitherBiological or biochemical processesChemical processes
Thermal processes.
-
8/13/2019 A Presentation on Bioenergy
7/30
Thermal conversion
Thermal conversion processes use heat as the dominantmechanism to convert biomass into another chemical form.The basic alternatives are combustion, torrefaction,pyrolysis, and gasification.
Direct combustion for immediate heat. Dry homogeneousinput is preferred.
They are differentiated principally by the extent to which thechemical reactions involved are allowed to proceed (mainlycontrolled by the availability of oxygen and conversiontemperature).
-
8/13/2019 A Presentation on Bioenergy
8/30
Thermal conversion processes contd
The output depends on temperature, type of input materialand treatment process. In some processes the presence of water is necessary andtherefore the material need not be dry. If output ofcombustible gas is the main product, the process is calledgasification.
-
8/13/2019 A Presentation on Bioenergy
9/30
Combustion
The oldest and most common method of harnessingenergy from biomass.It is simply the oxidation of wood/plant material to
produce heat.The heat produced can be used directly and it canalso be used for generating electricity. (CHP)
-
8/13/2019 A Presentation on Bioenergy
10/30
Gasification
A process that converts organic materials into carbonmonoxide, hydrogen and carbon dioxide and othercombustible gas. Achieved by reacting the material at high temperatures
(>700C), without combustion, with a controlled amountof oxygen and/or steam.The resulting gas mixture is called syngas (fromsynthesis gas or synthetic gas ) or producer gas and isitself a fuel.Syngas may be burned directly in gas engines, used toproduce methanol and hydrogen, or converted intosynthetic fuel.
-
8/13/2019 A Presentation on Bioenergy
11/30
Gasification
-
8/13/2019 A Presentation on Bioenergy
12/30
Chemical conversion processes
A range of chemical processes may be used to convert biomass into other forms, such as to produce a fuel that ismore conveniently used, transported or stored, or to exploitsome property of the process itself.
Biorefining is the process of "refining" multiple productsfrom biomass as a feedstock or raw material much like apetroleum refinery that is currently in use. A biorefinery is a facility like a petroleum refinery that
comprises the various unit operations and relatedequipment to produce various bioproducts including fuels,power, materials and chemicals from biomass.
-
8/13/2019 A Presentation on Bioenergy
13/30
Chemical conversion process contd
By producing multiple products, a biorefinery takesadvantage of the various components in biomass and theirintermediates therefore maximizing the value derived fromthe biomass feedstock. Inset is a biorefinery .
-
8/13/2019 A Presentation on Bioenergy
14/30
Biochemical conversion processes
Biochemical or biological conversion makes use of theenzymes of bacteria and other micro-organisms to breakdown biomass.In most cases micro-organisms are used to perform theconversion process: anaerobic digestion, fermentation andcomposting. Another chemical process used in converting straight and waste vegetable oils into biodiesel is transesterification.
Another way of breaking down biomass is by breakingdown the carbohydrates and simple sugars to make alcohol.
-
8/13/2019 A Presentation on Bioenergy
15/30
Anaerobic digestion
Anaerobic digestion is a series of processes in whichmicroorganisms break down biodegradable material in theabsence of oxygen.It is used for industrial or domestic purposes to manage waste and/or to release energy. Much of the fermentation used industrially to produce foodand drink products, as well as home fermentation, usesanaerobic digestion. Silage is produced by anaerobic
digestion .
-
8/13/2019 A Presentation on Bioenergy
16/30
Anaerobic digestion contd
Many microorganisms are involved in the process ofanaerobic digestion. These organisms feed upon the initialfeedstock, which undergoes a number of differentprocesses, converting it to intermediate molecules,
including sugars, hydrogen, and acetic acid, before finally being converted to biogas.Feedstocks can include biodegradable waste materials, suchas waste paper, grass clippings, leftover food, sewage, and
animal waste.The three principal products of anaerobic digestion are biogas, digestate, and water
-
8/13/2019 A Presentation on Bioenergy
17/30
Anaerobic digestion
-
8/13/2019 A Presentation on Bioenergy
18/30
Summary of conversion processes
Biological conversion:- Anaerobic DigestionFermentation
Thermal conversion:- CombustionGasificationPyrolysis
Chemical conversion:- Bio-refining.
-
8/13/2019 A Presentation on Bioenergy
19/30
Forms of Bioenergy
Bioenergy may exist in different forms. These are mainly;BiopowerHeat
BiofuelsCombined heat and power (co-generation)
-
8/13/2019 A Presentation on Bioenergy
20/30
Biopower
Biopower is electricity generated from combustion of biomass, either alone or in combination with coal,natural gas or other fuel (termed co-firing). Most biopower plants are direct-fired systems. That is,
biomass feedstock are burned in a boiler to producehigh-pressure steam which runs turbines connected toelectric generators.The electricity produced can be distributed for industrial,residential or commercial use. The steam generated from combustion of biomassfeedstock can also be used directly power mechanicalprocesses in industrial settings
-
8/13/2019 A Presentation on Bioenergy
21/30
Heat
Processes like combustion, pyrolysis and gasificationproduce heat in large quantities which is harnessed.
Gasifiers offer a flexible option for thermal applications, asthey can be retrofitted into existing gas fueled devices suchas ovens, furnaces, boilers, etc., where syngas may replacefossil fuels.
-
8/13/2019 A Presentation on Bioenergy
22/30
Biofuels
Biofuel is liquid, gas and solid fuels produced from twotypes of biomass materials plant sugars and starches(e.g., grains), and lignocellulosic materials (e.g., leaves,stems and stalks).
Liquid and gas biofuels are produced through fermentation,gasification, pyrolysis, torrefaction, and transesterificationconversion technologies. The primary use of liquid and gas biofuels is transportation
They include ethanol, biodiesel, syngas, biogas, methanol,char and bio-coal and bioethers.
-
8/13/2019 A Presentation on Bioenergy
23/30
Combined heat and power.
Combined heat and power (CHP), also known as co-generation, is the simultaneous production of electricityand heat from a single fuel source, including biomass.In a gas turbine CHP plant, hot exhaust gases from thecombustion process are captured in a heat recovery unitand used to heat steam which is then used in heating andcooling of various indoor environments. In steam boiler CHP plants steam is produced that runs
electric generators and for heating/cooling.
-
8/13/2019 A Presentation on Bioenergy
24/30
Environmental impact
Using biomass as a fuel produces air pollution in the form ofcarbon monoxide, carbon dioxide, NOx (nitrogen oxides), VOCs (volatile organic compounds), particulates and otherpollutants, in some cases at levels above those from
traditional fuels.Biomass systems can reduce waste energy from 66% to 25%compared to traditional fossil fuels, meaning a significantlysmaller amount of input material (biomass) is used,
therefore having a positive effect on the global environmentand use of fuel.
-
8/13/2019 A Presentation on Bioenergy
25/30
Environmental impact contd
Modern biomass systems use filters. These filters capturecarbon and other pollutants before they enter theatmosphere. Thus in the biomass lifecycle, the pollutantsare captured by trees and crops, they are burnt, pollutants
are captured and less are released back into theenvironment. Any pollutants released are then reabsorbed by trees and plants
-
8/13/2019 A Presentation on Bioenergy
26/30
Economic impact
In combination with a significant energy efficiency effort,there is almost nothing better for the local economy thanincreased reliance on biomass fuels. From amacroeconomic perspective, there are three different
engines that can be applied to drive local economicdevelopment;Economic growth through business expansion (earnings) oremployment
Import substitution; andEfficiency improvement
-
8/13/2019 A Presentation on Bioenergy
27/30
Pricing of biomass against production
-
8/13/2019 A Presentation on Bioenergy
28/30
BENEFITS
The biomass material acquisition is comparatively cheaper.Biomass is environmentally friendly compared to fossilfuelsBiomass can be sourced locally.The use of biomass fuel provides an economic incentive tomanage woodland which improves biodiversity.In rural economic development and stability: we spend billions of dollars each year importing oil, biomass couldreplace half of this and direct the rest to other sectors
-
8/13/2019 A Presentation on Bioenergy
29/30
Conclusion
Biomass provides low CO2 emissions, heat andpower. like other renewable energy sources, good planning
and managing will give higher efficiency. Systems for it use are still under-development andimproved utilisation of biomass is expected.Considering the benefits mentioned above; biomassis a promising source of renewable energy anddeveloping it should be a key issue.
-
8/13/2019 A Presentation on Bioenergy
30/30
References
www.bioenergyconsult.com/tag/biomass-combustion-process/http//en.wikipedia.org/wiki/gasifier
http//en.wikipedia.org/wiki/biomasshttp://www.biomassenergycentre.org.ukhttp//en.wikipedia.org/wiki/anaerobic digestion.http//www.wgbn.wisc.edu/http//en.wikipedia.org/wikihttp//en.wikipedia.org/Biomass_heating_system