MSE0290 Biomass Eduard Lat õš ov Nature of biomass Contents Resources Utilisation Technologies Planning Summary Nature of biomass Nature of biomass Biomass mainly in the form of wood is the oldest form of energy used by humans ID: 801596
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Slide1
Slide2Sustainable
Energy TechnologiesMSE0290
Biomass
Eduard
Lat
õš
ov
Slide3Nature
of
biomass
Contents
Resources
Utilisation
Technologies
Planning
Summary
Slide4Nature
of
biomass
Slide5Nature
of
biomass
Biomass, mainly in the form of wood, is the oldest form of energy used by humans.
Traditionally
, biomass has been utilized through direct combustion, and this process is still widely used in many parts of the world.Source: http://www.heatilator.com/Shopping-Tools/Blog/How-to-Buy-a-Wood-Fireplace-Part-1-of-2.aspxRead more: Biomass resource facilities and biomass conversion processing for fuels and chemicals, Ayhan Demirbaş, Energy Conversion and ManagementVolume 42, Issue 11, July 2001, Pages 1357–1378
Slide6Source
: http://eng.marmore.com.tr/what-is-renewable-energy-and-biomass-
Nature
of
biomass
Slide7Nature
of
biomass
Source
:
https://www.iea.org/publications/freepublications/publication/2012_Bioenergy_Roadmap_2nd_Edition_WEB.pdfTraditionally, direct combustion. Now….
Slide8Nature
of
biomass
Traditionally,
direct combustion
. Now….
Slide9Nature
of
biomass
Classification
Slide10Nature
of
biomass
Manual for biofuel users
Author: Villu Vares, Ülo Kask, Peeter
Muiste, Tõnu Pihu, Sulev Soosaar, Tallinna Tehnikaülikool,
Classification
Slide11Manual for biofuel users
Author: Villu Vares, Ülo Kask, Peeter
Muiste, Tõnu Pihu, Sulev Soosaar, Tallinna Tehnikaülikool,
Nature
of
biomass
Classification
Slide12Nature
of
biomass
Sustainable?/!
Slide13Nature
of
biomass
The critical difference between biomass fuels and fossil fuel, is that of
fossil
and contemporary carbon. Burning fossil fuels results in converting stable carbon sequestered millions of years ago into atmospheric carbon dioxide (when the global environment has adapted to current levels). Burning biomass fuels however, returns to the atmosphere contemporary carbon recently taken up by the growing plant, and currently being taken up by replacement growth.
Source: http://www.biomassenergycentre.org.uk/portal/page?_pageid=76,535178&_dad=portal&_schema=PORTAL
Sustainable?/!
Slide14Source
:
https://www.iea.org/publications/freepublications/publication/2012_Bioenergy_Roadmap_2nd_Edition_WEB.pdf
Nature
of
biomass
Sustainable?/!
Slide15Sustainable?/!
Nature
of
biomass
Slide16Nature
of
biomass
Sustainable?/!
Slide17Nature
of
biomass
Properties
Slide18Nature
of
biomass
Components of solid fuel
Properties
Slide19Nature
of
biomass
Example
:
The following relationship is valid between the ash content in the dry matter and that in the as-received fuel (Aar): A = Aar x 100/(100 – Mar), where A is the ash content and M the moisture content. As the moisture content of fuel varies a lot, in reference tables the content of ash and volatiles is given on dry matter basis.
Properties
Components of solid fuel
Slide20Nature
of
biomass
The calorific value is usually expressed in MJ/kg or kJ/kg
T
he net (lower) versus gross (higher) calorific values The higher (gross) calorific value is calculated assuming that the water vapour in flue gas both from the fuel moisture content and as a combustion product of hydrogen has completely condensed. The condensation heat of water vapour in flue gases is not taken into account for calculation of the lower
(net) calorific value.
PropertiesCalorific valueDifference is mainly caused by moisture!
Slide21Nature
of
biomass
Mostly,
the flue gas is discharged from the boiler to the stack at the temperature of
over 100 °C, i.e., at the temperature much higher than the dew-point and under such conditions the condensation energy of water vapour remains unused.
PropertiesCalorific valueThe higher the moisture content and hydrogen content are, the bigger is the difference between the gross (higher) and net (lower) calorific values!
Slide22Nature
of
biomass
Properties
Calorific value
Boiler
efficiency is >100%?Can be in condensing boilers!Reason: lower (net) calorific value as a
bases for calculations!100%(HIGHER)15% - to
evaporate85% (left HIGHER)100% (lower)FUEL ENERGYCOMBUSTIONHEAT LOSSES5% (HIGHER)5.9% (lower)
AVAILABLE HEAT100 MWh85MWh15MWh5 MWh80 MWh
BOILER EFFICIENCY
80% (HIGHER)
94.1 (
lower
)
Slide23Nature
of
biomass
Properties
Calorific value
100%
(HIGHER)15% -
to evaporate85% (left HIGHER)100% (lower)FUEL ENERGYCOMBUSTIONHEAT LOSSES5% (HIGHER)5.9% (lower)
AVAILABLE HEAT100 MWh85MWh15MWh5 MWh80 MWh
BOILER EFFICIENCY80% (HIGHER)94.1 (lower)CONDENSE 50%, 7.5 MWh87.5 MWh
87.5%
~103%!!!
Slide24Nature
of
biomass
Properties
The calorific value
can
be either that of a moist (ar), dry (d) or dry ash-free (daf) fuel. The calculation formulae for the net (lower) and gross (higher) calorific values are (Hd – hydrogen content by the weight % in dry fuel; calorific value in MJ/kg):
Calorific valueFOR INFORMATION:
Slide25Nature
of
biomass
Fusibility
of
ash1 – the initial state: before heating the peak of ash cone is sharp;IT – initial point of deformation: the sharp peak is rounding;ST – softening temperature, the ash cone deforms to such extent that the height of the structure reduces to the size of its diameter (H = B); HT – the point of formation of hemisphere or, the cone collapses and becomes dome-shaped (H = 1/2·B); FT – flow temperature, the liquid ash dissipates along the surface. beginning of deformation (initial temperature) IT = 1150 – 1490 °C; softening temperature
ST = 1180 – 1525 °C; the point of hemisphere formation HT = 1230 – 1650 °C; flow temperature FT = 1250 – 1650 °C.
Slide26Nature
of
biomass
Fusibility
of
ashSLUGGING PROBLEMS
Slide27Resources
Slide28Resources
T
he
global distribution of photosynthesis, including both oceanic phytoplankton and terrestrial vegetation. Dark red and blue-green indicate regions of high photosynthetic activity in ocean and land respectively.
Slide29Resources
The earth's natural biomass replacement represents an
energy supply of around
3
000 EJ (3×1021 J) a year, of which just under 2% in 1998 was used as fuel. It is not possible, however, to use all of the annual production of biomass in a sustainable manner. One analysis provided by the United Nations Conference on Environment and Development (UNCED) estimates that biomass could potentially supply about half of the present world primary energy consumption by the year 2050.Source:
Ramage J, Scurlock J. Biomass. Renewable energy-power for a sustainable future. In: Boyle G, editor. Oxford: Oxford University Press; 1996
Slide30Utilisation
Slide31Utilisation
TOTAL
Comparison of primary bioenergy demand in this roadmap and global technical bioenergy potential estimate in 2050
Source
:
https://www.iea.org/publications/freepublications/publication/2012_Bioenergy_Roadmap_2nd_Edition_WEB.pdf
Slide32Bioenergy for Heat and Power
Utilisation
Slide33Utilisation
Bioenergy for Heat and Power
Slide34Utilisation
Bioenergy for Heat and Power
Organisation
for Economic Co-operation and
Development
List available here: http://www.oecd.org/about/membersandpartners/list-oecd-member-countries.htm
Slide35Utilisation
Bioenergy for Heat and Power
Slide36Utilisation
Bioenergy for Heat and Power
CO2 emission reductions from bioenergy electricity
and bioenergy use in industry and buildings compared to
a business as usual scenario (6°C Scenario)
Slide37Cumulative technology contributions to power sector emission reductions in ETP 2014 hi-Ren Scenario, relative to 6DS, up to 2050
Utilisation
Slide38Biofuels for Transport
Utilisation
Slide39Utilisation
Biofuels for Transport
Slide40Utilisation
Biofuels for Transport
Slide41Technologies
Slide42Technologies
Slide43Technologies
Slide44Technologies
… different technologies.
Focus on direct burning.
Slide45Boiling point 100
o
C pressure 760 mmHg = 0,101 MPa
Boiling – without temperature increase
evaporation
2260 kJ/kg to evaporate 1 kg of H2O at 100oC
LiquidSteam
Technologies
Rankine cycle
Slide46Blue area – heat losses in condenser
, red area – useful energy of turbine
. Goal – increase red area. How?1). Decrease condensing process
(4-5) temperature (lowering the condenser pressure). 2). Increase vaporization temperature (depends on pressure). Process (1-2).3).
Increase steam superheating temperature. Superheating process (2-3).http://www.gunt.de
TechnologiesRankine cycle
Slide47Planning
Slide48Planning
Overview of possible operating parameters and generating costs
for bioenergy electricity by 2030
Overview of bioenergy power plant conversion efficiencies and cost components
Capital and O&M costsSCALE EFFECTmain improvement area
Slide49Planning
CHP
HEAT ONLY
CHP versus HEAT ONLY
Slide50Bioenergy electricity generation costs 2010 and 2030,
compared to coal and natural gas based power generation
Planning
LCOE
Slide51Liquid fuels
Slide52Summary
Cons
Energy intensive to produce. In some cases, with little or no net gain
.
Land utilization can be considerable. Can lead to deforestation.
Requires water to growNot totally clean when burned (NOx, soot, ash, CO, CO2)May compete directly with food production (e.g. corn, soy)Some fuels are seasonalHeavy feedstocks require energy to transport.Overall process can be expensiveSome methane and CO2 are emitted during productionNot easily scalableDisadvantages
Slide53Pros
Truly a renewable fuelWidely available and naturally distributed
Generally low cost inputsAbundant supplyCan be domestically produced for energy independenceLow carbon, cleaner than fossil fuelsCan convert waste into energy, helping to deal with waste
Summary
A
dvantages
Slide54Any questions?
Slide55