msc program - renewable energy in central and eastern europe univ. prof. dipl. ing. dr. hermann...
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MSc Program - Renewable Energy in Central and Eastern Europe
Univ. Prof. Dipl. Ing. Dr. Hermann Hofbauer Modul 2 - Biomass, Biogas, and Biofuels Fundamentals of Thermal Biomass Utilization
Fundamentals of Thermal Biomass Utilization
(Grundlagen der thermischen Nutzung von Biomasse)
Univ. Prof. Dipl. Ing. Dr. Hermann Hofbauer
Vienna University of Technology
(TU Wien)
MSc Program - Renewable Energy in Central and Eastern Europe
Univ. Prof. Dipl. Ing. Dr. Hermann Hofbauer Modul 2 - Biomass, Biogas, and Biofuels Fundamentals of Thermal Biomass Utilization
Content
A Definitions and Energy Units
B Overview about Biomass Utilization (Austria, Europe, World)
C Fuel Related Characteristics of Biomass
D Fundamentals of Thermal Conversion of Biomass
E Principles of Energy Transformation
MSc Program - Renewable Energy in Central and Eastern Europe
Univ. Prof. Dipl. Ing. Dr. Hermann Hofbauer Modul 2 - Biomass, Biogas, and Biofuels Fundamentals of Thermal Biomass Utilization
Conversion of EnergyExample: Biomass to Electricity
Clausius Rankine Process (Steam Process)
ChemicalEnergy
Combustion
Clausius Rankine Process (steam process)
El. Generator
ThermalEnergy
MechanicalEnergy
ElectricalEnergy
Biomass
Electricity
MSc Program - Renewable Energy in Central and Eastern Europe
Univ. Prof. Dipl. Ing. Dr. Hermann Hofbauer Modul 2 - Biomass, Biogas, and Biofuels Fundamentals of Thermal Biomass Utilization
Chemical Energy
Energy chemically bound in fuels (e.g. biomass)
Echem = m.Ho
m … Mass of fuel [kg]
Ho … Gross calorific value [kJ/kg]
MSc Program - Renewable Energy in Central and Eastern Europe
Univ. Prof. Dipl. Ing. Dr. Hermann Hofbauer Modul 2 - Biomass, Biogas, and Biofuels Fundamentals of Thermal Biomass Utilization
Potential Energy (Gravitational Energy)
Energy which is stored in a mass due to a certain height difference (e.g. hydro power)
Epot = m.g.h
m … Mass [kg]
g … Gravity (9,81) [m/s2]
h … Height difference [m]
MSc Program - Renewable Energy in Central and Eastern Europe
Univ. Prof. Dipl. Ing. Dr. Hermann Hofbauer Modul 2 - Biomass, Biogas, and Biofuels Fundamentals of Thermal Biomass Utilization
Potential Energy (Gravitational Energy)
Weigth = m.g
Base LevelHeight h
Epot = m.g.h
MSc Program - Renewable Energy in Central and Eastern Europe
Univ. Prof. Dipl. Ing. Dr. Hermann Hofbauer Modul 2 - Biomass, Biogas, and Biofuels Fundamentals of Thermal Biomass Utilization
Kinetic Energy
Energy which has got a moving mass (e.g. wind energy).
Ekin = m.v2/2
m … Mass [kg]
v …Velocity of the mass [m/s]
MSc Program - Renewable Energy in Central and Eastern Europe
Univ. Prof. Dipl. Ing. Dr. Hermann Hofbauer Modul 2 - Biomass, Biogas, and Biofuels Fundamentals of Thermal Biomass Utilization
Kinetic Energy
Distance = x meter in time t sec
Velocity = v
Force = F
Velocity = 0
Ekin = m.v2/2
MSc Program - Renewable Energy in Central and Eastern Europe
Univ. Prof. Dipl. Ing. Dr. Hermann Hofbauer Modul 2 - Biomass, Biogas, and Biofuels Fundamentals of Thermal Biomass Utilization
Pressure (Flow) Energy
Energy stored in a fluid under pressure (e.g. steam turbine)
Ep = p.V
p … Pressure of fluid [Pa]
V … Volume (Area.x) [m3]
MSc Program - Renewable Energy in Central and Eastern Europe
Univ. Prof. Dipl. Ing. Dr. Hermann Hofbauer Modul 2 - Biomass, Biogas, and Biofuels Fundamentals of Thermal Biomass Utilization
Pressure (Flow) Energy
Piston Fluid
Force
Are
a
Pre
ssu
re
Ep = p.V
MSc Program - Renewable Energy in Central and Eastern Europe
Univ. Prof. Dipl. Ing. Dr. Hermann Hofbauer Modul 2 - Biomass, Biogas, and Biofuels Fundamentals of Thermal Biomass Utilization
Thermal Energy
Energy, which contains a mass (fluid) due to its temperature (e.g. thermal energy in flue gas).
Eth = m.c.T
m … Mass [kg]
c … Specific heat [kJ/kg.K]
T … Temperature difference [K]
MSc Program - Renewable Energy in Central and Eastern Europe
Univ. Prof. Dipl. Ing. Dr. Hermann Hofbauer Modul 2 - Biomass, Biogas, and Biofuels Fundamentals of Thermal Biomass Utilization
Conversion of Chemical Energy !?
Convert chemical energy (e.g.1 kg of biomass with18 MJ/kg) into:
• Potential Energy
• Kinetic Energy
• Thermal Energy
MSc Program - Renewable Energy in Central and Eastern Europe
Univ. Prof. Dipl. Ing. Dr. Hermann Hofbauer Modul 2 - Biomass, Biogas, and Biofuels Fundamentals of Thermal Biomass Utilization
Multiple Choice Test
The net calorific value of wood is about 18 MJ/kg. Which mass kg can be lifted 1 m in height with the same amount
of energy ?
1.800 kg
18.000 kg
180.000 kg
1.800.000 kg
MSc Program - Renewable Energy in Central and Eastern Europe
Univ. Prof. Dipl. Ing. Dr. Hermann Hofbauer Modul 2 - Biomass, Biogas, and Biofuels Fundamentals of Thermal Biomass Utilization
Multiple Choice Test
The net calorific value of wood is about 18 MJ/kg. How many litters of water can be heated up from 25 °C to 100
°C with the same amount of energy ?
1 lit
18 lit
57 lit
94 lit