Read the RIRDC report![]() Bioenergy. Electricity from oil mallee trees in WA.
Torrefaction ? Whats that ? Read more .......... |
![]() |
The new paradigm ... weeds as biomass.
![Picture](/uploads/3/0/0/8/3008545/5009076.jpg?503x345)
The cheapest form of biomass feedstock for energy production is waste. Green waste from gardens, sawdust from logging, forest litter and dead trees and especially WEEDS!
Using slash and char can significantly reduce the incidence of wild bushfires.
MIMOSA PIGRA as a fuel for power generation.
Using slash and char can significantly reduce the incidence of wild bushfires.
MIMOSA PIGRA as a fuel for power generation.
Primary energy sources: past, present and future.
( from Thermodynamic analysis of biomass gasification and torrefaction. Mark Jan Prins (2005)
Biomass, in particular wood, has historically been an important energy source for fires, ovens and stoves. During the Industrial Revolution, coal displaced biomass because of its high energy content and because it is available in large quantities at low cost. At the beginning of the 20th century, oil (which was discovered in the U.S. in 1859) supplied only 4% of the world’s energy. Decades later it became the most important energy source. Developed countries are especially dependent on oil, which supplies about 96% of their transportation energy. With world energy demand projected to rise by about 40% from now to 2020, it is possible that natural gas, which supplies almost 25% of the world’s energy demand today, overtakes oil as the most important energy source. This trend is also supported by environmental concerns such as global warming which have resulted in calls for increased use of natural gas. Looking beyond the era of natural gas, coal may become increasingly used, but this requires CO2 sequestration. Eventually, fossil fuel reserves will dwindle. Can the oldest fuel, biomass, make a comeback?
Photosynthesis stores 5-8 times more energy in biomass than man currently consumes from all sources. Biomass, currently the fourth largest energy source in the world, could therefore in principle become the main energy source. Several scenarios for the future (e.g. Shell, 2001) - predict a strong increase in the use of biofuels between 2025 and 2050.
Desk studies have identified entrained-flow gasification as a promising option for the large scale production of syngas from biomass. This biosyngas then is a versatile feedstock for the production of transportation fuels, chemicals and electricity. However, an entrained-flow gasifier requires sub-millimetre size feedstock particles and to reduce biomass to this size is known to be difficult and expensive due to the fibrous structure and the tenacity of many types of biomass, woody biomass in particular. The fibrous structure of fresh biomass makes it very difficult and costly to reduce its particle size down to below 500 microns. Torrefaction, a thermal treatment of biomass in the temperature range of 200 °C to 300 °C in absence of oxygen, is capable of enhance the size reduction characteristics. Torrefaction partially destroys the fibrous structure of biomass while retaining 70-90% of the calorific value of the biomass feed. The properties of torrefied wood were found to be in between wood and coal. Compared to the original wood, torrefaction decreases the content of volatiles from ca. 80% to 60-75% and the moisture content from typically 10% to 3%, whereas the heating value increases by 5-25%. The properties of torrefied wood depend on the type of wood used, and the reaction temperature and residence time that is applied.
Electricity from biomass
The world’s first biomass-fired IGCC (integrated gasification combined cycle) is the Värnamo plant, which uses a circulating fluidized bed gasifier. It was built between 1991 and 1993 and can produce 6 MW of electricity and 9 MW of heat from wood chips. The greatest hurdle towards wider commercialization of this technology remains the requirement, set by the gas turbine manufacturers, to produce tar and particulate free gas.
Assuming that entrained flow gasifiers can indeed be technically fully proven and ultra-clean synthesis gas produced, an even better option is application of this gas in fuel cells. Biomass derived synthesis gas could be directly converted into electricity using a stationary fuel cell, such as a Molten Carbonate Fuel Cell (MCFC) or Solid Oxide Fuel Cell (SOFC). Such cells can handle methane-containing synthesis gas, which is reformed inside the cell. The successful operation of a SOFC using gasified biomass has been shown in a 2002 demonstration Colorado (Community Power Corporation, 2002). Three different biomass fuels were individually gasified in a downdraft gasifier and converted to electric power in a small laboratory fuel cell.
( from Thermodynamic analysis of biomass gasification and torrefaction. Mark Jan Prins (2005)
Biomass, in particular wood, has historically been an important energy source for fires, ovens and stoves. During the Industrial Revolution, coal displaced biomass because of its high energy content and because it is available in large quantities at low cost. At the beginning of the 20th century, oil (which was discovered in the U.S. in 1859) supplied only 4% of the world’s energy. Decades later it became the most important energy source. Developed countries are especially dependent on oil, which supplies about 96% of their transportation energy. With world energy demand projected to rise by about 40% from now to 2020, it is possible that natural gas, which supplies almost 25% of the world’s energy demand today, overtakes oil as the most important energy source. This trend is also supported by environmental concerns such as global warming which have resulted in calls for increased use of natural gas. Looking beyond the era of natural gas, coal may become increasingly used, but this requires CO2 sequestration. Eventually, fossil fuel reserves will dwindle. Can the oldest fuel, biomass, make a comeback?
Photosynthesis stores 5-8 times more energy in biomass than man currently consumes from all sources. Biomass, currently the fourth largest energy source in the world, could therefore in principle become the main energy source. Several scenarios for the future (e.g. Shell, 2001) - predict a strong increase in the use of biofuels between 2025 and 2050.
Desk studies have identified entrained-flow gasification as a promising option for the large scale production of syngas from biomass. This biosyngas then is a versatile feedstock for the production of transportation fuels, chemicals and electricity. However, an entrained-flow gasifier requires sub-millimetre size feedstock particles and to reduce biomass to this size is known to be difficult and expensive due to the fibrous structure and the tenacity of many types of biomass, woody biomass in particular. The fibrous structure of fresh biomass makes it very difficult and costly to reduce its particle size down to below 500 microns. Torrefaction, a thermal treatment of biomass in the temperature range of 200 °C to 300 °C in absence of oxygen, is capable of enhance the size reduction characteristics. Torrefaction partially destroys the fibrous structure of biomass while retaining 70-90% of the calorific value of the biomass feed. The properties of torrefied wood were found to be in between wood and coal. Compared to the original wood, torrefaction decreases the content of volatiles from ca. 80% to 60-75% and the moisture content from typically 10% to 3%, whereas the heating value increases by 5-25%. The properties of torrefied wood depend on the type of wood used, and the reaction temperature and residence time that is applied.
Electricity from biomass
The world’s first biomass-fired IGCC (integrated gasification combined cycle) is the Värnamo plant, which uses a circulating fluidized bed gasifier. It was built between 1991 and 1993 and can produce 6 MW of electricity and 9 MW of heat from wood chips. The greatest hurdle towards wider commercialization of this technology remains the requirement, set by the gas turbine manufacturers, to produce tar and particulate free gas.
Assuming that entrained flow gasifiers can indeed be technically fully proven and ultra-clean synthesis gas produced, an even better option is application of this gas in fuel cells. Biomass derived synthesis gas could be directly converted into electricity using a stationary fuel cell, such as a Molten Carbonate Fuel Cell (MCFC) or Solid Oxide Fuel Cell (SOFC). Such cells can handle methane-containing synthesis gas, which is reformed inside the cell. The successful operation of a SOFC using gasified biomass has been shown in a 2002 demonstration Colorado (Community Power Corporation, 2002). Three different biomass fuels were individually gasified in a downdraft gasifier and converted to electric power in a small laboratory fuel cell.