Biomass is a renewable, economic and readily available resource of energy that has potential to substitute fossil fuels in many applications such as heat, electricity and biofuels. The increased use of the agricultura...Biomass is a renewable, economic and readily available resource of energy that has potential to substitute fossil fuels in many applications such as heat, electricity and biofuels. The increased use of the agricultural biomass can help the agricultural based societies in achieving energy security and creating employment without causing environmental degradation. However, the viability and feasibility of electricity generation from agricultural biomass depends upon the availability of biomass supply at a competitive cost. The present study investigates the availability of agricultural biomass for distributed power generation in Greece (Kozani). The study concludes with a discussion on significance and challenges of decentralized electricity generation for rural energy supply, including brief description about economical, social, environmental and technical aspects of bioelectricity. With the application of the life cycle analysis applied, the environmental and economic impacts that will occur in the region of Kozani in Greece, where a biomass wood pellets production workshop is operating, have been assessed. The total annual emission of CO 657.9 gr, HC 22.36 gr, PM 67.94 and NOx 8.832,2 gr was calculated. The economic evaluation estimated the payback period for the investment in this plant to be approximately 3 years.展开更多
NIR spectroscopy was used to measure the moisture concentration of wood pellets. Pellets were conditioned to various moisture levels between 0.63% and 14.16% (wet basis) and the moisture concentration was verified usi...NIR spectroscopy was used to measure the moisture concentration of wood pellets. Pellets were conditioned to various moisture levels between 0.63% and 14.16% (wet basis) and the moisture concentration was verified using a standard oven method. Samples from various moisture levels were separated into two groups, as calibration and validation sets. NIR absorption spectral data from 400 nm to 2500 nm with 0.5 nm intervals were collected using pellets within the calibration and validation sample sets. Spectral wavelength ranges were taken as independent variables and the MC of the pellets as the dependent variable for the analysis. Measurements were obtained on 30 replicates within each moisture level. Partial Least Square (PLS) analysis was performed on both raw and preprocessed spectral data of calibration set to determine the best calibration model based on Standard Error of Calibration (SEC) and coefficient of multiple determinations (R2). The PLS model that yielded the best fit was used to predict the moisture concentration of validation group pellets. Relative Percent Deviation (RPD) and Standard Error of Prediction (SEP) were calculated to validate goodness of fit of the prediction model. Baseline and Multiple Scatter Corrected (MSC) reflectance spectra with 1st derivative model gave the highest RPD value of 4.46 and R2 of 0.95. Also it’s SEP (0.670) and RMSEP (0.782) were less than the other models those had RPD value more than 3.0 with less number of factors. Therefore, this model was selected as the best model for moisture content prediction of wood pellets.展开更多
Upgraded wood pellets were produced and evaluated by torrefaction of wood pellets. In this study, conventional wood pellets were initially prepared and subsequently torrefied on a laboratory and then larger scale. Dur...Upgraded wood pellets were produced and evaluated by torrefaction of wood pellets. In this study, conventional wood pellets were initially prepared and subsequently torrefied on a laboratory and then larger scale. During the laboratory scale production, pellets from wooden parts of Japanese cedar (sugi, Cryptomeria japonica) and Japanese oak (konara, Quercus serrata) trees were heat- treated in an inert gas oven under nitrogen atmosphere around 170°C - 320°C. For the Japanese cedar, the calorific values were improved by heat treatment up to 260°C. By heat treatment at 240°C, the upgrade ratio of higher heating value (HHV) was nearly 30% and the energy yield was 97%. For the Japanese oak, the calorific values were improved by heat treatment up to 320°C. By heat treatment at 280°C, the upgrade ratio of HHV exceeded 30% and the energy yield was 84%. On a larger scale, a conventional charcoal oven was modified for torrefied wood pellet production, meaning that torrefied wood pellet with 25 MJ/kg of calorific value was produced during heat treatment at 350°C. A mixture of conventional and torrefied pellets was applied to a commercial pellet stove, and torrefied wood pellets produced in this study might be usable as fuel for conventional pellet stoves.展开更多
The problem of Caesium-137 (137 Cs) contamination of the imported wood pellet used for burning has been reported in Italy since June 2009. Since then, sampling and analysis were performed at the crossing border points...The problem of Caesium-137 (137 Cs) contamination of the imported wood pellet used for burning has been reported in Italy since June 2009. Since then, sampling and analysis were performed at the crossing border points of the provinces of Trieste and Gorizia, on request of the Health and Customs Border Bureau. This paper presents the results of the analysis performed on 65 samples from August 2010 to March 2012, which covered a total of products over 1500 tons of various origins, imported from Eastern Europe and the Balkans. Most of the samples showed very low 137 Cs activity concentrations;only a few hot spots showed 137 Cs activity concentrations higher than 100 Bq·kg-1. The results of dose evaluations for wood pellet stoves users under the hypotheses assumed in this study were largely below the threshold of radiological relevance.展开更多
Alabama imports coal from other states to generate electricity. This paper assessed the direct and indirect economic impacts of wood pellet production to be co-fired with coal for power generation in Alabama. Four siz...Alabama imports coal from other states to generate electricity. This paper assessed the direct and indirect economic impacts of wood pellet production to be co-fired with coal for power generation in Alabama. Four sizes of wood pellet plants and regional input-output models were used for the analysis. The results showed that the economic impact increases with the size of the plant. Wood pellet production will have a multiplier effect on the economy especially, forest-related services, retail stores, the health service industry, and tax revenue for the government. Domestic wood pellet production can reduce the use of imported coal, allow the use of local woody biomass, and create economic activities in Alabama’s rural communities. Policies that support the production of wood pellet will serve to encourage the use of wood for power generation and support the rural economies.展开更多
To suppress the global environment pollutions, we tried to develop a new-type solar drying house by improving a typical agricultural green-house, so that an all weather-type solar drying house was invented ultimately....To suppress the global environment pollutions, we tried to develop a new-type solar drying house by improving a typical agricultural green-house, so that an all weather-type solar drying house was invented ultimately. This house is capable to dry raw wood materials (Ogako) into suitable moisture content (Mc) to make a wood pellet. The all weather-type solar Ogako drying house is covered with a triple transparent film, and an open/close free-type shield sheet is spread along with house’s inner surface with a small space, which is opened when solar radiation is incident on the house in daytime and closed to prevent heat loss from the house while out of sun shining in night. Inside of the all weather-type solar Ogako drying house, there are four belt-conveyors over which four top radiation panels are hanged, and on which four Ogako agitators are touched, a turn-table, two hoppers, four small fans, and besides, a floor heating is molded in concrete floor. Also on the north wall outside the house, two insulated cylinders (chimney) are stood up vertically to exhaust inside moist air passively. Then, to make clearly the operation performance of the house, the drying tests for the proof examination were conducted nineteen times at first test site in Ashoro where is located east-central part of Hokkaido, Japan. As a result of the drying test for the proof examination, it was made clear that the all weather-type solar Ogako drying house is practically useful as a supplementary apparatus to produce the dried Ogako, and consequently to suppress CO2 exhaustion.展开更多
The change in physical properties of wood pellets,with a focus on particle size distributions due to pellet breakage and attrition,was studied in a large-scale(∼450 ton/h)transportation system.Critical locations with...The change in physical properties of wood pellets,with a focus on particle size distributions due to pellet breakage and attrition,was studied in a large-scale(∼450 ton/h)transportation system.Critical locations with a high probability of breakage through the whole transportation system were chosen and sampled to study the effect of transportation system design and operation on the mechanical properties of pellets.Bulk density,mechanical durability,moisture content,and particle size distribution of pellets were characterized for each sample.Analysis of variance showed that there were significant differences between the percentages of small particles(<5.6 mm)in the samples taken at different locations,especially at one with a vertical free fall of 7.8 m.On average,this relatively long drop increased the proportion of particles<5.6 mm in the samples from 8.73%to 14.09%,and that of particles<3.15 mm from 4.82%to 9.01%.Moreover,the measurements showed a wide deviation in the mechanical durability values,between a minimum of 90.8%and a maximum of 98.7%,which were not correlated to the sampling points but related to pellet properties.It can be concluded that pellet transportation systems require more dedicated design strategies to prevent breakage and attrition.展开更多
Pulverizing is an essential unit operation in co-firing biomass with coal.Pulverizers are only compatible with pellet forms of fibrous biomass materials and crush them down to their original forming particle sizes.Tha...Pulverizing is an essential unit operation in co-firing biomass with coal.Pulverizers are only compatible with pellet forms of fibrous biomass materials and crush them down to their original forming particle sizes.That is why the data on the size distribution of the particles forming a biomass pellet is crucial to achieving optimum combustion conditions.The current study determines the internal particle size distribution of pellets after wet disintegration,following Iso 17830 standard,and aims to suggest improvements to the mentioned standard based on new measured evidence.Experiments were carried out on white wood pellets(no bark)and brown wood pellets containing bark at four water temperatures:20,40,60,and 95℃,with or without stirring.The particle size distribution of the pre-pelletizer wood particles was also measured and compared with particles in the formed pellets.Ambient water temperature of 20℃ was found to be adequate for the complete disintegration of pellets,and no mechanical stirring was required.About 30% of particles in the disintegrated pellets were 0.5-1.0 mm.Pelletization changes the particle size distribution to smaller particles.The disintegrated bark pellets contained more fines than white pellets.展开更多
文摘Biomass is a renewable, economic and readily available resource of energy that has potential to substitute fossil fuels in many applications such as heat, electricity and biofuels. The increased use of the agricultural biomass can help the agricultural based societies in achieving energy security and creating employment without causing environmental degradation. However, the viability and feasibility of electricity generation from agricultural biomass depends upon the availability of biomass supply at a competitive cost. The present study investigates the availability of agricultural biomass for distributed power generation in Greece (Kozani). The study concludes with a discussion on significance and challenges of decentralized electricity generation for rural energy supply, including brief description about economical, social, environmental and technical aspects of bioelectricity. With the application of the life cycle analysis applied, the environmental and economic impacts that will occur in the region of Kozani in Greece, where a biomass wood pellets production workshop is operating, have been assessed. The total annual emission of CO 657.9 gr, HC 22.36 gr, PM 67.94 and NOx 8.832,2 gr was calculated. The economic evaluation estimated the payback period for the investment in this plant to be approximately 3 years.
文摘NIR spectroscopy was used to measure the moisture concentration of wood pellets. Pellets were conditioned to various moisture levels between 0.63% and 14.16% (wet basis) and the moisture concentration was verified using a standard oven method. Samples from various moisture levels were separated into two groups, as calibration and validation sets. NIR absorption spectral data from 400 nm to 2500 nm with 0.5 nm intervals were collected using pellets within the calibration and validation sample sets. Spectral wavelength ranges were taken as independent variables and the MC of the pellets as the dependent variable for the analysis. Measurements were obtained on 30 replicates within each moisture level. Partial Least Square (PLS) analysis was performed on both raw and preprocessed spectral data of calibration set to determine the best calibration model based on Standard Error of Calibration (SEC) and coefficient of multiple determinations (R2). The PLS model that yielded the best fit was used to predict the moisture concentration of validation group pellets. Relative Percent Deviation (RPD) and Standard Error of Prediction (SEP) were calculated to validate goodness of fit of the prediction model. Baseline and Multiple Scatter Corrected (MSC) reflectance spectra with 1st derivative model gave the highest RPD value of 4.46 and R2 of 0.95. Also it’s SEP (0.670) and RMSEP (0.782) were less than the other models those had RPD value more than 3.0 with less number of factors. Therefore, this model was selected as the best model for moisture content prediction of wood pellets.
文摘Upgraded wood pellets were produced and evaluated by torrefaction of wood pellets. In this study, conventional wood pellets were initially prepared and subsequently torrefied on a laboratory and then larger scale. During the laboratory scale production, pellets from wooden parts of Japanese cedar (sugi, Cryptomeria japonica) and Japanese oak (konara, Quercus serrata) trees were heat- treated in an inert gas oven under nitrogen atmosphere around 170°C - 320°C. For the Japanese cedar, the calorific values were improved by heat treatment up to 260°C. By heat treatment at 240°C, the upgrade ratio of higher heating value (HHV) was nearly 30% and the energy yield was 97%. For the Japanese oak, the calorific values were improved by heat treatment up to 320°C. By heat treatment at 280°C, the upgrade ratio of HHV exceeded 30% and the energy yield was 84%. On a larger scale, a conventional charcoal oven was modified for torrefied wood pellet production, meaning that torrefied wood pellet with 25 MJ/kg of calorific value was produced during heat treatment at 350°C. A mixture of conventional and torrefied pellets was applied to a commercial pellet stove, and torrefied wood pellets produced in this study might be usable as fuel for conventional pellet stoves.
文摘The problem of Caesium-137 (137 Cs) contamination of the imported wood pellet used for burning has been reported in Italy since June 2009. Since then, sampling and analysis were performed at the crossing border points of the provinces of Trieste and Gorizia, on request of the Health and Customs Border Bureau. This paper presents the results of the analysis performed on 65 samples from August 2010 to March 2012, which covered a total of products over 1500 tons of various origins, imported from Eastern Europe and the Balkans. Most of the samples showed very low 137 Cs activity concentrations;only a few hot spots showed 137 Cs activity concentrations higher than 100 Bq·kg-1. The results of dose evaluations for wood pellet stoves users under the hypotheses assumed in this study were largely below the threshold of radiological relevance.
文摘Alabama imports coal from other states to generate electricity. This paper assessed the direct and indirect economic impacts of wood pellet production to be co-fired with coal for power generation in Alabama. Four sizes of wood pellet plants and regional input-output models were used for the analysis. The results showed that the economic impact increases with the size of the plant. Wood pellet production will have a multiplier effect on the economy especially, forest-related services, retail stores, the health service industry, and tax revenue for the government. Domestic wood pellet production can reduce the use of imported coal, allow the use of local woody biomass, and create economic activities in Alabama’s rural communities. Policies that support the production of wood pellet will serve to encourage the use of wood for power generation and support the rural economies.
文摘To suppress the global environment pollutions, we tried to develop a new-type solar drying house by improving a typical agricultural green-house, so that an all weather-type solar drying house was invented ultimately. This house is capable to dry raw wood materials (Ogako) into suitable moisture content (Mc) to make a wood pellet. The all weather-type solar Ogako drying house is covered with a triple transparent film, and an open/close free-type shield sheet is spread along with house’s inner surface with a small space, which is opened when solar radiation is incident on the house in daytime and closed to prevent heat loss from the house while out of sun shining in night. Inside of the all weather-type solar Ogako drying house, there are four belt-conveyors over which four top radiation panels are hanged, and on which four Ogako agitators are touched, a turn-table, two hoppers, four small fans, and besides, a floor heating is molded in concrete floor. Also on the north wall outside the house, two insulated cylinders (chimney) are stood up vertically to exhaust inside moist air passively. Then, to make clearly the operation performance of the house, the drying tests for the proof examination were conducted nineteen times at first test site in Ashoro where is located east-central part of Hokkaido, Japan. As a result of the drying test for the proof examination, it was made clear that the all weather-type solar Ogako drying house is practically useful as a supplementary apparatus to produce the dried Ogako, and consequently to suppress CO2 exhaustion.
基金This study has received funding from the Top Consortium for Knowledge and Innovation for the Biobased Economy(TKI-BBE),under grant number BBE-1713(Biomassa pellets:Degradatie tij-dens transport en handling).
文摘The change in physical properties of wood pellets,with a focus on particle size distributions due to pellet breakage and attrition,was studied in a large-scale(∼450 ton/h)transportation system.Critical locations with a high probability of breakage through the whole transportation system were chosen and sampled to study the effect of transportation system design and operation on the mechanical properties of pellets.Bulk density,mechanical durability,moisture content,and particle size distribution of pellets were characterized for each sample.Analysis of variance showed that there were significant differences between the percentages of small particles(<5.6 mm)in the samples taken at different locations,especially at one with a vertical free fall of 7.8 m.On average,this relatively long drop increased the proportion of particles<5.6 mm in the samples from 8.73%to 14.09%,and that of particles<3.15 mm from 4.82%to 9.01%.Moreover,the measurements showed a wide deviation in the mechanical durability values,between a minimum of 90.8%and a maximum of 98.7%,which were not correlated to the sampling points but related to pellet properties.It can be concluded that pellet transportation systems require more dedicated design strategies to prevent breakage and attrition.
文摘Pulverizing is an essential unit operation in co-firing biomass with coal.Pulverizers are only compatible with pellet forms of fibrous biomass materials and crush them down to their original forming particle sizes.That is why the data on the size distribution of the particles forming a biomass pellet is crucial to achieving optimum combustion conditions.The current study determines the internal particle size distribution of pellets after wet disintegration,following Iso 17830 standard,and aims to suggest improvements to the mentioned standard based on new measured evidence.Experiments were carried out on white wood pellets(no bark)and brown wood pellets containing bark at four water temperatures:20,40,60,and 95℃,with or without stirring.The particle size distribution of the pre-pelletizer wood particles was also measured and compared with particles in the formed pellets.Ambient water temperature of 20℃ was found to be adequate for the complete disintegration of pellets,and no mechanical stirring was required.About 30% of particles in the disintegrated pellets were 0.5-1.0 mm.Pelletization changes the particle size distribution to smaller particles.The disintegrated bark pellets contained more fines than white pellets.
