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00708 Methane productivity of manure, straw and solid fractions of manure
07 Alternative energy sources (bioconversion energy) drying is usually a more economic drying system when the amortization time is short. However, the competitiveness of multi-stage drying improves as the amortization time becomes longer.
05•00703 Defining leaf traits linked to yield in short-rotation coppice Salix Robinson, K. M. et al. Biomass and Bioenergy, 2004, 26, (5), 417 431. Short-rotation coppice Salix genotypes of differing biomass yields were studied over two growing seasons with the long-term aim of identifying traits definitive of high yield for the breeding of elite energy crops. In the first season, basic leaf and stem traits were measured in six Salix genotypes, to identify morphological characteristics associated with high biomass yields. Thereafter, S. viminalis L. 'L78183' (low yield) and the hybrid genotype S. sehwerinii E. Wolf x S. viminalis L. 'Tora' (high yield) were compared. Maximum stem heights and stem diameters increased with biomass yield. 'Tora' produced more sylleptic branches on the leading stems than 'L78183'. Leaf traits differed significantly between the two genotypes: individual leaf area and cell number per leaf was greater in 'Tora', whereas cell area was greater in 'L78183', suggesting that final leaf areas were attained in 'Tora' through the production of many, small cells, and in 'L78183' through fewer, large cells. Leaf extension rates were higher in 'Tora' than 'L78183'. This result was mirrored for leaf production rate. Leaf area index, examined at two coppice stages, was higher in "L78183' (values of 2.06 and 1.67) than in 'Tora' (maximum value 1.43) which had a very open canopy. Furthermore, A / C j analysis revealed the low-yielding genotype as the most photo-synthetically efficient at the individuai leaf level whereas light response curves suggest that 'Tora' utilized light more efficiently. The results presented in this study suggest that leaf extension rate, final leaf size and cell number per leaf may be indicative of yield, and may be useful as selection criteria for potentially high-yielding hybrids for biomass use.
05•00704 stover
Distribution of aboveground biomass in corn
Pordesimo, L. O. et al. Biomass and Bioenergy, 2004, 26, (4), 337-343. Corn stover can be a principal feedstock for bio-energy and industrial applications because of its abundance and its current under-utilization. Development of strategies/systems for the post-harvest handling of corn stover involves quantifying what corn stover biomass is available over time after grain physiological maturity has been reached. It also involves understanding how the biomass is distributed in the different aboveground components of the corn plant. The objectives of this preliminary investigation were to measure the allocation of biomass to aboveground components of the corn plant over time and to develop relationships for estimating total aboveground corn plant biomass through simple corn plant dimensional measurements. Aboveground biomass distribution for two corn cultivars (Pioneer 32K61 and 32K64 Bt) was studied in standing plants from roughly 1 week before grain physiological maturity until 4 weeks after grain harvest from other plots in the field. Over the monitoring period, the amount of dry matter in stover averaged 50% of the total aboveground dry plant mass with stalks comprising 50% of the stover dry matter at the time grain was harvested. This study indicated that the more conservative 0.8:1 stover:grain fresh weight ratio, rather than the 1:1 widely used, may be more realistic at the grain harvest moisture range of 18-31% w.b. Such precondition has not been clearly emphasized in the literature. Regression equations involving stalk diameter and plant height for DeKalb 626 derived to estimate fresh green weight and dry matter of the corn plant above the ground had a maximum R 2 of 0.75.
05100705 Efficient energy systems with C02 capture and storage from renewable biomass in pulp and paper mills M6llersten, K. et al. Renewable Energy, 2004, 29, (9), 1583-1598. This paper investigates the impact of combining CO2 capture and storage with alternative systems for biomass-based combined heat and power production (CHP) in Kraft pulp and paper mills. The study compares heat, power, and COz balances of systems with alternative configurations of the CHP and CO2-capture systems. Because the captured CO2 comes from renewable biomass, the studied systems yield negative CO2 emissions. It is shown that pulp mills and integrated pulp and paper mills have the potential to become net exporters of biomassbased electricity while at the same time removing CO2 from the atmosphere on a net basis. The study shows that that the overall best CO2 abatement is achieved when CO2 capture is carried out within a biomass integrated gasifier with combined cycle where the syngas undergoes a CO-shift reaction. This configuration combines efficient energy conversion with a high CO2 capture efficiency. Furthermore, cost curves are constructed, which show how the cost of CO2 capture and storage in pulp and paper mills depends on system configuration and the CO2 transportation distance.
05/00706 Experiment and modelling of parameters influencing natural wind drying of willow chunks Giglcr, J. K. et al. Biomass and Bioenerg.r, 2004, 26, (6), 507-514.
104
Fuel and Energy Abstracts
March 2005
The objective of this study was to investigate the parameters that govern the drying process of willow chunks. Indicative chunk drying trials were conducted to assess the potential of natural wind drying. Supportive model simulations were conducted to gain insight into the influence of different process parameters (particle size, pile depth) on drying. Natural wind drying experiments showed that willow chunks could be dried from 50% (wet basis) to around 10% within 5 months. Internal heating in the pile did not occur and dry matter losses were reasonably low (3.5-5%). The drying time of willow chunks depended on drying air conditions, particle size and pile dimensions (depth). The particle size of chunks should be large enough to create a low airflow resistance in the pile, but small enough to avoid that internal diffusion of moisture limits the drying process.
05/00707
Intermittent drying of bioproducts - an overview
Chua, K. J. et al. Bioresource Technology, 2003, 90, (3), 285-295. Unlike the conventional practice of supplying energy for batch drying processes at a constant rate, newly developed intermittent drying processes employ time-varying heat input taiiored to match the drying kinetics of the material being dried. The energy required may be supplied by combining different modes of heat transfer (e.g. convection coupled with conduction or radiation or dielectric heating simultaneously or in a pre-selected sequence) in a time-varying fashion so as to provide optimal drying kinetics as welt as quality of the bioproduct. This is especially important for drying of heat-sensitive materials (such as foods, pharmaceutical, neutraceutical substances, herbs, spices and herbal medicines). Intermittent heat supply is beneficial only for materials which dry primarily in the falling rate period where internal diffusion of heat and moisture controls the overall drying rate. Periods when little or no heat is supplied for drying allow the tempering period needed for the moisture and heat to diffuse within the material. As the moisture content increases at the surface of the biomaterial during the tempering period, the rate of drying is higher when heat input is resumed. It is possible to control the heat input such that the surface temperature of the product does not exceed a pre-determined value beyond which thermal damage of the material may occur. This process results in reduction in the use of thermal energy as well as the mass of air used in convective drying. Thus, the thermal efficiency of such a process is higher. The quality of the product, as such colour and ascorbic acid content, is also typically superior to that obtained with a continuous supply of heat. However, in some cases, there will be a nominal increase in drying time. In the case of microwave-assisted and heat pump drying, for example, the capital cost of the drying system can also be reduced by drying in the intermittent mode. This paper provides an overview of the basic process, selected results from experiments and mathematical models for a variety of biomaterials dried in a wide assortment of dryers. It begins with a classification of intermittent drying processes that may be applied e.g. time-varying temperature, air flow rate, operating pressure as well as heat input by different modes and in different temporal variations. The beneficial effects of improving the quality of dried bioproducts by different intermittent processes are also included and discussed.
05/00708 Methane productivity of manure, straw and solid fractions of manure M¢ller, H. B. et al. Biomass and Bioenergy, 2004, 26, (5), 485~495. The methane productivity of manure in terms of volatile solids (VS), volume and livestock production was determined. The theoretical methane productivity is higher in pig (516 1 kg -1 VS) and sow (530 1 kg -1 VS) manure than in dairy cattle manure (469 1 kg- l VS), while the ultimate methane yield in terms of VS is considerably higher in pig (356 1 kg- 1 VS) and sow manure (275 1 kg -1 VS) than in dairy cattle manure (148 1 kg -1 VS). Methane productivity based on livestock units (LU) shows the lowest methane productivity for sows (165 m 3 CH4 LU 1), while the other animal categories are in the same range (282301 m 3 CH4 LU-1). Pre-treatment of manure by separation is a way of making fractions of the manure that have a higher gas potential per volume. Theoretical methane potential and biodegradability of three types of fractions deriving from manure separation were tested. The volumetric methane yield of straw was found to be higher than the yield from total manure and the solid fractions of manure, due to the higher VS content, and hence the use of straw as bedding material will increase the volumetric as well as the livestock-based methane productivity.
05/00709 Syngas production by biomass gasification using Rh/Ce02/Si02 catalysts and fluidized bed reactor Tomishige, K. et al. Catalysis Today, 2004, 89, (4), 389M03. This study has developed novel catalysts for gasification of biomass with much higher energy efficiency than conventional methods (noncatalyst, dolomite, commercial steam reforming Ni catalyst). From the result of the gasification of cellulose over novel Rh/CeOJSiO2 catalysts, it was found that the gasification process consists of the reforming of tar and the combustion of solid carbon. Novel R h / C e O J SiO2 was tested in the gasification with air, pyrogasification, and steam
05•00703 Defining leaf traits linked to yield in short-rotation coppice Salix Robinson, K. M. et al. Biomass and Bioenergy, 2004, 26, (5), 417 431. Short-rotation coppice Salix genotypes of differing biomass yields were studied over two growing seasons with the long-term aim of identifying traits definitive of high yield for the breeding of elite energy crops. In the first season, basic leaf and stem traits were measured in six Salix genotypes, to identify morphological characteristics associated with high biomass yields. Thereafter, S. viminalis L. 'L78183' (low yield) and the hybrid genotype S. sehwerinii E. Wolf x S. viminalis L. 'Tora' (high yield) were compared. Maximum stem heights and stem diameters increased with biomass yield. 'Tora' produced more sylleptic branches on the leading stems than 'L78183'. Leaf traits differed significantly between the two genotypes: individual leaf area and cell number per leaf was greater in 'Tora', whereas cell area was greater in 'L78183', suggesting that final leaf areas were attained in 'Tora' through the production of many, small cells, and in 'L78183' through fewer, large cells. Leaf extension rates were higher in 'Tora' than 'L78183'. This result was mirrored for leaf production rate. Leaf area index, examined at two coppice stages, was higher in "L78183' (values of 2.06 and 1.67) than in 'Tora' (maximum value 1.43) which had a very open canopy. Furthermore, A / C j analysis revealed the low-yielding genotype as the most photo-synthetically efficient at the individuai leaf level whereas light response curves suggest that 'Tora' utilized light more efficiently. The results presented in this study suggest that leaf extension rate, final leaf size and cell number per leaf may be indicative of yield, and may be useful as selection criteria for potentially high-yielding hybrids for biomass use.
05•00704 stover
Distribution of aboveground biomass in corn
Pordesimo, L. O. et al. Biomass and Bioenergy, 2004, 26, (4), 337-343. Corn stover can be a principal feedstock for bio-energy and industrial applications because of its abundance and its current under-utilization. Development of strategies/systems for the post-harvest handling of corn stover involves quantifying what corn stover biomass is available over time after grain physiological maturity has been reached. It also involves understanding how the biomass is distributed in the different aboveground components of the corn plant. The objectives of this preliminary investigation were to measure the allocation of biomass to aboveground components of the corn plant over time and to develop relationships for estimating total aboveground corn plant biomass through simple corn plant dimensional measurements. Aboveground biomass distribution for two corn cultivars (Pioneer 32K61 and 32K64 Bt) was studied in standing plants from roughly 1 week before grain physiological maturity until 4 weeks after grain harvest from other plots in the field. Over the monitoring period, the amount of dry matter in stover averaged 50% of the total aboveground dry plant mass with stalks comprising 50% of the stover dry matter at the time grain was harvested. This study indicated that the more conservative 0.8:1 stover:grain fresh weight ratio, rather than the 1:1 widely used, may be more realistic at the grain harvest moisture range of 18-31% w.b. Such precondition has not been clearly emphasized in the literature. Regression equations involving stalk diameter and plant height for DeKalb 626 derived to estimate fresh green weight and dry matter of the corn plant above the ground had a maximum R 2 of 0.75.
05100705 Efficient energy systems with C02 capture and storage from renewable biomass in pulp and paper mills M6llersten, K. et al. Renewable Energy, 2004, 29, (9), 1583-1598. This paper investigates the impact of combining CO2 capture and storage with alternative systems for biomass-based combined heat and power production (CHP) in Kraft pulp and paper mills. The study compares heat, power, and COz balances of systems with alternative configurations of the CHP and CO2-capture systems. Because the captured CO2 comes from renewable biomass, the studied systems yield negative CO2 emissions. It is shown that pulp mills and integrated pulp and paper mills have the potential to become net exporters of biomassbased electricity while at the same time removing CO2 from the atmosphere on a net basis. The study shows that that the overall best CO2 abatement is achieved when CO2 capture is carried out within a biomass integrated gasifier with combined cycle where the syngas undergoes a CO-shift reaction. This configuration combines efficient energy conversion with a high CO2 capture efficiency. Furthermore, cost curves are constructed, which show how the cost of CO2 capture and storage in pulp and paper mills depends on system configuration and the CO2 transportation distance.
05/00706 Experiment and modelling of parameters influencing natural wind drying of willow chunks Giglcr, J. K. et al. Biomass and Bioenerg.r, 2004, 26, (6), 507-514.
104
Fuel and Energy Abstracts
March 2005
The objective of this study was to investigate the parameters that govern the drying process of willow chunks. Indicative chunk drying trials were conducted to assess the potential of natural wind drying. Supportive model simulations were conducted to gain insight into the influence of different process parameters (particle size, pile depth) on drying. Natural wind drying experiments showed that willow chunks could be dried from 50% (wet basis) to around 10% within 5 months. Internal heating in the pile did not occur and dry matter losses were reasonably low (3.5-5%). The drying time of willow chunks depended on drying air conditions, particle size and pile dimensions (depth). The particle size of chunks should be large enough to create a low airflow resistance in the pile, but small enough to avoid that internal diffusion of moisture limits the drying process.
05/00707
Intermittent drying of bioproducts - an overview
Chua, K. J. et al. Bioresource Technology, 2003, 90, (3), 285-295. Unlike the conventional practice of supplying energy for batch drying processes at a constant rate, newly developed intermittent drying processes employ time-varying heat input taiiored to match the drying kinetics of the material being dried. The energy required may be supplied by combining different modes of heat transfer (e.g. convection coupled with conduction or radiation or dielectric heating simultaneously or in a pre-selected sequence) in a time-varying fashion so as to provide optimal drying kinetics as welt as quality of the bioproduct. This is especially important for drying of heat-sensitive materials (such as foods, pharmaceutical, neutraceutical substances, herbs, spices and herbal medicines). Intermittent heat supply is beneficial only for materials which dry primarily in the falling rate period where internal diffusion of heat and moisture controls the overall drying rate. Periods when little or no heat is supplied for drying allow the tempering period needed for the moisture and heat to diffuse within the material. As the moisture content increases at the surface of the biomaterial during the tempering period, the rate of drying is higher when heat input is resumed. It is possible to control the heat input such that the surface temperature of the product does not exceed a pre-determined value beyond which thermal damage of the material may occur. This process results in reduction in the use of thermal energy as well as the mass of air used in convective drying. Thus, the thermal efficiency of such a process is higher. The quality of the product, as such colour and ascorbic acid content, is also typically superior to that obtained with a continuous supply of heat. However, in some cases, there will be a nominal increase in drying time. In the case of microwave-assisted and heat pump drying, for example, the capital cost of the drying system can also be reduced by drying in the intermittent mode. This paper provides an overview of the basic process, selected results from experiments and mathematical models for a variety of biomaterials dried in a wide assortment of dryers. It begins with a classification of intermittent drying processes that may be applied e.g. time-varying temperature, air flow rate, operating pressure as well as heat input by different modes and in different temporal variations. The beneficial effects of improving the quality of dried bioproducts by different intermittent processes are also included and discussed.
05/00708 Methane productivity of manure, straw and solid fractions of manure M¢ller, H. B. et al. Biomass and Bioenergy, 2004, 26, (5), 485~495. The methane productivity of manure in terms of volatile solids (VS), volume and livestock production was determined. The theoretical methane productivity is higher in pig (516 1 kg -1 VS) and sow (530 1 kg -1 VS) manure than in dairy cattle manure (469 1 kg- l VS), while the ultimate methane yield in terms of VS is considerably higher in pig (356 1 kg- 1 VS) and sow manure (275 1 kg -1 VS) than in dairy cattle manure (148 1 kg -1 VS). Methane productivity based on livestock units (LU) shows the lowest methane productivity for sows (165 m 3 CH4 LU 1), while the other animal categories are in the same range (282301 m 3 CH4 LU-1). Pre-treatment of manure by separation is a way of making fractions of the manure that have a higher gas potential per volume. Theoretical methane potential and biodegradability of three types of fractions deriving from manure separation were tested. The volumetric methane yield of straw was found to be higher than the yield from total manure and the solid fractions of manure, due to the higher VS content, and hence the use of straw as bedding material will increase the volumetric as well as the livestock-based methane productivity.
05/00709 Syngas production by biomass gasification using Rh/Ce02/Si02 catalysts and fluidized bed reactor Tomishige, K. et al. Catalysis Today, 2004, 89, (4), 389M03. This study has developed novel catalysts for gasification of biomass with much higher energy efficiency than conventional methods (noncatalyst, dolomite, commercial steam reforming Ni catalyst). From the result of the gasification of cellulose over novel Rh/CeOJSiO2 catalysts, it was found that the gasification process consists of the reforming of tar and the combustion of solid carbon. Novel R h / C e O J SiO2 was tested in the gasification with air, pyrogasification, and steam