- Email: [email protected]
02867 Methods for determination of moisture content inwoodchips for power plants—a review
07 Alternative energy sources (bioconversion energy) anion exchange neutralized (AEN) hydrolysate contained substantially lower levels of the inhibiting compounds furfural, 5-hydroxymethylfurfural, and acetic acid compared to the lime neutralized hydrolysate. In batch fermentations the ethanol yields and final ethanol concentration of the two hydrolysates were similar at 0.32-0.43 g/g and 29-44 g/t, respectively. Sugar consumption in the A E N fermentations was superior. Coupling of a membrane pervaporation unit to a fed-batch fermentation of A E N hydrolysate maintained the ethanol concentration below 25 g/l with complete sugar utilization for approximately 5 days. A concentrated ethanol stream of 17 wt% ethanol was produced by the pervaporation unit.
04/02864 Growth, biomass, carbon storage and nutrient distribution in Gmefina arborea Roxb, stands on red lateritic soils in central India Swamy, S. L. et al. Bioresource Technology, 2003, 90, (2), 109-126. Growth, biomass, carbon storage and nutrient (N, P and K) variations in 1 to 6-year-old chronosequence plantations of Gmelina arborea were studied in three degraded red lateritic sites in central India. Growth parameters (dbh, total height and number of branches) varied significantly due to difference in age and site quality, but tree density showed non-significant variation. Stand biomass ranged from 3.94 (1-year-old) to 53.67 Mg ha i (6-year-old) and stand carbon in 6-yearold plantations ranged from 24.12 to 31.12 Mg ha 1 at different sites. Among the tree components, the stem wood accounted for maximum C (56.25% at site 1l) followed by branches (19.8% at site 3), roots (18.51% at site 2.) and foliage (7.01% at site 3). Mean annual C accretion at 6 years age of plantation was highest in site 3 and it was 0.35, 2.66, 0.965 and 0.87 Mg ha -a for leaf, stem, branches and roots, respectively. Quantity of nutrients increased with age. Total nitrogen accumulation in 6-year-old stands at the three sites ranged from 212.9 to 279.5 kg h a - 1 with a mean annual storage of 238.43 kg h a - 1 and total K ranged from 1 170.8 to 220.5 kg h a - with a mean annual storage of 189.93 kg h a - . Phosphorous accumulation was lowest with a mean storage of 16.75 kg ha -~. The organic carbon and nutrients in the soils improved significantly after 6 years of G. arborea planting. Soil organic carbon increased from 8.46 to 14.02 Mg ha -1 within 6 years. At soil depths 0 20 cm, 21-40 cm and 41-60 cm, available N enhanced by 14.85%, 11.98% and 11.25%, K by 10%, 9.13% and 10.63%, whereas phosphorous declined by 26% 23% and 20% respectively. At 6 years G. arborea stands sequestered 31.37 Mg h a - l carbon. The nutrient management strategies in relation to carbon accretion in G. arborea stands on degraded lateritic sites are discussed.
04•02865 Hydrogen-rich gas from fruit shells via supercritical water extraction Demirbas, A. International Journal of Hydrogen Energy, 2004, 29, (12), 1237-1243. In this study, the aqueous conversion of whole fruit shell to hydrogen rich gas under low temperature, but supercritical conditions was investigated. The ,fields of total extraction products from supercritical water extraction increase with increasing temperature for all runs. The yields of hydrogen (YHs) increase with increasing temperature and pressure for all runs and the increase of YHs with pressure are higher than those with temperature. Compared with other biomass thermochemical processes such as pyrolysis, gasification, air gasification or steam gasification, the supercritical water gasification can directly deal with the wet biomass without drying, and have high gasification efficiency at lower temperature.
04/02866 International biofuel trade - a study of the Swedish import: Ericsson, K. and Nilsson, L. R. Biomass and Bioenergy, 2004, 26, (3), 205-220. Following the development of large-scale use of biomass energy in the EU, international biofuel trade is a plausible scenario and something that is already taking place in Northern Europe. This paper focuses on Swedish biofuel imports, both direct and indirect imports, the latter deriving from the fact that part of the imported pulpwood and timber end up as fuel The objective is to describe the biomass import flows, the actors involve<] and analyse the fundamental drivers for the trade flows. The rapid expansion of biomass energy, that has taken place in district heating since the early 1990s in Sweden, has been met partly by imports. The direct biofuel import was estimated to 18 PJ for 2000, which corresponded to 26% of the biofuel supply in district heating. The total indirect biofuel import was estimated to 9 PJ of which 5.5 PJ is consumed in the district heating sector. Sawmill wood chips, decaydamaged stemwood and pellets are imported from Estonia and Latvia, whereas used wood and solid recovered fuels a r e imported from Germany and the Netherlands. Tall oil and pellets are imported from North America. Key factors related to the Swedish biofuel import are analysed, both from the view of Swedish demand and from the view of supply in the Baltic countries as well as supply from Germany or the Netherlands. National differences in energy policy are perhaps the most important driving force behind the seemingly strange trade flows.
Structures in the different national energy systems are also discussed as well as the transformation process that has taken place in the forest sector in the Baltic countries.
04/02867 Methods for determination of moisture content in woodchips for power plants-a review Nystr6m, J. and Dahlquist, E. Fuel, 2004, 83, (7 8), 773-779. The aim of this article is to show which methods that are suitable for moisture determination according to their usefulness in power plants and their standard error of performance. Moisture content is measured either in a fuel flow or a fuel bulk where the sample has to be specifically representative of the bulk. In order to be able to apply feed forward control, moisture content for chips bulk or flow should be measured automatically and on-line. According to the literature, NIR and RF are today the best-suited methods for measuring moisture content in, respectively, fuel flow and fuel bulks. It shall be pointed out that the conditions during which the SEP has been calculated, differ between the compared methods.
04•02868 Photoproduction of hydrogen from acetate by a chemoheterotrophic bacterium Rhodopseudomonas palustris P4 Oh, Y.-K_ et al. International Journal of Hydrogen Energy, 2004, 29, (11), 1115 1121. Rhodopseudomonas palustris P4 can produce H2 either from CO by water-gas shift reaction or from various sugars by anaerobic fermentation. Fermentative H2 production by P4 is fast, but its yield is relatively low due to the formation of various organic acids. In order to increase H2 production yield from glucose, P4 was investigated for the photo-fermentation of acetate which is a major by-product of fermentative H2 production. Experiments were performed in batch modes using both light-grown and dark-grown cells. When the darkgrown P4 was challenged with light and acetate, H2 was produced with the consumption of acetate after a lag period of 25 h. H2 production was inhibited when a nitrogen source, especially ammonium, is present. When the dark-fermentation broth containing acetate was adopted for photo-fermentation with light-grown cells, H2 production and concomitant acetate consumption occurred without a lag period. The H2 yield was estimated as 2.4-2.8 tool H2/mol acetate and the specific H2 production rate was as 9.8 ml H2/g cell h. The fact that a single strain can perform both dark- and light-fermentation gives a great advantage in process development. Compared to a one-step dark-fermentation, the combined dark- and light-fermentation can increase the H2 production yield on glucose by two-fold.
04102869 Polymerization of soybean oil via permanganate oxidation with sub/supercritical CO2 Mercang6z, M. et al. Chemical Engineering and Processing, 2004, 43, (8), 1015-1027. The reaction of soybean oil with aqueous KMnO4 solution, in the presence of dense CO2, is investigated by monitoring the amount of carbon-carbon double bonds and the fatty acid distribution of soybean oil. Experiments are performed with soybean oil and a model compound (methyl oleate) at 25 and 50°C and 70, 120 and 130 bar. Reactor configuration (batch and semi-batch), reaction time, and product-storage period on the extent of the reaction are studied. With the semi-batch configuration, water feed rates ranging from 0.023 to 0.250 ml/min are studied. Effect of reaction time is investigated with batch periods of 1, 3, 8, 12, 16, 24, 32 and 40 h. Physical inspections and tests, as well as instrumental analysis are carried out on the soybeanoil-derived products, which are observed to change their characteristics in time in storage vials. The consumption of soybean triglyceride double bonds (STDB) are observed to increase from 23.5 to 32.6%, when the water feed rate in the semi-batch experiments was increased from 0.023 to 0.250 ml/min. A saturation behaviour is obselved for the consumption of STDB with increasing batch reaction time. STDB consumption is 8% for one-hour reaction time, increasing to 30.1% for 16 h and 42% for 40 h. The samples obtained continued to react during storage, losing more than 80% of their carbon-carbon double bonds and attaining a rubber-like structure. Since there is no permanganate remaining in the collected samples, the change in the remaining fatty acid distribution and the observations about the product physical properties suggest that the depletion of STDB is due to air-oxidation polymerization, possibly initiated at the oil-water interface and accelerated by permanganate in the presence of dense CO2.
04/02870
Production of cellulases and hemicellulases by
Aspergillus niger KK2 from lignocellulosic biomass
Kang, S. W. et al. Bioresource Technology, 2004, 91, (2), 153-156. To investigate the production of cellulases and hemicellulases from Aspergillus niger KK2, solid state fermentation (SSF) was performed by using different ratios of rice straw and wheat bran. When A. niger KK2 was grown on rice straw alone as a solid support in SSF, the maximum FPase activity was 19.5 IU g - 1 in 4 days. Also, CMCase (129 IU g-J), 3-glucosidase (100 IU g 1 ), xylanase (5070 IU g - 1 ) and 3-
Fuel and Energy Abstracts November 2004 405
04/02864 Growth, biomass, carbon storage and nutrient distribution in Gmefina arborea Roxb, stands on red lateritic soils in central India Swamy, S. L. et al. Bioresource Technology, 2003, 90, (2), 109-126. Growth, biomass, carbon storage and nutrient (N, P and K) variations in 1 to 6-year-old chronosequence plantations of Gmelina arborea were studied in three degraded red lateritic sites in central India. Growth parameters (dbh, total height and number of branches) varied significantly due to difference in age and site quality, but tree density showed non-significant variation. Stand biomass ranged from 3.94 (1-year-old) to 53.67 Mg ha i (6-year-old) and stand carbon in 6-yearold plantations ranged from 24.12 to 31.12 Mg ha 1 at different sites. Among the tree components, the stem wood accounted for maximum C (56.25% at site 1l) followed by branches (19.8% at site 3), roots (18.51% at site 2.) and foliage (7.01% at site 3). Mean annual C accretion at 6 years age of plantation was highest in site 3 and it was 0.35, 2.66, 0.965 and 0.87 Mg ha -a for leaf, stem, branches and roots, respectively. Quantity of nutrients increased with age. Total nitrogen accumulation in 6-year-old stands at the three sites ranged from 212.9 to 279.5 kg h a - 1 with a mean annual storage of 238.43 kg h a - 1 and total K ranged from 1 170.8 to 220.5 kg h a - with a mean annual storage of 189.93 kg h a - . Phosphorous accumulation was lowest with a mean storage of 16.75 kg ha -~. The organic carbon and nutrients in the soils improved significantly after 6 years of G. arborea planting. Soil organic carbon increased from 8.46 to 14.02 Mg ha -1 within 6 years. At soil depths 0 20 cm, 21-40 cm and 41-60 cm, available N enhanced by 14.85%, 11.98% and 11.25%, K by 10%, 9.13% and 10.63%, whereas phosphorous declined by 26% 23% and 20% respectively. At 6 years G. arborea stands sequestered 31.37 Mg h a - l carbon. The nutrient management strategies in relation to carbon accretion in G. arborea stands on degraded lateritic sites are discussed.
04•02865 Hydrogen-rich gas from fruit shells via supercritical water extraction Demirbas, A. International Journal of Hydrogen Energy, 2004, 29, (12), 1237-1243. In this study, the aqueous conversion of whole fruit shell to hydrogen rich gas under low temperature, but supercritical conditions was investigated. The ,fields of total extraction products from supercritical water extraction increase with increasing temperature for all runs. The yields of hydrogen (YHs) increase with increasing temperature and pressure for all runs and the increase of YHs with pressure are higher than those with temperature. Compared with other biomass thermochemical processes such as pyrolysis, gasification, air gasification or steam gasification, the supercritical water gasification can directly deal with the wet biomass without drying, and have high gasification efficiency at lower temperature.
04/02866 International biofuel trade - a study of the Swedish import: Ericsson, K. and Nilsson, L. R. Biomass and Bioenergy, 2004, 26, (3), 205-220. Following the development of large-scale use of biomass energy in the EU, international biofuel trade is a plausible scenario and something that is already taking place in Northern Europe. This paper focuses on Swedish biofuel imports, both direct and indirect imports, the latter deriving from the fact that part of the imported pulpwood and timber end up as fuel The objective is to describe the biomass import flows, the actors involve<] and analyse the fundamental drivers for the trade flows. The rapid expansion of biomass energy, that has taken place in district heating since the early 1990s in Sweden, has been met partly by imports. The direct biofuel import was estimated to 18 PJ for 2000, which corresponded to 26% of the biofuel supply in district heating. The total indirect biofuel import was estimated to 9 PJ of which 5.5 PJ is consumed in the district heating sector. Sawmill wood chips, decaydamaged stemwood and pellets are imported from Estonia and Latvia, whereas used wood and solid recovered fuels a r e imported from Germany and the Netherlands. Tall oil and pellets are imported from North America. Key factors related to the Swedish biofuel import are analysed, both from the view of Swedish demand and from the view of supply in the Baltic countries as well as supply from Germany or the Netherlands. National differences in energy policy are perhaps the most important driving force behind the seemingly strange trade flows.
Structures in the different national energy systems are also discussed as well as the transformation process that has taken place in the forest sector in the Baltic countries.
04/02867 Methods for determination of moisture content in woodchips for power plants-a review Nystr6m, J. and Dahlquist, E. Fuel, 2004, 83, (7 8), 773-779. The aim of this article is to show which methods that are suitable for moisture determination according to their usefulness in power plants and their standard error of performance. Moisture content is measured either in a fuel flow or a fuel bulk where the sample has to be specifically representative of the bulk. In order to be able to apply feed forward control, moisture content for chips bulk or flow should be measured automatically and on-line. According to the literature, NIR and RF are today the best-suited methods for measuring moisture content in, respectively, fuel flow and fuel bulks. It shall be pointed out that the conditions during which the SEP has been calculated, differ between the compared methods.
04•02868 Photoproduction of hydrogen from acetate by a chemoheterotrophic bacterium Rhodopseudomonas palustris P4 Oh, Y.-K_ et al. International Journal of Hydrogen Energy, 2004, 29, (11), 1115 1121. Rhodopseudomonas palustris P4 can produce H2 either from CO by water-gas shift reaction or from various sugars by anaerobic fermentation. Fermentative H2 production by P4 is fast, but its yield is relatively low due to the formation of various organic acids. In order to increase H2 production yield from glucose, P4 was investigated for the photo-fermentation of acetate which is a major by-product of fermentative H2 production. Experiments were performed in batch modes using both light-grown and dark-grown cells. When the darkgrown P4 was challenged with light and acetate, H2 was produced with the consumption of acetate after a lag period of 25 h. H2 production was inhibited when a nitrogen source, especially ammonium, is present. When the dark-fermentation broth containing acetate was adopted for photo-fermentation with light-grown cells, H2 production and concomitant acetate consumption occurred without a lag period. The H2 yield was estimated as 2.4-2.8 tool H2/mol acetate and the specific H2 production rate was as 9.8 ml H2/g cell h. The fact that a single strain can perform both dark- and light-fermentation gives a great advantage in process development. Compared to a one-step dark-fermentation, the combined dark- and light-fermentation can increase the H2 production yield on glucose by two-fold.
04102869 Polymerization of soybean oil via permanganate oxidation with sub/supercritical CO2 Mercang6z, M. et al. Chemical Engineering and Processing, 2004, 43, (8), 1015-1027. The reaction of soybean oil with aqueous KMnO4 solution, in the presence of dense CO2, is investigated by monitoring the amount of carbon-carbon double bonds and the fatty acid distribution of soybean oil. Experiments are performed with soybean oil and a model compound (methyl oleate) at 25 and 50°C and 70, 120 and 130 bar. Reactor configuration (batch and semi-batch), reaction time, and product-storage period on the extent of the reaction are studied. With the semi-batch configuration, water feed rates ranging from 0.023 to 0.250 ml/min are studied. Effect of reaction time is investigated with batch periods of 1, 3, 8, 12, 16, 24, 32 and 40 h. Physical inspections and tests, as well as instrumental analysis are carried out on the soybeanoil-derived products, which are observed to change their characteristics in time in storage vials. The consumption of soybean triglyceride double bonds (STDB) are observed to increase from 23.5 to 32.6%, when the water feed rate in the semi-batch experiments was increased from 0.023 to 0.250 ml/min. A saturation behaviour is obselved for the consumption of STDB with increasing batch reaction time. STDB consumption is 8% for one-hour reaction time, increasing to 30.1% for 16 h and 42% for 40 h. The samples obtained continued to react during storage, losing more than 80% of their carbon-carbon double bonds and attaining a rubber-like structure. Since there is no permanganate remaining in the collected samples, the change in the remaining fatty acid distribution and the observations about the product physical properties suggest that the depletion of STDB is due to air-oxidation polymerization, possibly initiated at the oil-water interface and accelerated by permanganate in the presence of dense CO2.
04/02870
Production of cellulases and hemicellulases by
Aspergillus niger KK2 from lignocellulosic biomass
Kang, S. W. et al. Bioresource Technology, 2004, 91, (2), 153-156. To investigate the production of cellulases and hemicellulases from Aspergillus niger KK2, solid state fermentation (SSF) was performed by using different ratios of rice straw and wheat bran. When A. niger KK2 was grown on rice straw alone as a solid support in SSF, the maximum FPase activity was 19.5 IU g - 1 in 4 days. Also, CMCase (129 IU g-J), 3-glucosidase (100 IU g 1 ), xylanase (5070 IU g - 1 ) and 3-
Fuel and Energy Abstracts November 2004 405