07 Alternative Energy Sources (bioconversion 00/00314 Determination of the quality of biogas by flame temperature measurement Mandal, T‘. er al. Energy Conver,y. Manage., 1999, 40. (1I), 122~-1228. A prototype experimental procedure has been developed to find the quality of biogas produced by cowdung, using its flame temperature. The variation of flame temperature of the sample of biogas collected from a laboratory scale anaerobic digester per week has been studied to find the change in quality of the same throughout the retention period. The result has been verified by determining changes in the percentage of methane in the biogas. 00/00315
Energy- and exerg analysis of rape seed oil methyl production under Hwedish conditions
Hovelius, K. and Hansson. P.-A. Biomass & Bioeneru. 1999. 17. (4). 27Y290. In this study the rape seed oil methyl ester (RME) production chain was analysed with respect to its energy- and exergy efficiencies. The differences between results from an ordinary energy analysis and an exergy analysis of the production were also quantified and discussed. The sensitivity of the results to changes in some of the most important input parameters were then analysed in order to find production strategies that increase the exergy efficiency. The Ttudy was applied to rape seed cultivation situated in southern Sweden. The rape seed oil was hot pressed in a large-scale plant and the RME was esterfied in the same factory as that in which in the rape seed oil was pressed. Both direct and indirect energy and exergy flows used for RMF production were included. The analysis showed that a large part of the energy and exergy used to produce RME was related to nitrogen fertilizers and diesel fuels. Another important conclusion was that the exergy efficiency of the production in general is higher than the energy efficiency. A third conclusion was that it is possible, by using alternative production strategies. to improve the exergy efficiency without decreasing the energy efficiency.
dry weights varied between species, between sub-genera, and also between harvests. Biomass yields at comparative population densities tended to increase with subsequent coppice harvests, even though no irrigation. fertilizer pest management systems or weed control methods were applied. Six species-E. hrookerana. E. hotryoides. E. hotr~oid~v x saligatla and E. o\‘ata of the subenus S~mph~omyrrus and E. &to and E. oh&ylro of the suhgenus Monoca/~vpruv gave satisfactory yields which exceeded IO ODtiha/year in any one of the five harvests. This provided mean annual incremental yields over the IS-year period ranging between 12-34 ODtihalyear for these species when grown in the small plots. Commercial scale crop yields are likely to be considerably lower. However the six top yielding Euca!yptus species identified can be recommended for consideration in commercial plantings of short rotation coppice forestry schemes when grown on fertile soils in a temperate climate.
Fuel cell power plants using digestion gases
Kobuchi. A. and Taniguchi, H. Jpn. Kokai Tokkyo Koho JP I I 113.723 [YY 03,723] (Cl. HOlM8106). 6 Jan 1997. h, pp. (In Japanese) The paper describes fuel cell power plants that use digestion gases. Thev are equipped with a digestion tank for methane fermentation of organic wastes, one membrane apparatus is used for the separation of gas from concentrated carbon dioxide from high-concentrated methane (Ml). a second membrane apparatus has the roles of separating highly concentrated carbon dioxide form methane (M2). M2 is circulated to the former membrane apparatus and Ml is used as a fuel for the fuel cell. The recoverv ratio of methane is high.
Fuel characteristics of short rotation forest
biomass Energy from biomass do non-technical barriers 00/00316 prevent an increased use? R(isch. C. and Kaltschmitt. M. Biomass & Bioenergv. 1999. 16. (5). 347356. The aim of this paper is the identification and analysis of certain nontechnical barriers which could hinder a wider use of solid biofuels for the provision of useful energy within Europe. First the financial challenges to carry out a successful project are discussed. Then the problems which could arise due to legal and administrative reasons which affect the construction and operation of a biomass fired plant are identified. This is also true for the organisational and perception challenges which influence the further use of biomass for energy. Finally, instruments and measures to overcome these barriers to reduce the risk of non-technical delays or failures are presented.
Estimating Swedish biomass energy supply 00100317 Johansson. J. and Lundqvist. U. Biomass & Bioener~. 1999, 17, (l), 85-93. Biomass is suggested to supply an increasing amount of energy in Sweden. There have been several studies estimating the potential supply of biomass energy, including that of the Swedish Energy Commission in 1995. The Energy Commission based its estimates of biomass supply on five other analyses which presented a wide variation in estimated future supply, in large part due to differing assumptions regarding important factors. In this paper, these studies are assessed, and the estimated potential biomass energy supplies are discussed regarding prices, technical progress and energy policy. The supply of logging residues depends on the demand for wood products and is limited by ecological, technological and economic restrictions. The supply of stemwood from early thinning for energy and of straw from cereal and oil seed production is mainly dependent upon economic considerations. One major factor for the supply of willow and reed canary grass is the size of arable land projected to be not needed for food and fodder production. Future supply of biomass energy depends on energy prices and technical progress, both of which are driven by energy policy priorities. Biomass energy has to compete with other energy sources as well as with alternative uses of biomass such as forest products and food production. Technical progress may decrease the costs of biomass energy and thus increase the competitiveness. Economic instruments, including carbon taxes and subsidies and allocation of research and development resources, are driven by energy policy goals and can change the competitiveness of biomass energy. OOIOO316
Eucalyptus species for biomass energy in New II: Coppice performance
Sims, R. E. H. Biomass & Eioenergy, 1999, 17, (4). 333-343. Coppice re-growth and related yields of twelve species of the subgenus Spmphyomyrrus and seven species of the subgenus Monocalypttrs were monitored over five 3-year rotations. Planted in small plots at an original planting density equivalent to 2200 stems/ha, the resulting population densities (trees/ha and shoots/ha) varied with species and with each rotation as tree mortality increased to varying degrees following every successive harvest. Only eight of the 19 species planted had survival rates exceeding SO% of the initial population density after the fifth and final harvest. E. hrookerana and E. ovata were the most vigorous species with survival rates exceeding 80% of the original planting. Eight of the species had died out completely before the final harvest. Overall, species from the sub-genus Symphyomyrtus had higher survival rates than those from the sub-genus Monoca1ypru.s. Tree height shoot stump diameter and above ground biomass
Senelwa, K. and Sims, R. E. H. Bmmao & Biocwer~~. IYYY. 17. (I). 127140. Fuel characteristics of biomass from 12 tree species grown under a short rotation forestry regime were analysed. E. g/oh&~. E. uifcnr and A. dealhata had the biggest trees while A. ghr/i~?osa, P. ~omet~~o.wand 5. matsudana I a/ha 1002 had the smallest trees when the trees were harvested at the age of 3, 4 and S years. Higher heating value (HHV) ranged from 19.6-20.5 MJikg for wood, 17.4-20.6 MJikg for bark and 19.524.1 MJ/kg for leaves, with the highest values for wood and bark being obtained from Pinus radiata. Wood basic density ranged from 250-500 kg/ m3; ash content. 0.7-1.4%: volatile matter content, 9l.S-95.1%: fixed carbon content, 4.2-7.3%; and extractives content. 3.3-l 1.9rir. Wood properties were significantly different from those of hark and also different from those of leaves. Except basic density and the proportion of bark on the stem. properties of wood did not vary with either cutting age or stocking density. Wood from coppice crops did not differ from that of single stem. first harvest crops. Differences in tree size for species planted at similar plant populations determine species yields. Variations in properties between species and between tree parts have implications for feedstock handling, transport, drying, storage and on the design of conversion systems.
00100321 Fuelwood characteristics of selected indigenous tree species from central India Jain, R. K. and Singh, B. Bioresource Technoloa, 1999. 68, (3), 305-308. Thirty tree species indigenously growing in their natural habitat in subtropical forest of central India were collected and fuelwood properties viz. moisture, silica, ash, density, carbon, nitrogen, volatile matter. calorifie value and fuel value index (FVI) calculated to screen desirable species for potential production of fuelwood in these areas. The present study revealed that Acer ohlongum, Bet& alo~~oides. GreGlIeu rohusta, Linionia acidi.wima, Lyonia ovalifolia, hiadhuca indica, M&a azedarch, Morinda rinctoria, Myrica sapida, Prunus cornuta, Pyrus pashia, Quercu~ langinosa, Rhamnus rricprerer arid Stereospermum qylocarpum possess excellent fuelwood qualities.
Generation and conversion of carbonaceous fine particles during bubbling fluidlsed bed gasification of a biomass fuel
Miccio, F. Fuel, 1999, 78, (12). 1473-1481. This article presents an experimental research concerning the biomass gasification in bubbling fluidized bed. The attention is focused on the role played by comminution phenomena during the conversion of fuel particles, and on the occurrence of post-conversion of elutriated chars in the freeboard. The aim is pursued by means of measurements of bed carbon load, elutriation rate as well as particulate concentration at various heights of the freeboard in a laboratory scale facility equipped with an isokinetic probe. The results of experiments show that fines generation is relevant during gasification and post-conversion of particles takes place after their release from the bed. The carbon post-conversion in the freeboard achieves a maximum value of 70%, even when the operating conditions are unfavourable for gasification. The results are also confirmed by measurements of gas composition in the freeboard. The laboratory analyses of samples taken during experiments could confirm that a percolative fragmentation takes place in parallel with carbon post-conversion.
Fuel and Energy Abstracts