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Stalk material cutting energy
2005
Smits, M.(Latvia Univ. of Agriculture, Jelgava (Latvia))E-mail:mareksmi@llu.lv | Kronbergs, E.(Latvia Univ. of Agriculture, Jelgava (Latvia))
Systainable energy systems and food security can be obtained in rural areas by usage of renewable energy resources and development of agro-ecotechnologies. Substitution of fossil feedstock for energy and raw materials by biomass is important measure also for greenhouse gas (GHG) emission mitigation. The article presents investigation of reed biomass size reduction processes flattening and cutting. The necessity to reduce the size of common reeds (Phragmites australis) to particles smaller than 3 mm for solid biofuel production is determined by compaction properties of biomass. It was stated that unflattened reed stem cutting energy consumption is 2 times more than flattened stem cutting energy. There are no sufficient differences in the energy consumption values for single flattened reed stalk cutting with different shaped knives. The average difference is approximately 2.4 kJ square m with knife edge angles 90 deg and 20 deg.
Показать больше [+] Меньше [-]Internal stresses of biomass compositions
2005
Nulle, I.(Latvia Univ. of Agriculture, Jelgava (Latvia))E-mail:Imants.Nulle@llu.lv | Kakitis, A.(Latvia Univ. of Agriculture, Jelgava (Latvia))
Relevant resources for biomass energy production are cereal straw residues and emergent vegetation from wetlands. This bulk herbaceous biomass is a material with low density. Density of briquetted straw and reed has been increased from 60 kg mE-3 to 1000 kg mE-3. The storage, dosage and mixing of biomass bulk materials before compacting are necessary, which requires working knowledge of the bulk properties of materials. The angle of repose of straw, reed and peat particles was investigated. It was stated that angle of repose of straw and reed varies between 45-55 degrees. The angle of repose of peat particles varies between 37-50 degrees. The stress ratio between horizontal and vertical stress is important for equipment design. This ratio was investigated for different size particles of straw, reed and peat. Stress ratio of straw particles varies between ~ 0.6-0.71.
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