TY - JOUR A1 - Everard, C.D. A1 - Schmidt, Martin A1 - McDonnell, K.P. A1 - Finnan, J. T1 - Heating processes during storage of Miscanthus chip piles and numerical simulations to predict self-ignition N2 - Miscanthus x Giganteus (Miscanthus) energy crop was examined at laboratory scale to assess its self-heating and self-ignition risks during storage. Chipped Miscanthus (18 mm) from February and March harvests, in 2012, were assessed as well as ground Miscanthus (3 mm) from the March harvest. February and March crops had moisture contents of 41.6 and 20.2%, respectively. Self-ignition temperatures were independent of moisture although moisture did affect the time from the beginning of storage until storage temperature was reached. Ground Miscanthus had lower self-ignition temperatures than chipped Miscanthus. Isothermal respirometric tests carried out showed increase risk of self-heating in the February crop compared to the March crop due to increased microbial activity. Numerical simulations were used to determine critical enhanced start temperatures, e.g. caused by microbial decomposition, of the stored Miscanthus. Safe storage conditions have been derived from the investigations. The numerical simulations demonstrated that self-ignition was possible in Miscanthus chip piles with a height greater than 6 m if there was significant heat release from microbiological activity. Reliable assessment of self-heating and self-ignition risks in large scale Miscanthus energy crop clamps or piles are required to prevent losses due to decomposition and fire damage. KW - Miscanthus x Giganteus KW - Hot storage test KW - Respirometric rates KW - Self-heating KW - Self-ignition KW - Numerical simulations KW - Biomass storage PY - 2014 DO - https://doi.org/10.1016/j.jlp.2014.06.003 SN - 0950-4230 SN - 1873-3352 VL - 30 SP - 188 EP - 196 PB - Butterworth CY - Guildford, Surrey AN - OPUS4-31149 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Everard, C.D. A1 - Finnan, J. A1 - McDonnell, K.P. A1 - Schmidt, Martin T1 - Evaluation of self-heating in Miscanthus x giganteus energy crop clamps and the implications for harvesting time N2 - Miscanthus x giganteus energy crop grown in Ireland was harvested on 21st of February and 28th of March 2012 to examine the effects of harvesting time on self-heating during storage of Miscanthus chips in clamps (98 m³) under weather sheltered conditions. There was a relatively large difference in moisture content, of 21.4%, between Miscanthus crop harvested in February and March (41.6 and 20.2%, respectively). Temperature evolution over a storage period of up to 125 days was monitored at different heights and distances from the centre within the clamps. Maximum temperature in the February constructed clamp reached 69 °C compared to 28 °C in the March constructed clamp. Microbial activity was monitored via carbon dioxide and oxygen gas measurements. The high moisture clamp showed higher microbial activity and a volume yield loss of 4.3% due to decomposition in the top section of the clamp. Quality indices post-storage were also assessed. Calorific values from Miscanthus sampled 1 m below the top surface were similar after storage for both February and March constructed clamps, i.e. 18.52 and 18.70 MJ kg-1, respectively. A reliable assessment of self-heating in Miscanthus chip clamps has important consequences for both self-ignition risk and biomass quality. KW - Self-heating KW - Miscanthus x giganteus KW - Biomass storage KW - Self-ignition KW - Biomass quality PY - 2013 DO - https://doi.org/10.1016/j.energy.2013.06.022 SN - 0360-5442 VL - 58 SP - 350 EP - 356 PB - Elsevier CY - Amsterdam [u.a.] AN - OPUS4-29054 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -