Miscanthus as energy crop: Environmental assessment of a miscanthus biomass production case study in France

Environmental performance assessment of Napier grass for bioenergy production

“…(3) average soil loss from crops in Thailand is 25 t/(ha·y) (Pansak, Hilger et al 2008); (4) organic matter in soil is 1.5% (Norsuwan, Marohn et al 2014) with the energy content 14.6 GJ/t (Cohen, Brown et al 2006);(5) replanting new crops required initial Napier stems about 3,100 -3,800 kg/ha; (6) initial Napier stems for cultivation were considered as an external input; (7) diesel fuel consumption rate for Napier grass growing and harvesting was estimated from data referred from (Morandi, Perrin et al 2016); (8) for Napier grass transporting the truck capacity and distance from cultivation field to the plant were approximately 3 tons per trip and 56 km per trip, respectively. (9) data for all agricultural machinery was obtained from (Morandi, Perrin et al 2016); (10) all machines for Napier grass cultivation were assumed to have 20 years lifetime; (11) the fresh biomass (initial moisture 30%) was sun-dried before transporting to the biorefinery site (after sundried moisture 15%); (12) Napier grass annual production rate (fresh Napier grass) is 70-80 t/(ha·y), which was hence assumed to be 75 t/(ha·y) (DEDE 2013); (13) the energy content of Napier grass is 18 MJ/kg (Flores, Urquiaga et al 2012).…”

“…Within this period of time, the UEV of output (Napier grass biomass) and input (initial Napier stem) were assumed to be equal. Iteration is often applied to deal with this issue (Morandi, Perrin et al 2016), but the procedure employed in this study was derived from the mathematical formula described below studying equation (6).…”

“…However, comparison of the resource use for the cultivation of biomass by collating UEVs from different studies may be misleading due to the different assumptions and contexts of each study. For example, some literature values did not consider the indirect labor (Coppola, Bastianoni et al 2009, Pereira and Ortega 2010, Morandi, Perrin et al 2016), some did not take into account the renewability of the economic inputs (Lin and Sagisaka 2012) and some did not describe their assumptions relating to labor accounting, which was the main emergy input into their system (Goh andLee 2010, Pereira and. For those reasons, recalculation on the same basis is required as attempted in Table 3.…”

“…Alternatively, biomass residues, such as straw, husk and other agricultural co-products or wastes are the type of promising feedstock for advanced biofuels. Another alternative could be those perennial warmseason grasses, such as Napier grass (Pennisetum purpureum), Miscanthus (Morandi, Perrin et al 2016), Indiangrass and switchgrass (Felix and Tilley 2009). These crops could produce reasonable yields even under severe conditions on marginal or degraded lands abandoned from agricultural usage with low maintenance (Campbell, Lobell et al 2008).…”

“…Neglecting this portion of energy may probably cause a misleading conclusion. The study on cultivating Miscanthus as energy crop reveals that different logistic strategies affect the emergy used or the environmental cost of the entire process (Morandi, Perrin et al 2016).…”