Life cycle assessment: an application to poplar for energy cultivated in Italy

Abstract

The development of the bioenergy sector has led to an increasing interest in energy crops. Short rotation coppices (SRC) are forestry management systems in which fast-growing tree species are produced under intensive cultivation practices to obtain high wood chips yields. In Italy, most SRC plantations consist of poplar biomass-clones. SRC plantations can be carried out with different management systems with diverse cutting times; consequently, the cultivation system can be crucial for attaining high yields depending on: i) short and ii) medium cutting frequency. Nowadays, the larger part of Italian SRC is based on 2-year cutting short rotation forestry (SRF) but the best quality of wood chips is linked to 5-year plantation medium rotation forestry (MRF). This work compares an SRF and an MRF poplar plantation located in the Po Valley in northern Italy. In particular, a life cycle assessment (LCA) was carried out to evaluate their energy demand and greenhouse gas emissions. The LCA software SimaPro 7.10 was used to create the LCA model and to assure an accurate impact assessment calculation. The analysis shows several differences between MRF and SRF in terms of fertiliser requirements and intensive agricultural activities. Results highlight that MRF produces a more sustainable wood chip production than SRF according to energy and environmental con-cerns. Furthermore, hot spots were identified in both SRF and MRF due to the high energy consumption and the related emissions. These hot spots were: i) mineral fertilisation; ii) mechanical weed-control; iii) harvesting and biomass transport.

Anaerobic digestion of different feedstocks: Impact on energetic and environmental balances of biogas process

“…The result of our study are in accordance with the literature (Bachmaier et al, 2013;Pöschl et al, 2010Pöschl et al, , 2012Wulfa et al, 2006;Bacenetti et al, 2012aBacenetti et al, , 2012bSchumacher et al, 2010;Meyer-Aurich et al, 2012), which shows that electricity production from biogas has huge potential for energy savings and a reduction of GHG emissions.…”

“…Also, 1 kWh of electricity (kWh e ) produced in a CHP using biogas was the functional unit (FU) for the entire electricity production system. The selection of these FUs is in agreement with other biogas LCA studies (Dressler et al, 2012;Pöschl et al, 2012;Bacenetti et al, 2012aBacenetti et al, , 2012b.…”

Time-dependent climate impact of heat production from Swedish willow and poplar pellets – In a life cycle perspective

“…A similar pattern has been reported in other LCA studies of willow cultivation [37,69]. Gasol et al [70] and Bacenetti et al [71] concluded that emissions connected to fertilisation cause the largest climate impact in a poplar cultivation system. The direct N 2 O soil emissions originate from the N fertiliser applied and from the N content in the residues.…”

“…The climate impact from cultivation of willow and poplar has also been investigated in several other studies (e.g. [16,70,71]). …”

Environmental impacts of bioenergy wood production from poplar short‐rotation coppice grown at a marginal agricultural site in Germany

“…Therefore, a comprehensive evaluation of SRC cultivation focusing on the GHG balance of such systems together with other environmental impacts, for example, NO 3 leaching losses, needs to have a long‐term perspective. Also, differences in management practices, in particular changing rotation cycle length, can have significant impacts on biomass yield and environmental effects such as soil C storage or soil N 2 O emissions (e.g., Fang et al ., ; Bacenetti et al ., ).…”