Novel Miscanthus Germplasm-Based Value Chains: A Life Cycle Assessment

Abstract

In recent years, considerable progress has been made in miscanthus research: improvement of management practices, breeding of new genotypes, especially for marginal conditions, and development of novel utilization options. The purpose of the current study was a holistic analysis of the environmental performance of such novel miscanthus-based value chains. In addition, the relevance of the analyzed environmental impact categories was assessed. A Life Cycle Assessment was conducted to analyse the environmental performance of the miscanthus-based value chains in 18 impact categories. In order to include the substitution of a reference product, a system expansion approach was used. In addition, a normalization step was applied. This allowed the relevance of these impact categories to be evaluated for each utilization pathway. The miscanthus was cultivated on six sites in Europe (Aberystwyth, Adana, Moscow, Potash, Stuttgart and Wageningen) and the biomass was utilized in the following six pathways: (1) small-scale combustion (heat)—chips; (2) small-scale combustion (heat)—pellets; (3) large-scale combustion (CHP)—biomass baled for transport and storage; (4) large-scale combustion (CHP)—pellets; (5) medium-scale biogas plant—ensiled miscanthus biomass; and (6) large-scale production of insulation material. Thus, in total, the environmental performance of 36 site × pathway combinations was assessed. The comparatively high normalized results of human toxicity, marine, and freshwater ecotoxicity, and freshwater eutrophication indicate the relevance of these impact categories in the assessment of miscanthus-based value chains. Differences between the six sites can almost entirely be attributed to variations in biomass yield. However, the environmental performance of the utilization pathways analyzed varied widely. The largest differences were shown for freshwater and marine ecotoxicity, and freshwater eutrophication. The production of insulation material had the lowest impact on the environment, with net benefits in all impact categories expect three (marine eutrophication, human toxicity, agricultural land occupation). This performance can be explained by the multiple use of the biomass, first as material and subsequently as an energy carrier, and by the substitution of an emission-intensive reference product. The results of this study emphasize the importance of assessing all environmental impacts when selecting appropriate utilization pathways.

Life cycle assessment of ethanol production from miscanthus: A comparison of production pathways at two European sites

“…In Aberystwyth, feedstock production takes place on a marginal site, which is characterized by shallow soils, a slow establishment phase and low yields. Furthermore, the British site is characterized by higher precipitation rates and comparatively low soil clay content (Hastings et al, ; Wagner, Kiesel, Hastings, Iqbal, & Lewandowski, ; van der Weijde, Dolstra, Visser, & Trindade, ). The system boundaries include transport of biomass from the field to the refinery and all processes of the conversion in the plant (pretreatment, enzymatic hydrolysis, fermentation and distillation/separation).…”

Economic and environmental performance of miscanthus cultivated on marginal land for biogas production

“…The selection of the relevant impact categories was based on Wagner et al. (). They analysed the relevance of various impact categories in the assessment of miscanthus‐based value chains and recommended the inclusion of climate change (CC)—which corresponds to global warming potential—agricultural land occupation (ALO), human toxicity (HT), marine (MET) and freshwater ecotoxicity (FET), as well as marine (ME) and freshwater eutrophication (FE) (Wagner et al., ).…”

“…Herbicide application is usually only necessary in the first 2 years and in the recultivation process. A typical application regime over the whole cultivation period can be described as follows: 10 L/ha Round up (Monsanto, active ingredient 360 g/L glyphosate); 3.5 L/ha Stomp Aqua (BASF, active ingredient 455 g/L pendimethalin); 1.5 L/ha Calisto (Syngenta, active ingredient 100 g/L mesotrione); 0.2 L/ha Arrat (BASF, active ingredient 100 g/L tritosulfuron and 500 g/L dicamba); and 1 L/ha Dash, (BASF, an emulsifiable concentrate) (Wagner et al., ). Based on a cultivation period of 20 years, this corresponds to an average of 0.81 L herbicides per hectare and year.…”

Markets, Sustainability Management and Entrepreneurship

“…Climate change and resource depletion are most commonly chosen. However, for biomass production and utilization, relevant potential ecological impacts also include land and water use, marine ecotoxicity, human toxicity and freshwater eutrophication (Wagner et al 2017). Therefore, it is recommended that those impact categories should be chosen for which relevant impacts are anticipated in the biobased value chain under analysis (Wagner et al 2017).…”

“…The environmental impact categories most relevant for perennial crop-based value chains are, among others: climate change, fossil fuel depletion, eutrophication and acidification (Wagner et al 2017). These were therefore chosen for the LCA.…”