Perennial grasses as lignocellulosic feedstock for second-generation bioethanol production in Mediterranean environment

Abstract

In this paper the suitability of three perennial, herbaceous, lignocellulosic grasses (Arundo donax, Saccharum spontaneous spp. aegyptiacum and Miscanthus x giganteus) for the production of second-generation bioethanol in semi-arid Mediterranean environment was stud- .9 Mg ha -1 , respectively) and Miscanthus (19.6±2.8 and 17.2±1.6 Mg ha -1 , respectively). Structural polysaccharides of the raw material were higher in Miscanthus (63.4% w/w) followed by Saccharum (61.5% w/w) and Arundo (57.6% w/w). The same trend was identified for the cellulose content (41.0%, 36.8% and 34.6%, respectively). The highest values in the total hemicellulose complex were observed in Saccharum (24.7%), followed by Arundo (23.1%) and Miscanthus (22.4%). The composition of structural polysaccharides leads to a higher theoretical ethanol yield (TEY) from one dry ton of Miscanthus feedstock (kg DM Mg -1 ), followed by Saccharum and Arundo. On the other hand, the TEY per unit surface (Mg ha -1 ) was greater in Arundo than in Saccharum and Miscanthus. When compared to other lignocellulosic sources used in the second-generation bioethanol technology, such as agricultural residues, woody species and other herbaceous perennial crops, Arundo, Saccharum and Miscanthus showed a great potential in terms of TEY ha -1 .Given the high levels of biomass yield and composition of structural polysaccharides, the three species might be introduced into the Mediterranean cropping systems to supply lignocellulosic biomass for second-generation industrial plants or bio-refineries.

Saccharum spontaneum L. ssp. aegyptiacum (Willd.) Hack. a potential perennial grass for biomass production in marginal land in semi-arid Mediterranean environment

“…In terms of composition for biochemical conversion, fiber content was comparable to that of other monocot species as A. donax, Miscanthus × giganteus, corn stover, wheat straw, rice straw, and switchgrass (Scordia et al, 2014). Our results are similar to the structural polysaccharides composition reported by Scordia et al (2010), who have also shown the potentiality of S. spontaneum spp.…”

Soil Erosion Mitigation by Perennial Species Under Mediterranean Environment

“…Hack. ), among others, might help to contain soil erosion in sloping areas, increase carbon storage in the soil, and provide lignocellulosic biomass for energy and advanced biofuels [24,25].…”

Biomass characteristics in Mediterranean populations of Piptatherum miliaceum—A native perennial grass species for bioenergy

“…In smilo grass, the mean percentage of leaves was 26.5% in 2013 (range 24-29.4) and 15% in 2014 (range 12.3-17.8), 2-3 times higher than the value (8%) reported from miscanthus leaves (Scordia et al, 2014).…”

“…The lowest percentage of tillers weight was 48.1% (PM08) in 2013 and 59% in 2014 (PM05). For miscanthus grown in Mediterranean environments, it has been reported that stems constitute about 75% of the standing crop biomass in autumn (Ercoli et al, 1999) and up to 92% in winter (Scordia et al, 2014).…”

“…), switchgrass (Panicum virgatum L.), and woody species (Lewandowski et al, 1999;Venturi et al, 1999;Clifton-Brown et al, 2001;Angelini et al, 2009). Unfortunately, in Mediterranean environments, the sustainable cultivation of lignocellulosic no-food crops relies on a poor assortment of dedicated species and varieties (Mantineo et al, 2009;Ledda et al, 2013;Scordia et al, 2014), due to the lack of species able to face summer drought under rainfed regime. In this framework, some perennial grasses may represent suitable potential bioenergy feedstock, as they show a drought avoidance or tolerance strategy (Volaire et al, 2009) associated to high water use efficiency (Lelièvre et al, 2011).…”