Valorization of landscape management grass

Abstract

The aim of this review was to investigate and develop possible material and energetic utilization strategies for grass from nature conservation areas, which is harvested late in the year and currently largely unused. Compared to freshly harvested grass, it contains less proteins and higher contents of fibers. Landscape management grass has therefore poor forage quality and is not suitable as animal feed. Due to its high calorific value, grass biomass can be used as a material for combustion. However, combustion technology must be adapted to the high contents of inorganics. Fresh grass is a widely used feedstock in biogas plants; late-harvested grass however shows lower biogas yields. The integrated generation of solid fuel and biogas represents a promising combination of combustion and digestion. Grass biomass can also be used in a green biorefinery (GBR) or a lignocellulose biorefinery (LCB). A GBR uses fresh green biomass, producing a protein concentrate (recovery of 30–60%, w/w) and a fiber fraction (recovery of up to 95%, w/w). It is supposed that late-harvested grass is less suitable due to low contents of exploitable components. An LCB operates on dry lignocellulosic feedstock and produces a wide range of carbohydrate products. To date, no LCB or GBR operating on late-harvested grass from semi-natural grasslands was described, and further research on the practical implementation is needed.

Waste reintroduced in the kitchen: life cycles inventories of representative waste-to-nutrition pathways

“…These have already been extensively reviewed and led to the development of numerous pilot-scale and commercial-scale facilities in Europe (Hermansen et al, 2017;Krenz and Pleissner, 2022). So far, scaled projects remain focused on biore ning premium green crops (such as alfalfa, grassclover, etc.…”

Waste reintroduced in the kitchen: life cycles inventories of representative waste-to-nutrition pathways

“…Green biore ning (GB) here refers to process work ows building on the separation of green biomasses into a press pulp and a green juice fraction. GB already attests several pilot-and commercial-scale facilities in Europe, yet mostly targeting premium green crops such as alfalfa or grassclover (Hermansen et al, 2017;Krenz and Pleissner, 2022). Proposed GB LCI model was designed to assess the performances of formulating proteins concentrates from green residual streams (e.g.…”

Comparison of Different Mechanical Pretreatment Methods for the Anaerobic Digestion of Landscape Management Grass

“…Landscape management grass is defined as grass biomass produced by activities that primarily and predominantly pursue the goals of nature conservation and landscape management, within the scope of the German Federal Nature Conservation Act [9]; are not selectively cultivated; and have a maximum of two cuts per year [5,9,10]. According to an estimate by Meyer et al 2018 [11], between 20 and 110 million tons of excess grass could be available in the European Union by 2030, with meadows and permanent grassland accounting for the largest share.…”

“…The use of landscape management grass offers many opportunities, such as the valorization of agricultural residues [12] for biogas production from biomass, without land competition with food production [5,6,[13][14][15]. Additionally, the maintenance and conservation of these areas increases the biodiversity of wildlife and plants by preserving their habitats [9,10,[16][17][18]. The German Federal Nature Conservation Act goes even further in this regard, addressing the importance of the long-term conservation of diversity, distinctiveness, and beauty.…”

“…The German Federal Nature Conservation Act goes even further in this regard, addressing the importance of the long-term conservation of diversity, distinctiveness, and beauty. In addition, the act also takes into account the recreational value of nature and landscape, the protection of which includes the maintenance, development, and, if necessary, restoration of nature and landscape as a general principle [9,10]. In this context, farmers act as both landscape managers and energy producers in order to maintain the viability of these areas and simultaneously use the harvested biomass for sustainable energy production from agricultural residues.…”