Excellence in Excrements: Upcycling of Herbivore Manure into Nanocellulose and Biogas

Abstract

The demand for animal products has significantly increased over the past decades as a result of the growing population and the heightened standards of living. Increased livestock farming does not only yield desired products but also significant quantities of wastes, particularly manure whose storage and application are being monitored with a tightening network of regulations. The problem is that manure is considered merely as a substrate for biogas production or as a fertilizer, whereas the substantial portion of fibers residing in herbivore manure has remained underutilized. Here, we propose a manure management system, in which not only biogas and fertilizer precursors but also high-value materials in the form of (nano)­cellulose are produced. We show that high biogas yields can be achieved for elephant manure and the remaining substrate enables effortless isolation of cellulose nanofibers, leading to a significant reduction of the environmental impact compared with traditional systems based on wood.

Exzellente Exkremente: Biogas und Papierprodukte aus Tierdung

“…Dies könnte u. a. durch neue Wege in der Produktion sowie innovative Rohstoffe überwunden werden. Nutzung von Tierdung aus der Landwirtschaft zur NC-Herstellung würde einen niedrigeren Energieverbrauch ermöglichen, da die Vorbehandlung der Cellulose durch (Wieder-)Kauen und (Teil-)Verdauung bereits für eine teilweise Defi brillierung sorgt [10].…”

Comparison of a system expansion and allocation approach for the handling of multi-output processes in life cycle assessment – a case study for nano-cellulose and biogas production from elephant manure

“…First, the manure is anaerobically fermented in a biogas plant, leading to biogas production as a co-product. Subsequently, the cellulose-containing fermentation residue is used to produce a pulp intermediate, which is then turned into NFC through a grinding step (Weiland et al, 2021) (see Figure 3 for the production route). The exact procedure is described in Weiland et al (2021).…”

“…Subsequently, the cellulose-containing fermentation residue is used to produce a pulp intermediate, which is then turned into NFC through a grinding step (Weiland et al, 2021) (see Figure 3 for the production route). The exact procedure is described in Weiland et al (2021). In Krexner et al (2022), a comprehensive LCA about the environmental impacts of this novel approach (labeled as manure scenario) compared to the status quo production of NFC from wood pulp (labeled as wood chips scenario) is assessed by using a system expansion approach.…”

Extraction of microfibrillated cellulose from elephant egesta and evaluating its reinforcing ability in pectin/alginate packaging films

“…Studies have been done in the field of extraction of cellulose from animal waste such as cow dung, 30 horse manure, 31 and elephant egesta 32 . Animal's digestive system initiates fiber breakdown, which makes the method of conversion of waste into cellulose fibers an energy‐efficient process 33 . Cellulose contains linear chains made up of glucose units linked by β‐1,4‐glycosidic linkage.…”

“…They do not have fiber‐digesting enzymes like other herbivores. As a result, there egesta is rich in fiber which composes of 40 wt% cellulose, 23 wt% lignin, and 10 wt% hemicellulose 33 . MFC obtained from the biowaste is incorporated into pectin/SA composite to fabricate edible films for packaging applications.…”