Coupled Biogas and Fiber Production from Agricultural Residues and Energy Crops with Steam Explosion Treatment

Abstract

The global demand for packaging materials and energy is constantly increasing, requiring the exploration of new concepts. In this work, we presented a bioeconomic concept that uses steam explosion and phase separation to simultaneously generate fibers for the packaging industry and biogas substrate for the energy sector. The concept focused on fiber-rich residues and fiber-rich ecological energy crops from agriculture. Feasibility of the concept in the laboratory using feedstocks, including Sylvatic silphia silage, Nettle silage, Miscanthus, Apple pomace, Alfalfa stalks, and Flax shives was confirmed. Our results showed that we were able to separate up to 26.2% of the methane potential while always extracting a smaller percentage of up to 17.3% of organic dry matter (ODM). Specific methane yields of 297–486 LCH4 kgODM−1 in the liquid and 100–286 LCH4 kgODM−1 in the solid phase were obtained. The solid phases had high water absorption capacities of 216–504% due to the steam explosion, while the particle size was not significantly affected. The concept showed high potential, especially for undried feedstock.

Proximate Composition of Sludge from Different Types of Animal Manure

“…Crude fiber content indicated the amount of cell wall composed of cellulose, hemicellulose, and lignin. Hülsemann et al (2023) and Patinvoh et al (2017) stated that the fiber substrate is highly resistant to microbes during anaerobic digestion, especially the lignocellulose. Therefore, a high crude fiber content left in biogas slurry could indicate low efficient biogas production.…”