Biogaserzeugung und -nutzung

Floating layer formation, foaming, and microbial community structure change in full-scale biogas plant due to disruption of mixing and substrate overloading

“…Although the VOA/TIC is specific for each biogas plant, a sudden change in the VOA/TIC curve indicates a process disturbance. The accumulation of intermediates of the biogas producing process is known to be a consequence of failure of the microbial process that can be due to organic overloading [28]. One and two days before foaming appeared, the early warning indicators EWI-VFA/Ca and EWI-PO 4 /Ca increased by a factor of 2 ( Figure 4).…”

Foam formation in full-scale biogas plants processing biogenic waste

“…The aluminum concentration in the grease separator content was indeed much lower at a value of 1.42 mg/L. Zinc also has an inhibitory effect on anaerobic digestion -in concentrations from 400 mg/L in the form of free ions and from 160 mg/L as zinc carbonate [37]. However, it is questionable whether the contents of both elements can cause negative effects after dilution in the digesters.…”

Anaerobic digestion of monocotyledons in particleboard production – a concept of process integration to increase substitution of wood raw material

“…Therefore, the biochemical processes include disintegration from homogeneous particulates to carbohydrates, proteins and lipids, extracellular hydrolysis of these particulate substrates to sugars, amino acids, and long-chain fatty acids, acidogenesis from sugars and amino acids to volatile fatty acids and hydrogen, acetogenesis of long-chain fatty acids and volatile fatty acids to acetate, and methanogenesis from acetate and hydrogen, Fig. 1 (Batstone et al 2002;Scholwin et al 2009). The composition and location of the wax layer makes its conversion into methane by these enzymes likely to be easier and faster than the lignocellulosic parts of the plant material for two reasons: first, the components of the wax layer are builtup of quite small molecules, which allow their conversion into methane without depolymerisation, and second, they are not linked to lignin (Tong and McCarty 1991).…”