Anaerobic digestion of fines from recovered paper processing – Influence of fiber source, lignin and ash content on biogas potential

Valorization of Waste Streams from Deinked Pulp Mills through Anaerobic Digestion of Deinking Sludge

“…Pure lignin, however, is composed of 65% carbon (Luo 2010). In a prior study, the fines fractions from mechanical pulps showed carbon contents of up to 51.7%, presumably because of the elevated lignin content (Steffen et al 2016). Fatty acids, as a chemical component of the sodium soap applied in laboratory flotation (see Methods section), can also lead to elevated carbon contents in DS (fatty acids: 16-to 18-carbonchain amphoteric molecules; Zhao et al 2004).…”

“…The AMPTS II is a standardized laboratory set-up specially designed for the automatic determination of the biochemical methane potential (BMP) of any biodegradable material (Rodriguez-Chiang and Dahl 2015; Ghasimi et al 2016;Steffen et al 2016).…”

“…In the DS samples, however, this ratio was found to be between 0.6 and 5.1 (data not shown). The presence of lignincontaining fiber fines could result in low values of degradability and methane yields (Steffen et al 2016). According to Deviatkin et al (2015), the AD of DS does not seem to be a viable option without pretreatment, which is done in order to enhance the accessibility for microorganisms.…”

“…The fermentation of DS70 showed the lowest total methane yield by a considerable amount, with 122.1 mL/gVS. In a previous study, the biogas potential of various fines from secondary and virgin fiber pulps was investigated (Steffen et al 2016). It could be concluded that the presence of fines from mechanical pulps strongly inhibited AD, which was reflected in low methane yields of only 28 mL/gVS (thermomechanical pulp fines).…”

“…To the authors' knowledge, there is no thorough investigation yet available regarding this topic. Building on the results of a prior study (Steffen et al 2016), the authors further aim to expand their investigations into potential waste streams from the processing of PfR for use in biogas production.…”