Improved Anaerobic Digestion by the Addition of Paper Tube Residuals: Pretreatment, Stabilizing, and Synergetic Effects

Abstract

This study deals with the addition of paper tube residuals to a nitrogen-rich mixture of organic waste obtained from industrial and municipal activities. This nitrogen-rich mixture, called buffer tank substrate (BTS) in the following text, is used in a large-scale biogas plant. The effects were investigated in semi-continuous co-digestion processes, and variations in operational conditions were studied. The addition of paper tubes had stabilizing effects, prevented the failure of the process, and made it possible to decrease the hydraulic retention time from 25 to 20 days. Furthermore, synergetic effects were found, with 15−34% higher methane yields, when paper tubes were co-digested with BTS. Moreover, steam explosion pretreatment of the paper tube waste with the addition of 0−2% NaOH was evaluated by batch digestion experiments. Increasing the NaOH concentrations used in the pretreatment resulted in increasing methane yields, with the highest of 403 N mL of CH 4 g −1 of volatile solids (VS) corresponding to an increase by 50% compared to that when untreated paper was digested (268 N mL of CH 4 g −1 of VS). The long-term effects of this best pretreatment were further investigated by continuous co-digestion experiments, leading to a higher methane yield when pretreated paper tubes were used in the co-digestion process compared to untreated.

Sustainability assessment of biogas production from buffalo grass and dung: biogas purification and bio-fertilizer

“…Codigestion is defined as the digestion of mixtures of at least two waste materials for improving AD efficiency. Many successful codigestions of substrates have increased methane potential substantially compared to the mono digestion of the substrates (González–Fernández et al 2011 ; Teghammar et al 2013 ). These study results clearly demonstrated and agreed with González–Fernández et al ( 2011 ) and Teghammar et al ( 2013 ).…”

“…Many successful codigestions of substrates have increased methane potential substantially compared to the mono digestion of the substrates (González–Fernández et al 2011 ; Teghammar et al 2013 ). These study results clearly demonstrated and agreed with González–Fernández et al ( 2011 ) and Teghammar et al ( 2013 ). Co-digestion of buffalo grass and buffalo dung produced higher accumulated biogas (15,521 ml) and rich methane content (71%) compared to mono digestion.…”

Techno-economic study of NMMO pretreatment and biogas production from forest residues

“…sewage sludge or protein-rich substrates have problems with a too low C/N ratio, which means a lack of carbohydrate-rich substrates. Addition of carbon-rich materials, such as lignocelluloses, was previously shown to both stabilize sensitive processes as well as result in good synergetic effects [39]. These synergetic effects have implied higher methane yields when a lignocellulosic-rich material (i.e., paper tube residuals) has been digested with nitrogen-rich substrate mixture compared to the expected methane production calculated from the methane potentials of the single substrate streams alone.…”

Evaluation of mango, longan and lychee trees pruning leaves for the production of biogas via anaerobic fermentation

“…Due to the complexity and variability of biomass chemical structures, the optimal pretreatment method and conditions depend on the types of lignocellulose present. Several structural and compositional properties were found to have impacts on the biodegradability of lignocellulosic biomass, including cellulose crystallinity, accessible surface area, degree of cellulose polymerization, presence of lignin and hemicellulose, and degree of hemicellulose acetylation (Van Soest et al, 1991;Tang et al, 2011;Saha et al, 2013;Teghammar et al, 2013;Vázquez-Rowe et al, 2015;Tsai et al, 2016;Unpaprom et al, 2017;Vu et al, 2018;Tran et al, 2019;Manmai et al, 2020). The goal of pretreatment is to alter such properties to improve biomass amenity to enzymes and microbes.…”