title: Effect of moisture on pretreatment efficiency for anaerobic digestion of lignocellulosic substrates.
abstract: The present study evaluates the effect of moisture in low-temperature and ultrasound pretreatment on lignocellulosic substrates anaerobic biodegradability, where brewer's spent grain was used as model substrate. Besides moisture content, low-temperature pretreatment was also evaluated in terms of temperature (60-80°C) and exposure time (12-72 h). Likewise, ultrasonication was also evaluated in terms of specific energy (1000-50,000 kJ kg TS(-1)). In addition, the effect of substrate particle size reduction by milling pretreatment was also considered. The results clearly demonstrated that substrate moisture (total solid concentration) is a significant parameter for pretreatment performance, although it has been rarely considered in pretreatment optimisation. Specifically, moisture optimisation increased the methane yield of brewer's spent grain by 6% for low-temperature pretreatment (60°C), and by 14% for ultrasound pretreatment (1000 kJ kg TS(-1)) towards the control (without pretreatment). In both pretreatments, the experimental optimum total solid concentration was 100 gTS kg(-1). Thus, lowering substrate moisture, a strategy suggested attaining energetic pretreatment feasibility, needs to be analysed as another pretreatment variable since it might have limited correlation. Finally, a preliminary energetic balance of the pretreatments under study showed that the extra methane production could not cover the energetic pretreatment expenses.
authors: Department of Chemical Engineering, University of Barcelona, C/Martí i Franquès, No. 1, 6th Floor, 08028 Barcelona, Spain; Centre for Solid Waste Bioprocessing, Schools of Civil and Chemical Engineering, The University of Queensland, St. Lucia Campus, 4072 QLD, Australia.
authors: M
authors: M
authors: Peces
authors: Department of Chemical Engineering, University of Barcelona, C/Martí i Franquès, No. 1, 6th Floor, 08028 Barcelona, Spain; Advanced Water Management Centre, The University of Queensland, St. Lucia Campus, 4072 QLD, Australia. Electronic address: s.astals@awmc.uq.edu.au.
authors: S
authors: S
authors: Astals
authors: Department of Chemical Engineering, University of Barcelona, C/Martí i Franquès, No. 1, 6th Floor, 08028 Barcelona, Spain.
authors: J
authors: J
authors: Mata-Alvarez
mesh_terms: D001673:Biodegradation, Environmental; D056804:Biofuels / Q000032:analysis; D003080:Cold Temperature; D008031:Lignin / Q000378:metabolism*; D008697:Methane / Q000032:analysis; D010316:Particle Size; D012037:Refuse Disposal / Q000379:methods*; D000069453:Ultrasonic Waves
chemical_list: D056804:Biofuels; C036909:lignocellulose; D008031:Lignin; D008697:Methane
keywords: Anaerobic digestion; Energy crops; Pre-treatment; Thermal; Ultrasonication