title: Chemical and enzymatic sequential pretreatment of oat straw for methane production.
abstract: Oat straw was subjected to sequential pretreatment: acid/alkaline/enzymatic, to convert the lignocellulosic material in soluble sugars. The hydrolysates from acid pretreatment (2% HCl, 90 °C) and enzymatic pretreatment (cellulase, pH 4.5, 45 °C) were used as substrates in two lab-scale UASB reactors for methane production. The acid and enzymatic hydrolysates contained 25.6 and 35.3g/L of total sugars, respectively, which corresponded to a COD of 23.6 and 30.5 g/L, respectively. The UASB reactor fed with acid hydrolysate achieved a maximum methane yield of 0.34 L CH(4)/g COD at an organic loading rate (OLR) of 2.5 g COD/L-d. In the reactor fed with enzymatic hydrolysate the methane yield was 0.36 LCH(4)/g COD at OLR higher than 8.8 g COD/L-d. The anaerobic digestion of both hydrolysates was feasible without the need of a detoxification step. The sequential pretreatment of oat straw allowed to solubilize 96.8% of hemicellulose, 77.2% of cellulose and 42.2% of lignin.
authors.affiliation: División de Ciencias Ambientales, Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa San José 2055, Lomas 4ª. Secc, San Luis Potosí, SLP, Mexico.
authors.forename: Francisco
authors.initials: F
authors.lastname: Gomez-Tovar
authors.forename: Lourdes B
authors.initials: LB
authors.lastname: Celis
authors.forename: Elías
authors.initials: E
authors.lastname: Razo-Flores
authors.forename: Felipe
authors.initials: F
authors.lastname: Alatriste-Mondragón
mesh_terms: D000693:Anaerobiosis / Q000187:drug effects; D018554:Avena / Q000737:chemistry*; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors / Q000382:microbiology; D001709:Biotechnology / Q000379:methods*; D002244:Carbon / Q000032:analysis; D002480:Cellulase / Q000494:pharmacology*; D002482:Cellulose / Q000378:metabolism; D005232:Fatty Acids, Volatile / Q000032:analysis; D006851:Hydrochloric Acid / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D008031:Lignin / Q000378:metabolism; D008697:Methane / Q000378:metabolism*; D011134:Polysaccharides / Q000378:metabolism; D012722:Sewage / Q000382:microbiology; D012995:Solubility / Q000187:drug effects; D014866:Waste Products / Q000032:analysis*
chemical_list: D005232:Fatty Acids, Volatile; D011134:Polysaccharides; D012722:Sewage; D014866:Waste Products; C036909:lignocellulose; D002244:Carbon; C007916:hemicellulose; D002482:Cellulose; D008031:Lignin; D002480:Cellulase; D008697:Methane; D006851:Hydrochloric Acid