Anaerobic digestion of hydrothermally-pretreated lignocellulosic biomass: Influence of pretreatment temperatures, inhibitors and soluble organics on methane yield. (July 2019)

• Record Type: Journal Article
• Authors: Phuttaro, Chettaphong; Sawatdeenarunat, Chayanon; Surendra, K.C.; Boonsawang, Piyarat; Chaiprapat, Sumate; Khanal, Samir Kumar
• Is Part Of: Bioresource technology. Volume 284(2019)
• Page Start: 128
• Page End: 138
• Publication Date: 2019-07
• Subjects: Lignocellulosic biomass -- Napier grass -- Hydrothermal pretreatment -- Anaerobic digestion -- Inhibitory by-products; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2019.03.114
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: Hydrothermal pretreatment (HTP) temperatures governed digestibility of energy crop. HTP at 175 °C improved CH4 yield by 35% in batch digestion compared to control. HTP at 200 °C resulted in a significant formation of inhibitory furan derivatives. Higher soluble fraction contributed to inhibition to anaerobic digestion process. Shifts of volatile fatty acids profile and ratio linked closely to system stability. Abstract: Anaerobic digestion (AD) of lignocellulosic biomass has received significant attention for bioenergy production in recent years. However, hydrolysis is a rate-limiting in AD of such feedstock. In this study, effects of hydrothermal pretreatment of Napier grass, a model lignocellulosic biomass, on methane yield were examined through series of batch and semi-continuous studies. In batch studies, the highest methane yield of 248.2 ± 5.5 NmL CH4 /g volatile solids (VS)added was obtained from the biomass pretreated at 175 °C, which was 35% higher than that from the unpretreated biomass. The biomass pretreated at 200 °C resulted in formation of 5-hydroxymethylfurfural and furfural, which significantly inhibited methanogenesis. In semi-continuous studies, digester fed with the biomass pretreated at 200 °C at organic loading rate (OLR) of 4 g VS/L.d resulted in digester failure. Thus, OLRsoluble /OLRtotal ratio <200 is proposed as an operating criterion for effective operation of digester fed with pretreated biomass slurry.