Improvement of gaseous bioenergy production from spent coffee grounds Co-digestion with pulp wastewater by physical/chemical pretreatments. (12th December 2022)

• Record Type: Journal Article
• Authors: Shen, Ming-Yan; Huang, Zong-Hao; Kuo, Yu-Ting; Hsu, Jie; Yang, Han-Wen; Peng, Chi-Yen; Chu, Chen-Yeon
• Is Part Of: International journal of hydrogen energy. Volume 47:Number 96(2022)
• Page Start: 40664
• Page End: 40671
• Publication Date: 2022-12-12
• Subjects: Hydrolysis -- Biogas -- Coffee waste -- Pulp wastewater -- Co-digestion; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2022.10.041
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Two steps of hydrolysis and anaerobic biogas production processes was investigated in this study. In the first step, subcritical water (SBW) hydrolysis and chemical (acid/alkali) pretreatments were carried out to enhance hydrolysis efficiency by obtaining and analyzing the total volatile fatty acids (TVFA), chemical oxygen demand (COD), and total sugar productions from spent coffee grounds (SCG) hydrolysate. The subcritical water (SBW) hydrolysis under the condition of temperature 150 °C for 30 min can greatly improve the organic matter breakdown and reached the COD concentration of 1010 g/L which was 30% higher than the untreated raw SCG. For chemical pretreatments, it was found that the alkaline hydrolysis of SCG resulted in the greatest total sugar concentration of 181 g/L whereas the operation conditions were 2.0 M NaOH at 60 °C for 1 h. The peak of TVFA concentration 3725 mg/L was found at the acid hydrolysis of SCG with 1.0 M H2 SO4 acid, 60 °C for 1 h. The optimal biomethane yield of 115 mL/g COD was obtained when 1.0 M H2 SO4 acid hydrolysate co-digestion with pulp wastewater which increase methane yield production 8 times of raw pulp wastewater. The pretreatment process was confirmed in this study can significant improve the converting of the biowastes to bioenergy efficiency. Graphical abstract: Image 1 Highlights: Two steps of hydrolysis and anaerobic biogas production processes was investigated. The SBW process can improve 30% hydrolysis efficiency from untreated raw SCG. The optimal bioCH4 yield obtained for hydrolysate co-digestion with pulp wastewater. The beverage company can convert SCG to green energy under their ESG policy.