Conjoint effect of microwave irradiation and metal nanoparticles on biogas augmentation from anaerobic digestion of green algae. (7th June 2019)

• Record Type: Journal Article
• Authors: Zaidi, Asad A.; RuiZhe, Feng; Malik, Adil; Khan, Sohaib Z.; Bhutta, Asad J.; Shi, Yue; Mushtaq, Kashif
• Is Part Of: International journal of hydrogen energy. Volume 44:Number 29(2019)
• Page Start: 14661
• Page End: 14670
• Publication Date: 2019-06-07
• Subjects: Anaerobic digestion -- Biogas -- Green algae -- Kinetic models -- MW pretreatment -- Nanoparticles (NPs); Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2019.02.245
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Pretreatment of biomass is a commonly applied technique for improving its biodegradability; however, such methods are energy intensive, which affects the overall efficiency. This study aims to provide an energy efficient solution by combining microwave (MW) pretreatment of algal biomass (Enteromorpha) and metal nanoparticles (NPs). The MW pretreatment of the biomass was in the form of a slurry (liquid:solid 20:1), while pretreatment time and MW pretreatment power were 6min and 600 W, respectively. Nickel (Ni) and Cobalt (Co) NPs with a concentration of 1 mg/L were used. Batch-wise anaerobic digestion was carried out for a period of 264 h. The results showed that MW pretreatment initiates early hydrolysis of green algae thus reducing lag time. NPs had a positive influence in biogas production at the later stages of anaerobic digestion. The highest total biogas production of 53.60ml/gTS was attained by Co NPs + MW pretreatment whereas maximum biohydrogen of 59.52% (v/v) was produced by Ni NPs + MW pretreatment group. Energy analysis showed that combined utilization of MW pretreatment and metal NPs produced added energy while consuming less input energy than MW pretreatment alone. The kinetic parameters were calculated by using modified Gompertz and Logistic function model for each experimental case. Highlights: Synergistic effect of MW pretreatment and NPs resulted in positive energy balance. Co NPs + MW pretreatment showed 42% cumulative increase in biogas yield. Co NPs + MW pretreatment achieved an energy ratio of 1.185. Reaction kinetics is determined by modified Gompertz and Logistic model. Modified Gompertz model has better predicting ability for synergistic effect.