Integration of flash vessel in water scrubbing biogas upgrading system for maximum methane recovery. (September 2019)

• Record Type: Journal Article
• Authors: Kapoor, Rimika; Subbarao, P.M.V.; Vijay, Virendra Kumar
• Is Part Of: Bioresource technology reports. Volume 7(2019)
• Publication Date: 2019-09
• Subjects: Water scrubbing -- CH4 recovery -- Flash vessel -- Response surface methodology -- Energy requirement; Biomass energy -- Periodicals; Biotransformation (Metabolism) -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Waste products as fuel -- Periodicals; Waste products as fuel; Organic wastes; Factory and trade waste; Biotransformation (Metabolism); Biomass energy; Agricultural wastes; Periodicals; Electronic journals; 662.88
• DOI: 10.1016/j.biteb.2019.100251
• Languages: English
• ISSNs: 2589-014X

Abstract

Abstract: High CH4 purity in upgraded biogas concomitantly results in high CH4 loss during water scrubbing biogas upgrading process. In the current study, central composite design based on response surface methodology was used to recover maximum CH4 by optimizing a flash vessel integrated in a water scrubbing biogas upgrading system. Optimum CH4 recovery of 8.46% was achieved from flash vessel at 2 bar flash pressure and 90 second retention time with simultaneous bioCH4 recovery of 90.73% from the scrubbing column with 0.77% CH4 loss from the system. CCD predicted values were confirmed experimentally under the modelled optimum conditions and showed strong agreement with an R 2 value > 0.98. Flash gas blended with biogas was recirculated into the water scrubbing column for upgrading. At 10 Nm 3 /h gas flow rate, pressure of 12 bar and 2.1 m 3 /h water flow rate, 91.3% CH4 in upgraded gas was obtained with energy consumption of 0.29 kWh/Nm 3 . Highlights: Flash vessel was integrated in water scrubbing system for CH4 recovery. Process was optimized by compact composite design with response surface methodology. At optimized conditions 8.76% CH4 was recovered from spent water by flash vessel. BioCH4 recovery increased to 90.76% and CH4 loss reduced to 0.77%. Recirculation and upgrading of flash gas in scrubbing column consumed 0.29 kWh/Nm 3 .