Fermentative hydrogen production in packed-bed and packing-free upflow reactors

Abstract

Fermentative hydrogen production from a synthetic wastewater containing 10 g/L of sucrose was studied in two upflow reactors at 268C for 400 days. One reactor was filled with packing rings (RP) and the other was packing free (RF). The effect of hydraulic retention time (HRT) from 2 h to 24 h was investigated. Results showed that, under steady state, the hydrogen production rate significantly increased from 0.63 L/L/d to 5.35 L/L/d in the RF when HRT decreased from 24 h to 2 h; the corresponding rates were 0.56 L/L/d to 6.17 L/L/d for the RP. In the RF, the hydrogen yield increased from 0.96 mol/mol-sucrose at 24 h of HRT to the maximum of 1.10 mol/mol-sucrose at 8 h of HRT, and then decreased to 0.68 mol/molsucrose at 2 h. In the RP, the yield increased from 0.86 mol/mol-sucrose at 24 h of HRT to the maximum of 1.22 mol/mol-sucrose at 14 h of HRT, and then decreased to 0.78 mol/mol-sucrose at 2 h. Overall, the reactor with packing was more effective than the one free of packing. In both reactors, sludge agglutinated into granules. The microbial community of granular sludge in RP was investigated using 16S rDNA based techniques. The distribution of bacterial cells and extracellular polysaccharides in hydrogen-producing granules was investigated by fluorescence-based techniques. Results indicated that most of the N-acetylgalactosamine/galactose-containing extracellular polysaccharides were distributed on the outer layer of the granules with a filamentous structure.

Evaluation of hydrogen and methane production from sugarcane vinasse in an anaerobic fluidized bed reactor

“…According to the study, this species can produce acetic acid, succinic acid, isobutyric acid and isovaleric acid from the degradation of starch, sucrose and glucose. Li et al [43] found the presence of Prevotella spp. in fixed bed reactors used for H 2 production from sucrose at HRT 2 h. Won et al [44] verified that Prevotella spp.…”

Lactic Acid Bacteria in Hydrogen-Producing Consortia: On Purpose or by Coincidence?

“…One of the disadvantages of this method is underestimation of the true bacterial diversity due to the fact that only the most prominent DGGE bands are analyzed. Various studies have shown that DGGE bands representing LAB are one of the most dominant bands (Fang et al, 2002;Kim et al, 2006;Li et al, 2006;Wu et al, 2006;Hung et al, 2007;Ren et al, 2007;Jo et al, 2007;Lo et al, 2008;Sreela-or et al, 2011). Another method of analyzing the biodiversity of hydrogen-producing consortia is cloning and sequencing of the 16S rDNA gene amplified on the total DNA isolated from the culture probes.…”

“…It is noteworthy that (i) those papers discuss efficient systems of biohydrogen production and (ii) studies were performed under optimal conditions for hydrogen production (Fang et al, 2002;Kim et al, 2006;Li et al, 2006;Wu et al, 2006;Hung et al, 2007).…”

Biohydrogen Production from Biomass and Wastes via Dark Fermentation: A Review

“…Among the types of reactor used for continuous hydrogen production, are the CSTR [32,89,90,117,170] and several variations of hybrid and attached growth reactors, such as the Upflow Anaerobic Sludge Blanket reactor, the UASB [171], the Packed Bed Reactor, PBR [172], Anaerobic Sequencing Batch Reactor, ASBR [173], the Fixed Bed Bioreactor with Activated Carbon, the FBBAC [27], the Anaerobic Fluidized Bed Reactor, the AFBR [174,175], the Carrier-Induced Granular Sludge Bed, the CIGSB [176], Membrane Bioreactor, the MBR [50] and the Rhomboidal reactor [60]. A direct comparison of the performance of the different types of reactor configurations that have been studied in terms of hydrogen productivity is not possible, since the operational parameters (feedstocks and operating conditions) along with the reactor configuration, in all these studies, are quite different.…”