CO₂ utilization via a novel anaerobic bioprocess configuration with simulated gas mixture and real stack gas samples

Abstract

COV: coefficient of variation; Gt: gigatone; IEA: International Energy Agency; IPCC: International Panel on Climate Change; MBBR: moving bed biofilm reactor; MJ: Megajoule; UASB: upflow anaerobic sludge blanket; VFR: volumetric feeding rate.

Comparative analysis of the effect of cell immobilization on the hydrogenothrophic biomethanation of CO2

“…Each experiment was sustained until a pseudo steady‐state condition is reached, and then, next experiment was initiated with a new gas feeding rate. Coefficient of variation (COV) less than 20% (Eqn ) was considered for pseudo steady state condition for each performance parameter such as methane formation rate, hydrogen utilization rate, methane content in the headspace 45 where S is the standard deviation; X ort , average value…”

“…Argon (Linde, Turkey) was utilized as the carrier gas at a flow rate of 20 mL/min. Standard gas mixture of high purity hydrogen, methane and carbon dioxide (30% H₂, 40% CH₄ and 30% CO₂) was used for GC calibration 45 …”

“…Some parameters used to determine the performances of bioreactors in hydrogenotrophic biomethanation are reported as follows; MFR (methane formation rate) (Eqn ), hydrogen consumption (Eqn ), 45 GHSV (gas hourly space velocity) and gas retention time 34–36 . Besides these parameters, Eqn and Eqn were used in this study to determine the microbial inventory in different parts of the bioreactor and also suspended sludge.…”

Biological Hydrogen Methanation with Carbon Dioxide Utilization: Methanation Acting as Mediator in the Hydrogen Economy

“…Another configuration tested was hybrid systems, thus denoted because cellular biomass is present in the reactor forming granules, whereas the primary substrate is the gas injected into the reactor. This type of configuration has been tested for the conversion of H 2 :CO 2 mixtures by Daglioglu et al [150], reporting a methane production rate of 19 L/L reactor d with an H 2 injection rate of 19.2 L/L reactor d (gas injection rate of 24 L gas/L reactor d at an H 2 :CO 2 ratio of 4:1), resulting in a methane yield higher than the theoretical value of 0.25 L CH 4 /L H 2 . Microbial analysis indicated that in addition to hydrogenotrophic species, acetoclastic species were also observed in the system, although the feeding substrate was exclusively conformed by the H 2 :CO 2 mixture [151].…”