scholarly journals Ex-situ biogas upgrading in thermophilic up-flow reactors: the effect of different gas diffusers and gas retention times

2021 ◽  
pp. 125694
Author(s):  
Parisa Ghofrani Isfahani ◽  
Panagiotis Tsapekos ◽  
Maria Peprah ◽  
Panagiotis Kougias ◽  
Xinyu Zhu ◽  
...  
Keyword(s):  
Ex Situ ◽  
Biogas Upgrading ◽  
Flow Reactors

Optimization of hydrogen dispersion in thermophilic up-flow reactors for ex situ biogas upgrading

2017 ◽  
Vol 234 ◽  
pp. 310-319 ◽  
Author(s):  
Ilaria Bassani ◽  
Panagiotis G. Kougias ◽  
Laura Treu ◽  
Hugo Porté ◽  
Stefano Campanaro ◽  
...  
Keyword(s):  
Ex Situ ◽  
Biogas Upgrading ◽  
Flow Reactors

Ex-situ biogas upgrading and enhancement in different reactor systems

2017 ◽  
Vol 225 ◽  
pp. 429-437 ◽  
Author(s):  
Panagiotis G. Kougias ◽  
Laura Treu ◽  
Daniela Peñailillo Benavente ◽  
Kanokwan Boe ◽  
Stefano Campanaro ◽  
...  
Keyword(s):  
Ex Situ ◽  
Biogas Upgrading

scholarly journals Innovative ex-situ biological biogas upgrading using immobilized biomethanation bioreactor (IBBR)

2020 ◽  
Vol 81 (6) ◽  
pp. 1319-1328 ◽  
Author(s):  
Katie Baransi-Karkaby ◽  
Mahdi Hassanin ◽  
Sharihan Muhsein ◽  
Nedal Massalha ◽  
Isam Sabbah
Keyword(s):  
Anaerobic Digestion ◽  
Natural Gas ◽  
Production Rate ◽  
Organic Waste ◽  
Consumption Rate ◽  
Energy Resource ◽  
Hydrogen Gas ◽  
Ex Situ ◽  
Biogas Upgrading ◽  
Immobilized Microorganisms

Abstract Biogas, which typically consists of about 50–70% of methane gas, is produced by anaerobic digestion of organic waste and wastewater. Biogas is considered an important energy resource with much potential; however, its application is low due to its low quality. In this regard, upgrading it to natural gas quality (above 90% methane) will broaden its application. In this research, a novel ex-situ immobilized biomethanation bioreactor (IBBR) was developed for biologically upgrading biogas by reducing CO2 to CH4 using hydrogen gas as an electron donor. The developed process is based on immobilized microorganisms within a polymeric matrix enabling the application of high recirculation to increase the hydrogen bioavailability. This generates an increase in the consumption rate of hydrogen and the production rate of methane. This process was successfully demonstrated at laboratory-scale system, where the developed process led to a production of 80–89% methane with consumption of more than 93% of the fed hydrogen. However, a lower methane content was achieved in the bench-scale system, likely as a result of lower hydrogen consumption (63–90%). To conclude, the IBBRs show promising results with a potential for simple and effective biogas upgrading.

scholarly journals Ex-situ biogas upgrading to methane and removal of VOCs in a system of zero valent iron and anaerobic granular sludge

2021 ◽  
Author(s):  
Nikolaos Lytras ◽  
Maria Andronikou ◽  
Georgia Chrysanthou ◽  
Marinos Stylianou ◽  
Agapios Agapiou ◽  
...  
Keyword(s):  
Granular Sludge ◽  
Zero Valent Iron ◽  
Ex Situ ◽  
Anaerobic Sludge ◽  
Anaerobic Granular Sludge ◽  
Biogas Upgrading ◽  
Initial Ph ◽  
Low Mass ◽  
Scrap Iron ◽  
Branched Chain

Abstract In the current study, a novel process of ex-situ biogas upgrading to biomethane is presented which is based on a system consisted of anaerobic sludge and zero valent iron (ZVI). The ZVI when is added in an aquatic system with anaerobic granular sludge generates H2 under anaerobic abiotic conditions. Then, the H2 and CO2 are converted by the hydrogenotrophic methanogens to CH4. Biogas upgrading to biomethane was achieved in 4 days in a system of anaerobic granular sludge, 50 g L1 ZVI initial pH 5 and 20 g L1 NaHCO3. In this system when zero valent scrap iron (ZVSI) was added instead of ZVI required longer period (21 days) to achieve biogas upgrading. Volatile organic compounds (VOCs) analysis in raw biogas (in system of anaerobic sludge and ZVI) showed mainly the reduction of low mass straight- and branched-chain alkanes (C6-C10); however, no other particular trend regarding the removal of other VOCs was observed. H2S and NH3 were found to be substantially reduced, when the anaerobic sludge was exposed to ZVI compared to no decrease in serum bottles free of ZVI.

scholarly journals Microbial Consortiums of Hydrogenotrophic Methanogenic Mixed Cultures in Lab-Scale Ex-Situ Biogas Upgrading Systems under Different Conditions of Temperature, pH and CO

2020 ◽  
Vol 8 (5) ◽  
pp. 772
Author(s):  
Jun Xu ◽  
Fan Bu ◽  
Wenzhe Zhu ◽  
Gang Luo ◽  
Li Xie
Keyword(s):  
Microbial Consortium ◽  
16S Rrna Gene Sequencing ◽  
Mixed Cultures ◽  
Ex Situ ◽  
Microbial Consortia ◽  
Rrna Gene ◽  
Biogas Upgrading ◽  
The Core ◽  
Rrna Gene Sequencing ◽  
Archaea Community

In this study, hydrogenotrophic methanogenic mixed cultures taken from 13 lab-scale ex-situ biogas upgrading systems under different temperature (20–70 °C), pH (6.0–8.5), and CO (0–10%, v/v) variables were systematically investigated. High-throughput 16S rRNA gene sequencing was used to identify the microbial consortia, and statistical analyses were conducted to reveal the microbial diversity, the core functional microbes, and their correlative relationships with tested variables. Overall, bacterial community was more complex than the archaea community in all mixed cultures. Hydrogenotrophic methanogens Methanothermobacter, Methanobacterium, and Methanomassiliicoccus, and putative syntrophic acetate-oxidizing bacterium Coprothermobacter and Caldanaerobacter were found to predominate, but the core functional microbes varied under different conditions. Multivariable sensitivity analysis indicated that temperature (p < 0.01) was the crucial variable to determine the microbial consortium structures in hydrogenotrophic methanogenic mixed cultures. pH (0.01 < p < 0.05) significantly interfered with the relative abundance of dominant archaea. Although CO did not affect community (p > 0.1), some potential CO-utilizing syntrophic metabolisms might be enhanced. Understanding of microbial consortia in the hydrogenotrophic methanogenic mixed cultures related to environmental variables was a great advance to reveal the microbial ecology in microbial biogas upgrading process.

scholarly journals Thermophilic Biogas Upgrading via ex Situ Addition of H2 and CO2 Using Codigested Feedstocks of Cow Manure and the Organic Fraction of Solid Municipal Waste

ACS Omega ◽  
2020 ◽  
Vol 5 (28) ◽  
pp. 17367-17376
Author(s):  
Patrick T. Sekoai ◽  
Nicolaas Engelbrecht ◽  
Stephanus P. du Preez ◽  
Dmitri Bessarabov
Keyword(s):  
Municipal Waste ◽  
Ex Situ ◽  
Cow Manure ◽  
Organic Fraction ◽  
Biogas Upgrading ◽  
Solid Municipal Waste

scholarly journals High-resolution 16S biogas upgrading communities: contrasting in situ and ex situ setups

2019 ◽  
Vol 1 (1A) ◽  
Author(s):  
Jamie A. FitzGerald ◽  
Marcus Voelklein ◽  
Marcus J Claesson ◽  
Jerry D. Murphy ◽  
Alan D.W. Dobson
Keyword(s):  
High Resolution ◽  
Ex Situ ◽  
Biogas Upgrading

Techno-economic analysis of biogas upgrading via amine scrubber, carbon capture and ex-situ methanation

2018 ◽  
Vol 212 ◽  
pp. 1191-1202 ◽  
Author(s):  
Truc T.Q. Vo ◽  
David M. Wall ◽  
Denis Ring ◽  
Karthik Rajendran ◽  
Jerry D. Murphy
Keyword(s):  
Economic Analysis ◽  
Carbon Capture ◽  
Ex Situ ◽  
Biogas Upgrading

An in situ and ex situ TEM study of the formation of thin cobalt silicide films by molecular beam epitaxy on the silicon (100) surface

1988 ◽  
Vol 46 ◽  
pp. 884-885
Author(s):  
D. Loretto ◽  
J. M. Gibson ◽  
S. M. Yalisove ◽  
R. T. Tung
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Defect Density ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Ex Situ ◽  
Metal Base ◽  
In Situ Experiments ◽  
Potential Applications

The cobalt disilicide/silicon system has potential applications as a metal-base and as a permeable-base transistor. Although thin, low defect density, films of CoSi2 on Si(111) have been successfully grown, there are reasons to believe that Si(100)/CoSi2 may be better suited to the transmission of electrons at the silicon/silicide interface than Si(111)/CoSi2. A TEM study of the formation of CoSi2 on Si(100) is therefore being conducted. We have previously reported TEM observations on Si(111)/CoSi2 grown both in situ, in an ultra high vacuum (UHV) TEM and ex situ, in a conventional Molecular Beam Epitaxy system.The procedures used for the MBE growth have been described elsewhere. In situ experiments were performed in a JEOL 200CX electron microscope, extensively modified to give a vacuum of better than 10-9 T in the specimen region and the capacity to do in situ sample heating and deposition. Cobalt was deposited onto clean Si(100) samples by thermal evaporation from cobalt-coated Ta filaments.

The use of transmission and analytical electron microscopy in studying reactions and phase transformations in thin film

1993 ◽  
Vol 51 ◽  
pp. 842-843
Author(s):  
K. Barmak
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Phase Transformations ◽  
Analytical Electron Microscopy ◽  
Ex Situ ◽  
Multilayer Thin Films ◽  
Absolute Concentration ◽  
Analytical Electron ◽  
Deposition Step

Generally, processing of thin films involves several annealing steps in addition to the deposition step. During the annealing steps, diffusion, transformations and reactions take place. In this paper, examples of the use of TEM and AEM for ex situ and in situ studies of reactions and phase transformations in thin films will be presented.The ex situ studies were carried out on Nb/Al multilayer thin films annealed to different stages of reaction. Figure 1 shows a multilayer with dNb = 383 and dAl = 117 nm annealed at 750°C for 4 hours. As can be seen in the micrograph, there are four phases, Nb/Nb3-xAl/Nb2-xAl/NbAl3, present in the film at this stage of the reaction. The composition of each of the four regions marked 1-4 was obtained by EDX analysis. The absolute concentration in each region could not be determined due to the lack of thickness and geometry parameters that were required to make the necessary absorption and fluorescence corrections.

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