The Experts below are selected from a list of 32673 Experts worldwide ranked by ideXlab platform

Katharina Landfester - One of the best experts on this subject based on the ideXlab platform.

Frederik R Wurm - One of the best experts on this subject based on the ideXlab platform.

Albert Barberan - One of the best experts on this subject based on the ideXlab platform.

  • dynamics and complexity of dark fermentation microbial communities Producing Hydrogen from sugar beet molasses in continuously operating packed bed reactors
    Frontiers in Microbiology, 2021
    Co-Authors: Anna Detman, Daniel Laubitz, Aleksandra Chojnacka, Ewa Wiktorowskasowa, Jan Piotrowski, Agnieszka Salamon, Wiktor Kaźmierczak, Mieczyslaw Blaszczyk, Albert Barberan
    Abstract:

    This study describes the dynamics and complexity of microbial communities Producing Hydrogen-rich fermentation gas from sugar-beet molasses in five packed-bed reactors (PBRs). The bioreactors constitute a part of a system Producing Hydrogen from the by-products of the sugar-beet industry that has been operating continuously in one of the Polish sugar factories. PBRs with different working volumes, packing materials, construction and inocula were tested. This study focused on analysis (based on 16S rRNA profiling and shotgun metagenomics sequencing) of the microbial communities selected in the PBRs under the conditions of high (>100 cm3/g COD of molasses) and low (<50 cm3/g COD of molasses) efficiencies of Hydrogen production. The stability and efficiency of the Hydrogen production are determined by the composition of dark fermentation microbial communities. The most striking difference between the tested samples is the ratio of Hydrogen producers to lactic acid bacteria. The highest efficiency of Hydrogen production (130-160 cm3/g COD of molasses) was achieved at the ratios of HPB to LAB ≈ 4:2.5 or 2.5:1 as determined by 16S rRNA sequencing or shotgun metagenomics sequencing, respectively. The most abundant Clostridium species were C. pasteurianum and C. tyrobutyricum. A multiple predominance of LAB over HPB (3:1-4:1) or clostridia over LAB (5:1-60:1) results in decreased Hydrogen production. Inhibition of Hydrogen production was illustrated by overproduction of short chain fatty acids and ethanol. Furthermore, concentration of ethanol might be a relevant marker or factor promoting a metabolic shift in the DF bioreactors processing carbohydrates from Hydrogen-yielding toward lactic acid fermentation or solventogenic pathways. The novelty of this study is identifying a community balance between Hydrogen producers and lactic acid bacteria for stable Hydrogen Producing systems. The balance stems from long-term selection of Hydrogen-Producing microbial community, operating conditions such as bioreactor construction, packing material, hydraulic retention time and substrate concentration. This finding is confirmed by additional analysis of the proportions between HPB and LAB in dark fermentation bioreactors from other studies. The results contribute to the advance of knowledge in the area of relationships and nutritional interactions especially the cross-feeding of lactate between bacteria in dark fermentation microbial communities.

Aleksandra Chojnacka - One of the best experts on this subject based on the ideXlab platform.

  • dynamics and complexity of dark fermentation microbial communities Producing Hydrogen from sugar beet molasses in continuously operating packed bed reactors
    Frontiers in Microbiology, 2021
    Co-Authors: Anna Detman, Daniel Laubitz, Aleksandra Chojnacka, Ewa Wiktorowskasowa, Jan Piotrowski, Agnieszka Salamon, Wiktor Kaźmierczak, Mieczyslaw Blaszczyk, Albert Barberan
    Abstract:

    This study describes the dynamics and complexity of microbial communities Producing Hydrogen-rich fermentation gas from sugar-beet molasses in five packed-bed reactors (PBRs). The bioreactors constitute a part of a system Producing Hydrogen from the by-products of the sugar-beet industry that has been operating continuously in one of the Polish sugar factories. PBRs with different working volumes, packing materials, construction and inocula were tested. This study focused on analysis (based on 16S rRNA profiling and shotgun metagenomics sequencing) of the microbial communities selected in the PBRs under the conditions of high (>100 cm3/g COD of molasses) and low (<50 cm3/g COD of molasses) efficiencies of Hydrogen production. The stability and efficiency of the Hydrogen production are determined by the composition of dark fermentation microbial communities. The most striking difference between the tested samples is the ratio of Hydrogen producers to lactic acid bacteria. The highest efficiency of Hydrogen production (130-160 cm3/g COD of molasses) was achieved at the ratios of HPB to LAB ≈ 4:2.5 or 2.5:1 as determined by 16S rRNA sequencing or shotgun metagenomics sequencing, respectively. The most abundant Clostridium species were C. pasteurianum and C. tyrobutyricum. A multiple predominance of LAB over HPB (3:1-4:1) or clostridia over LAB (5:1-60:1) results in decreased Hydrogen production. Inhibition of Hydrogen production was illustrated by overproduction of short chain fatty acids and ethanol. Furthermore, concentration of ethanol might be a relevant marker or factor promoting a metabolic shift in the DF bioreactors processing carbohydrates from Hydrogen-yielding toward lactic acid fermentation or solventogenic pathways. The novelty of this study is identifying a community balance between Hydrogen producers and lactic acid bacteria for stable Hydrogen Producing systems. The balance stems from long-term selection of Hydrogen-Producing microbial community, operating conditions such as bioreactor construction, packing material, hydraulic retention time and substrate concentration. This finding is confirmed by additional analysis of the proportions between HPB and LAB in dark fermentation bioreactors from other studies. The results contribute to the advance of knowledge in the area of relationships and nutritional interactions especially the cross-feeding of lactate between bacteria in dark fermentation microbial communities.

Zuoyi Zhang - One of the best experts on this subject based on the ideXlab platform.

  • combining dual fluidized bed and high temperature gas cooled reactor for co Producing Hydrogen and synthetic natural gas by biomass gasification
    Energies, 2021
    Co-Authors: Yangping Zhou, Yujie Dong, Zuoyi Zhang
    Abstract:

    Biomass gasification to produce burnable gas now attracts an increasing interest for production flexibility in the renewable energy system. However, the biomass gasification technology using dual fluidized bed which is most suitable for burnable gas production still encounters problems of low production efficiency and high production cost. Here, we proposed a large-scale biomass gasification system to combine dual fluidized bed and high-temperature gas-cooled reactor (HTR) for co-production of Hydrogen and synthetic natural gas (SNG). The design of high-temperature gas-cooled reactor biomass gasification (HTR-BiGas) consists of one steam supply module to heat inlet steam of the gasifier by HTR and ten biomass gasification modules to co-produce 2000 MWth Hydrogen and SNG by gasifying the unpretreated biomass. Software for calculating the mass and energy balances of biomass gasification was developed and validated by the experiment results on the Gothenburg biomass gasification plant. The preliminary economic evaluation showed that HTR-BiGas and the other two designs, electric auxiliary heating and increasing recirculated product gas, are economically comparative with present mainstream production techniques and the imported natural gas in China. HTR-BiGas is the best, with production costs of Hydrogen and SNG around 1.6 $/kg and 0.43 $/Nm3, respectively. These designs mainly benefit from proper production efficiencies with low fuel-related costs. Compared with HTR-BiGas, electric auxiliary heating is hurt by the higher electric charge and the shortcoming of increasing recirculated product gas is its lower total production. Future works to improve the efficiency and economy of HTR-BiGas and to construct related facilities are introduced.