Separate H2 and CO production from CH4-CO2 cycling of Fe-Ni

Fe-Ni materials with varying Ni loading are developed for separate H2 and CO production by CH4-CO2 chemical looping. The product streams are obtained by first feeding CH4, which decomposes to H2 and carbon. The latter acts as reductant for the subsequent CO2 feed, which together with Fe re-oxidation yields CO. After 25 CH4-CO2 cycles, 10Fe5Ni@Zr has a higher H2 space-time-yield than 10Fe0Ni@Zr (〖20mmol∙s〗^(-1)∙kg_(Fe+Ni)^(-1) vs. 〖15mmol∙s〗^(-1)∙kg_(Fe+Ni)^(-1)), a 2.6 times higher CO (〖57mmol∙s〗^(-1)∙kg_(Fe+Ni)^(-1)) and lower deactivation. This improvement has two reasons: (i) CH4 activation over Ni leading to cracking, (ii) product hydrogen causing deeper FeO reduction. Deactivation follows from accumulated carbon, non-reactive for CO2. On Ni and Fe sites, carbon can be removed by lattice oxygen or CO2, yielding more CO compared to the theoretical value for Fe oxidation. However, carbon that migrates away from the metals requires oxygen for removal, which restores the activity of the Ni-containing samples.

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Construction and characterization of a novel glucose dehydrogenase-leucine dehydrogenase fusion enzyme for the biosynthesis of l-tert-leucine

Microbial Cell Factories ◽

10.1186/s12934-020-01501-2 ◽

2021 ◽

Vol 20 (1) ◽

Author(s):

Langxing Liao ◽

Yonghui Zhang ◽

Yali Wang ◽

Yousi Fu ◽

Aihui Zhang ◽

...

Keyword(s):

Glucose Dehydrogenase ◽

Catalytic Efficiency ◽

Space Time ◽

Cofactor Regeneration ◽

Enzyme Complex ◽

Regeneration System ◽

Regeneration Rate ◽

Leucine Dehydrogenase ◽

Fusion Enzyme ◽

Space Time Yield

Abstract Background Biosynthesis of l-tert-leucine (l-tle), a significant pharmaceutical intermediate, by a cofactor regeneration system friendly and efficiently is a worthful goal all the time. The cofactor regeneration system of leucine dehydrogenase (LeuDH) and glucose dehydrogenase (GDH) has showed great coupling catalytic efficiency in the synthesis of l-tle, however the multi-enzyme complex of GDH and LeuDH has never been constructed successfully. Results In this work, a novel fusion enzyme (GDH–R3–LeuDH) for the efficient biosynthesis of l-tle was constructed by the fusion of LeuDH and GDH mediated with a rigid peptide linker. Compared with the free enzymes, both the environmental tolerance and thermal stability of GDH–R3–LeuDH had a great improved since the fusion structure. The fusion structure also accelerated the cofactor regeneration rate and maintained the enzyme activity, so the productivity and yield of l-tle by GDH–R3–LeuDH was all enhanced by twofold. Finally, the space–time yield of l-tle catalyzing by GDH–R3–LeuDH whole cells could achieve 2136 g/L/day in a 200 mL scale system under the optimal catalysis conditions (pH 9.0, 30 °C, 0.4 mM of NAD+ and 500 mM of a substrate including trimethylpyruvic acid and glucose). Conclusions It is the first report about the fusion of GDH and LeuDH as the multi-enzyme complex to synthesize l-tle and reach the highest space–time yield up to now. These results demonstrated the great potential of the GDH–R3–LeuDH fusion enzyme for the efficient biosynthesis of l-tle.

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Synthesis of pure and uniform nano-sized TS-1 crystal with high titanium content and high space-time yield

Inorganic Chemistry Frontiers ◽

10.1039/d1qi01022k ◽

2021 ◽

Author(s):

Lejian Zhang ◽

Xiaoxiao Zhu ◽

Xinping Wang ◽

Chuan Shi

Keyword(s):

Selective Oxidation ◽

Cost Efficiency ◽

Environmental Issues ◽

Titanium Content ◽

Space Time ◽

Titanium Silicalite ◽

Oxidation Reactions ◽

High Space ◽

Space Time Yield ◽

Selective Oxidation Reactions

Anatase-free titanium silicalite-1 (TS-1) zeolite with high framework titanium content is highly required for catalysing selective oxidation reactions, while its synthesis generally suffers from cost, efficiency and environmental issues. Herein,...

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Enhanced lattice oxygen reactivity over Fe2O3/Al2O3 redox catalyst for chemical-looping dry (CO2) reforming of CH4: Synergistic La-Ce effect

Journal of Catalysis ◽

10.1016/j.jcat.2018.09.022 ◽

2018 ◽

Vol 368 ◽

pp. 38-52 ◽

Cited By ~ 25

Author(s):

Mingchen Tang ◽

Kuo Liu ◽

Dean M. Roddick ◽

Maohong Fan

Keyword(s):

Lattice Oxygen ◽

Chemical Looping ◽

Co2 Reforming ◽

Co2 Reforming Of Ch4 ◽

Redox Catalyst ◽

Oxygen Reactivity

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Rapid CHO cell process intensification for mAb production: Implementation of an intensified fed-batch with doubled space-time yield

10.1021/scimeetings.1c01319 ◽

2021 ◽

Author(s):

Markus Markus ◽

Julia Niemann ◽

Dirk Martens ◽

Rene Wijfefls

Keyword(s):

Process Intensification ◽

Space Time ◽

Cell Process ◽

Fed Batch ◽

Cho Cell ◽

Space Time Yield ◽

Mab Production

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space‐time yield

Catalysis from A to Z ◽

10.1002/9783527809080.cataz15519 ◽

2020 ◽

Author(s):

C.‐D. Frohning

Keyword(s):

Space Time ◽

Space Time Yield

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Accelerated Electro-Fermentation of Acetoin in Escherichia coli by Identifying Physiological Limitations of the Electron Transfer Kinetics and the Central Metabolism

Microorganisms ◽

10.3390/microorganisms8111843 ◽

2020 ◽

Vol 8 (11) ◽

pp. 1843

Author(s):

Sebastian Beblawy ◽

Laura-Alina Philipp ◽

Johannes Gescher

Keyword(s):

Escherichia Coli ◽

Electron Transfer ◽

Point Mutations ◽

Selective Adaptation ◽

Space Time ◽

Transport Chain ◽

Whole Cell Biocatalyst ◽

Genes Encoding ◽

Space Time Yield ◽

Respiratory Conditions

Anode-assisted fermentations offer the benefit of an anoxic fermentation routine that can be applied to produce end-products with an oxidation state independent from the substrate. The whole cell biocatalyst transfers the surplus of electrons to an electrode that can be used as a non-depletable electron acceptor. So far, anode-assisted fermentations were shown to provide high carbon efficiencies but low space-time yields. This study aimed at increasing space-time yields of an Escherichia coli-based anode-assisted fermentation of glucose to acetoin. The experiments build on an obligate respiratory strain, that was advanced using selective adaptation and targeted strain development. Several transfers under respiratory conditions led to point mutations in the pfl, aceF and rpoC gene. These mutations increased anoxic growth by three-fold. Furthermore, overexpression of genes encoding a synthetic electron transport chain to methylene blue increased the electron transfer rate by 2.45-fold. Overall, these measures and a medium optimization increased the space-time yield in an electrode-assisted fermentation by 3.6-fold.

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Comparison of Photocatalytic Membrane Reactor Types for the Degradation of an Organic Molecule by TiO2-Coated PES Membrane

Catalysts ◽

10.3390/catal10070725 ◽

2020 ◽

Vol 10 (7) ◽

pp. 725 ◽

Cited By ~ 3

Author(s):

Chhabilal Regmi ◽

Shabnam Lotfi ◽

Jonathan Cawettiere Espíndola ◽

Kristina Fischer ◽

Agnes Schulze ◽

...

Keyword(s):

Specific Energy Consumption ◽

Space Time ◽

Pollutant Removal ◽

Design Flow ◽

Membrane Reactors ◽

Process Efficiency ◽

Efficient Design ◽

Reactor Performance ◽

Flow Through ◽

Space Time Yield

Photocatalytic membrane reactors with different configurations (design, flow modes and light sources) have been widely applied for pollutant removal. A thorough understanding of the contribution of reactor design to performance is required to be able to compare photocatalytic materials. Reactors with different flow designs are implemented for process efficiency comparisons. Several figures-of-merit, namely adapted space-time yield (STY) and photocatalytic space-time yield (PSTY), specific energy consumption (SEC) and degradation rate constants, were used to assess the performance of batch, flow-along and flow-through reactors. A fair comparison of reactor performance, considering throughput together with energy efficiency and photocatalytic activity, was only possible with the modified PSTY. When comparing the three reactors at the example of methylene blue (MB) degradation under LED irradiation, flow-through proved to be the most efficient design. PSTY1/PSTY2 values were approximately 10 times higher than both the batch and flow-along processes. The highest activity of such a reactor is attributed to its unique flow design which allowed the reaction to take place not only on the outer surface of the membrane but also within its pores. The enhancement of the mass transfer when flowing in a narrow space (220 nm in flow-through) contributes to an additional MB removal.

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Efficient synthesis of Ibrutinib chiral intermediate in high space-time yield by recombinant E. coli co-expressing alcohol dehydrogenase and glucose dehydrogenase

RSC Advances ◽

10.1039/c8ra08100j ◽

2019 ◽

Vol 9 (4) ◽

pp. 2325-2331 ◽

Cited By ~ 1

Author(s):

Yitong Chen ◽

Baodi Ma ◽

Songshuang Cao ◽

Xiaomei Wu ◽

Yi Xu

Keyword(s):

Alcohol Dehydrogenase ◽

Glucose Dehydrogenase ◽

Space Time ◽

Optically Active ◽

Efficient Synthesis ◽

E Coli ◽

Efficient Process ◽

High Space ◽

Space Time Yield

A simple and efficient process for the synthesis of optically active (S)-N-boc-3-hydroxy piperidine was developed using the “designer cells” co-expressing alcohol dehydrogenase and glucose dehydrogenase.

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