Biological Hydrogen Production Research Articles

Breakthroughs in Low-Cost Hydrogen Production Methods for Fuel Cells

Traditional hydrogen production, like steam methane reforming (SMR), is limited by high greenhouse gas emissions and fossil fuel dependency. However, integrating renewable energy with innovative production technologies offers a more sustainable and cost-effective pathway. Electrolysis, powered by renewable sources such as wind and solar, is a promising method that has seen efficiency improvements through advancements in proton exchange membrane (PEM) and anion exchange membrane (AEM) technologies. Additionally, research into thermochemical water splitting, which utilizes high-temperature heat from solar or nuclear energy, presents a scalable alternative for industrial hydrogen production. Biological hydrogen production using microorganisms, such as algae and bacteria, offers further innovation by leveraging natural processes for hydrogen generation. The integration of renewable energy into hydrogen production not only lowers costs but also provides an effective means of energy storage, contributing to grid stability and reducing reliance on fossil fuels. This paper explores recent breakthroughs in low-cost hydrogen production methods, essential for advancing the hydrogen economy and promoting fuel cells as a clean energy solution.

Biological Hydrogen Production: A Comprehensive Review for Converting Wastes into Wealth

Biological Hydrogen Production: A Comprehensive Review for Converting Wastes into Wealth

Analysis of the performance and microbial community of continuous dark fermentation combined with steady static magnetic field

The effect of external static magnetic field on hydrogen production and its mechanism were studied by continuous dark fermentation with no pretreatment excess sludge as inoculum. The results showed that under conditions of 37 ± 1 ℃, HRT 8 h, OLR 15 g/(L· d) and no control of influent pH, 78 mT external static magnetic field by adding magnets on both sides of the reactor could accelerate the enrichment of Ethanoligenens and improve the activity of reduced coenzyme I (96 %), ferredoxin oxidoreductase (29 %) and pyruvate: ferredoxin oxidoreductase (7 %) so that the maximum hydrogen productivity could reach 1.657 L H2/L, which was 5 times higher than that of non-magnetic group. Moreover, the n-caproic acid production could also increase due to the enrichment of carbon chain elongation microorganisms. The decline of hydrogen production was mainly due to hydrogenotrophic methanogenesis and acetic acid accumulation. This study was benefit to understand the interaction mechanism between magnetic field and microorganisms during the process of biological hydrogen production.

External Electrons Directly Stimulate Escherichia coli for Enhancing Biological Hydrogen Production.

External electric field has the potential to influence metabolic processes such as biological hydrogen production in microorganisms. Based on this concept, we designed and constructed an electroactive hybrid system for microbial biohydrogen production under an electric field comprised of polydopamine (PDA)-modified Escherichia coli (E. coli) and Ni foam (NF). In this system, electrons generated from NF directly migrate into E. coli cells to promote highly efficient biocatalytic hydrogen production. Compared to that generated in the absence of electric field stimulation, biohydrogen production by the PDA-modified E. coli-based system is significantly enhanced. This investigation has demonstrated the mechanism for electron transfer in a biohybrid system and gives insight into precise basis for the enhancement of hydrogen production by using the multifield coupling technology.

Shewanella oneidensis-based artificial conductive micro-niche for hydrogen augmentation

The synergetic integration of living microorganisms and nonliving matrices into a new artificial micro-ecological system is a crucial challenge in bio-manufacturing especially towards the development of sustainable energy technology. Here we develop a way of creating a Shewanella oneidensis based conductive micro-niche to boost hydrogen production by integrating graphene, polydopamine and alginate. We reveal that both the respiratory metabolism induces localized hypoxic conditions inside the micro-niche and the wired-up extracellular electron reverses transfer pathway from the outer environment to the periplasmic hydrogenases, contributing to the enhanced hydrogen production rate which is about 12.7 folds enhancement compared with that of the free Shewanella oneidensis in solution. Significantly, the whole assembly process shows good biocompatibility, ensuring that the Shewanella oneidensis inside the micro-niche could maintain hydrogen production for 30 days. Overall, it is anticipated the hybrid integration of microorganisms and abiotic material will provide an effective strategy to modulate green biomanufacturer as well as enhance biological hydrogen production.

Predicting the Structure of Enzymes with Metal Cofactors: The Example of [FeFe] Hydrogenases.

The advent of deep learning algorithms for protein folding opened a new era in the ability of predicting and optimizing the function of proteins once the sequence is known. The task is more intricate when cofactors like metal ions or small ligands are essential to functioning. In this case, the combined use of traditional simulation methods based on interatomic force fields and deep learning predictions is mandatory. We use the example of [FeFe] hydrogenases, enzymes of unicellular algae promising for biotechnology applications to illustrate this situation. [FeFe] hydrogenase is an iron-sulfur protein that catalyzes the chemical reduction of protons dissolved in liquid water into molecular hydrogen as a gas. Hydrogen production efficiency and cell sensitivity to dioxygen are important parameters to optimize the industrial applications of biological hydrogen production. Both parameters are related to the organization of iron-sulfur clusters within protein domains. In this work, we propose possible three-dimensional structures of Chlorella vulgaris 211/11P [FeFe] hydrogenase, the sequence of which was extracted from the recently published genome of the given strain. Initial structural models are built using: (i) the deep learning algorithm AlphaFold; (ii) the homology modeling server SwissModel; (iii) a manual construction based on the best known bacterial crystal structure. Missing iron-sulfur clusters are included and microsecond-long molecular dynamics of initial structures embedded into the water solution environment were performed. Multiple-walkers metadynamics was also used to enhance the sampling of structures encompassing both functional and non-functional organizations of iron-sulfur clusters. The resulting structural model provided by deep learning is consistent with functional [FeFe] hydrogenase characterized by peculiar interactions between cofactors and the protein matrix.

A novel microbial community restructuring strategy for enhanced hydrogen production using multiple pretreatments and CSTR operation

To achieve rapid enrichment of the targeted hydrogen-producing bacterial population and reconstruction of the microbial community in the biological hydrogen-producing reactor, the activated sludge underwent multiple pretreatments using micro-aeration, alkaline treatment, and heat treatment. The activated sludge obtained from the multiple pretreatments was inoculated into the continuous stirred tank reactor (CSTR) for continuous operations. The community structure alteration and hydrogen-producing capability of the activated sludge were analyzed throughout the operation of the reactor. We found that the primary phyla in the activated sludge population shifted to Proteobacteria, Firmicutes, and Bacteroidetes, which collectively accounted for 96.69% after undergoing several pretreatments. This suggests that the multiple pretreatments facilitated in achieving the selective enrichment of the fermentation hydrogen-producing microorganisms in the activated sludge. The CSTR start-up and continuous operation of the biological hydrogen production reactor resulted in the reactor entering a highly efficient hydrogen production stage at influent COD concentrations of 4000 mg/L and 5000 mg/L, with the highest hydrogen production rate reaching 8.19 L/d and 9.33 L/d, respectively. The main genus present during the efficient hydrogen production stage in the reactor was Ethanoligenens, accounting for up to 33% of the total population. Ethanoligenens exhibited autoaggregation capabilities and a superior capacity for hydrogen production, leading to its prevalence in the reactor and contribution to efficient hydrogen production. During high-efficiency hydrogen production, flora associated with hydrogen production exhibited up to 46.95% total relative abundance. In addition, redundancy analysis (RDA) indicated that effluent pH and COD influenced the distribution of the primary hydrogen-producing bacteria, including Ethanoligenens, Raoultella, and Pectinatus, as well as other low abundant hydrogen-producing bacteria in the activated sludge. The data indicates that the multiple pretreatments and reactor's operation has successfully enriched the hydrogen-producing genera and changed the community structure of microbial hydrogen production.

Domain Archaea – system overview, metabolism, biotechnological potential

An overview of Archaea, the most ancient domain of life, was carried out. The phylogenetic relationship of Archaea with bacteria and eukaryotes are considered, and the morpho-physiological characteristics of their main groups are given. The biotechnological potential of Archaea is discussed. Cost-effective products of Archaeal biosynthesis are bacterioruberin, squalene, bacteriorhodopsin and diester/tetraether lipids. The production of other metabolic products of Archaea, such as carotenoids, hydrogen, polyhydroxyalkanoates and methane, are in advanced stages of development. While the biological production of methane and hydrogen currently lags behind the profitability of petrochemical plants, research aimed at enhancing the efficiency of this process with the involvement of Archaea holds strategic significance. Archaea also represent a promising target for application in nanotechnology and bioengineering. The aim of the present review is to unveil the biotechnological potential of Archaea, provide an overview of the main groups within this domain, their morphophysiological characteristics, present a generalized metabolite profile of these groups, and outline the spectrum of productions involving these intriguing microorganisms.

Fuzzy controller system utilization to increase the hydrogen production bioreactor capacity: toward sustainability and low carbon technology

Abstract The utilization of bio-hydrogen as a fuel source holds immense promise as a renewable energy option, offering compelling economic and environmental advantages. This study investigates the economic and environmental advantages of bio-hydrogen as a renewable energy source compared to fossil fuels, focusing on the reduction of greenhouse gas emissions such as carbon dioxide and carbon monoxide. The enhancement of anaerobic hydrogen production reactor capacity is explored through the application of a fuzzy controller system. Numerical simulations demonstrate that the fuzzy controller outperforms other methods in augmenting biological hydrogen production, effectively addressing the inherent non-linear characteristics of the system. In contrast, limitations in robustness against system uncertainty are observed with the non-linear controller. Exceptional tracking of desired values by the fuzzy controller, even in the presence of model uncertainty, results in a lower integral of time multiplied by squared error (ITSE) performance index compared to non-linear and proportional–integral controllers. Emphasizing the viability of the fuzzy method for regulating hydrogen production processes, potential gains of up to 95% in biological hydrogen production are indicated compared to open-loop configurations. This clean-burning fuel holds promise for industrial applications, contributing to the reduction of harmful gas emissions. The findings underscore the transformative potential of the fuzzy controller system in advancing sustainable hydrogen production and its significant role in addressing environmental concerns.

Biohydrogen Production from Buckwheat Residue Using Anaerobic Mixed Bacteria

In the world, wastes/residues from agricultural activities are rapidly increasing, causing environmental problems. These wastes/residues can be used for the production of biohydrogen as a raw material. In this context, buckwheat crop residue, which has not been found in any study on biohydrogen production potential in the literature research, was investigated for biological hydrogen production via the dark fermentation method. This study was conducted in anaerobic batch bioreactors containing buckwheat or buckwheat extract + pretreated anaerobic mixed bacteria + nutrients, in a darkroom, at 37 ± 1 °C. Gas analyses, organic acid analyses and taxonomic content analyses were performed in bioreactors under different operating conditions (initial pH and organic loading rate). Biological hydrogen production was determined in all bioreactors. In addition, hydrogen production was found to be higher in bioreactors where biomass was used directly. The maximum biohydrogen production was determined to be 11,749.10−4 mL at 1.20 g. buckwheat/L and 446.10−4 mL at 1.20 g. buckwheat extract/L at pH 4.5. According to the taxonomic content species’ level ratios, (i) in bioreactors where biomass was used directly, Hathewaya histolytica and Clostridium butyricum were detected at pH values of 4.5 and 4.0, respectively; and (ii) in bioreactors where biomass extract liquid was used, Clostridium butyricum and Clostridium tertium were determined as the most dominant bacteria at pH values of 4.5 and 4.0, respectively.

CWO/SiO2 spectral beam splitter coating for photothermal synergetic catalysis: Design and development

Solar-energy-driven hydrogen production from biomass is a key technology for green hydrogen production. Photothermal synergistic catalysis is an effective means to enhance biological hydrogen production. In this study, a spectral beam splitter coating (SBSC) adapted for photothermal synergetic catalysis is designed and developed based on cesium tungsten bronze (CWO) and silicon dioxide (SiO2) in a sol–gel system. The CWO/SiO2 SBSC exhibits short-wavelength transmittance up to 85.7 % and absorption of near-infrared (NIR) light up to 91.3 % by adjusting the lifting speed, filling factor, and curing temperature. Evaluation model calculations reveal that the CWO/SiO2 SBSC can significantly improve the hydrogen production rate when the reaction solution temperature is 80 °C and that the integrated solar energy conversion efficiency is 3.7 times that without the SBSC. The results demonstrate the high durability of the CWO/SiO2 SBSC as well as its promising application scope in the photothermal synergetic catalysis of biomass hydrogen.

Biological production of hydrogen: From basic principles to the latest advances in process improvement

The development of net-zero emission fuels is a priority area of modern research due to the imminent reduction of fossil fuel reserves and environmental problems caused by their combustion. One of the promising fuels is hydrogen, which has a high heat of combustion and is eco-friendly, forms water as the only byproduct. Recently, methods of hydrogen production by microorganisms, which use directly the solar energy or utilize the organic waste during fermentation, have been intensively developed and applied. In this review, the basic principles of the main light-dependent (biophotolysis, photofermentation) and light-independent (dark fermentation and microbial electrolysis) methods of biological hydrogen production are discussed. Particular attention is paid to the advantages and disadvantages of these methods, the possibility of combining them into a single system, as well as various strategies for improving biohydrogen production aimed at transition from laboratory research to full-scale application.

Biological hydrogen and furfural production from steam-exploded vine shoots

Vine shoots are an agricultural waste rich in carbohydrates that can be considered as a promising energy source alternative. The objective of this work was to propose a process strategy for the valorisation of this residual biomass, including the chemical conversion of solubilised sugars into furfural and the biological conversion of cellulosic glucose into H2. Vine shoots were subjected to steam explosion pretreatment, and its operational conditions were optimised as 190 °C and 1.6% H2SO4 impregnated biomass. These pretreatment conditions allowed to recover 68.2% of the hemicellulose sugars and 18.2% of glucose in the prehydrolysate and 45.3% glucose by enzymatic hydrolysis. Thus, the pretreated solid obtained under optimised conditions was subjected to enzymatic hydrolysis and the slurry generated was used as a substrate by Clostridium butyricum for fermentation into biohydrogen (830.7 mL/L and a yield of 3550 mL per 100 g of raw vine shoots) and organic acids (1495.3 mg acetic acid/L and 1726.8 mg butyric acid/L). Based on furfural production, the chemical conversion of xylose in the prehydrolysate was optimised in a microwave reactor at 202 °C, using 0.195 M FeCl3 as a catalyst, with a furfural production of 15 g/L and 73% yield.

Enhancing the biological hydrogen production in a novel way of using co-substrates

Enhancing the biological hydrogen production in a novel way of using co-substrates

Coriolus versicolor laccase-based inorganic protein hybrid synthesis for application in biomass saccharification to enhance biological production of hydrogen and ethanol

In this study, a bio-friendly inorganic protein hybrid-based enzyme immobilization system using partially purified Coriolus versicolor laccase (CvLac) was successfully applied to biomass hydrolysis for the enhancement of sugar production aimed at generating biofuels. After four days of incubation, the maximum CvLac production was achieved at 140 U/mg of total protein in the presence of inducers such as copper and wheat bran after four days of incubation. Crude CvLac immobilized through inorganic protein hybrids such as nanoflowers (NFs) using zinc as Zn3(PO4)2/CvLac hybrid NFs (Zn/CvLac-NFs) showed a maximum encapsulation yield of 93.4% and a relative activity of 265% compared to free laccase. The synthesized Zn/CvLac-NFs exhibited significantly improved activity profiles and stability compared to free enzymes. Furthermore, Zn/CvLac-NFs retained a significantly high residual activity of 96.2% after ten reuse cycles. The saccharification of poplar biomass improved ∼2-fold in the presence of Zn/CvLac-NFs, with an 8-fold reduction in total phenolics compared to the control. The Zn/CvLac-NFs treated biomass hydrolysate showed high biological hydrogen (H2) production and ethanol conversion efficiency of up to 2.68 mol/mol of hexose and 79.0% compared to the control values of 1.27 mol of H2/mol of hexose and 58.4%, respectively. The CvLac hybrid NFs are the first time reported for biomass hydrolysis, and a significant enhancement in the production of hydrogen and ethanol was reported. The synthesis of such NFs based on crude forms of diverse enzymes can potentially be extended to a broad range of biotechnological applications.

Biological Hydrogen Production from Urban and Industrial Wastewater

Biological hydrogen production is a process in which microorganisms convert organic matter into hydrogen gas. This renewable energy production method is of great interest as an environmentally friendly and sustainable energy source. Biological hydrogen production can be accomplished using different methods. The dark fermentation method is a process in which organic substances are converted into hydrogen gas by microorganisms in anaerobic (oxygen-free) environments. In this method, organic materials are subjected to the fermentation process and hydrogen gas is released. This process also offers a solution for waste management. Photo fermentation is a process in which photosynthetic organisms convert organic materials into hydrogen gas using light energy. The light is absorbed by the photosynthetic pigments and provides the necessary energy for hydrogen gas production. In this method, clean hydrogen gas can be produced using solar energy. Biological hydrogen production methods have several advantages. These include the use of renewable resources, low greenhouse gas emissions, waste management and low energy consumption. However, there are also some disadvantages depending on the methods, for example limited light access or the difficulty of obtaining the purity of hydrogen gas. Biological hydrogen production is a promising method to meet clean and sustainable energy needs. Continuous research and development studies continue to increase the efficiency of these methods and eliminate their disadvantages. In the future, with the more widespread use of biological hydrogen production methods, the diversity of clean energy sources will increase and environmental sustainability will be ensured.

Metabolomics of Escherichia coli for Disclosing Novel Metabolic Engineering Strategies for Enhancing Hydrogen and Ethanol Production.

The biological production of hydrogen is an appealing approach to mitigating the environmental problems caused by the diminishing supply of fossil fuels and the need for greener energy. Escherichia coli is one of the best-characterized microorganisms capable of consuming glycerol-a waste product of the biodiesel industry-and producing H2 and ethanol. However, the natural capacity of E. coli to generate these compounds is insufficient for commercial or industrial purposes. Metabolic engineering allows for the rewiring of the carbon source towards H2 production, although the strategies for achieving this aim are difficult to foresee. In this work, we use metabolomics platforms through GC-MS and FT-IR techniques to detect metabolic bottlenecks in the engineered ΔldhΔgndΔfrdBC::kan (M4) and ΔldhΔgndΔfrdBCΔtdcE::kan (M5) E. coli strains, previously reported as improved H2 and ethanol producers. In the M5 strain, increased intracellular citrate and malate were detected by GC-MS. These metabolites can be redirected towards acetyl-CoA and formate by the overexpression of the citrate lyase (CIT) enzyme and by co-overexpressing the anaplerotic human phosphoenol pyruvate carboxykinase (hPEPCK) or malic (MaeA) enzymes using inducible promoter vectors. These strategies enhanced specific H2 production by up to 1.25- and 1.49-fold, respectively, compared to the reference strains. Other parameters, such as ethanol and H2 yields, were also enhanced. However, these vectors may provoke metabolic burden in anaerobic conditions. Therefore, alternative strategies for a tighter control of protein expression should be addressed in order to avoid undesirable effects in the metabolic network.

Magnetic nitrogen-doped activated carbon improved biohydrogen production.

Low biological hydrogen (bioH2) production due to non-optimal metabolic pathways occurs frequently. In this work, magnetic nitrogen-doped activated carbon (MNAC) was prepared and added into the inoculated sludge with glucose as substrate to enhance hydrogen (H2) yield by mesophilic dark fermentation (DF). The highest H2 yield appeared in 400 mg/L AC (252.8 mL/g glucose) and 600 mg/L MNAC group (304.8 mL/g glucose), which were 26.02% and 51.94% higher than that of 0 mg/L MNAC group (200.6 mL/g glucose). The addition of MNAC allowed for efficient enrichment of Firmicutes and Clostridium-sensu-stricto-1, accelerating the metabolic pathway shifted towards butyrate type. The Fe ions released by MNAC facilitated electron transfer and favored the reduction of ferredoxin (Fd), thereby obtaining more bioH2. Finally, the generation of [Fe-Fe] hydrogenase and cellular components of H2-producing microbes (HPM) during homeostasis was discussed to understand on the use of MNAC in DF system.

Algal biohydrogen production: Impact of biodiversity and nanomaterials induction

Fossil fuels are limited in nature and are not environmentally friendly, thus using them to meet the rising energy needs is insufficient. Another major cause of global warming, which is recognized as one of the greatest hazards to the world, is fossil fuels. Finding alternative energy sources that can counteract the drawbacks of fossil fuels is urgently needed. Due to its low environmental impact and a variety of possible sustainable production methods, biohydrogen is one such alternative energy source that has attracted enormous interest and demand. Due to their wide range of environments, rapid growth, and polyphyletic nature, algae-based biological hydrogen production techniques are gaining significant interest. Nevertheless, the main obstacles to the sustainable and commercial application of the algal biohydrogen generation process are low yield, constrained light penetration, low biomass concentration, and expensive downstream processes. Increased attention to algal diversity may help to overcome the limitation of low algal biomass production and yield while enhancing penetration ability. Additionally, the usage of nanomaterials may speed up the process by altering the entire process' response mechanism. Therefore, this review explores algal diversity as one of the strategies of algal biohydrogen production along with elaboration of the impacts of nanomaterials in different pathways of biohydrogen production, namely dark fermentation, photo-fermentation, direct and indirect biophotolysis. Advances in biohydrogen production employing diversified groups of algae with the application of nanomaterials have been extensively summarized with current update mechanisms and existing roadblocks. As a result, the utilization of nanomaterials as a novel and sustainable catalyst has also been thoroughly described for prospective scaling up of algal biohydrogen production.

Exploring the feasibility of biological hydrogen production using seed sludge pretreated with agro-industrial wastes

The effect of applying agro-industrial waste (AIW), such as potash extract (PE), cassava-steep wastewater (CSWW), and corn-steep liquor (CSTL), as an alternative material to pretreat digested cattle slurry (DCS) for biological hydrogen production was examined. In this study, the pretreated (PT) DCS was employed for H2 fermentation in batch cultures utilising glucose and sucrose as substrates. The result showed that, at 55 °C and pH 5.5, the pretreated DCS's daily volumetric hydrogen production (VHP) was higher than the untreated DCS. Although heat-shocked DCS produced a higher daily VHP of 135 NmL H2 g−1 VS on the second day using glucose as substrates, it is followed by PE-PT DCS, which gave a peak daily VHP of 115 NmL H2 g−1 VS but at a shorter time. When sucrose was the carbon source, the highest peaks were recorded in all the laboratory reactors on day two, with the highest daily VHP of 211 NmL H2 g−1 VS achieved in PE-PT DCS digesters. After the different DCS PT studies, the dominant phylum Firmicutes, represented by the Clostridium and Ruminococcus, were the most abundant bacteria compared to the untreated DCS, which was more diverse. Further research is required to optimise the conditions for AIW DCS pretreatment.