Biohydrogen Production Process Research Articles

Surfactants-induced photo-fermentative biohydrogen production from corncob

Surfactants could improve the mass transfer capacity by avoiding agglomeration and sedimentation of substrate. This study evaluated the effects of diverse Tween series surfactants on hydrogen production performance of photo-fermentative biohydrogen production (PFHP) process. Tween 80 was found to be the most suitable surfactant. The maximum cumulative hydrogen yield (CHY) reached 49.38 ± 1.90 mL/g TS under 0.20% (v/v) Tween 80 addition. Highest energy recovery efficiency of 3.41 ± 0.13% and substrate conversion efficiency of 94.93 ± 0.44% were obtained, which was 50.37% and 1.7% higher than that of the control group, respectively. The effect of diverse Tween series surfactants on photosynthetic bacteria (PSB) was further studied. Results showed that Tween 80 significantly improved the growth and activity of PSB. The modified Han-Levenspiel model was adopted to analyze the effects of Tween 80 addition on PFHP. Results indicated that the reaction system was non-competitive inhibition, the predicted critical concentration of Tween 80 was 0.42% (v/v). This study provides a way to increase the CHY of corncob by the PFHP process.

Synergetic Effect Evaluation of Light and Mass Transfer Enhancement Strategies on Photo Fermentative Biohydrogen Production Process: Illumination, Oscillation, and High Solid Level

Synergetic Effect Evaluation of Light and Mass Transfer Enhancement Strategies on Photo Fermentative Biohydrogen Production Process: Illumination, Oscillation, and High Solid Level

Bio-Hydrogen Production Using Landfill Leachate Considering Different Photo-Fermentation Processes.

Recently, it has become imperative to find new sustainable and renewable sources of energy, in order to avoid dependence on non-renewable traditional energy resources. This would help to overcome the depleting of natural resources for energy production. Hydrogen gas production using biological processes is one of the most attractive solutions in this regard, due to its high energy content and ecofriendly nature. Production of hydrogen using single photo-fermentation process and landfill leachate as substrate was carried out in this paper, by utilizing batch bio-reactor and anaerobic conditions. The pH value and temperature, play an essential role in a bio-hydrogen production process. Thus, in this study, the pH values considered were 6, 6.5, and 7.2, respectively, at a controlled temperature of 37 ± 1°C. This study investigated various schemes that have the possibility of producing hydrogen using; landfill leachate alone, with leachate and addition of inoculum such as sewage sludge, and with substrate such as sucrose and glucose. All experiments were conducted with and without mixing, for effective comparative study. Heat and pH pretreatment were applied in each experiment with the objectives of decreasing the activities of methane-producing bacteria and enhancing the activities of hydrogen-producing bacteria. The hydraulic retention time used in this study was 48 h, in order to obtain optimal performance of the schemes employed. Analysis of liquid leachate was performed for each experiment, and based on the obtained results, the maximum yield of hydrogen produced was 5,754 ml H2/L, with a medium pH scale of 6.0, fermentation temperature of 37 ± 1°C and constant mixing speed of 100 rpm.

Comparative life cycle assessment of biochar-based lignocellulosic biohydrogen production: Sustainability analysis and strategy optimization

Lignocellulose has been considered a potential feedstock for biohydrogen production. Recently, a novel closed-loop concept of biochar approach was developed for enhanced lignocellulosic biohydrogen production. This study therefore targets to analyze the environmental impacts of the three existing lignocellulosic biohydrogen production processes, and evaluate the environmental performance of applying biochar in each process at this early stage of technological development. The results suggest that biochar dosing shows better environmental performance for all impact categories, especially in the consolidate bioprocessing case. Electricity consumption was found to be the dominant cause of environmental impact over the life cycle, while by-products generation was also found to have an effect on the life-cycle impacts. Future research focuses on the biohydrogen production scale, the electricity generation scheme transition towards renewable and cleaner energetic systems, and recovery the by-products to the maximum extent, that will make lignocellulosic biohydrogen production more environmentally sustainable.

Biohydrogen production from wastewater-based microalgae: Progresses and challenges

Microalgae originating from wastewater has been exhibiting particularly promising results in terms of biohydrogen production and wastewater treatment. This paper aims to review the factors affecting production, pretreatment techniques to improve synthesis, advanced technologies utilized for enhancing biohydrogen production, and techno-economic feasibility evaluation of the processes at a commercial scale. Microalgae possess metabolic components to synthesize biohydrogen using photobiological and fermentative processes but must undergo pretreatment for efficient biohydrogen production. The efficiency of these processes is influenced by factors such as the microalgae species, light intensity, cell density, pH, temperature, substrates, and the type of bioreactors. Moreover, many limitations, such as oxygen sensitivity, altered thylakoid constitution, low photon conversion efficiency, light capture disruption, and the evolution of harmful by-products hinder the sustainability of biohydrogen production processes. High operational and maintenance costs serve as the major bottleneck in the scaling up of the process as an industrial technology. Therefore, future research needs to be directed towards increasing optimization of the processes by reducing energy and resource demand, recycling metabolic wastes and process components, genetically engineered microalgae to adopt more efficient routes, and conducting pilot studies for commercialization.

Thematic issue: advanced biohydrogen production processes from organic materials

Thematic issue: advanced biohydrogen production processes from organic materials

Developing single‐substrate steady‐state model for biohydrogen production in continuous anaerobic activated sludge–rotating biological contactor system: Novel insights on the process

Kinetic-modeling studies are a key step to attain economically practical technology in terms of efficient scheme and bioreactor scale-up to describe the substrate utilization, biomass growth, and product formation in the biohydrogen production process. Kinetic-modeling study of biohydrogen production from molasses using mixed culture was investigated in an anaerobic activated sludge-rotating biological contactor. Single-substrate with endogenous metabolism and Luedeking–Piret model was used to describe the kinetic parameters at different dilution rate (0.032-0.167 h−1) with influent concentration of 6, 15, and 24 g COD/L. The maximum experimentally estimated value of μmax, kS, and Yx/s was found to be 0.053 h−1, 9.98 g/L, and 0.11 g/g in dilution 0.167 h−1, respectively. It can be concluded that increase in dilution rate is a suitable for microbial activities in the biological hydrogen production process. Accordingly, maximum specific growth rate and hydrogen production rate will be increased. Contrariwise, decrease in dilution rate is associated with lower biomass concentration and higher endogenous metabolism. Therefore, dilution rate is an important parameter in production of biohydrogen in this bioreactor and should be kept in an appropriate range.

Biohydrogen: A life cycle assessment and comparison with alternative low-carbon production routes in UK

This study focuses on the production of hydrogen from municipal solid waste (MSW) for applications in transportation. A life cycle assessment (LCA) was conducted on a semi-commercial advanced gasification process for Biohydrogen (Bio-H2) production from MSW to evaluate its environmental impact on five impact categories: Climate Change, Acidification, Eutrophication Fresh Water, Ecotoxicity Freshwater and Photochemical Ozone Formation (human health). The biogenic composition of waste and the effect of carbon sequestration were analysed for Bio-H2, uncovering a net-negative carbon process. The counterfactual case of MSW incineration further bolsters the carbon savings associated to Bio-H2. The production of Bio-H2 from waste is proven to be competitive against alternative hydrogen productions routes, namely blue hydrogen (Blue-H2) produced via steam methane reforming/autothermal reforming coupled with carbon capture and storage (CCS), and green hydrogen (Green-H2) from solar and offshore wind, with respect to climate change. These climate change advantages are shown to carry forward in the context of decarbonisation of electricity grid mix, as analysed by scenarios taken for 2030 and ‘net-zero’ 2050.

Hybrid Process for Bio-hydrogen and Methane Production from Hydrogenic Effluent: A Mini Review

Hydrogenic effluent is the effluent from the bio-hydrogen production process via dark fermentation. It mainly consists of volatile fatty acids, residual sugars, and organic solid residues with a high carbon oxygen demand (COD), which prohibits direct discharge to the environment. Therefore, a post-process after dark fermentation to utilize the organic substances in the hydrogenic effluent is needed to complete the organic conversion and reduce the COD load. This review discussed the use of organic substances in the hydrogenic effluent to produce bioenergy, including bio-hydrogen, through photo fermentation and microbial electrolysis cells, and to produce methane by anaerobic digestion. Furthermore, the advantages and disadvantages of using hydrogenic effluent to generate bio-hydrogen and methane and the challenges and future perspectives on utilizing the hydrogenic effluent are discussed.

Extremum seeking control and gradient estimation based on the Super-Twisting algorithm

This article addresses the problem of extremum seeking of a continuous-time dynamical system with a single input and a single output. A Super-Twisting-based optimization algorithm is proposed to compute the input that leads to the extremum value of an unknown convex objective function. Our optimization algorithm requires the input–output gradient of the system’s response at steady state, which we compute throughout a Super-Twisting-based differentiator. Feasibility of the proposed extremum seeking strategy is demonstrated by two simulation examples. The first one is an example of interest in academy. The second one is a novel biohydrogen production process.

Improvement of CO2 and Acetate Coupling into Lactic Acid by Genetic Manipulation of the Hyperthermophilic Bacterium Thermotoga neapolitana.

Capnophilic lactic fermentation (CLF) represents an attractive biotechnological process for biohydrogen production and synthesis of L-lactic acid from acetate and CO2. The present study focuses on a genetic manipulation approach of the Thermotoga neapolitana DSM33003 strain to enhance lactic acid synthesis by the heterologous expression of a thermostable acetyl-CoA synthetase that catalyses the irreversible acetate assimilation. Because of the scarcity of available genetic tools, each transformation step was optimized for T. neapolitana DSM33003 to cope with the specific needs of the host strain. Batch fermentations with and without an external source of acetate revealed a strongly increased lactate production (up to 2.5 g/L) for the recombinant strain compared to wild type. In the engineered bacterium, the assimilation of CO2 into lactic acid was increased 1.7 times but the hydrogen yield was impaired in comparison to the wild type strain. Analysis of fermentation yields revealed an impaired metabolism of hydrogen in the recombinant strain that should be addressed in future studies. These results offer an important prospective for the development of a sustainable approach that combines carbon capture, energy production from renewable source, and the synthesis of high value-added products, which will be addressed in future studies.

Photo-fermentative biohydrogen production from corncob treated by microwave irradiation

The complex structure of corncob is the bottleneck that restricts its efficient biohydrogen production. Hence, effective treatment is an important exploration to break this limitation. The effect of microwave irradiation (MI) on photo-fermentative biohydrogen production (PFHP) process was evaluated in this paper. Diverse conditions (irradiation time, microwave power, and surfactant addition) were applied. Comparisons of cumulative hydrogen yield (CHY), microstructure, liquid products, and substrate conversion efficiency (Sconv) were conducted. Results showed that the highest CHY of 27.34 ± 1.13 mL/g TS was achieved when the corncob was treated by MI assisted with surfactant addition. Optimal treatment conditions (5.51 min irradiation time, 772.03 W microwave power, and 0.08 g/L rhamnolipids addition) were obtained. MI assisted with surfactant addition helped with the structure destroys and content degradation, displaying a great improves on PFHP. Lower ethanol content and higher butyric acid content were obtained. An 80.94% increase in CHY and Sconv of 90.44% were obtained than untreated corncob.

Characteristics of the process of biohydrogen production from simple and complex substrates with different biopolymer composition

The work investigated the characteristics of the dark fermentation (DF) process of a number of simple (starch, sunflower oil, peptone, both separately and mixed) and complex (dog food, pig feed, sewage sludge) substrates using a mixed culture of microorganisms, with a controlled pH (5.5), at 55 °C. Peptone and sunflower oil were characterized by the lowest production of H2, namely 5.0 and 2.3 ml H2/g COD, respectively. The specific hydrogen yield from starch was 1.55 mol H2/mol hexose. The addition of peptone and sunflower oil to starch reduced the specific yield of hydrogen from starch by 23%. A large difference in hydrogen production was observed during DF of complex substrates. The specific hydrogen yield from dog food was 46.5 ml H2/g COD or 143.4 ml H2/g carbohydrates; from pig feed – 32.1 ml H2/g COD or 91.6 ml H2/g carbohydrates; and from sewage sludge – 9.3 ml H2/g COD or 98.0 ml H2/g carbohydrates. Possible relationships between the biopolymer composition of substrates and characteristics of the DF process were analyzed using Spearman's rank correlation coefficients. The concentration of carbohydrates, as well as the ratio of carbohydrates/proteins and carbohydrates/fats, were the main factors influencing the high specific yield of H2, its content in biogas, as well as the ratio of H2/soluble metabolites. The concentration of proteins had a statistically significant positive effect on the accumulation of acetate and succinate, and carbohydrates - on the accumulation of caproate.

Recycling of shrub landscaping waste: Exploration of bio-hydrogen production potential and optimization of photo-fermentation bio-hydrogen production process

Shrub landscaping waste, derived from afforestation of city, has increased annually, making it a promising feedstock for energy production. In this work, the photo-fermentation bio-hydrogen production potential from shrub landscaping waste was evaluated. Eight kinds of shrub landscaping wastes (Photinia fraseri, Buxus megistophylla, Buxus sinica, Pittosporum tobira, Sabina Chinensis, Berberis thunbergii, Ligustrum vicaryi and Ligustrum quihoui) were selected as substrate and the photo-fermentation bio-hydrogen production process of which was optimized. Buxus megistophylla was found to be the most suitable substrate for photo-fermentation bio-hydrogen production. Moreover, the initial pH value, temperature and substrate concentration had significant influence on photo-fermentation bio-hydrogen production. The maximum cumulated hydrogen yield of Buxus megistophylla was 73.82 ± 0.06 mL/g TS under the optimal conditions of light intensity of 3000 Lux, substrate mass concentration of 21.49 g/L, temperature of 29.78 °C, inoculant amount of 25% and initial pH value of 6.78.

Biohydrogen production using kitchen waste as the potential substrate: A sustainable approach

This review explores the sustainable feasibility of kitchen wastes to implement as an effective substrate for biohydrogen production through dark fermentation. Being organic in nature, kitchen wastes are enomerous source of nutrients and carbohydrate, which are produced in huge quantity in our daily life, and therefore can be potentially used for biohydrogen production through microbial technique. The review discussed in detail about the impact of kitchen waste, its availability and sustainability on the biohydrogen production process along with future scope at industrial scale for the production of sustainable and renewable energy. In addition, recent advances, and their possibility to enhance the fermentative biohydrogen production using kitchen waste have been covered. Emphasis is also made on the application of nanomaterials to increase the yield of biohydrogen production and to make the entire process more economical and sustainable while using kitchen wastes as substrate for the microbial fermentation. Finally, advantages, limitations and future prospects of the process of biohydrogen production using kitchen wastes as potential substrate have been discussed.

A comprehensive review on advanced thermochemical processes for bio-hydrogen production via microwave and plasma technologies

Substantial advances in research, thriving use, and further product recovery contribute to improvements and variations in current biomass processing thermochemical processes. This study offers a summary of the concepts, methods, benefits, and demerits of biomass thermochemical conversions such as pyrolysis and gasification using microwave and plasma technologies for bio-hydrogen production. This article also offers a comprehensive overview of the evolving biogas for bio-hydrogen production. These technologies generate up to 95% bio-hydrogen and can process a wide variety of biomass and waste. The current study also includes assessing the overall description of the microwave plasma cycle and the effect of several operational parameters on H2 performance. This extensive knowledge will help potential researchers to interlink with industry to make feasible, sustainable hydrogen production.

Yeast fermentation towards biodiesel: Maximizing resource recovery by integrating with biohydrogen production in biorefinery framework

This study presents an effective and sustainable approach for biodiesel production through oleaginous yeast fermentation by utilizing volatile fatty acids (VFAs) rich acidogenic effluents as an alternative feedstock. Experiments were designed in two stages to obtain high cell density and lipid productivity. Primarily, oleaginous yeast (Cryptococcus curvatus; MTCC 2698) was grown on glucose with varied initial concentrations at 25 °C. Maximum biomass concentration of 4.2 ± 0.05 g/L was achieved with 40 g/L glucose, which was subjected to the second stage along with the supplementation of 5 g/L of selected VFAs viz., acetic acid, propionic acid, butyric acid and mixed VFAs. Highest lipid concentration of 33.5% (w/w) was obtained with acetic acid supplementation followed by mixed VFAs (23% w/w). Further, to validate results from initial studies, yeast strain was cultivated on real field VFAs rich acidogenic effluent derived from renewable biohydrogen production process. Maximum of 4.85 ± 0.05 g/L biomass and 29.3% (w/w) of lipid was observed during real field application fatty acid profiling of produced lipids showed predominance of palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1) and linoleic acid (C18:2) which has potential utility for biodiesel production. Integration of bioprocesses in a biorefinery format helps to maximize resource recovery apart from minimizing waste generation. The study confirms feasible utilization of acidogenic effluent as an alternative feedstock for the production of microbial lipids through yeast fermentation.

Performance evaluation of bio-hydrogen and bio-methane cogeneration from corn stover over a range of initial pH and temperature

Temperature and pH are key factors that have significant effects on the anaerobic fermentation process. Hence, in this study, a combined bio-hydrogen and bio-methane production process over a range of initial pH and temperature was evaluated. Corn stover was taken as substrate, bio-hydrogen and bio-methane yield, biogas composition and energy conversion efficiency were analyzed. Results showed that the highest hydrogen yield of 69.02 ± 1.75 mL/g VS was obtained with fermentation conditions at initial pH 8 and 35 °C, and the highest methane yield of 249.36 ± 9.81 mL/g VS was obtained from the photofermentation effluent at initial pH 6 and 30 °C. Highest hydrogen and methane contents in the produced biogas were 14.42% and 46.46%, respectively. Furthermore, the highest energy conversion efficiency of 48.83% was obtained with fermentation condition at pH 6 and 30 °C.

Development of novel strategies for higher fermentative biohydrogen recovery along with novel metabolites from organic wastes: The present state of the art.

Depletion of fossil fuels and environmental concern has compelled us to search for alternative fuel. Hydrogen is considered as a dream fuel as it has high energy content (142kJg-1 ) and is not chemically bound to carbon. At present, fossil fuel-based methods for producing hydrogen require high-energy input, which makes the processes expensive. The major processes for biohydrogen production are biophotolysis, microbial electrolysis, dark fermentation, and photofermentation. Fermentative hydrogen production has the additional advantages of potentially using various waste streams from different industries as feedstock. Novel strategies to enhance the productivity of fermentative hydrogen production include optimization in pretreatment methods, integrated fermentation systems (sequential and combined fermentation), use of nanoparticles as additives, metabolic engineering of microorganisms, improving the light utilization efficiency, developing more efficient photobioreactors, etc. More focus has been given to produce biohydrogen in a biorefinery approach in which, along with hydrogen gas, other metabolites (ethanol, butyric acid, 1,3-propanediol, etc.) are also produced, which have direct/indirect industrial applications. In present review, various emerging technologies that highlight biohydrogen production methods as effective and sustainable methods on a large scale have been critically reviewed. The possible future developments are also outlined.

Investigation of the interaction between lighting and mixing applied during the photo-fermentation biohydrogen production process from agricultural waste

To better clarify the effect of lighting and mixing on the hydrogen production from agricultural waste, experiments under diverse constant and dynamic light intensities and mixing speeds were conducted. Cumulative hydrogen yield, hydrogen production rate, OD660, pH, reducing sugar concentration were monitored. Results showed that mixing had positive effects on high substrate concentration. The interaction between lighting and mixing was drawn. Higher light intensity (7000 Lux) was suitable for hydrogen production under mixing. Higher light intensity with higher mixing speed (150 RPM) showed the highest cumulative hydrogen yield of 78.1 mL/g TS. Different periods of hydrogen production process required distinct lighting and mixing. Combined with Gompertz model, dynamic lighting and mixing strategies were discussed. Dynamic light intensity (4000-7000-4000 Lux) accompanied with dynamic mixing speed (50-150-50 RPM) was the optimal condition for PFHP. Highest hydrogen yield of 84.7 mL/g TS and highest light conversion efficiency of 36.32% were obtained.