Potential For Hydrogen Generation Research Articles

Quantification of Methane Emissions Rate Using Landgem Model and Estimating the Hydrogen Production Potential from Municipal Solid Waste Landfill Site

In India, solid waste is deposited mostly in uncontrolled open landfills without proper segregation and handling methods. Organic wastes dumped in a landfill undergo anaerobic decomposition and emit landfill gases like methane and carbon dioxide. Landfill gases are a significant contributor to greenhouse gases and greatly impact climate change. In the interim, reducing gas emissions and controlling and recycling such gasses is important from environmental hygienic, and global perspectives. Landfill gas has tremendous potential to convert as a source of alternative fuel. The present study estimates the CH4 (Methane) and CO2 (Carbon dioxide) emissions and quantifies the renewable energy available and hydrogen production potential using the LandGEM 3.02 empirical models for the Kanuru, Vijayawada landfill. It was observed that methane emission peaked in 2042 with an emission rate according to the model was 2.51E+08 Metric tons CO2 equivalents. The gas-recovery system is an essential component in landfills for extracting energy with 75-80% efficiency; the generation rate of greenhouse gases will reduce to around 1.78E06 Mg of CO2 eq. The predicted methane emissions vary from 1.33E6-9.22E6 cu.m per year for the period of 2010-2042. It was also estimated that annual energy production from LFG emissions was from 1.8-130 GWh per year, and hydrogen production potential was 0.6-43.3 Gg per year. The study concludes that projected scientific data will assist policymakers in creating sustainable MSW management by bridging the gap between sustainable renewable energy production and protecting the environment. The basic objectives of the study include the quantification of landfill gas production using the LandGEM model for Vijayawada, assessing the electricity generation potential of the landfill methane gas emitted, methane and carbon dioxide recovery from landfills with energy conversion could reduce GHG emissions, and estimation of hydrogen generation potential from the landfill methane emissions.

Enhanced kinetics of photocatalytic hydrogen evolution by interfacial Co-C bonded strongly coupled S-scheme inorganic perovskite/organic graphdiyne (CnH2n-2) heterojunction

The special intrinsic properties and structure of graphdiyne (GDY) bring new space for innovation in the field of photocatalysis. In this work, we utilized the in-situ high-temperature calcination strategy to induce the formation of Co-C chemical bonds at the interface of the catalyst and tightly bound organic GDY to inorganic perovskite CoTiO3 to form an S-scheme heterojunction with strong coupling of chemical bonds. Co-C chemically bonded strongly coupled S-scheme heterojunctions play an active role in promoting the effective separation of photo-induced carriers, lowering the hydrogen generation potential, reducing the resistance to photo-induced electron migration, delaying the lifetime of photogenerated electrons, and enhancing the photo-reduction ability. Kelvin probe force microscopy verifies the formation of built-in electric fields at the heterojunction interface. In situ irradiation XPS to verify the formation of S-scheme heterojunctions base on DFT as a guide for the theory and photo-Tafel as an aid. The in-situ irradiation XPS in-depth study and Kelvin probe force microscopy reveals the migration path of photogenerated carriers in 20%-GCTO. Among them, the introduction of Co-C chemical bond plays the role of a high-speed transfer channel for the migration of photogenerated electrons. This work provides a new strategy for designing in situ induced interfacial covalent bond formation in S-scheme heterojunctions and constructing inorganic/organic heterojunctions.

Mechanistic insights into the deprotonation of methanol by facile synthesized 3D flower-like BiOX (X= Cl, Br, I) catalysts for rapid hydrogen generation from NaBH4 methanolysis: The ‘X’ factor

Bismuth oxyhalides (BiOX, X = Cl, Br, I) have been showing promising catalytic activity in various applications due to their electronic properties and unique layered structure. However, their catalytic potential for hydrogen generation from chemical hydrides is unrevealed. Herein, BiOX (X = Cl, Br, I) catalysts were prepared via a simple co-precipitation method. The physical and chemical characteristics of the as-prepared samples were then duly characterized using various techniques such as X-ray diffractometer spectroscopy (XRD), Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), Nitrogen adsorption-desorption, and Scanning electron microscope (SEM). The catalysts were then applied to NaBH4 methanolysis for the production of hydrogen. Among the BiOX catalysts, BiOCl exhibits excellent performance which is attributed to the highest electronegativity possessed by the Cl− halogens clinging onto the catalytic layers, simply overriding the substitution reactions. Subsequently, superior performances were depicted with rapid generation of hydrogen, High rate of hydrogen generation, HGR = 42,740 mL H2 g−1min−1, and calculated activation energy of Ea = 43.5 kJ/mol with stability for over 5 successive cycles. Withal, a plausible mechanism based on the exchange reactions promoted by the BiOX catalysts, which comprises interlacing [Bi2O2] slabs with double halogen slabs coupled with a strong ionic nature is illustrated in line with the experimental results.

Utilization of food waste for hydrogen-based power generation: Evidence from four cities in Ghana

Hydrogen gas will be an essential energy carrier for global energy systems in the future. However, non-renewable sources account for 96% of the production. Food wastes have high hydrogen generation potential, which can positively influence global production and reduce greenhouse gas (GHG) emissions. The study evaluates the potential of food waste hydrogen-based power generation through biogas steam reforming and its environmental and economic impact in major Ghanaian cities. The results highlight that the annual hydrogen generation in Kumasi had the highest share of 40.73 kt, followed by Accra with 31.62 kt, while the least potential was in Tamale (3.41 kt). About 2073.38 kt was generated in all the major cities. Hydrogen output is predicted to increase from 54.61 kt in 2007 to 119.80 kt by 2030. Kumasi produced 977.54 kt of hydrogen throughout the 24-year period, followed by Accra with 759.76 kt, Secondi-Takoradi with 255.23 kt, and Tamale with 81.85 kt. According to the current study, Kumasi had the largest percentage contribution of hydrogen (47.15%), followed by Accra (36.60%), Secondi-Takoradi (12.31%), and Tamale (3.95%). The annual power generation potential in Kumasi and Accra was 73.24 GWh and 56.85 GWh. Kumasi and Accra could offset 8.19% and 6.36% of Ghana's electricity consumption. The total electricity potential of 3728.35 GWh could displace 17.37% of Ghana's power consumption. This electricity generated had a fossil diesel displacement capacity of 1125.90 ML and could reduce GHG emissions by 3060.20 kt CO2 eq. Based on the findings, the total GHG savings could offset 8.13% of Ghana's carbon emissions. The cost of power generation from hydrogen is $ 0.074/kWh with an annual positive net present value of $ 658.80 million and a benefit-to-cost ratio of 3.43. The study lays the foundation and opens policy windows for sustainable hydrogen power generation in Ghana and other African countries.

Form of the Occurrence of Aluminium in Municipal Solid Waste Incineration Residue—Even Hydrogen Is Lost

In the bottom ash (BA) of municipal solid waste incineration, the content of iron and aluminum is relatively high. The efficiency of eddy current extraction of non-ferrous metals (including aluminium) routinely used in incineration plants is limited. The determination of the form of occurrence of aluminium or aluminium-rich components in BA is important in terms of its recovery or utilisation. BA from a newly built incineration plant in Poland was analysed using chemical analysis, X-ray diffraction, optical microscopy, and scanning electron microscopy with chemical microanalysis. Samples of water-quenched BA were analysed. For comparison, a non-quenched sample (collected above a water tank) was analysed. The obtained results indicate that aluminium-rich components in BA are present in both the melt phase and quench phase. In the melt phase (glassy material), the content of aluminium is low (usually below 2 wt%). Aluminium-rich components present in glass, inherited after aluminium products are usually oxidised, and occur as platy or irregular forms. Aluminium components in the quench phase are significantly transformed with the common presence of Cl− and SO42− phases formed during reaction with the quench water. Secondary phases form simple or complex rims around metallic or slightly oxidised cores, of which the size is significantly reduced during transformations. The variety in the forms of aluminium occurrence in BA makes its recovery challenging and inefficient. The reduced content of metallic aluminium indicates that the potential for hydrogen generation of BA is low.

Hydrogen production from landfill biogas: Profitability analysis of a real case study

Hydrogen is not only considered as a cornerstone within renewable energy portfolio but it is also a key enabler for CO2 valorisation being a central resource for industrial decarbonization. This work evaluates the profitability of hydrogen production via combined biogas reforming and water–gas shift reaction, based on a real case scenario for landfill biogas plant in Seville (Spain). A techno-economic model was developed based on a process model and the discounted cash-flow method. A biogas flow of 700 m3/h (input given by the landfill biogas plant) was used as plant size and the analysis was carried out for two different cases: (1) use of already available energy sources at the industrial plant, and (2) solar energy generation to power the process. The economic outputs obtained showed that under the current circumstances, this hydrogen production route is not profitable. The main reason is the relatively low current hydrogen prices which comes from fossil fuels. A revenues analysis indicates that hydrogen from biogas selling prices between 2.9 and 5.7 €/kg would be needed to reach profitability, which are considerably higher than the current hydrogen cost (1.7 €/kg). A subsidy scheme is suggested to improve the competitiveness of this hydrogen production process in the short-medium term. A cost analysis is also performed, revealing that electricity prices and investment costs have a high impact on the total share (23–40% and 8–22%, respectively). Other potential costs reduction such as catalyst, labour and manteinance & overhead are also evaluated, showing that cutting-down production costs is mandatory to unlock the potential of hydrogen generation from biogas. Our work showcases the techno-economic challenge that green energy policies face in the path toward sustainable societies.

Transient Surface Photovoltage Spectroscopy of (NH4)2Mo3S13/WSe2 Thin-Film Photocathodes for Photoelectrochemical Hydrogen Evolution.

Hydrogen produced from solar energy has the potential to replace petroleum in the future. To this respect, there is a need in the abandoned and efficient materials that can continuously split water molecules using solar energy. In this report, an ammonium thiomolybdate (ATM: (NH4)2Mo3S13) is evaluated as a p-type semiconductor film photocathode for hydrogen evolution reaction. The ATM thin films are prepared by spin-coating on fluorine-doped tin oxide substrates, and their structural, morphological, optical, photoelectrical, and photoelectrochemical (PEC) properties are studied. Transient surface photovoltage (TSPV) spectroscopy and spectroscopic ellipsometry indicate the band gap Eg = 1.9 eV for the ATM thin films. Furthermore, the photovoltage of the ATM thin films measured by TSPV is correlated to the photocurrents measured by the PEC characterization that can be used to evaluate the material potential for hydrogen generation. The films exhibit a low photocurrent density of 46 μA cm-2 at 0 VRHE. However, its combination with WSe2 thin-film photocathodes results in a significant increase in photocurrent density up to 4.6 mA cm-2 at 0 VRHE (100 times). The reason for such a strong charge carrier transfer effect for ATM/WSe2 heterojunction photocathodes is studied by TSPV spectroscopy that allows a comprehensive evaluation of potential photovoltaic materials toward PEC hydrogen production. Furthermore, the photovoltage generated by a WSe2 thin film is 30 times lower than that of its single crystal, which indicates that the quality of WSe2 thin films should be improved for faster PEC hydrogen evolution.

Decarbonizing Vehicle Transportation with Hydrogen from Biomass Gasification: An Assessment in the Nigerian Urban Environment

Tailpipe emissions from vehicles consist of CO2 and other greenhouse gases, which contribute immensely to the rise in global temperatures. Green hydrogen produced from the gasification of biomass can reduce the amount of CO2 emissions to zero. This study aims to provide a modelling framework to optimize the production of hydrogen from biomass waste obtained from different cities, for use in the road transport sector in Nigeria. A gasification model with post-treatment shift conversion and CO2 removal by adsorption is proposed. In this study, six cities are simulated based on technical and environmental considerations, using the Aspen Plus software package. The results revealed that Kaduna has the highest hydrogen generation potential of 0.148 million metric tons per year, which could reduce CO2 emissions to 1.60 and 1.524 million metric tons by the displacement of an equivalent volume of gasoline and diesel. This amounts to cost savings of NGN 116 and 161.8 billion for gasoline and diesel, respectively. In addition, the results of the sensitivity analysis revealed that the steam-to-biomass ratio and the temperature of gasification are positively correlated with the amount of avoided CO2 emissions, while the equivalence ratio shows a negative correlation.

Wind power resource assessment and wind-hydrogen generation potential: a case study

ABSTRACT A case study of assessing wind power generation potentials for seven locations in a district of India is presented in the paper with special focus on small wind turbines with low cut in speeds operating in hybrid complementary mode with a hydrogen generation system. The major motivation for the study is to accelerate the efforts for the region toward carbon neutral status. The wind speeds are obtained for one hour time intervals for all days for 20 years during the time period 2001–2020 for the seven locations from European Center for Medium-Range Weather Forecasts Reanalysis v5 (ERA-5) data. Mean wind speeds for the period are analyzed and wind rose diagrams are generated using the WindroseAxes library in Python environment. Wind power potential assessment has been carried out using the data. From the analysis, it has been noted that the coastal and southern regions of the district get higher wind speeds and have higher power generation potential. Analysis has shown that based on the Beaufort scale, usually the available wind speed is in the calm to moderate breeze types (<0.3–8 m/s). Study has shown that deployment of small wind turbines may be beneficial, to potentially facilitate decentralized power generation. A small wind turbine with cut-in speed 2.5 m/s and cutoff speed 15.5 m/s is selected for the study. The region has a generic upper speed availability of 8 m/s. The corresponding wind power potential values are 0.84 and 27.58 kW. Hydrogen, considered as an energy carrier, and a clean fuel for the future, is proposed as an option for complementary energy storage. Hydrogen, generated from wind energy through electrolysis, may be stored and used to meet the peak power demands. A preliminary analysis of the hydrogen generation potential of the region via the power-to-gas route is also presented. The analysis also points to the necessity for developing small wind turbines, which can generate power at lower cut-in speeds, for maximum utilization of wind power generation potential. The methodology can be adapted to other regions.

Green hydrogen production potential for Turkey with solar energy

The current study develops a hydrogen map concept where renewable energy sources are considered for green hydrogen production and specifically investigates the solar energy-based hydrogen production potential in Turkey. For all cities in the country, the available onshore and offshore potentials for solar energy are considered for green hydrogen production. The vacant areas are calculated after deducting the occupied areas based on the available governmental data. Abundant solar energy as a key renewable energy source is exploited by photovoltaic cells. To obtain the hydrogen generation potential, monocrystalline and polycrystalline type solar cells are considered, and the generated renewable electricity is directed to electrolysers. For this purpose, alkaline, proton exchange membrane (PEM), and solid oxide electrolysers (SOEs) are considered to obtain the green hydrogen. The total hydrogen production potential for Turkey is estimated to be between 415.48 and 427.22 Million tons (Mt) depending on the type of electrolyser. The results show that Erzurum, Konya, Sivas, and Van are found to be the highest hydrogen production potentials. The main idea is to prepare hydrogen map in detail for each city in Turkey, based on the solar energy potential. This, in turn, can be considered in the context of the current policies of the local communities and policy-makers to supply the required energy of each country.

New insights of the interaction of H2S with mackinawite FeS in a wet environment: An ab initio molecular dynamics study

Mackinawite FeS is the most common corrosion product in the early stage of steel in H2S environment and also has an effective catalysis for hydrodesulfurization, hydrogen release reactions and heavy metal ion removal since its high specific surface area and reactive surface like other van der Waals materials. In this paper, ab initio molecular dynamics (AIMD) is used to study the interactions between small molecules (H2S, H2O and H) and FeS at 300 K. The calculation results show that the primary dissociation of H2S only occurs on the FeS(111) surface and H2S is chemically adsorbed on the (011) and (100) surfaces but physically adsorbed on the (001) surface. It will dissociate and generate H atoms when different amounts H2S or H2O molecules appear in the interlayer of FeS, in which H2S is more prone to dissociation. The dissociated H atoms will be “captured” by Fe/S atoms in mackinawite FeS, leading to the shrink of layer. Moreover, H atoms could combine into H2, which suggests that layered FeS has great potential for hydrogen generation. The diffusion coefficient of H atoms in mackinawite FeS layer is estimated about 1.67 × 10−8 m2/s. These findings have significant meaning for application of mackinawite FeS in corrosion science, hydrogen generation, hydrogen storage and other fields.

CoNi bimetallic alloy cocatalyst-modified g-C3N4 nanosheets for efficient photocatalytic hydrogen production

Non-precious and Earth-abundant cocatalysts have emerged as promising alternatives to precious metal catalysts for hydrogen generation from photocatalytic water splitting. In this work, CoNi/g-C3N4 photocatalyst composed of g-C3N4 nanosheets and CoNi alloyed nanoparticles was prepared by a simple solvothermal and chemical reduction method. Bimetallic CoNi alloy was found to accelerate charge transfer and inhibit electron and hole recombination, thereby enhancing the photocatalytic activity of CoNi/g-C3N4. Under optimal conditions, the hydrogen production rate of CoNi/g-C3N4 reached up to 354.4 μmol h−1 g−1 with visible light (λ > 420 nm) in triethanolamine aqueous solution; this value greatly exceeded that of g-C3N4 by a factor of 188 times. A mechanism explaining the excellent photocatalytic performance was proposed accordingly. These results suggest that g–C3N4–based photocatalysts have good potential for hydrogen generation.

NiCo-BDC nanosheets coated with amorphous Ni-S thin film for high-efficiency oxygen evolution reaction and urea oxidation reaction

Electrolysis is a promising method for storing energy in the form of hydrogen fuel, which is of great importance for the application of renewable energy. Due to the sluggish anodic reaction of water splitting, exploration of high-efficiency and cost-effective electrocatalysts enabling low driving potential for hydrogen generation is highly desirable. Here, we report a bifunctional electrocatalyst consisting of two-dimensional NiCo-BDC nanosheet arrays coated with Ni-S thin layers, presenting promising catalytic activity and durability for oxygen evolution reaction (OER) and urea oxidation reaction (UOR). Impressively, this anode could reach a current density of 10 mA cm−2 at an overpotential of 229 mV in 1.0 M KOH for OER. For UOR, only a small potential of 1.31 V (vs. reversible hydrogen electrode) is required for driving a current density of 10 mA cm−2 in 1.0 M KOH with 0.33 M urea. Furthermore, a full electrochemical cell was constructed using the as-prepared catalyst as anode and the Pt/C as cathode. For overall water splitting, only a low potential of 1.53 V is required to gain a current density of 10 mA cm−2 in 1.0 M KOH, whereas the urea-mediated electrolysis cell demonstrates a lower operating potentials of 1.46 V at 10 mA cm−2. This work presents a solid step towards lowing the driving potential for hydrogen generation via water splitting.

Surface Roughed and Pt-Rich Bimetallic Electrocatalysts for Hydrogen Evolution Reaction.

Platinum-based alloys with low cost transition metals have been considered as promising electrocatalysts in the field of sustainable energy conversion and storage. Herein, chloroplatinic acid, cobalt chloride, and carbon nanotubes are used as platinum, cobalt precursors, and carriers, respectively, to prepare rich Pt dealloying PtCo nanoparticles (SD-PtCo/CNT) via co-liquid phase reduction and chemical dealloying methods. The characterization and test results confirm that PtCo alloy nanoparticles are evenly dispersed on carbon nanotubes, further dealloying and resulting in the partial dissolving of cobalt, simultaneously generating a rich Pt layer and roughly active surface. Benefiting from the unique structure, the SD-PtCo/CNT catalyst displays obviously enhanced HER activity in both acidic and alkaline conditions. In 1.0 M KOH, SD-PtCo/CNT exhibits a low overpotential of 78 mV at 10 mA/cm2 and a small tafel slope (38.28 mV/dec). In 0.5 M H2SO4, SD-PtCo/CNT still shows the superior performance compared with un-dealloying PtCo/CNT, with an overpotential of 17 mV at 10 mA/cm2 and corresponding tafel slope of 21.35 mV/dec. The high HER activity of SD-PtCo/CNT can be attributed to the formation of a platinum rich layer and the uniformly dispersed PtCo nanoparticles supported on superior conductive carbon nanotubes, suggesting its great potential for hydrogen generation via water splitting.

Catalytic Reforming: A Potentially Promising Method for Treating and Utilizing Wastewater from Biogas Plants.

This study investigated catalytic reforming, which is a thermochemical process, as a pioneering method to treat biogas slurry (wastewater from biogas plants) and generate hydrogen. Experimental validation for treating biogas slurries from digested cattle manure, fish intestine, and wheat straw was performed on Ni/α-Al2O3 catalyst. The results showed that the total organic carbon, total nitrogen, and PO43- ion contents in biogas slurry could be reduced by 98.69, 98.01, and 99.32%, respectively. The highest hydrogen yield was obtained in the treatment of biogas slurry from digested cattle manure at 750 °C, in which the hydrogen yield and hydrogen concentration were 13.85 Lhydrogen/LBS and 79.77 vol %, respectively. Changes in the crystalline phase and structure of the catalyst were observed during catalytic reforming of biogas slurry. Active metal oxidization and carbon deposition were likely to be important factors affecting catalytic stability. The mass flow evaluation verified the hydrogen generation potential by the catalytic reforming of biogas slurry, which was close to the methane generation capability of the upstream biogas plant. However, additional effort is required to address the high energy consumption of this method. These findings provide fundamental knowledge about the potential of applying thermochemical techniques to treat and utilize high total organic carbon-containing wastewaters.

Remarkably Enhanced Hydrogen Generation of Organolead Halide Perovskites via Piezocatalysis and Photocatalysis

AbstractTo alleviate photoinduced charge recombination in semiconducting nanomaterials represents an important endeavor toward high‐efficiency photocatalysis. Here a judicious integration of piezoelectric and photocatalytic properties of organolead halide perovskite CH3NH3PbI3 (MAPbI3) to enable a piezophotocatalytic activity under simultaneous ultrasonication and visible light illumination for markedly enhanced photocatalytic hydrogen generation of MAPbI3 is reported. The conduction band minimum of MAPbI3 is higher than hydrogen generation potential (0.046 V vs normal hydrogen electrode), thereby rendering efficient hydrogen evolution. In addition, the noncentrosymmetric crystal structure of MAPbI3 enables its piezoelectric properties. Thus, MAPbI3 readily responds to external mechanical force, creating a built‐in electric field for collective piezophotocatalysis as a result of effective separation of photogenerated charge carriers. The experimental results show that MAPbI3 powders exhibit superior piezophotocatalytic hydrogen generation rate (23.30 µmol h−1) in hydroiodic acid (HI) solution upon concurrent light and mechanical stimulations, much higher than that of piezocatalytic (i.e., 2.21 µmol h−1) and photocatalytic (i.e., 3.42 µmol h−1) hydrogen evolution rate as well as their sum (i.e., 5.63 µmol h−1). The piezophotocatalytic strategy provides a new way to control the recombination of photoinduced charge carriers by cooperatively capitalizing on piezocatalysis and photocatalysis of organolead halide perovskites to yield highly efficient piezophotocatalysis.

Investigation of hydrogen production potential of the LASER inertial confinement fusion fission energy (LIFE) engine

The main purpose of this paper is to research of the time-dependent hydrogen production possibility of the Laser Inertial Confinement Fusion Fission Energy (LIFE) engine using steam methane reforming (SMR), sulfur–iodine (S–I) thermochemical water splitting and high temperature electrolysis (HTE) cycles. The fuel zone of the LIFE engine contains 90 vol% Flibe coolant and 10 vol% TRISO coated minor actinides. Firstly, to examine the time-dependent hydrogen generation potential of this reactor, the time-dependent neutronic performance of the reactor has been performed with using the MCNP neutron transport code. As a result of neutronic calculations, tritium production (TBR), energy multiplication factor (M) and fuel burnup (BU) values have been computed. Secondly, the total power required for SMR, S–I and HTE cycle process have been calculated by using the time dependent energy multiplication factor obtained from the neutronic results. Depending on this total power, the change of hydrogen production with operation time in the LIFE engine has been investigated. As a result of the calculations, it has been found that the LIFE engine has a good both neutronic performance and hydrogen production by SMR, S–I and HTE cycle process.

Highly active electrocatalysts of CeO2 modified NiMoO4 nanosheet arrays towards water and urea oxidation reactions

Efficient anodic electrocatalysts are of great importance for the water and urea electrolysis to lower the overall potential for hydrogen generation. NiMoO4 is recently considered as a promising electrocatalyst towards water and urea oxidation reactions while its catalytic properties are still not comparable to the state-of-the-art catalysts. Herein, decorating CeO2 nanoparticles on NiMoO4 nanosheets is proposed and realized by the facile post-annealing treatment of NiMoO4 with absorbed Ce3+ ions. Due to the strong interaction between CeO2 and NiMoO4, the surface chemical states are modulated with more defects as catalytic sites. By optimizing the ratio of CeO2 to NiMoO4, the obtained catalyst of CeO2 modified NiMoO4 exhibited significantly enhanced activity with lower overpotentials and remarkable durability as compared with NiMoO4 for water and urea oxidation. Therefore, this facile method of post decorating CeO2 nanoparticles promoted the activity of NiMoO4, contributing to the robust anodes for low-cost and stable hydrogen generation.

Zn‐Al hydrotalcite‐derived Co x Zn y AlO z catalysts for hydrogen generation by auto‐thermal reforming of acetic acid

Auto-thermal reforming (ATR) of acetic acid (HAc) is considered as a promising route for hydrogen generation from renewable resources, while oxidation, coking, and sintering need to be addressed for durable catalysts in ATR. In the current work, Zn-Al hydrotalcite-derived CoxZnyAlOz catalysts were prepared by co-precipitation and evaluated in a fixed-bed tubular quartz continuous-flow reactor. The Co0.70Zn3.30AlO5.5 ± δ catalyst presented a HAc conversation near 100% and a stable hydrogen yield near 3.01 mol-H2/mol-HAc. The characterization results of XRD, H2-TPR, BET, SEM, XPS, and TG indicated that the hydrotalcite structure was obtained via co-precipitation method; over the hydrotalcite-derived mixed oxides, (a) the specific surface area was increased with high dispersion of Co, (b) the phases of ZnO with spinel of ZnAl2O4,CoAl2O4, Co3O4, and ZnCo2O4 were beneficial to improve resistance to coking and oxidation, and (c) the relative stability of Co species over ZnO and spinel phases helps to suppress sintering. Meanwhile, ratio of O/C and temperatures near 0.28 and 650 °C, respectively, were also evaluated and proposed as optimized conditions for hydrogen generation, and the durable Co0.70Zn3.30AlO5.5 ± δ catalyst produced a rate of 114.9 mmol-H2/s/g-catalyst in a 15-hour ATR test, showing promising potential for hydrogen generation.

Electricity generation prospective of hydrogen derived from biogas using food waste in south-western Nigeria

Hydrogen gas when produced from renewable energy sources and fed into fuel cells has the potential to produce energy in a sustainable manner. This present work estimates the electricity generation and environmental potentials of hydrogen produced from biogas. The biogas is produced in an anaerobic digester using the food component of the municipal solid waste collected from the selected cities in the South-Western Nigeria. The amount of hydrogen produced is determined using the stoichiometric chemical equations of biogas steam reforming process with water-gas shift reaction. The environmental benefit is estimated by considering ecological analysis of the system. The amount of fossil fuel that could be replaced by using the generated hydrogen gas for electricity production and the associated greenhouse gas emission that could be prevented are also evaluated. The results reveal that Lagos has the highest hydrogen generation potential of about 285 million kg (0.285 million tons) per year followed by Ibadan with 93 million kg (0.093 million tons) per year while the least production occurred in Osogbo. About 411 million kg (0.411 million tons) is produced from the reforming process in all the locations over the timeframe of 20 years (i.e., 2017–2036). This hydrogen production is equivalent to about 1.02% of the global hydrogen production in 2011 put at around 40.5 million tons. The total amount of hydrogen gas produced could generate about 19.46 million kWh of electricity per annum. An encouraging value of ecological efficiency of about 94.33% was achieved using hydrogen as source of energy. The results also show that a total of 7.446 million litres of diesel fuel could be replaced by hydrogen gas in the selected cities which is equivalent to 1.489 Billion Naira. The total amount of carbon dioxide and carbon monoxide emissions that could be avoided is about 16.031 million kg and 45.477 thousand kg. The sensitivity analysis showed that steam reforming efficiency and waste collection rate have positive correlation to hydrogen yield and electricity generation potential.