Production Rate Research Articles

Pyrolysis characteristics and hydrogen production mechanism of biomass impregnated with transition metals

The application of metal impregnation pretreatment to improve the quality of biomass pyrolysis gas production is considered as a promising upgrading technology. Transition metals have been well developed for the unique structural characteristics. After impregnation pretreatment, the product distribution of biomass pyrolysis was changed, and the transfer path of H atoms and the formation mechanism of H2 can be revealed through analysis. The effects of impregnation pretreatment with three different transition metals (iron, cobalt, and nickel) on the pyrolysis characteristics of corn straw were evaluated in this work. Three transition metal solutions with concentrations of 0.5 M, 1 M, and 2 M were used to explore the influence of impregnation concentration on the yield and composition of the pyrolysis products. The results showed that iron promoted the formation of liquid products, whose proportion increased by 37.29% upon increasing the impregnation solution concentration. The addition of cobalt and nickel led to more pyrolysis gas generation. When the impregnation solution concentration was greater than 0.5 M, the gas production rate exceeded 45 wt%. Nickel simultaneously promoted the generation of H2 and CH4 in pyrolysis gas, whose yields were increased by 63% and 20% respectively compared with raw materials. Py-GC/MS analysis showed that Co-CS had strong decarboxylation characteristics during pyrolysis. Metal impregnation decreased the content of aromatic compounds in tar, which increased the stretching vibrations of C-H bonds in char. Ring-opening rearrangements of polycyclic aromatic hydrocarbons were promoted, which formed more -H. Nickel catalyzed the removal of CH3 and H groups and the rearrangement of C-O in volatile products, which formed more H2 and CH4. These findings provide an avenue to optimize the metal impregnation conditions to produce hydrogen via biomass pyrolysis.

Machine learning with analysis-of-variance-based method for identifying rice varieties

Rice, which has the highest production and consumption rates worldwide, is one of the main nutrients in our country because it is economical and nutritious. Rice undergoes various stages of production from the field to the dinner tables, with the cleaning phase involving separation of rice from unwanted materials. There are different varieties of rice such as arborio, basmati, aracadaga, ipsala, and jasmine. Therefore, it is necessary to identify rice varieties based on customer demands. Rice variety identification is primarily based on its outer appearance, including color, size, and shape. In this study, 75,000 rice grain images, including 15,000 images for each variety, were considered. Using a combination of 12 morphological features, four shape features, and 90 color features obtained from five different color spaces, 106 features were extracted from the images. An analysis of variance (ANOVA) was employed to select high-rank features, which were then fed to a support vector machine (SVM) for classification. The experimental results demonstrated that the utilization of 40 high-rank features yielded impressive outcomes, with a validation accuracy of 99.89 %, cost value of 16, test accuracy of 99.81 %, and cost value of 28. These high accuracy rates are particularly noteworthy, as they indicate the robustness and reliability of the proposed methodology in distinguishing between different rice varieties with minimal error. This high level of precision is critical for practical applications, such as quality control in rice production, to ensure that customers receive the specific rice variety they demand. Implementing this methodology in real-world scenarios could significantly enhance the efficiency and accuracy of the rice variety identification processes, benefiting both producers and consumers.

The Valorization of Fruit and Vegetable Wastes Using an Anaerobic Fixed Biofilm Reactor: A Case of Discarded Tomatoes from a Traditional Market

Tomato waste, characterized by high organic matter and moisture content, offers a promising substrate for anaerobic digestion, though rapid acidification can inhibit methanogenic activity. This study investigated the performance of a 10.25 L anaerobic fixed biofilm reactor for biogas production using liquid tomato waste, processed through grinding and filtration, at high organic loading rates, without external pH control or co-digestion. Four scouring pads were vertically installed as a fixed bed within a fiberglass structure. Reactor performance and buffering capacity were assessed over three stages with progressively increasing organic loading rates (3.2, 4.35, and 6.26 gCOD/L·d). Methane yields of 0.419 LCH4/gCOD and 0.563 LCH4/g VS were achieved during the kinetic study following stabilization. Biogas production rates reached 1586 mL/h, 1804 mL/h, and 4117 mL/h across the three stages, with methane contents of 69%, 65%, and 72.3%, respectively. Partial alkalinity fluctuated, starting above 1500 mg CaCO3/L in Stage 1, dropping below 500 mg CaCO3/L in Stage 2, and surpassing 3000 mg CaCO3/L in Stage 3. Despite periods of forced acidification, the system demonstrated significant resilience and high buffering capacity, maintaining stability through hydraulic retention time adjustments without the need for external pH regulation. The key stability indicators identified include partial alkalinity, effluent chemical oxygen demand, pH, and one-day cumulative biogas. This study highlights the effectiveness of anaerobic fixed biofilm reactors in treating tomato waste and similar fruit and vegetable residues for sustainable biogas production.

Prediction of hydrogen production in proton exchange membrane water electrolysis via neural networks

Advancements in water electrolysis technologies are crucial for green hydrogen production. Proton exchange membrane water electrolysis (PEMWE) is characterized by its efficiency and environmental benefits. The prediction and optimization of hydrogen production rates (HPRs) in PEMWE systems is difficult and still challenging because of the complexity of the system as well as the operational parameters. The integration of artificial intelligence (AI) and machine learning (ML) appears to be effective in optimization within the energy sector. Hence, this work employs the artificial neural network (ANN) to develop a model that accurately predicts HPR in PEMWE setups. A novel approach is introduced by employing the Levenberg–Marquardt backpropagation (LMBP) algorithm for training the ANN. This model is designed to predict HPR based on critical operational parameters, including anode and cathode areas (mm2), cell voltage (V) and current (A), water flow rate (mL/min), power (W), and temperature (K). The optimized ANN configuration features an architecture with 7 input nodes, two hidden layers of 64 neurons each, and a single output node. The performance of the ANN model was evaluated against conventional regression models using key metrics: mean squared error (MSE), coefficient of determination (R2), and mean absolute error (MAE). The findings of this study reveal that the developed ANN model significantly outperforms traditional models, achieving an R2 value of 0.9989 and an MAE of 0.012. In comparison, random forest (R2 = 0.9795), linear regression (R2 = 0.9697), and support vector machines (R2 = − 0.4812) show lower predictive accuracy, underscoring the ANN model's superior performance. This work demonstrates the efficiency of the LMBP in enhancing hydrogen production forecasts and sets a foundation for future improvements in PEMWE efficiency. By enabling precise control and optimization of operational parameters, this study contributes to the broader goal of advancing green hydrogen production as a viable and scalable alternative to fossil fuels, offering both immediate and long-term benefits to sustainable energy initiatives.

Numerical simulation of thermal performance of H2O-EGS and CO2-EGS based on thermal-hydraulic-mechanical coupling method

The use of hydrothermal geothermal methods in Enhanced Geothermal Systems (EGS) presents challenges like reduced thermal storage life and high external energy consumption. Due to its stable heat production time and lower external energy demand, CO2 has the potential to be substituted for H2O. The research zone for this study was chosen to be located in the HDR reservoir in the Gonghe Basin of Qinghai. A three-dimensional discrete fracture model based on a thermal-hydraulic-mechanical coupling method is established, where numerical simulations are conducted using COMSOL software. The discussion focuses on the comparison of heat production effects between H2O-EGS and CO2-EGS in different injection and extraction scenarios are discussed. The results indicate that by lowering the injection temperature and increasing the injection rate, the EGS net heat production rate can be increased, but it also accelerates the heat breakthrough time and shortens the reservoir life. Although CO2-EGS has a lower heat extraction rate in the early stage of thermal recovery than H2O-EGS, it has a longer stable heat production time and a more energy-efficient heat production process. Therefore, compared to H2O-EGS, CO2-EGS has more economic and social benefits.

Phenotypic and genotypic determination of resistance to common disinfectants among strains of Acinetobacter baumannii producing and non-producing biofilm isolated from Iran

BackgroundNosocomial infections are a global problem in hospitals all around the world. It is considered a major health problem, especially in developing countries. The increase in the patient’s stay in hospitals has increased the mortality rate, and consequently, the costs drastically increase. The main purpose of using disinfectants in the hospital environment is to reduce the risk of nosocomial infections. Ethylene diamine tetra acetic acid (EDTA) causes lysis and increases susceptibility to antimicrobial agents in the planktonic form of bacteria. This substance affects the permeability of the outer membrane of bacteria. It also prevents the formation of biofilms by bacteria.Materials and methodsIn the current study, 120 isolates of Acinetobacter baumannii (A. baumannii) were confirmed by phenotypic and genotypic methods. Antibiogram was performed and then the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of isolates against 5% sodium hypochlorite, ethanol %70, sayasept-HP 2%, chlorhexidine 2%, dettol 4/8% were evaluated. In addition, the disinfectant effect was re-evaluated with the mixture of EDTA solution. All isolates were examined for biofilm presence by crystal violet staining method in triplicates and repeated three times for each strain. Also for all isolates detection of efflux pump genes (Qac-E, qacE-Δ1, SUG-E) by PCR technique was done.ResultsAntibiogram results of A. baumannii showed that 6.7% were Multi-drug-resistant (MDR), and 89.2% were Extensively drug-resistant (XDR) isolates. The highest effect of disinfectants was related to 5% sodium hypochlorite, and the least effect was 70% ethanol. EDTA increases the efficacy of selected disinfectants significantly. The highest prevalence of the efflux pump genes was related to SUG-E (95%) and Qac-E (91.7%), and, the qacE-Δ1 gene with 12.5%. The biofilm production rate was 91.3% among all isolates.ConclusionThe best and safest way to disinfect hospital floors and surfaces is to choose the right disinfectants, and learn how to use them properly. In this study, a mixture of disinfectants and EDTA had a significant effect on bactericidal activity. it was found that improper use of disinfectants, especially the use of sub-inhibitory dilutions, increases the resistance of bacteria to disinfectants.

Local pH Gradients Alter Product Selectivity of Electrocatalytic Oxygen Reduction Reaction on La‐Cr‐Co Perovskites

AbstractThe electrochemical production of hydrogen peroxide through the oxygen reduction reaction (ORR) presents the interesting situation where the fully reduced form, H2O, is significantly favored by thermodynamics. Perovskite oxide based catalysts with slow kinetics, or large overpotentials, have been shown to enable production of H2O2 with good selectivity, but this comes at the expense of energy efficiency and production rates. We analyze the structure and electrocatalytic ORR capabilities of a perovskite oxide series based on LaCr1‐xCoxO3. We find that the crystal lattice distorts in two ways as Co content increases – anisotropic compression of the lattice is accompanied by a pinching of angles within the structure, which gives way to compression of B−O bonds at higher Co contents. Product selectivity is observed to change as a function of both catalyst composition and rotation rates of rotating ring‐disk electrode. The rotation‐dependent behavior is attributed to accelerated displacement of surface‐bound peroxide intermediates by a pH gradient at the catalyst surface, and composition‐dependent changes in selectivity are found to correlate to the angular distortion of the crystal lattice. These results highlight the importance of local environments in electrocatalyst reactions and demonstrate that structure and local pH can be used to manipulate product selectivity.

Muscle protein catabolism and splanchnic arginine consumption drive arginine dysregulation during Pseudomonas Aeruginosa induced early acute sepsis in swine.

Human sepsis is characterized by increased protein breakdown and changes in arginine and citrulline metabolism. However, it is unclear whether this is caused by changes in transorgan metabolism. We therefore studied in a Pseudomonas aeruginosa induced pig sepsis model the changes in protein and arginine related metabolism on whole body (Wb) and transorgan level. We studied 22 conscious pigs for 18 hours during sepsis, induced by infusing live bacteria (Pseudomonas aeruginosa) or after placebo infusion (control). We used stable isotope tracers to measure Wb and skeletal muscle protein synthesis and breakdown, as well as Wb, splanchnic, skeletal muscle, hepatic and portal drained viscera (PDV) arginine and citrulline disposal and production rates. During sepsis, arginine Wb production (p=0.0146), skeletal muscle release (p=0.0035) and liver arginine uptake were elevated (p=0.0031). Wb de novo arginine synthesis, citrulline production, and transorgan PDV release of citrulline, glutamine and arginine did not differ between sepsis and controls. However, Wb (p<0.0001) and muscle (p<0.001) protein breakdown were increased, suggesting that the enhanced arginine production is predominantly derived from muscle breakdown in sepsis. In conclusion, live-bacterium sepsis increases muscle arginine release and liver uptake, mirroring previous pig endotoxemia studies. In contrast to observations in humans, acute live-bacterium sepsis in pigs does not change citrulline production or arterial arginine concentration. We therefore conclude that the arginine dysregulation observed in human sepsis is possibly initiated by enhanced protein catabolism and splanchnic arginine catabolism, while decreased arterial arginine concentration and citrulline metabolism may require more time to fully manifest in patients.

SOME FEATURES OF CONSTRUCTING DISPLACEMENT CHARACTERISTICS AND WATERING DYNAMICS

The term «displacement characteristic» (DCh) was first proposed by D. A. Efros in 1959 to indicate the dependence of the accumulated oil withdrawal on the accumulated liquid withdrawal. Subsequently, DChfound wide application in the analysis of oil field development. Many authors proposed various modifications of the DCh coordinates, but directactual measurements of development parameters were always used - annual, accumulated measurements of oil, liquid, water production, water cut, liquid, oil, and water flow rates. Characteristics of oil displacement are called graphical dependences of accumulated oil production on accumulated or current values of liquid or water production, constructed based on actual data. With the help of cold water, three tasks were solved: assessment of recoverable oil reserves, calculation of the technological effect of geological and technical measures, and calculation of technological development indicators. But the main condition for application was the immutability of the development system.Recently, dependences that use parameters such as selection from geological or recoverable oil reserves have come to be classified as chemical dependencies. These dependencies have nothing to do with DCh. Justification of geological and recoverable oil reserves is an independent task; moreover, with the help of chemical recovery, recoverable reserves are found under the existing development system. Against the background of such a confusion of concepts, the definition of the concept of «standard» chemicals is introduced, which has no real meaning for an oil development facility.The dynamics of water cut refers to the change in water cut over time, for example, depending on the time of development of reserves, geological or recoverable. The dynamics of watering in this case has nothing to do with the cold water.The dry period is of great importance when developing an oil field. With the same finaloil recovery, the longer the water-free period, the better the economic indicators.Using the Buckley-Leverett function todetermine water cut is only possible when the flow is two-phase, oil and water. It is impossible to determine the anhydrous period using the Buckley-Leverett function, since it does not exist, therefore, constructing the dynamics of water supply only based on this function is incorrect.When conducting laboratory experiments on core material, in which the heterogeneity compared to the formation is minimal and can be identified with a one-dimensional flow, the anhydrous period is significant and reaches from 0.74 to 0.94 units. of the total volume of displaced oil.For a single-layer field, where there is only one homogeneous layer, the heterogeneity is greater than for the core, but less than for a heterogeneous development object. We can talk about an analogue of a two-dimensional flow with some degree of convention.Considering that these are not laboratory studies, where measurements are carried out more accurately, but production ones, the low-water-cut period (up to 10 %) is 0.4 of the total oil production from wells with simultaneous commissioning of wells. If the wells were commissioned at different periods of time, as is always the case in fields, then the dynamics of water supply are completely different, and water supply begins earlier than when all wells are commissioned simultaneously.

Forward J/ψ+J/ψ and J/ψ+ψ′ production with high-energy factorization

We calculate the cross sections of associated J/ψ+ψ′ and J/ψ+J/ψ production in pp collisions at s=13 TeV in the forward kinematic region. The high-energy factorization (kT-factorization) framework supplemented with the Catani-Ciafaloni-Fiorani-Marchesini evolution of gluon densities in a proton is applied. We demonstrate that the latest data on J/ψ+J/ψ production and first experimental data on J/ψ+ψ′ events taken very recently by the LHCb Collaboration can be described well by the color singlet terms and contributions from double parton scattering (DPS) with the standard choice for σeff parameter. The relative production rate σ(J/ψ+ψ′)/σ(J/ψ+J/ψ) is found to be sensitive to the DPS terms as well as to feeddown contributions. Published by the American Physical Society 2024

Hydrogen production with a novel coaxial cylindrical electrolyser: A CFD study

This study introduces a unique coaxial cylindrical electrode design for Alkaline Water Electrolysers (AWEs) that is analyzed to show possible enhancements over the traditional stacked plate design. It investigates the performance of the proposed coaxial AWE for enhanced hydrogen production. Through comprehensive computational simulations, key performance indicators, such as current density and hydrogen volume fraction, are analyzed across various operating parameters. The results of this study indicate that the production rate of hydrogen achieves its highest level at a volume percentage of 3.4 %. This rate is significantly influenced by the concentration of the electrolyte, the distance between the cathode and anode rings, and, to a lesser degree, the porosity of the separator. Consequently, the optimized conditions demonstrate a promising increase in current densities, reaching 1000 mA/cm2 at an operating voltage of 2 V, showcasing the potential for developing more efficient and cost-effective AWE systems. This study further contributes valuable insights into the design and operational improvements needed for the advancement of large-scale hydrogen production technologies.

Electronic interaction and band alignment between Cu sub-nanometric clusters and ZnIn2S4 nanosheets towards selective photoreduction of CO2 to CO

Engineering the electronic properties of heterogeneous photocatalysts with charge transfer regulated is an effective strategy to boost their CO2 reduction activity. Here, we drew inspiration from the strong metal-support interaction effect, and fabricated ZnIn2S4 supported-Cu sub-nanometric clusters photocatalyst. Within this catalyst, the formed CuS bond would redistribute interfacial charge, resulting in diverse chemical states of Cu atoms and the establishment of Ohmic contact between ZIS and Cu. The built-in electric field of such Ohmic contact benefited the migration of photoexcited electrons from ZIS to Cu. Further mechanistic studies unveiled the crucial role of positively charged Cu atom near the interface in facilitating H2O dissociation, and its adjacent Cu atom at the top-surface adopting a distinct chemical state could activate linear CO2 molecule into a bent configuration. These features substantially lowered energy barriers for CO2 adsorption and subsequent *COOH formation, and Cu-ZIS, accordingly, exhibited a remarkable CO production rate of 60.2 μmol g-1h−1, approximately 20.8-fold enhancement compared to ZIS counterpart.

Quasineutral multistability in an epidemiological-like model for defective-helper betacoronavirus infection in cell cultures

It is well known that, during replication, RNA viruses spontaneously generate defective viral genomes (DVGs). DVGs are unable to complete an infectious cycle autonomously and depend on coinfection with a wild-type helper virus (HV) for their replication and/or transmission. The study of the dynamics arising from a HV and its DVGs has been a longstanding question in virology. It has been shown that DVGs can modulate HV replication and, depending on the strength of interference, result in HV extinctions or self-sustained persistent fluctuations. Extensive experimental work has provided mechanistic explanations for DVG generation and compelling evidences of HV-DVGs virus coevolution. Some of these observations have been captured by mathematical models. Here, we develop and investigate an epidemiological-like mathematical model specifically designed to study the dynamics of betacoronavirus in cell culture experiments. The dynamics of the model is governed by several degenerate normally hyperbolic invariant manifolds given by quasineutral planes - i.e., filled by equilibrium points. Three different quasineutral planes have been identified depending on parameters and involving: (i) persistence of HV and DVGs; (ii) persistence of non-infected cells and DVG-infected cells; and (iii) persistence of DVG-infected cells and DVGs. Key parameters involved in these scenarios are the maximum burst size (B), the fraction of DVGs produced during HV replication (β), and the replication advantage of DVGs (δ). More precisely, in the case 0<B<1+β the system displays tristability, where all three scenarios are present. In the case 1+β<B<1+β+δ this tristability persists but attracting scenario (ii) is reduced to a well-defined half-plane. For B>1+β+δ, the scenario (i) becomes globally attractor. Scenarios (ii) and (iii) are compatible with the so-called self-curing since the HV is removed from the population. Sensitivity analyses indicate that model dynamics largely depend on DVGs production rate (β) and their replicative advantage (δ), and on both the infection rates and virus-induced cell deaths. Finally, the model has been fitted to single-passage experimental data using an artificial intelligence methodology based on genetic algorithms and key virological parameters have been estimated.

In-situ construction of N-doped Zn0.6Cd0.4S/oxygen vacancy-rich WO3 Z-scheme heterojunction compound for boosting photocatalytic hydrogen production

Photocatalytic water splitting technology for H2 production represents a promising and sustainable approach to clean energy generation. In this study, a high concentration of oxygen vacancies was introduced into tungsten trioxide (WO3) to create a vacancy-rich layer. This modified WO3 (WO3-x) was then combined with N-doped Zn0.6Cd0.4S through a hydrothermal synthesis, resulting in the formation of a Z-scheme heterojunction composite aimed at enhancing photocatalytic performance. Under visible light, the H2 production activity of the composite reached an impressive 8.52 mmol·g−1 without adding co-catalyst Pt. This corresponds to enhancements of 7.82 and 4.39 times the production yield of pure ZCS and ZCSN, respectively. However, the hydrogen production increased to 21.98 mmol·g−1 when Pt was added as a co-catalyst. Furthermore, an array of characterizations were employed to elucidate the presence of oxygen vacancies and the establishment of the Z-scheme heterojunction. This structural enhancement significantly facilitates the utilization of photo-generated electrons while effectively preventing photo-corrosion of ZCSN, thus improving material stability. Our study provides a new scheme for the incorporation of oxygen-rich vacancy and the construction of Z-scheme heterojunction, demonstrating a synergistic effect that greatly advances photocatalytic performance.

Synthesis of MgAl-LDH from three alkali sources for boosting flame retardancy of EP with APP

Epoxy resin (EP) is used in construction materials due to its low curing shrinkage, excellent chemical stability, and mechanical properties. However, its flammability limits applications in the field of construction. Co-precipitation method with sodium hydroxide as the alkali source and hydrothermal method with urea as the alkali source are the common ways to prepare MgAl-LDH. In this study, MgAl-LDH1 (abbreviated as LDH1) was prepared by using NaOH as the alkali source at 65 ℃ for 12 h, MgAl-LDH2 (abbreviated as LDH2) by using urea as the alkali source at 120 ℃ for 12 h, and MgAl-LDH3 (abbreviated as LDH3) was prepared by using triethanolamine as the alkali source at 100 ℃ for 2 h. Then, LDH1, LDH2, LDH3 were compounded with ammonium polyphosphate (APP) to synergistically enhance the flame retardant properties of EP (Composite material abbreviated as LDH1-APP-EP, LDH2-APP-EP, LDH3-APP-EP). The results showed that the best flame retardant effect was achieved after compounding APP (5 wt%) with LDH3 (5 wt%) prepared with triethanolamine as the alkali source. Compared with Pure-EP, the peak exothermic rate and peak smoke production rate of LDH3-APP-EP prepared with triethanolamine as the alkali source decreased by 74.54 % and 67.44 %, respectively. Compared with LDH prepared with NaOH and urea as the alkali source, LDH prepared with triethanolamine as the alkali source has a larger layer spacing and a higher weight loss percentage which releases more gases, moisture, and carbon layers formed by triethanolamine during the combustion process to reduce the heat release from the fire. It’s evident that LDH3-APP-EP prepared with triethanolamine as the alkali source has higher residual carbon densities and the lowest residual carbon values based on SEM and Raman test results. This result proves that the LDH3 with triethanolamine as the alkali source has a good effect on EP flame retardation in this paper which provided a new way to design new efficient flame retardants.

Synthesis and quantitative structure–activity relationship of unsaturated fatty acid amide propyl dimethyl tertiary amines and their application in clean fracturing fluid thickener in low temperature environment

Solve the problem of freezing and blocking of clean fracturing fluid thickener during winter fracturing operations in the north, which is conducive to improving the efficiency of fracturing operations and oil and gas production rate. In this paper, four kinds of fatty acid amidopropyl dimethyl tertiary amine were successfully prepared and characterized with FT-IR and 1H NMR. Their acid values and Krafft temperature are discussed. The molecular structures of the four kinds of fatty acid amidopropyl dimethyl tertiary amine salts were optimized using Gaussian09 software, then their single point energies were calculated. A quantitative structure–property relationship (QSPR) model was established to predict Krafft temperature of the four kinds of fatty acid amidopropyl dimethyl tertiary amine salts. N-(3-(Dimethylamino)propyl)oleamide (PKO-O), (9Z,12Z)-N-(3-(dimethylamino)propyl)octadeca-9,12-dienamide (PKO-LO) were selected as the main agent. The optimal thickener formulation O1-8 and O2-1 were optimized by single factor experiment and orthogonal test respectively. O2-1 thickener has high low-temperature stability at −5 °C. The viscosity increase property, gel breaking property, rheological property, and viscoelasticity of the clean fracturing fluid obtained by cross-linking O1-8 with O2-1 thickener were evaluated and the properties of O1-8 thickener are better. The result shows that the O1-8 thickener basically meets the conditions of the winter fracturing construction site, and has more practical application significance.

Comparison of Anaerobic Co-Digestion of Food Waste and Livestock Manure at Various Mixing Ratios under Mesophilic and Thermophilic Temperatures

In this study, the optimum mixing ratio of food waste (FW) and livestock manure (LM) was investigated to improve the methane yield efficiency and prohibit the inhibition factors (organic loading rate and NH4+) from inhibiting the anaerobic co-digestion of FW and LM under mesophilic and thermophilic conditions. The research involved the following: (I) the analysis of the characteristics of FW and LM, (II) the evaluation of the potential and toxicity of the anaerobic digestion of I have confirmed that there is no problem. FW and LM using the biochemical methane potential (BMP) and anaerobic toxicity assay (ATA) tests, (III) the evaluation of the anaerobic co-digestion of FW and LM using the BMP test, and (IV) the evaluation of the optimum mixing ratio using mathematical modeling. The characteristics of FW and LM were analyzed to evaluate the theoretical methane potential and inhibition factor. The BMP test was carried out to evaluate the concentration of the biodegradable organic matter, biogas production rate, and methane yield. The ATA test was carried out to evaluate the impact of the inhibition concentration. Ultimately, mathematical models, such as a first-order reaction and a modified Gompertz model, were implemented to evaluate the optimum mixing ratio for the anaerobic co-digestion of FW and LM. FW had a higher concentration of degradable organic matter than LM. The initial operational parameters of the anaerobic digestion were determined to be appropriate at an organic matter concentration of less than 2.5 g/L and a TN concentration of 2,000 mg/L. In conclusion, as a result of evaluation through mathematical models, it was determined that anaerobic microorganisms were more sensitive to inhibitory factors under the thermophilic condition than under the mesophilic condition, and the optimum mixing ratio of FW to LM was 5:1 (vol:vol) based on kinetic results (k: 0.080; Bu: 0.23 L CH4/g VSadded; P: 100.84 mL; Rm: 10.23 mL/day; λ: 1.44 days).

Highly Dispersed Pd‐CeOx Nanoparticles in Zeolite Nanosheets for Efficient CO2‐Mediated Hydrogen Storage and Release

AbstractFormic acid (FA) dehydrogenation and CO2 hydrogenation to FA/formate represent promising methodologies for the efficient and clean storage and release of hydrogen, forming a CO2‐neutral energy cycle. Here, we report the synthesis of highly dispersed and stable bimetallic Pd‐based nanoparticles, immobilized on self‐pillared silicalite‐1 (SP‐S‐1) zeolite nanosheets using an incipient wetness co‐impregnation technique. Owing to the highly accessible active sites, effective mass transfer, exceptional hydrophilicity, and the synergistic effect of the bimetallic species, the optimized PdCe0.2/SP‐S‐1 catalyst demonstrated unparalleled catalytic performance in both FA dehydrogenation and CO2 hydrogenation to formate. Remarkably, it achieved a hydrogen generation rate of 5974 molH2 molPd−1 h−1 and a formate production rate of 536 molformate molPd−1 h−1 at 50 °C, surpassing most previously reported heterogeneous catalysts under similar conditions. Density functional theory calculations reveal that the interfacial effect between Pd and cerium oxide clusters substantially reduces the activation barriers for both reactions, thereby increasing the catalytic performance. Our research not only showcases a compelling application of zeolite nanosheet‐supported bimetallic nanocatalysts in CO2‐mediated hydrogen storage and release but also contributes valuable insights towards the development of safe, efficient, and sustainable hydrogen technologies.

The Mechanism of Sodium Sulfate Coupled with Anaerobic Methane Oxidation Mitigating Methane Production in Beef Cattle

The aim of this experiment is to explore the effect of sodium sulfate (Na2SO4) on methane reduction in the rumen, and its impact on anaerobic methane-oxidizing archaea (ANME). Using mixed rumen fluid from four Angus cattle fistulas, this study conducted an in vitro fermentation. Adding Na2SO4 to the fermentation substrate resulted in sulfur concentrations in the substrate of 0.4%, 0.6%, 0.8%, 1.0%, 1.2%, 1.4%, 1.6%, 1.8%, 2.0%, 2.2%, and 2.4%. The gas production rate and methane yield were measured using an in vitro gas production method. Subsequently, the fermentation fluid was collected to determine the fermentation parameters. The presence of ANME in the fermentation broth, as well as the relationship between the number of bacteria, archaea, sulfate reducing bacteria (SRB), ANME, and the amount of Na2SO4 added to the substrate, were measured using qPCR. The results showed that: (1) the addition of Na2SO4 could significantly reduce CH4 production and was negatively correlated with CO2 production; (2) ANME-1 and ANME-2c did exist in the fermentation broth; (3) the total number of archaea, SRB, ANME-1, and ANME-2c increased with the elevation of Na2SO4. The above results indicated that Na2SO4 could mitigate methane production via sulfate-dependent anaerobic methane oxidation (S-DAMO) in the rumen. In the future management of beef cattle, including sodium sulfate in their diet can stimulate S-DAMO activity, thereby promoting a reduction in methane emissions.

Development of ruthenium-based catalysts for ammonia synthesis via polyol reduction method

In this work, ruthenium-based catalysts were synthesized via polyol reduction method with different metal oxides as support and caesium as promoter. The samples were characterized through XRD, ICP-OES, nitrogen physisorption and XPS. Then, the catalysts were tested for ammonia synthesis in the range of temperatures 548–673 K and pressures 1–5 MPa. The synthesized catalysts allowed an ammonia production rate approximately four times higher compared with the performances of similar catalytic formulations in literature (tested at same conditions). The best performance were achieved with the Cs–Ru/CeO2 (1%wt Cs, 5%wt Ru), reaching an ammonia production of nearly 73 mmol h−1∙gcat−1 at 673 K and 5 MPa. As showed by the XPS analysis, the increased Ce3+/Ce4+ ratio led to an enhancement of oxygen vacancies, which favoured the dissociative adsorption of nitrogen, that is the limiting step in the ammonia synthesis reaction. Such high catalytic activity can be ascribed to the beneficial effect of the polyol reduction method for the maximization of the exposure of active sites.