Search results for: hydrogen inhibition

Authors: M. Nasrullah, Siti Norsita, Lakhveer Singh, A. W. Zulrisam, Mimi Sakinah

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The purposes of this study were to investigate the effects of polyaluminum chloride (PAC) and hydrogen peroxide on COD removal by electrocoagulation. The current density was varied between 30-80 mA cm−2, polyaluminum chloride (1-3 g L-1) as coagulant aid and 1 and 2 percent of hydrogen peroxide as an oxidizing agent. It has been shown that 86.67% of COD was removed by the iron electrode in 180 min while 81.11% of COD was removed by the aluminum electrode in 210 min which indicate that iron was more effective than aluminum. As much as 88.25% COD was removed by using 80 mA cm−2 as compared to 72.86% by using 30 mA cm−2 in 240 min. When PAC and H2O2 increased, the percent of COD removal was increasing as well. The highest removal efficiency of 95.08% was achieved by adding 2% of H2O2 in addition of 3 g L−1 PAC. The general results demonstrate that electrocoagulation is very efficient and able to achieve more than 70% COD removal in 180 min at current density 30-80 mAcm-2 depending on the concentration of H2O2 and coagulant aid.

Keywords: electrocaogulation, palm oil mill effluent, hydrogen peroxide, polialuminum chloride, chemical oxygen demand

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Authors: Badr Eddine Lebrouhi, Melissa Lopez Viveros, Silvia De Los Santos, Kolthoum Missaoui, Pamela Ramirez Vidal

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Since the Paris Climate Agreement, numerous countries, including France, have committed to achieving carbon neutrality by 2050 by enhancing renewable energy capacity and decarbonizing various sectors, including aviation. In this way, the Occitanie region aspires to become a renewable energy pioneer and has focused on Toulouse's Blagnac airport—a prominent hub characterized by high-energy demands. As part of a holistic strategy to reduce the airport's energy dependency, green hydrogen has emerged as a promising alternative fuel, offering the potential to significantly enhance aviation's environmental sustainability. This study assesses the technical and economic aspects of green hydrogen production, particularly its potential to replace fossil kerosene in aviation at Toulouse-Blagnac airport. It analyzes future liquid hydrogen fuel demand, calculates energy requirements for electrolysis and liquefaction, considers diverse renewable energy scenarios, and assesses the Levelized Cost of Hydrogen (LCOH) for economic viability. The research also projects LCOH evolution from 2023 to 2050, offering a comprehensive view of green hydrogen's feasibility as a sustainable aviation fuel, aligning with the region's renewable energy and sustainable aviation objectives.

Keywords: Toulouse-Blagnac Airport, green hydrogen, aviation decarbonization, electrolysis, renewable energy, technical-economic feasibility

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Authors: M. Dekmouche, M. Hadjada, Z. Rahmani, M. Saidi

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The effect of iodide ions on the corrosion inhibition of mild steel in 20% sulfuric acid in the presence of 3-méthylthio-5-p-méthoxyphényl-1,2-dithiolylium against anion (I-) A1 synthesized in our laboratory,was studied by different electrochemical techniques such as electrochemical impedance spectroscopy, potentiodynamic polarization. The obtained results showed that A1 effectively reduces the corrosion rate of steel. The adsorption of 3-méthylthio-5-p-méthoxyphényl-1,2-dithiolylium against anion (I-) followed Langmuir and temkin adsorption isotherm.

Keywords: steel XC52, corrosion, inhibition, 3-méthylthio-5-p-méthoxyphényl-1, 2-dithiolylium against anion (I-) , sulfuric acid

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Authors: Mohsen Azarmjoo, Yasaman Azarmjoo, Zahra Alikhani Koopaei

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The increasing global population and continued growth in energy consumption underscore the need for renewable and sustainable energy sources more than ever. Soil batteries are a method for generating electrical energy by using recycled materials. Recycled materials include galvanized and copper sheets and recycled tires. Additionally, hydrogen, being a clean and efficient fuel, has the potential to replace fossil fuels. Consequently, hydrogen production from water presents a sustainable solution for energy supply. By utilizing aged materials, hydrogen production becomes more cost-effective and environmentally friendly. This article focuses on energy-deprived agricultural lands, explaining how soil batteries and hydrogen can provide the necessary energy for agricultural equipment, such as irrigation, lighting, greenhouse ventilation, and heating. The article explores the benefits of utilizing this method, emphasizing its potential to reduce environmental pollution through the use of recyclable materials. It is worth mentioning that these technologies face challenges, but their progress toward achieving zero-energy consumer standards positions them as promising future technologies for electricity generation. This article provides detailed insights into emerging technologies using a constructed case study involving soil batteries and a hydrogen fuel production device.

Keywords: electricity generation, soil batteries, tires, hydrogen, heat supply, water, aged materials, recycling, agricultural lands

Procedia PDF Downloads 37

Authors: Sony, Ashok N. Bhaskarwar

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Production of hydrogen from a renewable raw material without any co-synthesis of harmful greenhouse gases is the current need for sustainable energy solutions. The sulfur-iodine (SI) thermochemical cycle, using intermediate chemicals, is an efficient process for producing hydrogen at a much lower temperature than that required for the direct splitting of water. No net byproduct forms in the cycle. Hydrogen iodide (HI) decomposition is a crucial reaction in this cycle, as the product, hydrogen, forms only in this step. It is an endothermic, reversible, and equilibrium-limited reaction. The theoretical equilibrium conversion at 550°C is just a meagre of 24%. There is a growing interest, therefore, in enhancing the HI conversion to near-equilibrium values at lower reaction temperatures and by possibly improving the rate. The reaction is relatively slow without a catalyst, and hence catalytic decomposition of HI has gained much significance. Bi-metallic Ni-Co, Ni-Mn, Co-Mn, and tri-metallic Ni-Co-Mn catalysts over zirconia support were tested for HI decomposition reaction. The catalysts were synthesized via a sol-gel process wherein Ni was 3wt% in all the samples, and Co and Mn had equal weight ratios in the Co-Mn catalyst. Powdered X-ray diffraction and Brunauer-Emmett-Teller surface area characterizations indicated the polycrystalline nature and well-developed mesoporous structure of all the samples. The experiments were performed in a vertical laboratory-scale packed bed reactor made of quartz, and HI (55 wt%) was fed along with nitrogen at a WHSV of 12.9 hr⁻¹. Blank experiments at 500°C for HI decomposition suggested conversion of less than 5%. The activities of all the different catalysts were checked at 550°C, and the highest conversion of 23.9% was obtained with the tri-metallic 3Ni-Co-Mn-ZrO₂ catalyst. The decreasing order of the performance of catalysts could be expressed as: 3Ni-Co-Mn-ZrO₂ > 3Ni-2Co-ZrO₂ > 3Ni-2Mn-ZrO₂ > 2.5Co-2.5Mn-ZrO₂. The tri-metallic catalyst remained active till 360 mins at 550°C without any observable drop in its activity/stability. Among the explored catalyst compositions, the tri-metallic catalyst certainly has a better performance for HI conversion when compared to the bi-metallic ones. Owing to their low costs and ease of preparation, these trimetallic catalysts could be used for large-scale hydrogen production.

Keywords: sulfur-iodine cycle, hydrogen production, hydrogen iodide decomposition, bi-, and tri-metallic catalysts

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Authors: Manal A. Mohsen, Ahmed Tawfik

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Hydrogen production from cake wastewater by anaerobic dark fermentation via upflow anaerobic staged reactor (UASR) was investigated in this study. The reactor was continuously operated for four months at constant hydraulic retention time (HRT) of 21.57 hr, PH value of 6 ± 0.6, temperature of 21.1°C, and organic loading rate of 2.43 gCOD/l.d. The hydrogen production was 5.7 l H₂/d and the hydrogen yield was 134.8 ml H₂ /g COD_removed. The system showed an overall removal efficiency of TCOD, TBOD, TSS, TKN, and Carbohydrates of 40 ± 13%, 59 ± 18%, 84 ± 17%, 28 ± 27%, and 85 ± 15% respectively during the long term operation period. Based on the available results, the system is not sufficient for the effective treatment of cake wastewater, and the effluent quality of UASR is not complying for discharge into sewerage network, therefore a post treatment is needed (not covered in this study).

Keywords: cake wastewater industry, chemical oxygen demand (COD), hydrogen production, up-flow anaerobic staged reactor (UASR)

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Authors: Vaclav Heral

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Ideas about the mechanism of heterogeneous catalytic hydrogenation are diverse. The Horiuti-Polanyi mechanism is most often referred to, based on the idea of a semi-hydrogenated state. In our opinion, it does not represent a satisfactory explanation of the hydrogenation mechanism, because, for example: (1) It neglects the fact that the bond of atomic hydrogen to the metal surface is strongly polarized, (2) It does not explain why a surface deprived of atomic hydrogen (by thermal desorption or by alkyne) loses isomerization capabilities, but hydrogenation capabilities remain preserved, (3) It was observed that during the hydrogenation of 1-alkenes, the reaction can be of the 0th order to hydrogen and to the alkene at the same time, which is excluded during the competitive adsorption of both reactants on the catalyst surface. We offer an alternative mechanism that satisfactorily explains many of the ambiguities: It is the idea of an independent course of olefin isomerization, catalyzed by acidic atomic hydrogen bonded on the surface of the catalyst, in addition to the hydrogenation itself, in which a two-layer complex appears on the surface of the catalyst: olefin bound to the surface and molecular hydrogen bound to it in the second layer. The rate-determining step of hydrogenation is the conversion of this complex into the final product. We believe that the Horiuti-Polanyi mechanism is flawed and we naturally think that our two-layer theory better describes the experimental findings.

Keywords: acidity of hydrogenation catalyst, Horiuti-Polanyi, hydrogenation, two-layer hydrogenation

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Authors: S. Nigri, R. Oumeddour, F. Djazi

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The inhibition of the corrosion of copper in 1 M HNO3 solution by oleic acid was investigated by weight loss measurement, potentiodynamic polarization and scanning electron microscope (SEM) studies. The experimental results have showed that this compound revealed a good corrosion inhibition and the inhibition efficiency is increased with the inhibitor concentration to reach 98%. The results obtained revealed that the adsorption of the inhibitor molecule onto metal surface is found to obey Langmuir adsorption isotherm. The temperature effect on the corrosion behavior of copper in 1 M HNO3 without and with inhibitor at different concentration was studied in the temperature range from 303 to 333 K and the kinetic parameters activation such as Ea, ∆Ha and ∆Sa were evaluated. Tafel plot analysis revealed that oleic acid acts as a mixed type inhibitor. SEM analysis substantiated the formation of protective layer over the copper surface.

Keywords: oleic acid, weight loss, electrochemical measurement, SEM analysis

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Authors: Daniel Assefa, Engeda Dessalegn, Chetan Chauhan

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Moringa stenopetala is a socioeconomic valued tree that is widely available and cultivated in the Southern part of Ethiopia. The leaves have been traditionally used as a food source with high nutritional and medicinal values. The present work was carried out to evaluate the effect of thermal treatment on the total phenolic content, antioxidant and alpha-amylase inhibition activities of aqueous leaf extracts during maceration and different decoction time interval (5, 10 and 15 min). The total phenolic content was determined by the Folin-ciocalteu methods whereas antioxidant activities were determined by 2,2-diphenyl-1-picryl-hydrazyl(DPPH) radical scavenging, reducing power and ferrous ion chelating assays and alpha-amylase inhibition activity was determined using 3,5-dinitrosalicylic acid method. Total phenolic content ranged from 34.35 to 39.47 mgGAE/g. Decoction for 10 min extract showed ferrous ion chelating (92.52), DPPH radical scavenging (91.52%), alpha-amylase inhibition (69.06%) and ferric reducing power (0.765), respectively. DPPH, reducing power and alpha-amylase inhibition activities showed positive linear correlation (R2=0.853, R2= 0.857 and R2=0.930), respectively with total phenolic content but ferrous ion chelating activity was found to be weakly correlated (R2=0.481). Based on the present investigation, it could be concluded that major loss of total phenolic content, antioxidant and alpha-amylase inhibition activities of the crude leaf extracts of Moringa stenopetala leaves were observed at decoction time for 15 min. Therefore, to maintain the total phenolic content, antioxidant, and alpha-amylase inhibition activities of leaves, cooking practice should be at the optimum decoction time (5-10 min).

Keywords: alpha-amylase inhibition, antioxidant, Moringa stenopetala, total phenolic content

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Authors: Ahmed Farghali, Heba Amar, Mohamed Khedr

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NiAl-Layered Double Hydroxide (NiAl-LDH), one of anionic functional layered materials, has been prepared by a simple co-precipitation process. X-ray diffraction patterns confirm the formation of the desired compounds of NiAl hydroxide single phase and the crystallite size was found to be about 4.6 nm. The morphology of the prepared samples was investigated using scanning electron microscopy and the layered structure was appeared under the transmission electron microscope. The thermal stability and the function groups of NiAl-LDH were investigated using thermal gravimetric analysis (TGA) and Fourier transform infrared (FTIR) respectively. NiAl-LDH was investigated as a photo-catalyst for the degradation of some toxic dyes such as toluidine blue and bromopyrogallol red. It shows good catalytic efficiency in visible light and even in dark. For the first time NiAl-LDH was used for hydrogen storage application. NiAl-LDH samples were exposed to 20 bar applied hydrogen pressure at room temperature, 100 and -193 oC. NiAl-LDH samples appear to have feasible hydrogen storage capacity. It was capable to adsorb 0.1wt% at room temperature, 0.15 wt% at 100oC and storage capacity reached 0.3 wt% at -193 oC.

Keywords: NiAl-LDH, preparation, characterization, photo-catalysis, hydrogen storage

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Authors: Mandana Amiri, Sima Nouhi, Yashar Azizan-Kalandaragh

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Silver nanostructures have been successfully fabricated by using electrodeposition method onto indium-tin-oxide (ITO) substrate. Scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and ultraviolet-visible spectroscopy (UV-Vis) techniques were employed for characterization of silver nanostructures. The results show nanostructures with different morphology and electrochemical properties can be obtained by various the deposition potentials and times. Electrochemical behavior of the nanostructures has been studied by using cyclic voltammetry. Silver nanostructures exhibits good electrocatalytic activity towards the reduction of H₂O₂. The presented electrode can be employed as sensing element for hydrogen peroxide.

Keywords: electrochemical sensor, electrodeposition, hydrogen peroxide, silver nanostructures

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Authors: Maryam Hamlehdar, Guillermo A. Narsilio

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To enhance the feasibility of utilising geothermal hot sedimentary aquifers (HSAs) for clean hydrogen production, one approach is the implementation of solar-integrated geothermal energy systems. This detailed modelling study conducts a thermo-economic assessment of an advanced Organic Rankine Cycle (ORC)-based hydrogen production system that uses low-temperature geothermal reservoirs, with a specific focus on hot sedimentary aquifers (HSAs) over a 30-year period. In the proposed hybrid system, solar-thermal energy is used to raise the water temperature extracted from the geothermal production well. This temperature increase leads to a higher steam output, powering the turbine and subsequently enhancing the electricity output for running the electrolyser. Thermodynamic modeling of a parabolic trough solar (PTS) collector is developed and integrated with modeling for a geothermal-based configuration. This configuration includes a closed regenerator cycle (CRC), proton exchange membrane (PEM) electrolyser, and thermoelectric generator (TEG). Following this, the study investigates the impact of solar energy use on the temperature enhancement of the geothermal reservoir. It assesses the resulting consequences on the lifecycle performance of the hydrogen production system in comparison with a standalone geothermal system. The results indicate that, with the appropriate solar collector area, a combined solar-geothermal hydrogen production system outperforms a standalone geothermal system in both cost and rate of production. These findings underscore a solar-assisted geothermal hybrid system holds the potential to generate lower-cost hydrogen with enhanced efficiency, thereby boosting the appeal of numerous low to medium-temperature geothermal sources for hydrogen production.

Keywords: clean hydrogen production, integrated solar-geothermal, low-temperature geothermal energy, numerical modelling

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Authors: Amir Zeb, Shailima Rampogu, Minky Son, Ayoung Baek, Sang H. Yoon, Keun W. Lee

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Neurotoxic insults activate calpain, which in turn produces truncated p25 from p35. p25 forms hyperactivated Cdk5/p25 complex, and thereby induces severe neuropathological aberrations including hyperphosphorylated tau, neuroinflammation, apoptosis, and neuronal death. Inhibition of Cdk5/p25 complex alleviates aberrant phosphorylation of tau to mitigate AD pathology. PHA-793887 and Roscovitine have been investigated as selective inhibitors of Cdk5/p25 with IC50 values 5nM and 160nM, respectively, but their mechanistic studies remain unknown. Herein, computational simulations have explored the binding mode and interaction mechanism of PHA-793887 and Roscovitine with Cdk5/p25. Docking results suggested that PHA-793887 and Rsocovitine have occupied the ATP-binding site of Cdk5 and obtained highest docking (GOLD) score of 66.54 and 84.03, respectively. Furthermore, molecular dynamics (MD) simulation demonstrated that PHA-793887 and Roscovitine established stable RMSD of 1.09 Å and 1.48 Å with Cdk5/p25, respectively. Profiling of polar interactions suggested that each inhibitor formed hydrogen bonds (H-bond) with catalytic residues of Cdk5 and could remain stable throughout the molecular dynamics simulation. Additionally, binding free energy calculation by molecular mechanics/Poisson–Boltzmann surface area (MM/PBSA) suggested that PHA-793887 and Roscovitine had lowest binding free energies of -150.05 kJ/mol and -113.14 kJ/mol, respectively with Cdk5/p25. Free energy decomposition demonstrated that polar energy by H-bond between the Glu81 of Cdk5 and PHA-793887 is the essential factor to make PHA-793887 highly selective towards Cdk5/p25. Overall, this study provided substantial evidences to explore mechanistic interactions of the selective inhibitors of Cdk5/p25 and could be used as fundamental considerations in the development of structure-based selective inhibitors of Cdk5/p25.

Keywords: Cdk5/p25 inhibition, molecular modeling of Cdk5/p25, PHA-793887 and roscovitine, selective inhibition of Cdk5/p25

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Authors: Gregory Chown, Benjamin Infantolino, Christopher Wise, Rachel Holmes, Samantha O'Donnell, Katelyn Pfeiffer, Victoria Ward

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Background: There is a lack of understanding of how Kinesio Tape® physiologically works. Furthermore, few studies compare Kinesio Tape® to other forms of taping. The research question is: Does Kinesio Tape® cause a difference in muscle facilitation, inhibition, and pain, between Kinesio Tape® and no tape for collegiate athletes with self-reported shoulder pain? Method: This quantitative non-randomized design used a convenience sampling method. There were eleven participants with self-reported shoulder pain who were athletes on the men’s and women’s lacrosse and tennis teams. Participants attended one 30-45 minute session for data collection. Each participant received all three taping conditions and performed four repetitions of 120 degrees of active shoulder flexion for the three separate trials (no tape, Kinesio Tape® inhibition, and Kinesio Tape® facilitation). Surface electromyography (sEMG) electrodes were placed on the anterior deltoid, supraspinatus, and lower trapezius to measure muscle facilitation and inhibition. Each participant completed the visual analogue scale (VAS) before and after each trial to measure pain. Results: No statistical significance was found for pain scores on the VAS between the taping methods of facilitation, inhibition, and no tape (p = .118). No statistical significance was found for the percentage of change in muscle function for each taping method; Anterior deltoid (p = .993), supraspinatus (p = .997) and lower trapezius (p = .922). Conclusion: Based on the results, Kinesio Tape® appears to not have an effect on muscle function or pain when utilizing the facilitation or inhibition taping method when compared to no tape.

Keywords: Kinesio tape, muscle facilitation, muscle inhibition, pain

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Authors: Jerry John T. M., Sylas V. P., Shijo Joy

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Hydrogen is the most essential gas that can be used for many purposes. During the production of hydrogen using raw materials like Soil and leftover cooked rice water (kanjivellam), the major by-product formed is water. Soil is collected from three different places in kottayam district: Kallara, Meenachilar, and Athirampuzha. Collected samples are mixed with rice water and tested for traces of hydrogen using a biohydrogen sensor after 72 hours. The result was the presence of hydrogen in all the 3 samples. After streaking, PCR and gel electrophoresis detected the bacteria which produced the hydrogen. RGCB Thiruvananthapuram conducted the sequencing of the PCR resultant. And identified the bacterial strains. Five variants of Bacillus bacteria ( (1) Bacillus cereus strain JTM GenBank: OP278839.1 (2) Bacillus toyonensis strain JTM2 GenBank: OP278841.1 (3) Bacillus anthracis strain JTM_SR2989-3-R_H08 GenBank: OP278960.1 (4) Bacillus thuringiensis strain JRY1 GenBank: OP278976.1 (5) Bacillus anthracis strain JTM_SR2989-3-F_H07 GenBank: OP278959.1 ) are identified and successfully registered in NCBI Gen bank. These Bacillus bacteria are major types of Rhizobacteria that can form spores and can survive in the soil for a long time period under harsh environmental conditions. Also, plant growth is enhanced by PGPR (Plant growth promoting rhizobacteria) through the induction of systemic resistance, antibiosis, and competitive omission. The molecular sequencing was submitted to the NCBI Gen Bank, and the accession numbers were allotted for the bacterial cultures.

Keywords: bio hydrogen production, bacterial bio hydrogen production, plant related to bacillus bacteria., bacillus bacteria study

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Authors: Horng-Wen Wu, Yi Chao, Rong-Fang Horng

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This study is to develop a methanol steam reformer with a heat recovery zone, which recovers heat from exhaust gas of a diesel engine, and to investigate waste heat recovery ratio at the required reaction temperature. The operation conditions of the reformer are reaction temperature (200 °C, 250 °C, and 300 °C), steam to carbonate (S/C) ratio (0.9, 1.1, and 1.3), and N2 volume flow rate (40 cm3/min, 70 cm3/min, and 100 cm3/min). Finally, the hydrogen concentration, the CO, CO2, and N2 concentrations are measured and recorded to calculate methanol conversion efficiency, hydrogen flow rate, and assisting combustion gas and impeding combustion gas ratio. The heat source of this reformer comes from electric heater and waste heat of exhaust gas from diesel engines. The objective is to recover waste heat from the engine and to make more uniform temperature distribution within the reformer. It is beneficial for the reformer to enhance the methanol conversion efficiency and hydrogen-rich gas production. Experimental results show that the highest hydrogen flow rate exists at N2 of the volume rate 40 cm3/min and reforming reaction temperature of 300 °C and the value is 19.6 l/min. With the electric heater and heat recovery from exhaust gas, the maximum heat recovery ratio is 13.18 % occurring at water-methanol (S/C) ratio of 1.3 and the reforming reaction temperature of 300 °C.

Keywords: heat recovery, hydrogen-rich production, methanol steam reformer, methanol conversion efficiency

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Authors: Rashmi Gupta

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It is unclear whether arousal or valence modulates the response inhibition process. It has been suggested that irrelevant positive emotional information (e.g., happy faces) and negative emotional information (e.g., angry faces) interact with attention differently. In the present study, we used arousal-matched irrelevant happy and angry faces. These faces were used as stop-signals in the stop-signal paradigm. There were two kinds of trials: go-trials and stop-trials. Participants were required to discriminate between the letter X or O by pressing the corresponding keys on go-trials. However, a stop signal was occasionally presented on stop trials, where participants were required to withhold their motor response. A significant main effect of emotion on response inhibition was observed. It indicated that the valence of a stop signal modulates inhibitory control. We found that stop-signal reaction time was faster in response to irrelevant angry faces than happy faces, indicating that irrelevant angry faces facilitate the response inhibition process compared to happy faces. These results shed light on the interaction of emotion with cognitive control functions.

Keywords: attention, emotion, response inhibition, inhibitory control

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Authors: Andrea Leon, J. M. Florez, P. Vargas

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The effect of hydrogen adsorption on the magnetic properties of fcc Ni has been calculated using the linear-muffin-tin-orbital formalism and using the local-density approximation for the exchange y correlation. The calculations for the ground state show that the sequential addition of hydrogen atoms is found to monotonically reduce the total magnetic moment of the Ni fcc structure, as a result of changes in the exchange-splitting parameter and in the Fermi energy. In order to physically explain the effect of magnetization reduction as the Hydrogen concentration increases, we propose a Stoner impurity model to describe the influence of H impurity on the magnetic properties of Nickel.

Keywords: electronic structure, magnetic properties, Nickel hydride, stoner model

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Authors: C. Fúnez Guerra, B. Nieto Calderón, M. Jaén Caparrós, L. Reyes-Bozo, A. Godoy-Faúndez, E. Vyhmeister

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The global energy system is experiencing a change of scenery. Unstable energy markets, an increasing focus on climate change and its sustainable development is forcing businesses to pursue new solutions in order to ensure future economic growth. This has led to the interest in using hydrogen as an energy carrier in transportation and industrial applications. As an energy carrier, hydrogen is accessible and holds a high gravimetric energy density. Abundant in hydrocarbons, hydrogen can play an important role in the shift towards low-emission fossil value chains. By combining hydrogen production by natural gas reforming with carbon capture and storage, the overall CO2 emissions are significantly reduced. In addition, the flexibility of hydrogen as an energy storage makes it applicable as a stabilizer in the renewable energy mix. The recent development in hydrogen fuel cells is also raising the expectations for a hydrogen powered transportation sector. Hydrogen value chains exist to a large extent in the industry today. The global hydrogen consumption was approximately 50 million tonnes (7.2 EJ) in 2013, where refineries, ammonia, methanol production and metal processing were main consumers. Natural gas reforming produced 48% of this hydrogen, but without carbon capture and storage (CCS). The total emissions from the production reached 500 million tonnes of CO2, hence alternative production methods with lower emissions will be necessary in future value chains. Hydrogen from electrolysis is used for a wide range of industrial chemical reactions for many years. Possibly, the earliest use was for the production of ammonia-based fertilisers by Norsk Hydro, with a test reactor set up in Notodden, Norway, in 1927. This application also claims one of the world’s largest electrolyser installations, at Sable Chemicals in Zimbabwe. Its array of 28 electrolysers consumes 80 MW per hour, producing around 21,000 Nm3/h of hydrogen. These electrolysers can compete if cheap sources of electricity are available and natural gas for steam reforming is relatively expensive. Because electrolysis of water produces oxygen as a by-product, a system of Autothermal Reforming (ATR) utilizing this oxygen has been analyzed. Replacing the air separation unit with electrolysers produces the required amount of oxygen to the ATR as well as additional hydrogen. The aim of this paper is to evaluate the technical and economic potential of large-scale production of hydrogen for oil refining industry. Sensitivity analysis of parameters such as investment costs, plant operating hours, electricity price and sale price of hydrogen and oxygen are performed.

Keywords: autothermal reforming, electrolyser, hydrogen, natural gas, steam methane reforming

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Authors: Seok Hong Min, Tae Kwon Ha

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With increasing demands for high performance materials, intensive interest on the Ti has been focused. Especially, low cost production process of Ti has been extremely necessitated from wide parts and various industries. Tetrachloride (TiCl₄) is produced by fluidized bed using high TiO₂ feedstock and used as an intermediate product for the production of metal titanium sponge. Reduction of TiCl₄ is usually conducted by Kroll process using magnesium as a reduction reagent, producing metallic Ti in the shape of sponge. The process is batch type and takes very long time including post processes treating sponge. As an alternative reduction reagent, hydrogen in the state of plasma has long been strongly recommended. Experimental confirmation has not been completely reported yet and more strict analysis is required. In the present study, hydrogen plasma reduction process has been thermodynamically analyzed focusing the effects of temperature, pressure and concentration. All thermodynamic calculations were performed using the FactSage® thermodynamical software.

Keywords: TiCl₄, titanium, hydrogen, plasma, reduction, thermodynamic calculation

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Authors: M. E. Abalaka, O. A. Falusi, M. Galadima, D. Damisa

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The antimicrobial activity of aqueous, ethanolic and methanolic extracts of Chromolaena odorata (Siam weed) was evaluated against four wound isolates: Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae at the concentrations of 200mg/ml, 100mg/ml, 50mg/ml and 25mg/ml respectively. S. aureus and E. coli showed high susceptibility to the various extracts than the other test isolates. The aqueous extract showed activity against Staphylococcus aureus with a mean diameter of zone of inhibition of 16 ± 3.00 at concentration of 200mg/ml and as low as 8 ± 0.00 at concentration of 25mg/ml; E. coli showed susceptibility with a mean diameter of zone of inhibition of 18 ± 2.00 and 10 ± 0.00 at a concentration of 200mg/ml and 25mg/ml respectively. Pseudomonas aeruginosa and Klebsiella pneumoniae were resistant to the aqueous extract. Methanol extract showed activity against Staphylococcus aureus with a mean diameter of zone of inhibition at 28 ± 4.00 and 12 ± 2.30 at a concentration of 200mg/ml and 25mg/ml respectively; while E. coli was susceptible with mean diameter of zone of inhibition of 18 ± 2.00 and as low as 12 ± 0.00 at a concentration of 200mg/ml and 50mg/ml respectively, Pseudomonas aeruginosa showed considerable susceptibility with mean diameter of zone of inhibition of 13 ± 1.00 and 12 ± 0.00 at a concentration of 200mg/ml and 100mg/ml respectively. The ethanol extract showed activity against S. aureus with a mean diameter zone of inhibition of 15 ± 2.00 and 9 ± 0.00 at a concentration of 200mg/ml and 25mg/ml respectively: E. coli showed susceptibility with a mean diameter zone of inhibition of 20 ± 4.00 and 13 ± 2.00 at a concentration of 200mg/ml and 25mg/ml respectively. Pseudomonas aeruginosa showed considerable susceptibility with a mean diameter zone of inhibition of 13 ± 1.00 and 9 ± 0.00 at a concentration of 200mg/ml and 100mg/ml respectively. The results above indicate the efficacy and potency of the crude extracts of Chromolaena odorata leaf on the tested wound isolates.

Keywords: antibacterial, Chromolaena odorata, leaf extracts, test isolates

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Authors: Rafayel Azizyan, Valeri Arakelyan, Aram Gevorgyan, Varduhi Balayan, Emil Gevorgyan

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Currently, mathematical and computer modeling are widely used in different biological studies to predict or assess behavior of such complex systems as biological ones. This study deals with mathematical and computer modeling of bi-substrate enzymatic reactions, which play an important role in different biochemical pathways. The main objective of this study is to represent the results from in silico investigation of bi-substrate enzymatic reactions in the presence of uncompetitive inhibitors, as well as to describe in details the inhibition effects. Four models of uncompetitive inhibition were designed using different software packages. Particularly, uncompetitive inhibitor to the first [ES1] and the second ([ES1S2]; [FS2]) enzyme-substrate complexes have been studied. The simulation, using the same kinetic parameters for all models allowed investigating the behavior of reactions as well as determined some interesting aspects concerning influence of different cases of uncompetitive inhibition. Besides that shown, that uncompetitive inhibitors exhibit specific selectivity depending on mechanism of bi-substrate enzymatic reaction.

Keywords: mathematical modeling, bi-substrate enzymatic reactions, reversible inhibition

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Authors: H. Shiu, M.S. Lu, Y.P. Tsai

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This study explored the impacts of CuO, TiO2, SiO2 nanoparticles on biological phosphorus removal. Experimental results showed that the phosphorus removal ability of phosphorus accumulating organism (PAO) was initially inhibited when CuO nanoparticle concentration was 5 mgl-1. The inhibition of phosphorus removal for 1000 mgl-1 of TiO2 with sunlight was higher than without sunlight case. The inhibition of phosphorus removal began at 500 mgl-1 SiO2 nanoparticle concentration. Inhibition became apparent when SiO2 nanoparticle concentration was up to 1000 mgl-1.

Keywords: nano copper oxide, nano titanium dioxide, nano silica, enhanced biological phosphate removal

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Authors: Altoumi Alndalusi

Abstract:

High-temperature hydrogen attack (HTHA) failure is the common phenomena at elevated temperature in hydrogen environment in oil and gas field. The failure occurred once after four years at the internal surface of Platforming elbow. Both visual and microscopic examinations revealed that the failure was initiated due to blistering forming followed by large cracking at the inner surface. Crack morphology showed that the crack depth was about 50% of material wall thickness and its behavior generally was intergranular. This study concluded that the main reason led to failure due to incorrect material selection comparing to the platforming conditions.

Keywords: decarburization, failure, heat affected zone, morphology, partial pressure, plate form

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Authors: Melby Chacko, Jagannath Nayak

Abstract:

6061 Al-SiCp composite was solutionized at 350 °C for 30 minutes and water quenched. It was then underaged at 140 °C (T6 treatment). The aging behaviour of the composite was studied using Rockwell B hardness measurement. Corrosion behaviour of the underaged sample was studied in different concentrations of acetic acid and at different temperatures. Benzimidazole at different concentrations was used for the inhibition studies. Inhibition efficiency of benzimidazole was calculated for different experimental conditions. Thermodynamic parameters were found out which suggested benzimidazole is an efficient inhibitor and it adsorbed onto the surface of composite by mixed adsorption where chemisorption is predominant.

Keywords: 6061 Al-SiCp composite, T6 treatment, corrosion inhibition, chemisorption

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Authors: Same Noel Ngando, Yakub Abdulfatai Olatunji

Abstract:

Renewable energy micro-grids, such as those powered by solar or wind energy, are often intermittent in nature. This means that the amount of energy generated by these systems can vary depending on weather conditions or other factors, which can make it difficult to ensure a steady supply of power. To address this issue, energy storage systems have been developed to increase the reliability of renewable energy micro-grids. Battery systems have been the dominant energy storage technology for renewable energy micro-grids. Batteries can store large amounts of energy in a relatively small and compact package, making them easy to install and maintain in a micro-grid setting. Additionally, batteries can be quickly charged and discharged, allowing them to respond quickly to changes in energy demand. However, the process involved in recycling batteries is quite costly and difficult. An alternative energy storage system that is gaining popularity is hydrogen storage. Hydrogen is a versatile energy carrier that can be produced from renewable energy sources such as solar or wind. It can be stored in large quantities at low cost, making it suitable for long-distance mass storage. Unlike batteries, hydrogen does not degrade over time, so it can be stored for extended periods without the need for frequent maintenance or replacement, allowing it to be used as a backup power source when the micro-grid is not generating enough energy to meet demand. When hydrogen is needed, it can be converted back into electricity through a fuel cell. Energy consumption data is got from a particular residential area in Daegu, South Korea, and the data is processed and analyzed. From the analysis, the total energy demand is calculated, and different hybrid energy system configurations are designed using HOMER Pro (Hybrid Optimization for Multiple Energy Resources) and MATLAB software. A techno-economic and environmental comparison and life cycle assessment (LCA) of the different configurations using battery and hydrogen as storage systems are carried out. The various scenarios included PV-hydrogen-grid system, PV-hydrogen-grid-wind, PV-hydrogen-grid-biomass, PV-hydrogen-wind, PV-hydrogen-biomass, biomass-hydrogen, wind-hydrogen, PV-battery-grid-wind, PV- battery -grid-biomass, PV- battery -wind, PV- battery -biomass, and biomass- battery. From the analysis, the least cost system for the location was the PV-hydrogen-grid system, with a net present cost of about USD 9,529,161. Even though all scenarios were environmentally friendly, taking into account the recycling cost and pollution involved in battery systems, all systems with hydrogen as a storage system produced better results. In conclusion, hydrogen is becoming a very prominent energy storage solution for renewable energy micro-grids. It is easier to store compared with electric power, so it is suitable for long-distance mass storage. Hydrogen storage systems have several advantages over battery systems, including flexibility, long-term stability, and low environmental impact. The cost of hydrogen storage is still relatively high, but it is expected to decrease as more hydrogen production, and storage infrastructure is built. With the growing focus on renewable energy and the need to reduce greenhouse gas emissions, hydrogen is expected to play an increasingly important role in the energy storage landscape.

Keywords: renewable energy systems, microgrid, hydrogen production, energy storage systems

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Authors: C. Trapp, A. Vijay, M. Khorasani

Abstract:

Decentralised micro-grids with sector coupling can combat the spatial and temporal intermittence of renewable energy by combining power, transportation and infrastructure sectors. Intelligent energy conversion concepts such as electrolysers, hydrogen engines and fuel cells combined with energy storage using intelligent batteries and hydrogen storage form the back-bone of such a system. This paper describes a micro-grid based on Photo-Voltaic cells, battery storage, innovative modular and scalable Anion Exchange Membrane (AEM) electrolyzer with an efficiency of up to 73%, high-pressure hydrogen storage as well as cutting-edge combustion-engine based Combined Heat and Power (CHP) plant with more than 85% efficiency at the university campus to address the challenges of decarbonization whilst eliminating the necessity for expensive high-voltage infrastructure.

Keywords: sector coupling, micro-grids, energy self-sufficiency, decarbonization, AEM electrolysis, hydrogen CHP

Procedia PDF Downloads 157

Authors: Yousaf Ayub

Abstract:

A co-gasification process, which involves the utilization of both biomass and plastic waste, has been developed to enable the production of blue and green hydrogen. To support this endeavor, an Aspen Plus simulation model has been meticulously created, and sustainability analysis is being conducted, focusing on economic viability, energy efficiency, advanced exergy considerations, and exergoeconomics evaluations. In terms of economic analysis, the process has demonstrated strong economic sustainability, as evidenced by an internal rate of return (IRR) of 8% at a process efficiency level of 70%. At present, the process has the potential to generate approximately 1100 kWh of electric power, with any excess electricity, beyond meeting the process requirements, capable of being harnessed for green hydrogen production via an alkaline electrolysis cell (AEC). This surplus electricity translates to a potential daily hydrogen production of around 200 kg. The exergy analysis of the model highlights that the gasifier component exhibits the lowest exergy efficiency, resulting in the highest energy losses, amounting to approximately 40%. Additionally, advanced exergy analysis findings pinpoint the gasifier as the primary source of exergy destruction, totaling around 9000 kW, with associated exergoeconomics costs amounting to 6500 $/h. Consequently, improving the gasifier's performance is a critical focal point for enhancing the overall sustainability of the process, encompassing energy, exergy, and economic considerations.

Keywords: blue hydrogen, green hydrogen, co-gasification, waste valorization, exergy analysis

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Authors: M. Belhachemi, M. Monteiro de Castro, M. Casco, A. Sepúlveda-Escribano, F. Rodríguez-Reinoso

Abstract:

In this study, activated carbons were prepared from Algerian date pits using thermal activation with CO2 or steam. The prepared activated carbons were doped by vanadium oxide in order to increase the H2 adsorption capacity. The adsorbents were characterized by N2 and CO2 adsorption at 77 K and 273K, respectively. The hydrogen adsorption experiments were carried at 298K in the 0–100 bar pressure range using a volumetric equipment. The results show that the H2 adsorption capacity is influenced by the size and volume of micropores in the activated carbon adsorbent. Furthermore, vanadium doping of activated carbons has a slight positive effect on H2 storage.

Keywords: hydrogen storage, activated carbon, vanadium doping, adsorption

Procedia PDF Downloads 537

Authors: Hai Chi, Ibrahim Mehmeti, Kirill Ovchinnikov, Hegle Holo, Ingolf F. Nes, Dzung B. Diep

Abstract:

By using a panel of multiple indicator strains of different bacterial species and genera, we screened a large collection of bacterial isolates (over 1800 isolates) derived from raw milk, for bacteriocin producers with broad inhibition spectra (BIS). Fourteen isolates with BIS were identified, and by 16S rDNA sequencing they were found to belong to Lactococcus garvieae (10 isolates) and Enterococcus feacalis (4 isolates). Further analysis of the ten L. garvieae isolates revealed that they were very similar, if not identical, to each other in metabolic and genetic terms: they had the same fermentation profile on different types of sugars, repetitive sequence-based PCR (rep-PCR) DNA pattern as well as they all had the same inhibition profile towards over 50 isolates of different species. The bacteriocin activity from one of the L. garvieae isolates was assessed further. The bacteriocin which was termed garvicin KS, was found to be heatstable and proteinase-labile and its inhibition spectrum contained many distantly related genera of Firmicutes, comprising most lactic acid bacteria (LAB) as well as problematic species of Bacillus, Listeria, Streptococcus and Staphylococcus and their antibiotic resistant derivatives (e.g. VRE, MRSA). Taken together, the results indicate that this is a potent bacteriocin from L. garvieae and that its very broad inhibition spectrum can be a very useful property for use in food preservation as well as in infection treatments caused by gram-positive pathogens and their antibiotic-derivatives.

Keywords: bacteriocin, lactic acid bacteria, Lactococcus garvieae, antibiotics resistance

Procedia PDF Downloads 214