Process Sites Research Articles

Multidimensional Insights into Organics Stress on Anammox systems: From a "Molecule-Cell-Ecology" Perspective.

Anaerobic ammonium oxidation (anammox) is efficient and cost-effective for treating high-strength ammonia wastewater, but the organics in wastewater will affect its stability. To address this challenge, it is crucial to gain a deep understanding of the inhibitory effects and mechanisms of organics stress on anammox bacteria. The review provided a comprehensive classification of organics and evaluated their specific effects on the anammox system according to their respective characteristics. Based on the micro to macro perspective, the "molecule-cell-ecology" inhibitory mechanism of organics on anammox bacteria was proposed. The molecular observation systematically summarized the binding process and action sites of organics with anammox bacteria. At the cellular observation, the mechanisms of organics effects on extracellular polymeric substances, membranes, and anammoxosome of anammox bacteria were also expounded. At the ecological observation, the dynamic changes in coexisting populations and their role in organics transformation were further discussed. Further revelations on response mechanisms and inhibition mitigation strategies were proposed to broaden the applicability of anammox systems for organic wastewater. This review offered a multidimensional understanding of the organics inhibitory mechanism of anammox bacteria and provided a theoretical foundation for anammox systems.

Heteropolyacids combined with Y zeolite as superior solid acid catalysts to accelerate lactic acid esterification

AbstractBACKGROUNDEthyl lactate produced via esterification between lactic acid and ethanol can be used in plastics, polymers and food industries and renowned for its biodegradability and low toxicity. However, lactic acid self‐catalyzed esterification presents a slow reaction process, and acid catalysts are needed to improve the catalysis. Homogeneous acid catalysts like H2SO4 are corrosive, as well as being difficult to be seperated from the reaction media; therefore, advanced heterogeneous catalysts are more ideal. In this study, two kinds of heteropolyacid–zeolite catalysts, involving loading silicotungstic acid and phosphotungstic acid onto Y zeolite, were synthesized, characterized using X‐ray diffraction, NH3 temperature‐programmed desorption and scanning electron microscopy and analyzed for their catalytic efficiency in the catalytic esterfication.RESULTSResults showed that the Keggin structures of heteropolyacids were retained during the preparation process and strong acid sites of Y zeolite were enriched, which made the main contribution to the esterification of lactic acid and ethanol. Furthermore, the initial‐stage reaction rate of esterification was significantly enhanced. During the first hour of esterification, the conversion of lactic acid increased from 18% to 65%. Exp Dec1 index model was employed to determine the activation energies of 60HSiW‐Y and 60HPW‐Y, which exhibit values of 29.3 and 28.2 kJ mol−1, respectively.CONCLUSIONThis study indicates that Keggin structures of heteropolyacids play a key role in the esterification and heteropolyacid–zeolite catalysts can effectively catalyze the esterification. Meanwhile, the results of the kinetic experiments can be of reference significance for large‐scale industrial processes involving esterification. © 2024 Society of Chemical Industry (SCI).

Activation of Peroxymonosulfate by Co-Ni-Mo Sulfides/CNT for Organic Pollutant Degradation.

To explore advanced oxidation catalysts, peroxymonosulfate (PMS) activation by Co-Ni-Mo/carbon nanotube (CNT) composite catalysts was investigated. A compound of NiCo2S4, MoS2, and CNTs was successfully prepared using a simple one-pot hydrothermal method. The results revealed that the activation of PMS by Co-Ni-Mo/CNT yielded an exceptional Rhodamine B decolorization efficiency of 99% within 20 min for the Rhodamine B solution. The degradation rate of Co-Ni-Mo/CNT was 4.5 times higher than that of Ni-Mo/CNT or Co-Mo/CNT, and 1.9 times as much than that of Co-Ni/CNT. Additionally, radical quenching experiments revealed that the principal active groups were 1O2, surface-bound SO4•-, and •OH radicals. Furthermore, the catalyst exhibited low metal ion leaching and favorable stability. Mechanism studies revealed that Mo4+ on the surface of MoS2 participated in the oxidation of PMS and the transformation of Co3+/Co2+ and Ni3+/Ni2+. The synergism between MoS2 and NiCo2S4 reduces the charge transfer resistance between the catalyst and solution interface, thus accelerating the reaction rate. Interconnected structures composed of metal sulfides and CNTs can also enhance the electron transfer process and afford sufficient active reaction sites. Our work provides a further understanding of the design of multi-metal sulfides for wastewater treatment.

Fabrication of Biomedical Electrodes Using Printing Approaches

AbstractIn this review, we focus on the fabrication of electrodes, using printing techniques. Generally speaking, electrodes are comprised of a metal conductor with a metal lead (sometimes the same material) for the conduction of electrical current. Different inorganic and organic materials including metal, polymers, carbon, as well as their composites thereof, have been used for electrodes on different substrates. While material-dependent characteristics, including conductivity, optical transparency, corrosion resistance and biocompatibility, determine the choice of material, printing, as the manufacturing method, offers precise control over the geometry and scale of electrodes for selective and sensitive performance. Both 2D- and 3D-printed electrodes have been widely used as sensors for electrochemical applications as well as quantification of biological compounds, establishing contact with biological surfaces and systems, finding application in medical diagnosis, therapy and treatment of various conditions. Costa et al. (Energy Storage Mater 28:216–234, 2020), Mensing et al. (Sustain Mater Technol 25:e00190, 2020) depict the difference between the 2D and 3D printing techniques which can be used for fabrication of 2D and 3D electrodes. The 3D structure of the electrode provides advantages over the 2d electrodes in terms of its catalytic properties through enhancement in its mass transfer process, adsorption efficiency and active exposure sites (Mensing et al. in Sustain Mater Technol 25:e00190, 2020).

Comparative Analysis of Ultrasonic and Traditional Gas-Leak Detection Systems in the Process Industries: A Monte Carlo Approach

Gas leaks can cause disasters at process sites, including fires and explosions, and thus, effective gas-leak detection systems are required. This study investigated the limitations of conventional detectors and introduced an innovative ultrasonic sensor-based approach for continuous monitoring. A new configuration for a stationary remote ultrasonic gas-leak monitoring system is proposed. The selected material was 1-Butene. The detection probability was assessed through a simulation based on a gas-leak scenario, detailing the selection criteria for leak sites and simulation conditions. Computational fluid-dynamics (CFD) simulations were used to evaluate the detection capability of the existing system, whereas Monte Carlo simulations were used to compare it with the proposed ultrasonic system. The CFD simulation was performed by setting the lower detection limit of the concentration-measurement-type gas detector to 600 ppm, and the leak-detection time was approximately 8.895 s. A Monte Carlo simulation accounting for wind direction showed that the existing system’s average detection probability was 3.41%. By integrating the existing and new systems, the detection probability increased by 96.58% and 3.92% compared with that using only the concentration-measurement and ultrasonic measurement methods, respectively. These rates provide valuable insights for future applications in oil refining and petrochemical industries.

In situ growth of Ni/Ni3S2–MoO2 nanocrystals on carbon cloth for the enhanced electrocatalytic oxidation of methanol

The rational design and construction of high-performance Ni-based methanol oxidation catalyst is the key technology for direct methanol fuel cell (DMFC). In this work, Ni/Ni3S2–MoO2@CC composite is constructed by in-situ growth of Ni/Ni3S2–MoO2 nanoparticles on carbon cloth (CC) by a two-step method, which has excellent activity and stability for methanol oxidation reaction (MOR), that is, the current density (j) can reach 240.08 mA cm−2 at the potential of 1.67 V. The potentials at different j are 10 mA cm−2@1.37 V and 100 mA cm−2@1.50 V, respectively. Meanwhile, the retention rate of j is 90.36 % after 12 h CA stability test. Based on density functional theory (DFT) calculation, the excellent properties of Ni/Ni3S2–MoO2@CC composite are mainly attributed to its higher conductivity and higher carrier density accelerate the charge transfer in the MOR process, its Ni and Mo sites facilitate the adsorption of methanol as a reactant and desorption of carbon dioxide as a product, thus promoting the kinetics of MOR. In addition, the reaction mechanism of MOR on the Ni/Ni3S2–MoO2@CC is more likely to follow the formation path of CO* intermediates. This work provides a feasible route for the synthesis of high performance electrocatalysts for the MOR.

The γ-process nucleosynthesis in core-collapse super-novae

Neutron-capture processes made most of the abundances of heavy elements in the Solar System, however they cannot produce a number of rare proton-rich stable isotopes (p–nuclei) lying on the left side of the valley of stability. The γ–process, i.e., a chain of photodisintegrations starting on heavy nuclei, is recognized and generally accepted as a feasible process for the synthesis of p–nuclei in core collapse supernovae (CCSNe). However this scenario still leaves some puzzling discrepancies between theory and observations. We aim to explore in more detail the γ–process production from massive stars, using different sets of CCSNe models and the latest nuclear reaction rates. Here we show our preliminary analysis, by identifying the γ–process sites and focusing on progenitors of CCSNe that experience a C–O shell merger just before the collapse of the Fe core.

C2H2 selective hydrogenation over the single-atom Pt1/Cu catalysts: Unraveling the role of Pt active site type and its coordination environment in regulating catalytic performance

To unravel the role of active site type and its coordination environment in regulating catalytic performance, C2H2 selective hydrogenation over a series of single-atom Pt1/Cu catalysts was fully investigated using DFT calculations and microkinetic modeling. Four types of Pt active site, including the defect, step, corner, and terrace sites with the generalized coordination number (GCN) from 2.5 to 7.5, are examined. Our results indicate that Pt1/Cu catalysts with four types of active sites favor gas phase C2H4 formation in C2H2 hydrogenation process. C2H4 activity has an inverted volcanic-type curve relationship with d-band center and GCN of Pt active site. For the polymerization process, the corner and terrace sites with larger GCN values could prevent green oil. The screened PtGCN3.0 catalyst with corner site exhibits better C2H4 selectivity and activity and prevents green oil. Hence, tuning the type and GCN value of Pt active site well regulate C2H4 activity and selectivity, as well as catalyst stability, which provide useful structure information to rationally design Pt-based catalysts in C2H2 selective hydrogenation.

Study on activation mechanism and cleavage sites of recombinant butelase-1 zymogen derived from Clitoria ternatea

Asparagine endopeptidases (AEPs) were synthesized as a zymogen and were known to undergo pH-dependent autoproteolytic activation using their endopeptidase activity. Butelase-1, one of the few AEPs with ligation activity, can also be synthesized as a zymogen and activated at acidic pH in vitro, but the detailed activation process and potential activation sites of its zymogen are not fully understood. In this study, recombinant butelase-1 exhibited high ligation activity and ineffective endopeptidase activity, and its activities were strictly pH-dependent. The endopeptidase activity caused the activation of butelase-1 zymogen at acidic pH, which was autocatalytic, required sequential removal of C- and N-terminal pro-peptides, and was a bimolecular reaction. The pro-peptides were critical to the stability of butelase-1. Once the pro-peptides left the active domain, butelase-1 was quickly inactivated at pH 7.0. Based on the LC-MS/MS sequencing of activation products, Asp319 and Asn322 were identified as potential C-terminal pro-region hydrolysis sites of the butelase-1 zymogen, which was validated by site-directed mutagenesis. Our results provided a reasonable explanation for the self-activation of butelase-1 zymogen in vitro and provided supplementary information for the activation of AEP ligase zymogen.

Pseudocapacitive Co‐Free Trimetallic Ni‐Zn‐Mn Perovskite Fluorides Enable Fast‐Rechargeable Zn‐Based Aqueous Batteries

AbstractThe Zn‐ion batteries (ZIBs) have been largely confined by the sluggish diffusion kinetics of the cathode, and to develop the Co‐free electrode materials for Zn‐based aqueous batteries (ZABs) is of great importance for practical applications. Herein, a novel fast‐rechargeable ZAB constructed using a new type of pseudocapacitive Co‐free trimetallic Ni‐Zn‐Mn perovskite fluorides (ABF3, KNZMF) cathode is demonstrated. A deep study on the charge storage mechanisms of the KNZMF electrode materials has been conducted by various ex situ techniques, showing a typical conversion mechanism in the alkaline media along with the redox‐active or inert property for Ni/Mn or Zn species and the largely bulk phase transitions of ABF3 perovskite nanocrystals into amorphous metal oxides/(oxy)hydroxides nanosheets. Interestingly, the Co‐free KNZMF and Zn//KNZMF ZAB exhibit superior performance to the Co‐rich trimetallic Ni‐Co‐Mn ABF3 (KNCMF) and Zn//KNCMF ZAB, which is largely owing to the superior redox potential, OH− adsorption, deprotonation process, and surface electroactive sites of redox‐active Ni/Mn species confirmed by ex situ characterizations and density functional theory. The findings shed lights on developing advanced electrode materials for high performance electrochemical energy storage.

Site Suitability Analysis for Photovoltaic Power Plant Using Geographical Information System

Among the various renewable energy resources, solar energy potential is vastly and freely available in our country. Solar energy offers a clean, climate-friendly, abundant and inexhaustible energy resource to mankind. The costs of solar energy have been falling rapidly and are entering new areas of competitiveness. Solar Thermal Electricity (STE) and Solar Photo Voltaic Electricity (SPV) are becoming competitive against conventional electricity generation in tropical countries. In conventional methods, site selection based on integrating various performance indicators such as Temperature, DNI, Sunshine hours, Slope, Aspect and Land use are difficult. GIS provides an integrated approach to combine several factors and provides different scenarios for decision making. This paper describes the suitable site selection for installation of photovoltaic power plants using GIS. It involves three stages: the first stage requires the selection of study area based on power crisis in different districts. The second stage includes preparation of the layers such as Direct Normal Irradiance, Temperature, Sun Shine Hours Land use / land cover, Slope and Aspect for study area and at final stage weights for each layer is calculated with the help of Analytical Hierarchy Process and suitable sites for installation of photovoltaic power plants are derived using suitability analysis in GIS environment.

A first-principles study of hydrogen storage of high entropy alloy TiZrVMoNb

In this study, density functional theory calculations have been carried out to study the hydrogen storage properties of high entropy alloy (HEA) TiZrVMoNb. It reveals that a BCC→FCC phase transformation occurs when the hydrogen content reaches 1.5 wt% during hydrogenation process, and octahedral and tetrahedral interstitial sites are preferable for hydrogen occupation before and after phase transformation, respectively. Further energetic analyses show that different hydrogen occupations in HEAs play an important role in the thermal stability of hydrides. The maximum hydrogen storage capacity for TiZrVMoNb is predicted to be 2.65 wt%, which is comparable to the largest value of 2.7 wt% for TiZrVHfNb and larger than that of other reported HEA hydrogen storage materials reported in the literature. As compared with the previously reported HEA TiZrHfMoNb with the change of only one principal element, the TiZrVMoNb not only has much higher hydrogen storage capacity, but also has more moderate hydrogen desorption temperature. The difference in hydrogen storage properties between these two HEAs is mainly attributed to the atomic weight, site occupation, lattice distortion and chemical effect of metal elements. The present study thus suggests that the TiZrVMoNb HEA has great potential as hydrogen storage materials and proposes a strategy to enhance the hydrogen storage properties of HEAs.

Charge storage in binder-free 2D-hexagonal CoMoO4 nanosheets as a redox active material for pseudocapacitors

Binder-free CoMoO4 hexagonal nanosheets have been directly grown on the surface of conductive carbon fabric cloth (CoMoO4@CFC) as a hybrid electrode material for pseudocapacitors (PCs) with outstanding electrochemical properties. The as-prepared CoMoO4@CFC sample was structurally and morphologically characterized using various techniques. Microstructure analysis reveals that the hexagonal like 2D structure possesses mesoporous characteristics with abundant electroactive sites as a charge storage host. The CoMoO4@CFC was evaluated as a positive electrode material for pseudocapacitors, which revealed a maximum specific capacitance of 1210 F/g at 2.5 A/g with exceptional rate capability and outstanding cycling stability of 91% after 10,000 charge/discharge cycles. The 2D mesoporous hexagonal-like structure provides improved electrolyte movement during charging/discharging process and additional active sites for redox reactions. In addition, the charge storage quantification of diffusion and capacitive charge mechanism was determined by employing Power's law, and accordingly, the CoMoO4@CFC electrode was attributed to a high capacitive charge value of (80% at rate 2.5 mV/s). Thus, this work specifies simple and cost-effective method to fabricate pseudocapacitors electrode materials with high energy density and improved cyclic life for energy storage devices.

Analysis of Past Cybersecurity-related Incidents in the Process Industry and the Like

The process industry and similar sectors are undergoing a digital transition towards higher levels of automation. This, while ensuring advantages such as efficient process control, quick and safe response to abnormal conditions, improvement of product quality and continuous process optimization, it exposes the process sites to cybersecurity threats. A cyber-attack, besides economic and reputation damages, can potentially trigger major accidents (e.g. loss of containment of hazardous materials) with severe consequences on workers, population and the environment.In the present study, the cybersecurity-related incidents (CSIs) that occurred in the chemical, petrochemical, energy production, and water/wastewater sectors, were investigated. The analysis is based on the development of a database of 78 cybersecurity-related incidents. The aim of the study is to frame a clear picture of the cyber-attacks on IT-OT (Information Technology - Operational Technology) system of process facilities and to issue lessons learnt from past incidents.

Studying the Role of System Aggregation in Energy Targeting: A Case Study of a Swedish Oil Refinery

The definition of appropriate energy targets for large industrial processes is a difficult task since operability, safety and plant layout aspects represent important limitations to direct process integration. The role of heat exchange limitations in the definition of appropriate energy targets for large process sites was studied in this work. A computational framework was used which allows to estimate the optimal distribution of process stream heat loads in different subsystems and to select and size a site wide utility system. A complex Swedish refinery site is used as a case study. Various system aggregations, representing different patterns of heat exchange limitations between process units and utility configurations were explored to identify trade-offs and bottlenecks for energy saving opportunities. The results show that in spite of the aforementioned limitations direct heat integration still plays a significant role for the refinery energy efficiency. For example, the targeted hot utility demand is reduced by 50–65% by allowing process-to-process heat exchange within process units even when a steam utility system is available for indirect heat recovery. Furthermore, it was found that direct process heat integration is motivated primarily at process unit level, since the heat savings that can be achieved by allowing direct heat recovery between adjacent process units (25–42%) are in the same range as those that can be obtained by combining unit process-to-process integration with site-wide indirect heat recovery via the steam system (27–42%).

Ubiquitin-Specific E. coli Proteinase Does Not Require the Obligatory Presence of Dipeptide GlyGly at Processing Site

It is shown that, unlike eukaryotic ubiquitin-specific proteinases (deubiquitinating enzymes, DUBs), the E. coli deubiquitinase ElaD can process sites containing not only GlyGly but also GlyAla with equal efficiency. At the same time, the bacterial enzyme, like eukaryotic DUBs, fails to process sites containing AlaGly, AlaAla, or GlyPro dipeptides. In light of the functional mission of the E. coli deubiquitinating agent, its decreased specificity can be considered a valuable evolutional acquisition that allows expansion of the list of molecular targets attacked during pathogenesis.

Development of three novel benzothiazole-based ratiometric fluorescent chemosensor for detecting of hydrazine in serum and gas phase via ESIPT process and different recognition sites

In this article, we have successfully designed and synthesized three novel ratiometric fluorescent probes BTP-LA, BTP-LB and BTP-LN for detection of hydrazine based on benzothiazole-derived fluorophores and different recognition sites. The probes BTP-LA, BTP-LB and BTP-LN displays a good fluorescence ratio emission signals, high selectivity and large emission shifts (>100 nm) toward hydrazine. The three probes BTP-LA, BTP-LB and BTP-LN can be used not only to detect hydrazine in serum, but also to detect gaseous hydrazine in air. More importantly, compared with probes BTP-LB and BTP-LN, BTP-LA has lower saturation concentration (200 µM) and detection limits (1.22 × 10−7 M) to hydrazine.

Deactivation and Regeneration for the SO2-Poisoning of a Cu-SSZ-13 Catalyst in the NH3-SCR Reaction

Cu-SSZ-13 has been generally considered as the predominant commercial selective catalytic reduction (SCR) catalyst in the NH3-SCR reaction because of its superior activity and durability. However, in real applications, SCR catalysts readily undergo hydrothermal aging and sulfur poisoning. In this work, the deactivation and regeneration of a commercial Cu-SSZ-13 catalyst was investigated for SO2 exposures during hydrothermal aging and the effect of different regeneration temperatures was compared. By using XRD, SEM, H2-temperature programmed reduction (TPR), X–ray photoelectron spectra (XPS) and NH3-temperature programmed desorption (TPD) analysis, it was found that SO2 poisoning influenced the chabazite (CHA) structure even if regeneration cannot restore its original structure, the redox ability and ammonia storage performance also influenced by sulfation and the regeneration process. Moreover, the extent of a decrease in redox ability was more severe than acidity, suggesting that the amount of isolated Cu2+ and Cu+ reduction was responsible for irreversible deactivation over the Cu-SSZ-13 catalyst. Combined with the analysis of Ea values and pre-exponential factor of the SCR reaction, a more likely explanation for the irreversible deactivation was that active sites were lost mostly in sulfated and regenerated process sites.

Organic rankine cycle and steam turbine for intermediate temperature waste heat recovery in total site integration

The utilization of waste heat for heat recovery technologies in process sites has been widely known in improving the site energy saving and energy efficiency. The Total Site Heat Integration (TSHI) methodologies have been established over time to assist the integration of heat recovery technologies in process sites with a centralized utility system, which is also known as Total Site (TS). One the earliest application of TSHI concept in waste heat recovery is through steam turbine using the popular Willan’s line approach. The TSHI methodologies later were extended to integrate with wide range of heat recovery technologies in many literature, whereby Organic Rankine Cycle (ORC) has been reported to be the one of the beneficial options for heat recovery. In general, the medium to high temperature waste heat is recovered via condensing/backpressure steam turbine, whereas ORC is targeted for recovering the low temperature waste heat. However, it is known that condensing turbine is also able to generate power by condensing low grade steam to sub-ambient pressure, which is comparable with ORC integration. In this work, the integration of ORC and condensing turbine are considered for a multiple-process system to recover intermediate temperature waste heat through utility system. This study presents a numerical methodology to investigate the performance analysis of integration of ORC and condensing turbine in process sites for recovering waste heat from a centralized utility system. A modified retrofit case study is used to demonstrate the effectiveness application of the proposed methodology. The performance of ORC and condensing steam turbine are evaluated with the plant total utility costing as the objective function.

Убиквитин-специфичная протеиназа E. coli не нуждается в обязательном наличии дипептида GlyGly в сайте процессинга

It was shown that unlike eukaryotic ubiquitin-specific proteinases (DUBs deubiquitinating enzymes) deubiquitinase ElaD E.coli does not need obligatory presence of GlyGly dipeptide at the processing site and is capable to process sites GlyGly and GlyAla with equal efficiency. At the same time similar to eukaryotic DUB the bacterial enzyme does not process sites with dipeptides AlaGly, AlaAla or GlyPro. Considering functional mission of the deubiquitinating agent of E. coli, decrease in its specificity can be considered as valuable evolutional acquisition allowing to expand a list of the molecular targets being attacked during pathogenesis. ubiquitin, DUB, E. coli proteinase, elaD, virulence factor The authors sincerely thank the staff of the NRC «Kurchatov Institute» -GosNIIgenetika Drs. Skorokhodova A. Yu. and Goulevitch A.Yu. for designing and supplying the strain BL21(DE3)Ae/aD for the present work.