Ethylene Concentration Research Articles

Consumer‐oriented intelligent ripening control system for post‐ripening fruit

AbstractTo address the issues commonly encountered in traditional fruit ripening processes, which include reliance on manual experience, low efficiency, single control parameter, and significant fluctuations, a new intelligent fruit ripening control system has been designed. This system is based on a mathematical modeling algorithm, which allows for more effective and precise control over the ripening process. To ensure that the ripe fruits are transported to the fruit processing center in a low ripeness state, the proposed system adopts a strategy of precise control of temperature and ethylene, as well as range control of other environmental parameters. The RSSA‐PID model is used for ethylene and temperature control, which has high smoothness, fast response time, and high stability. Compared with the traditional PID model, the RSSA‐PID model has better dynamic performance and stability. Finally, the proposed system is applied to the ripening process of post‐ripening fruits, and the results show that the system achieves intelligent ripening, precise control, and low power consumption. The temperature and ethylene concentration are controlled within a variation of no more than 0.5%, and the humidity, oxygen, and carbon dioxide are maintained within reasonable thresholds. Overall, this paper provides a promising solution for the ripening process of post‐ripening fruits, which can benefit the fruit industry by improving the efficiency and quality of the supply chain.Practical ApplicationThe ripening chamber environment is a dynamic equilibrium environment with non‐linear characteristics because the fruits in the ripening chamber are constantly exchanging substances and energy with the environment through respiration and transpiration. An intelligent ripening control system (IRCS) for post‐ripening fruits is proposed in this paper (Figure 1). The whole ripening process runs automatically, which significantly reduces the ripening time and saves a lot of post‐processing time. The shorter ripening time combined with the latest intelligent software and hardware means that only as much energy as is actually needed is consumed. If the sales market changes, the fruit can be stored under air conditioning (CA) until the scheduled delivery date without significant further ripening and losses and complaints can be minimized.

Superficial scald development in ‘Granny Smith’ and ‘Nicoter’ apples: The role of key volatile compounds when fruit are stored under dynamic controlled atmosphere

A positive correlation of α-farnesene and its oxidation metabolites with superficial scald is commonly reported in apples stored in air or controlled atmosphere (CA) systems, where O2 levels are above the lower oxygen limit (LOL) tolerated by the fruit. Nevertheless, the LOL can be monitored by the dynamic controlled atmosphere (DCA) techniques and to provide different physiological responses. Therefore, this study aimed to evaluate key volatile metabolites from ‘Granny Smith’ and ‘Nicoter’ (‘Kanzi®’) apples stored under dynamic controlled atmosphere (DCA) monitored by respiratory quotient (RQ), i. e. at extremely low oxygen partial pressures (ELO) and correlate their emissions with the incidence of superficial scald (SS). The volatile compounds (VCs) were isolated by solid phase microextraction (HS-SPME) and analyzed by gas chromatography. For the first time, higher concentrations of α-farnesene and its oxidation metabolites (6-methyl-5-hepten-2-one, and 6-methyl-5-hepten-2-ol) were negatively correlated with SS in DCA-RQ. This is likely due to the higher levels of ethanol in fruit stored under this condition having an inhibitory effect on SS incidence even when α-farnesene, 6-methyl-5-hepten-2-one, and 6-methyl-5-hepten-2-ol accumulate. Additionally, SS is more correlated to internal ethylene concentration (IEC) than α-farnesene accumulation and their metabolites, even when fruit were stored under ELO, where ethylene action is reduced.

Assessment of CaO-based sorbent/spinel catalyst composites for the oxidative dehydrogenation of ethane in isothermal integrated CO2 capture and utilization

In this study, a comparative analysis of the isothermal integrated CO2 capture and utilization (ICCU) performance of MgB2O4 (B = Cr, Ga, Fe, Al)/CaCe15 was conducted. Results show that MgCr2O4/CaCe15 demonstrates exceptional performance, with CO2 uptake capacity, CO2 conversion, ethane conversion, ethylene selectivity, and ethylene yield after multiple cycles measuring at 0.22 g/g, 35.6 %, 19.6 %, 89 %, and 17.4 %, respectively. The dominant mechanism during the CO2 utilization stage was explored, and the coupling mechanism of catalytic dehydrogenation and reverse water–gas shift reaction is dominant. The reaction pathway during CO2 utilization was investigated, and results show that hydrogenation activation (CO2*+H* → HCOO* → CO*+OH*) is the primary pathway for CO2 dissociation, with the oxidative dehydrogenation of ethane mainly attributed to the activation of C–H on distinct C atoms, CH3CH3* → CH3CH2* → CH2CH2*. Meanwhile, the scission of the first C–H bond during CO2 utilization is the rate-determining step. Furthermore, we investigated the influencing factors and discovered that increasing the concentration of ethane and weight hourly space velocity both lead to a decrease in ethylene yield.

Modulation of ethylene and ROS-scavenging enzymes by multifarious plant growth-promoting endophytes in tomato (Solanum lycopersicum) plants to combat Xanthomonas -induced stress

The purpose of the current study was to explore root endophytes- Priestia megaterium T3 and Bacillus cereus T4 from Moringa olefiera for the suppression of leaf spot disease in tomato plants challenged with Xanthomonas vesicatoria. Both strains had plant growth-stimulating characteristics including auxin production, solubilization of inorganic phosphate and zinc complexes, and production of ammonia, siderophore, as well as hydrolytic enzymes. An agar well diffusion and fluorescence viability assay have validated the antibacterial effect of the cell-free culture supernatant of strains T3 and T4. Liquid chromatography-mass spectrometry (LC-MS) profiling has identified the secondary metabolites in the cell-free supernatant of strains T3 and T4. The bio-priming of tomato seeds with a consortium of T3 and T4 strains has significantly declined ethylene (by 0.61-fold) and hydrogen peroxide (H2O2, 0.64-fold) concentration thus, maintaining a lower content of ROS-induced malondialdehyde (MDA, 0.91-fold) as compared to control counterparts. Consequently, the leaf spot disease severity was reduced by ∼70% in consortium-treated tomato plants in contrast to their pathogen-challenged control. The consortia (T3+T4) treatment has facilitated induced systemic resistance by enhancing enzymatic activities of phenylalanine ammonia-lyase (PAL), peroxidase (PO), polyphenol oxidase (PPO), catalase (CAT), and ascorbate oxidase (AO) to detoxify the excessive Xanthomonas-induced ROS accumulation in tomato plants. Conclusively, bacterial endophytes modulate X. vesicatoria-induced ROS response and ethylene levels in tomato plants. The current findings indicate that plant growth-promoting endophytic bacterial strains hold the potential to sustainably enhance plant growth and suppress bacterial leaf spot disease in tomato plants.

GhXB38D represses cotton fibre elongation through ubiquitination of ethylene biosynthesis enzymes GhACS4 and GhACO1.

Ethylene plays an essential role in the development of cotton fibres. Ethylene biosynthesis in plants is elaborately regulated by the activities of key enzymes, 1-aminocyclopropane-1-carboxylate oxidase (ACO) and 1-aminocyclopropane-1-carboxylate synthase (ACS); however, the potential mechanism of post-translational modification of ACO and ACS to control ethylene synthesis in cotton fibres remains unclear. Here, we identify an E3 ubiquitin ligase, GhXB38D, that regulates ethylene biosynthesis during fibre elongation in cotton. GhXB38D gene is highly expressed in cotton fibres during the rapid elongation stage. Suppressing GhXB38D expression in cotton significantly enhanced fibre elongation and length, accompanied by the up-regulation of genes associated with ethylene signalling and fibre elongation. We demonstrated that GhXB38D interacts with the ethylene biosynthesis enzymes GhACS4 and GhACO1 in elongating fibres and specifically mediates their ubiquitination and degradation. The inhibition of GhXB38D gene expression increased the stability of GhACS4 and GhACO1 proteins in cotton fibres and ovules, resulting in an elevated concentration of ethylene. Our findings highlight the role of GhXB38D as a regulator of ethylene synthesis by ubiquitinating ACS4 and ACO1 proteins and modulating their stability. GhXB38D acts as a negative regulator of fibre elongation and serves as a potential target for enhancing cotton fibre yield and quality through gene editing strategy.

Short-term storage of ‘Honeycrisp’ apples at 0.5 oC does not improve control of bitter pit without increasing low temperature-induced physiological disorders

‘Honeycrisp’ apples are conditioned at 10 °C for 7 d before storage at 3 °C to reduce development of low temperature disorders such as soft scald. Conditioning, however, can result in greater risk of bitter pit development. A strategy to compromise between two types of disorder by storing fruit for short periods at 0.5 °C before being transferred to 3 °C showed promise in earlier research. Here, this strategy has been investigated over three years. Fruit were conditioned or not conditioned for 1 week at 10 °C before being stored at 0.5 or 3 °C. Fruit stored at 0.5 °C were moved to 3 °C after 1, 2, 3, 4, or 6 weeks in year 1; 5 weeks in year 2; and 1, 2, 3, 4, 6, or 8 weeks in year 3. Fruit quality and incidence of physiological disorders assessed after 16 weeks in years 1 and 2, and 20 weeks in year 3, plus 4 d at 20 °C. Internal ethylene concentration (IEC) and concentrations of acetaldehyde, ethanol and ethyl acetate of the fruit were measured during storage in year 3. Storage at 0.5 °C for different durations before transferring fruit to 3 °C in different years did not inhibit bitter pit or soft scald development compared with 0.5 or 3 °C with or without conditioning for 1 week at 10 °C. Fruit quality was not affected by storage temperature manipulation in any year. Bitter pit incidence correlated negatively with that of soft scald, and positively with IEC. Acetaldehyde, ethanol and ethyl acetate concentrations reached a maximum at 6–8 weeks of storage, but were not consistently related to treatment differences on soft scald incidence. However, volatile accumulations were associated with increasing severity ratings when fruit were categorized by disorder severity. Cavities and vascular browning of fruit were increased by short-term periods at 0.5 °C in year 3. Previous research suggesting that temperature manipulations could be used to manage soft scald and bitter pit incidence was not supported by this study.

NFC-Enabled Dual-Channel Flexible Printed Sensor Tag.

Wireless sensor tags in flexible formats have numerous applications; some are commercially available for specific target applications. However, most of these wireless sensor tags have been used for single-sensing applications. In this study, we designed a printed circuit board (PCB) module (13 mm × 13 mm) for near-field communication-enabled sensor tags with both electrical resistance and capacitance read-out channels that enables dual-channel sensing. As part of the wireless sensor tag, a square antenna pattern was printed directly on a flexible poly(ethylene terephthalate) (PET) substrate and integrated into the PCB module to demonstrate a dual-channel temperature and ethylene gas sensor. The temperature and ethylene sensors were printed using a positive temperature coefficient ink and a tin oxide (SnO2) nanoparticle ink, respectively. With dual sensing capabilities, this type of sensor tag can be used in smart packaging for the quality monitoring of fresh produce (e.g., bananas) by tracking temperature and ethylene concentration in the storage/transport environment.

Combined effects of ethylene scavenging‐active packaging system and modified atmosphere to reduce postharvest losses of ethylene sensitive produce: Banana and kiwifruit

AbstractEthylene scavenging‐active packaging is getting more interest to reduce postharvest losses of ethylene‐sensitive produce to overcome the limitations of traditional postharvest technologies. The aim of this study is to monitor behaviour of ethylene‐sensitive products to different ethylene scavenging systems combined with modified atmosphere packaging (MAP). Banana (Musa paradisicum L. var. Anamur) and kiwi (Actinidia deliciosa L. var. Hayward) were packaged with low‐density polyethylene (LDPE) bags containing ethylene scavenging sachet and ethylene scavenging‐active LDPE bags. Only passive MAP was used for bananas stored at 13°C for 12 d. Both passive and active MAP (5% O2, 5% CO2) were used for kiwi stored at 4°C for 30 d. LDPE bags with no ethylene absorber and unpackaged produces were the control groups. O2, CO2 and ethylene concentrations, mass loss, texture, colour, TSS %, titratable acidity and sensory analysis were performed during storage. O2% in the control LDPE bags decreased below 2% on 6th d, while LDPE bags containing sachet and active LDPE bags remained above critical O2 level for bananas during the entire storage. The lowest ethylene concentration was 0.45 μl L−1 in both active systems on 12th d. Equilibrium atmosphere was maintained in active and passive MAP after 5th d for kiwifruit. The lowest ethylene concentrations were determined as 0.47 μl L−1 and 0.50 μl L−1 in the sachet included LDPE and active LDPE, respectively under passive MAP at the end of the storage. In conclusion, bananas packaged with both active systems were acceptable for 9 d considering physicochemical and sensory properties. The kiwifruit was acceptable for 30 d using both ethylene absorbing systems under passive MAP.

Monitoring of methane in groundwater from the Vale of Pickering, UK: Temporal variability and source discrimination

Groundwater abstracted from aquifers in the Vale of Pickering, North Yorkshire, UK and monitored over the period 2015–2022, shows evidence of variable but commonly high concentrations of dissolved CH4. Sampled groundwater from the Jurassic organic-rich Kimmeridge Clay Formation (boreholes up to 180 m depth) has concentrations up to 57 mg/L, and concentrations up to 59 mg/L are found in groundwater from underlying confined Corallian Group limestone (borehole depths 50–227 m). The high concentrations are mainly from boreholes in the central parts of the vale. Small concentrations of ethane (C2H6, up to 800 μg/L) have been found in the Kimmeridge Clay and confined Corallian groundwaters, and of propane (C3H8, up to 160 μg/L) in deeper boreholes (110–180 m) from these formations. The concentrations are typically higher in groundwater from the deeper boreholes and vary with hydrostatic pressure, reflecting the pressure control on CH4 solubility. The occurrences contrast with groundwater from shallow Quaternary superficial deposits which have low CH4 concentrations (up to 0.39 mg/L), and with the unconfined and semi-confined sections of the Corallian aquifer (up to 0.7 mg/L) around the margins of the vale. Groundwater from the Quaternary, Kimmeridge Clay formations and to a small extent the confined Corallian aquifer, supports local private-water supplies, that from the peripheral unconfined sections of Corallian also supports public supply for towns and villages across the region.Dissolved methane/ethane (C1/C2) ratios and stable-isotopic compositions (δ13C-CH4, δ2H-CH4 and δ13C-CO2) suggest that the high-CH4 groundwater from both the Kimmeridge Clay and confined Corallian formations derives overwhelmingly from biogenic reactions, the methanogenesis pathway by CO2 reduction. A small minority of groundwater samples shows a more enriched δ13C-CH4 composition (−50 to −44 ‰) which has been interpreted as due to anaerobic or aerobic methylotrophic oxidation in situ or post-sampling oxidation, rather than derivation by a thermogenic route.Few of the existing groundwater sites are proximal to abandoned or disused conventional hydrocarbon wells that exist in the region, and little evidence has been found for an influence on groundwater dissolved gases from these sites. The Vale of Pickering has also been under recent consideration for development of an unconventional hydrocarbon (shale-gas) resource. In this context, the monitoring of dissolved gases has been an important step in establishing the high-CH4 baseline of groundwaters from Jurassic deposits in the region and in apportioning their sources and mechanisms of genesis.

Self-pruning in lime (<i>Citrus aurantifolia</i> Swingle) after treatments with ichiphon, abscisic acid and nitrogen, phosphorus, and potassium fertilizers

Self-pruning can lower production costs, especially in the case of annual crops such as citrus. The study aimed to determine self-pruning of lime treated with growth regulators and a fertilizer. Self-pruning was applied on a one-year-old of <i>Citrus aurantifolia</i> from February 2020 to April 2022 in Bogor, Indonesia. The treatments used NPK at three levels: 22.5:7.5:2.5 g/tree, 32.5:17.5:12.5 g/tree, and 42.5:27.5:22.5 g/tree, and growth regulators: 500 ppm ichiphon + 100 µM ABA, 750 ppm ichiphon + 50 µM ABA, and 1000 ppm ichiphon. Initial symptoms of self-pruning, namely leaf fall, which correlated with the ethylene concentration in the leaves, occurred in all treatment applications. The combination of the NPK fertilizer 32.5:17.5:12.5 g/tree with 750 ppm ichiphon + 50 M ABA gave the highest ethylene concentration. The highest concentration of ABA was found on the first day after the treatment with the NPK fertilizer 42.5: 27:5: 22.5 g/tree and growth regulators 500 ppm ichiphon + 100 M ABA; however, it did not differ from the treatment with the NPK fertilizer 42.5: 27.5:22.5 g/tree and the 1000 ppm ichiphon growth regulator on the fourth and twelfth days. The percentage of secondary, tertiary, and deciduous branches did not differ between the treatments. Self-pruning that occurs as a result of induction by ichiphon, abscisic acid, and NPK fertilizers, can be an alternative to mechanical pruning.

Hormonal crosstalk controls cell death induced by kinetin in roots of Vicia faba ssp. minor seedlings

Studies of vitality/mortality of cortex cells, as well as of the concentrations of ethylene (ETH), gibberellins (GAs), indolic compounds/auxins (ICs/AUXs) and cytokinins (CKs), were undertaken to explain the hormonal background of kinetin (Kin)-regulated cell death (RCD), which is induced in the cortex of the apical parts of roots of faba bean (Vicia faba ssp. minor) seedlings. Quantification was carried out with fluorescence microscopy, ETH sensors, spectrophotometry and ultrahigh-performance liquid chromatography tandem mass spectrometry (UHPLC‒MS/MS). The results indicated that Kin was metabolized to the transport form, i.e., kinetin-9-glucoside (Kin9G) and kinetin riboside (KinR). KinR was then converted to cis-zeatin (cZ) in apical parts of roots with meristems, to cis-zeatin riboside (cZR) in apical parts of roots without meristems and finally to cis-zeatin riboside 5’-monophosphate (cZR5’MP), which is indicated to be a ligand of cytokinin-dependent receptors inducing CD. The process may be enhanced by an increase in the amount of dihydrozeatin riboside (DHZR) as a byproduct of the pathway of zeatin metabolism. It seems that crosstalk of ETH, ICs/AUXs, GAs and CKs with the cZR5’MP, the cis-zeatin-dependent pathway, but not the trans-zeatin-dependent pathway, is responsible for Kin-RCD, indicating that the process is very specific and offers a useful model for studies of CD hallmarks in plants.

A simple model to simulate the Raman spectrum of methane in the range of 2800–3040 cm−1

AbstractRaman spectroscopy is a promising method to analyze natural gas. Measurement of hydrocarbon concentrations is required for quality control of this fuel. Despite the presence of intense characteristic peaks of hydrocarbons in the range of 2800–3040 cm−1, researchers avoid this region due to the overlap with a methane spectrum. This paper presents a simple method to simulate the Raman spectrum of methane in natural gas at different pressures and concentrations of nitrogen, carbon dioxide, and ethane. A detailed description of the algorithm and the empirical parameters necessary for the simulation are provided. The method can be used to improve the accuracy of the Raman gas analysis of natural gas and other methane‐bearing media.

Preparation of nano-Ag-Bi2WO6–TiO2/starch bionanocomposite membranes and mechanism of enhancing visible light degradation of ethylene

Ag–Bi2WO6–TiO2 (ABT) ternary composite photocatalyst was prepared using solvothermal and surface deposition method. Then, the nano photocatalyst was doped into the starch film liquid through internal loading method, and finally, ABT/starch composite film was constructed using tape casting method for visible light catalytic degradation of ethylene. Characterize and analyze the structure and physical properties of nano ABT/starch composite membranes prepared with different ABT loading amounts, and optimize the reaction conditions (ABT addition amount, light intensity, initial concentration of ethylene) on the visible light catalytic degradation performance for ethylene of the composite membrane. The results show that the nano ABT particles and starch molecules have good biocompatibility, and they can be well fused to form a film, without changing the crystal structure of ABT and generating other chemical bond. The results of photocatalytic degradation of ethylene showed that when the loading amount of ABT was 5 wt%, the light intensity was 60.5 mw/cm2, and the initial concentration of ethylene was 0.15 mg/L, the ABT/starch film had the best ethylene degradation performance, with a K′ value of 5.6111 × 10−4 min−1, which is 17.9 times that of the blank starch film. Under the optimal preparation conditions, the thickness, tensile strength, elongation at break of the starch composite film is 168.33 μm, 5.01 Mpa, 32.4%, respectively, and the maximum thermal decomposition temperature is 320.5 °C, which meets the requirements for food packaging materials. After 4 cycles, the catalytic degradation of ethylene by starch composite membrane only decreased by 13.98%, indicating good reusability.

Organic Aminoethoxyvinylglycine Is an Effective Alternative for Reducing Apple Preharvest Drop

Organic apple (Malus ×domestica Borkh.) growers lack effective strategies to manage preharvest drop. For susceptible cultivars, yield losses caused by preharvest drop can exceed 30% at the beginning of harvest. To address this issue, a formulation of aminoethoxyvinylglyine (AVG) designed for organic use was developed and compared with a commercially available AVG formulation. We evaluated the effects and interactions of the AVG formulation and application number on preharvest drop and fruit maturity in 2017 and 2018. We selected 30 pairs of mature ‘Oregon Spur II Red Delicious’/‘M. 111’ trees planted at the Mountain Horticultural Crops Research and Extension Center in Mills River, NC, USA. Trees were planted with spacing of 2.7 × 6.1 m, trained to a central leader, and received plant protectant sprays that adhered to local recommendations throughout the growing season. Both AVG formulations were applied at 132 mg⋅L−1 at 3 or 3 + 1 weeks before the anticipated harvest. An untreated control was also included for comparison. The experiment had six replicates and a randomized complete block design with a 2 × 2 augmented factorial treatment structure. A one-way analysis of variance was performed and single degree of freedom contrasts were used to compare treatment groups of interest. During both years, organic and conventional AVG were equally effective for reducing preharvest drop and delaying fruit softening and starch hydrolysis at harvest. During one year, increasing the number of applications of AVG reduced cumulative fruit drop, delayed fruit softening at harvest, and reduced internal ethylene concentrations. Inconsistencies in responses across years may be explained, in part, by abnormally warm temperatures observed in 2018. AVG approved for organic use appears to be a promising preharvest drop management technology with efficacy similar to that of conventional AVG.

MATHEMATICAL MODELLING OF THE DYNAMICS OF THERMAL CONVERSION OF METHANE-ETHANE MIXTURES IN A WIDE TEMPERATURE RANGE

A compact mechanism based on elementary radical reactions is proposed for the temperature conversion of methane-ethane mixtures. The kinetic model relying on this mechanism describes the literature data on the conversion of methane and ethane at millisecond time intervals in the temperature range 600-1400 °C. Within the kinetic model, the time dependences of the concentrations of hydrogen, ethylene, acetylene and benzene on the temperature and on the methane/ethane ratio in the initial mixture are determined in the isothermal approximation. Using the proposed mechanism for the calculations of axisymmetric gas-dynamic flows of reagents mixture, the yields of hydrogen and valuable unsaturated hydrocarbons in a non-isothermal tubular reactor are determined.

Photocatalytic degradation of ethylene in tubular microreactor coated with thin-film of TiO2: Mathematical modeling with experimental validation and geometry analysis using computational fluid dynamics simulations

The study aimed to establish a comprehensive understanding of the photocatalytic process and optimize the reactor design for efficient ethylene regulation to improve the shelf-life of fruits and vegetables. For this, it was performed 2D computational fluid dynamics modeling at two different reactor geometry (conventional cylindric reactor and annular cylindric reactor) using the conservation equations combined with Langmuir-Hinshelwood mechanism. A continuous single-phase multicomponent fluid flow with the reactor surface supported with a thin-film catalyst under UV-A light irradiation was simulated for initial ethylene concentration at 0.479–4.234 × 10−3 molC2H4 m−3 and inlet axial velocity at 0.0085–0.1019 m s−1. In the 2D CFD results, it was observed that the difference in ethylene concentration between the microreactor bulk and surface is only significant for high initial concentrations and axial velocities. Furthermore, it was found that the parabolic conversion profile remains unchanged for lengths greater than 10% of the reactor length across all geometries studied. The variation in reactor diameters resulted in a substantial reduction in ethylene conversion; however, the incorporation of an annular cylinder coated with a catalyst led to an enhancement in conversion rates, with improvements of approximately 28%, 17%, and 6% observed for diameters of 5 mm, 10 mm, and 20 mm, respectively. This reduction in improvement as diameter increase can be attributed to the laminar flow dynamics that impede the diffusion of ethylene molecules from the bulk to the catalytic surface. Consequently, the simulated data highlight the potential of employing a catalyst-doped annular cylinder as a promising strategy to increase ethylene conversion and extend the shelf life of fruits. However, it should be noted that the addition of an annular cylinder, while enhancing conversion, also introduces operational complexities and cost implications due to the significant increase in pressure drop associated with lower diameters.

Investigation of the ignition temperature of ethane-air mixtures at elevated pressure

Determining the ignition temperature of combustible substances is crucial in enhancing energy utilization efficiency and preventing fire and explosion accidents. This study investigates the ignition temperature of ethane-air mixtures with concentrations of 29.6%, 31.8%, and 34.4% at pressures up to 1 MPa in a 20 L spherical closed vessel, using a “heating” method. The high-pressure gas mixture was heated until spontaneous rapid reaction occurred in the reaction vessel. The study found that the ignition temperature of ethane in air decreases with an increase in initial pressure and ethane concentration. For example, at an ethane concentration of 31.8%, the ignition temperature decreased from 374℃ to 296℃ when the pressure increased from 0.3 MPa to 1 MPa. Additionally, larger container sizes resulted in lower ignition temperatures for ethane. Furthermore, the study simulated the self-oxidation reaction of ethane using the San Diego Mechanism kinetic reaction mechanism. The results revealed that the initial pressure's effect on important free radical reaction rates was the fundamental cause of autoignition. Under high-pressure conditions, the reaction between C2H5 and oxygen, C2H5 + O2<=>C2H4 + HO2, was the most critical reaction pathway. Overall, this study provides valuable insights into the ignition temperature of ethane-air mixtures and identifies key factors that influence autoignition. The findings can be utilized in improving safety measures and optimizing energy utilization in various industrial processes.

Direct conversion of methane to heavier gaseous alkanes using an electron beam

The circulation treatment of methane with 0.5 MeV electron beam in a cyclone-type reactor, which protects the synthesized products from back degradation, has been studied. As a result of the conversion, the content of methane in the circulating gas can be reduced to 30–43 wt%. The main products are C2C5 alkanes, and the ethane content in the mixture can reach almost 40 wt%. By-products are hydrogen and C6C13 high-octane gasoline alkanes. Electron beam treatment can also be used to concentrate helium in natural hydrocarbon mixtures. The key control factors for conversion are the composition of the feedstock, the rate of beam energy deposition in the gas, temperature, and the residence time of the gas components in the beam penetration area. The features of the use of powerful technological DC accelerators are noted.

Photocatalytic degradation of ethylene by mesoporous nano silica loaded chlorin e6

Green foods are usually harvested and stored before ripening, but excessive ethylene generated during storage can lead to the loss of vegetables and fruits. Photocatalytic oxidation provides a promising method to remove ethylene and extend the shelf life of green foods. In this study, a mesoporous nanosilica-loaded Ce6 composite nanomaterial (Ce6@SiO2) was designed and synthesized to adsorb ethylene into its pores and then degrade it under visible light illumination. The photosensitizer Ce6 in the mesopore produced large amounts of reactive oxygen species that degraded ethylene. The specific surface area was greatly increased by coating the material on the surface of a sodium alginate (SA) hydrogel membrane. This improved its degradation efficiency and facilitated the adsorption and degradation of ethylene during fruit storage. The ethylene removal capacity was studied by measuring the ethylene concentration and increases in the humidity in Tedlar gas bags. Practical applications were tested by observing color changes and surface decay of tomatoes stored with and without SA/Ce6@SiO2. The results showed the system may be used in practical commercial preservation systems.

Composition and Explosibility of Gas Emissions from Lithium-Ion Batteries Undergoing Thermal Runaway

Lithium-based batteries have the potential to undergo thermal runaway (TR), during which mixtures of gases are released. The purpose of this study was to assess the explosibility of the gaseous emission from LIBs of an NMC-based cathode during thermal runaway. In the current project, a series of pouch lithium-based battery cells was exposed to abuse conditions (thermal) to study the total amount of gases released and the composition of the gas mixture. First, the battery cells were placed in a closed vessel, and the pressure and temperature rise inside the vessel were measured. In a second step, the composition of gases was analysed using a Fourier transform Infrared (FTIR) spectrometer. We found that the amount of released gases was up to 102 ± 4 L, with a clear dependence on the battery capacity. This study showed that the concentration of gaseous emissions such as carbon monoxide (CO), methane (CH4), ethylene (C2H4), ethane (C2H6), and hydrogen cyanide (HCN) increased with higher cell capacity. Of the five studied flammable gases, the maximum concentrations of carbon monoxide (16.85 vol%), methane (7.6 vol%), and ethylene (7.86 vol%) were identified to be within their explosible range. Applying Le Chatelier’s law, a calculated lower explosion limit (LEL) of 7% in volume fraction was obtained for the gas mixture. The upper explosion limit (UEL) of the gas mixture was also found to be 31% in volume. A filter comprising pyrobubbles was used for the removal of the studied gas components released during the thermal abuse. The investigation revealed that the pyrobubbles filter was highly effect in the removal of HCN (up to 94% removal) and CO2 (up to 100% removal). Herein, we report the dependency of the method of thermal runaway trigger on the measured maximum temperature.