Ammonia Research Articles

Influence of ammonia-water fog formation on ammonia dispersion from a liquid spill

Ammonia is expected to play an important role in the green transition, both as a hydrogen carrier and a zero-emission fuel. The use of refrigerated ammonia is attractive due to its relatively high volumetric energy density and increased safety compared to pressurized solutions. Ammonia is highly toxic, and with new applications and increased global demand come stricter requirements for safe handling. Cold gaseous ammonia following a spill of refrigerated ammonia will in contact with humid air cause fog formation. In an environment rich in ammonia, these droplets will due to ammonia’s strong hygroscopicity consist of considerable amounts of liquid ammonia as well as water. Fog formation affects the ammonia-air density and thus influences the dispersion dynamics, with a potentially significant impact on hazardous zones. In this work, we present a CFD model including an ammonia-water fog formation model based on accurate thermodynamics. This includes modeling the vapor–liquid equilibrium and accounting for the exothermic mixing of ammonia and water. We apply this CFD model to relevant cases and demonstrate the significant impact of the fog. We analyze the effect of varying relative humidity, fog visibility, influence of wind, and pool evaporation rate. Finally, we model the Red Squirrel test 1F and show how the fog formation could have influenced the dispersion behavior.

A-034 Evaluation of the Analytical Performance of Five Chemistry Assays on the Atellica CI Analyzer

Abstract Background The Atellica® CI Analyzer is an automated, mid-throughput, integrated chemistry and immunoassay analyzer utilizing both Atellica® CH and Atellica® IM assays. This study evaluated the analytical performance of the Atellica® CH Alpha-1-antitrypsin (AAT), Ammonia (AMM), Amylase_2 (AMY_2), Cholinesterase_2 (CHE_2), Lipase (Lip) Assays on the Atellica CI Analyzer. Methods The Atellica CI assays use the same reagents and calibrators as the Atellica CH assays. Precision studies were performed according to CLSI EP05-A3 using human urine (AMY_2), serum (AAT, AMY_2, CHE_2, Lip), and plasma (AMM) samples. One aliquot of each sample pool was tested in duplicate in two runs per day for 20 days. MC studies were performed according to CLSI EP09-A3. Samples were analyzed using the Atellica CH and Atellica CI Analyzers. Results Across the five assays, repeatability CVs were <5.7% and within-laboratory CVs were <8.2%. Representative precision, and MC results observed for each assay across indicated sample ranges are presented in the table. Slopes determined using the Deming linear regression model were approximately equal to 1. Conclusions Atellica CH AAT, AMM, AMY_2, CHE_2, and Lip Assays on the Atellica CI Analyzer demonstrated good precision and equivalent performance to the same assays on the Atellica CH Analyzer.

Co3O4/CQDs composite for selective ammonia detection in exhaled human breath analysis

Co3O4 was synthesized using electrospinning method and different amounts of carbon quantum dots (CQDs) were subsequently doped into the Co3O4 matrix via grinding, resulting in Co3O4/CQDs composite materials with various ratios. Gas sensing tests revealed that the resulting composite Co3O4/CQDs sensors exhibited excellent performance at a low temperature of 50°C, with outstanding selectivity towards ammonia gas and rapid response and recovery characteristics. Specifically, response and recovery time for 50 ppm ammonia gas were 14 s and 164 s, respectively. The outcomes of the exhalation simulation test utilizing sensors composed of this material demonstrate that the sensor's response to simulated chronic kidney disease breath closely approximates that of pure biological samples (1.08), exceeding the average response value of healthy exhaled breath samples (1.0). This demonstrates the sensor's capability to differentiate between healthy individuals and chronic kidney disease patients despite significant water vapor and carbon dioxide interference. This study provides valuable insights for the development of more efficient ammonia sensors and their role in the early detection of chronic kidney disease.

Impact of SiGe pocket on different shape TFET structures for gas sensing application

Gas sensing requires highly sensitive and selective sensor technologies for environmental monitoring, industrial safety, and public health objectives. Although conventional MOSFET-based gas sensors are widely utilized, their detection of low quantities of gases, such as ammonia, is hindered by a number of severe constraints. TFET is emerged as the better device than MOSFET, particularly for the sensing applications. In this work we discussed the source engineered and shape engineered techniques to improve the performance of TFETs, specifically for ammonia gas detection. Comprehensive simulations on SILVACO TCAD and compared the four TFET structures SiGe-pocket DGTFET, SiGe-pocket vertical TFET SiGe-pocket Z-shape TFET, and SiGe-pocket U-shape TFET structure on the basis of various electrical characterization parameters. Significant improvements in efficiency and sensitivity are obtained by adjusting the work function of the molybdenum (4.40–4.60 eV) catalytic gate metal to find the optimal values. The findings reveal that the SiGe-pocket U-shape TFET structure exhibits superior performance, demonstrating an ION of 8.01 × 10−4 A/μm, an ION/IOFF ratio of 1.25×1013, and an OFF current sensitivity (SOFF) of 1.262. These results highlight the enhanced sensitivity and efficacy of the proposed SiGe-pocket U-shape tunnel FET in ammonia gas sensing applications, making it a promising candidate for practical uses in environmental monitoring and industrial safety.

Fluorescence switching of triarylamine-based polyamides with pendant pyrene units and its application in electrochromic smart displays

The pyrene group was directly connected to the triarylamine (TAA) unit through a benzene bridge via the Suzuki reaction to successfully prepare the diamine monomer. A series of new polyamides (PAs) based on TAA units were prepared by polycondensation. The PAs exhibited good solution processability and high thermal stability with the char yield in excess of 53% at 800°C in air atmosphere. In solvents with different polarities, these PAs showed solvatochromic effect and large stokes shift. Strongly photoluminescent PAs have a sensitive stimulus response to explosive and hazardous gas, and its fluorescence is easily turned off by the addition of trinitrophenol (TNP) and hydrogen chloride (HCl). And achieve fluorescence switching between exposure to HCl and ammonia (NH3) gas. The PAs exhibited a reversible color response in the electrochemical oxidation process, with no significant degradation in current and transmittance after 200 cycles. The sandwich structure multicolor electrochromic device can achieve electrochromic performance applied by different voltages.

Dispersion of anhydrous ammonia inside a confined space onboard a hypothetical ammonia-powered vessel

Abstract In order to ensure the responsible use of anhydrous ammonia as clean marine fuel, safety aspects in respect of its post-release consequence cannot be understated. This contribution is aimed to address the gaps of understanding associated to events of ammonia loss of containment (LoC) in enclosed spaces onboard ammonia-fuelled vessels. A forced ventilated fuel preparation room (FPR) onboard a container vessel is chosen as a study case with minor and major release scenarios, which is based on the orifice size. The dispersion analysis was performed using three-dimensional computational fluid dynamics. The analysis revealed that toxicity associated to the rapid and persistent ammonia vapor cloud buildup is by far the most significant hazard in the space. In the major release scenario, gradual evaporation of rainout pool increases the vapor cloud persistence even far beyond the leak isolation time. The results and finding above underlines the importance of concerted effort in mitigating not only the ammonia vapor cloud, but also the accumulated ammonia liquid pool.

Novel Ag-Doped- Poly (aniline-co-pyrrole)/Titanium-Dioxide Nanocomposite Sensor Material for Ammonia Detection in Spoiled Meat

Silver-doped poly(aniline-co-pyrrole)/titanium dioxide (Ag-doped PANI-PPy/TiO2) conducting copolymer-based nanocomposite ammonia gas sensor was synthesized through in situ chemical oxidative polymerization by taking different amounts (4%, 5%, 6%, 7%, and 8%) of Ag-TiO2 (1:1 ratio) nanoparticles. Zetasizer; dynamic light scattering, scanning electron microscopy, transmit ion electron microscopy, Fourier transform infrared, X-ray diffraction, UV–vis spectroscopy, differential scanning calorimetry, thermogravimetric analysis, and cyclic voltammetry characterization techniques were used to confirm the real formation of nanocomposites and to evaluate the detection performance of the sensor. The interaction sensitivity of the synthesized nanocomposite sensor with ammonia (NH3) was determined by changing the amounts of nanoparticles. Spectroscopic determination exhibited excellent porosity and a better shift in the absorption bands having band gaps (1.87 eV) for the Ag-doped PANI-PPy/TiO2 nanocomposite sensor than the PANI-PPy copolymer (3.17 eV). Morphological (10 μm) and nanoparticle arrangement studies (20 μm) have shown the uniform allocation of nanoparticles in the copolymer matrix when 6% of Ag-TiO2 (1:1 ratio) was added, while agglomeration occurred when <6% or >6% of Ag-TiO2 was added to the copolymer. A decrease in the amorphous domain of the copolymer with an increase in nanoparticles was observed from the X-ray diffraction and other results.

A Copper Phosphosulfide-Based Highly Sensitive Ammonia Gas Sensor at Room Temperature

A Copper Phosphosulfide-Based Highly Sensitive Ammonia Gas Sensor at Room Temperature

Synthesis, analysis and characterization of surfactant-assisted TiO2 nanoparticles for ammonia gas sensor applications

In our study, we focused on gas sensing, particularly ammonia detection. We synthesized and examined three types of nanoparticles: pure and conducting polymer-based TiO2 nanoparticles. The nanoparticles were prepared by an easy sol-gel approach. All of the samples were characterized using XRD, FTIR, UV-vis, FESEM, EDAX and BET. Gas sensing measurements were carried out for each sample. Among them, PEG-TiO2 stood out with remarkable gas sensing abilities, distinguishing it from other gas detection technologies. We thoroughly investigated the sensor performance, focusing close scrutiny to metrics such as response and recovery times. The greatest reduction in response time and recovery time (95 s / 123 s) was achieved at 25 ppm. These metrics provide insights into how quickly the sensor detects and recovers from the presence of the target gas. Our findings offer important insights for optimizing the sensor performance of PEG-TiO2, highlighting its remarkable gas sensing capabilities.

Enhanced ammonia gas sensing performance at room temperature of binder-free NiO, Cu and Co-doped NiO thin films synthesized via the SILAR method

We have comprehensively analyzed the influence of Cu and Co-doping on the structural, compositional, optical, and ammonia sensing characteristics of NiO thin films. The X-ray diffraction analysis revealed that pure NiO, Cu, and Co-doped NiO thin films possess a cubic structure. Remarkably, the Co-dopant caused a transformation in the crystallite size and surface structure of NiO. This alteration ultimately enhanced the sensing capabilities of Co-doped NiO thin films. The presence of Co decreased the amount of energy needed to activate Co-doped NiO, resulting in enhanced sensing capabilities of the doped samples for detecting 50 parts per million of ammonia with a response time of 20 s and recovery time of 16 s and having a percentage response of 76.25 %. The enhanced sensor responsiveness and selectivity of the Co-doped NiO sensor towards ammonia can be attributed to its increased surface area, smaller crystallite sizes, and superior surface properties. The remarkable results of Co-doped NiO thin films exhibited show a potential for use in the production of highly efficient ammonia gas-detecting devices.

IoT Based Poultry Cage Quality Monitoring System

This research aims to create a better cage quality monitoring system in poultry farms, the parameters observed in particular are ammonia gas, where this gas greatly affects the health and productivity of laying hens, the data taken is processed in percentage terms and a comparison of several conditions in the location where the equipment is placed. The system is made using ESP32 microcontroller as the main board, DHT22 as a temperature and humidity sensor, MQ135 as a sensor to detect ammonia gas levels, GY302/BH1750 as a light sensor, light sensor or light meter sensor is used to optimize the circadian cycle of laying hens, the monitor system uses data sent by the main board to the database and taken as output by the mobile application. At the implementation stage, the system is able to function properly where the monitor system can send and receive data with the database as an intermediary between hardware and software. The DHT22 sensor can detect temperature and humidity changes with minimal error, the error rate obtained for DHT22 sensor reaches 2.26%, the MQ135 sensor can detect ammonia gas levels according to set program, the GY302/BH1750 sensor can detect changes in light with quite optimal accuracy, all sensor activities can be monitored through the software that has been created, when the system is used for a long period of time periodically the main board will stop sending data to the database, This can last 30 to 40 minutes, with a reboot solution.

Direct electrosynthesis and separation of ammonia and chlorine from waste streams via a stacked membrane-free electrolyzer

Electrosynthesis, a viable path to decarbonize the chemical industry, has been harnessed to generate valuable chemicals under ambient conditions. Here, we present a membrane-free flow electrolyzer for paired electrocatalytic upcycling of nitrate (NO3−) and chloride (Cl−) to ammonia (NH3) and chlorine (Cl2) gases by utilizing waste streams as substitutes for traditional electrolytes. The electrolyzer concurrently couples electrosynthesis and gaseous-product separation, which minimizes the undesired redox reaction between NH3 and Cl2 and thus prevents products loss. Using a three-stacked-modules electrolyzer system, we efficiently processed a reverse osmosis retentate waste stream. This yielded high concentrations of (NH4)2SO4 (83.8 mM) and NaClO (243.4 mM) at an electrical cost of 7.1 kWh per kilogram of solid products, while residual NH3/NH4+ (0.3 mM), NO2− (0.2 mM), and Cl2/HClO/ClO− (0.1 mM) pollutants in the waste stream could meet the wastewater discharge regulations for nitrogen- and chlorine-species. This study underscores the value of pairing appropriate half-reactions, utilizing waste streams to replace traditional electrolytes, and merging product synthesis with separation to refine electrosynthesis platforms.

Preparation and mechanism study of highly sensitive NH3 gas sensor based on Au-modified CdS nanoparticles

A high-performance ammonia (NH3) gas sensor based on Au nanoparticles (AuNPs) modified CdS (Au/CdS) was synthesized by hydrothermal method, and the sensing mechanism of Au/CdS was studied by first-principles based on density functional theory (DFT). Experimental results show that the addition of AuNPs can effectively enhance CdS-based NH3 gas sensor performance. Au/CdS sensor exhibits high response (16580), short response/recovery time (2.25 s/1.25 s), and low limit detection (500 ppb), good repeatability and stability. Because AuNPs can effectively increase the generation of sulfur vacancies on the surface of CdS, increasing the amount of chemisorbed oxygen and providing more active sites for NH3. Furthermore, the good conductivity of AuNPs promotes the separation and transport of carriers on CdS surface, thereby improving the gas sensing performance. DFT calculations indicate that the ionization energy of Au is less than that of Cd, which causes some Cd atoms to lose their coordination with S atoms and increase sulfur vacancies on the surface of CdS. In Au/CdS sensors, sulfur vacancies accelerate the cleavage of NH3, and resulting electrons participate in charge transport, thereby enhancing the adsorption energy. This study introduces a new method for fabricating high performance NH3 sensor based on CdS rich in sulfur vacancies.

Single Atom Catalyst for Nitrate-to-Ammonia Electrochemistry.

Various life forms suffer from the negative effects of nitrate when it accumulates in water bodies, which is a major concern in the present day. The removal of nitrate from water bodies is a critical challenge, and the most effective method to achieve that is to change it into ammonia. Ammonia is a clean energy source and a vital input for the fertilizer industry. The Haber-Bosch process, which dominates the industrial production of ammonia, requires a lot of energy. A more sustainable way to produce ammonia is to use nitrate-contaminated water and reduce it to ammonia through electrocatalysis. This review is constituted of amalgamated articles featuring unique conditions that affect the productivity and activity of the transition metal single atom catalyst (TNMSAC) for the electrocatalytic nitrate reduction to ammonia (NRA) reaction. It explores factors such as nitrate ion adsorption, the characteristics of the central electroactive transition metal, the type of coordinating atoms, the impact of potential on stability, and the interplay among single atoms on the selectivity and yield of ammonia gas. In addition, this review also covers advanced concepts such as dual-atom catalysts, dual single atom catalysts, and single atom alloys. The review will provide valuable guidance for enhanced comprehension and strategic designing of TNMSAC for the electrocatalytic conversion of NRA, which will contribute to achieving a green ammonia economy.

Ternary TiO2/MoS2/ZnO hetero-nanostructure based multifunctional sensing devices

Novel sensing applications benefit from multifunctional nanomaterials responsive to various external stimuli such as mechanics, electricity, light, humidity, or pollution. While few such materials occur naturally, the careful design of synergized nanomaterials unifies the cross-coupled properties which are weak or absent in single-phase materials. In this study, 2D MoS2 integrated with ultrathin dielectric oxide layers forms hetero-nanostructures with significant impacts on carrier transport. The ternary TiO2/MoS2/ZnO hetero-nanostructures, along with their individual properties, improve the performance of multifunctional sensing devices. The synthesized hetero-nanostructure exhibits a responsivity of up to 16 mA/W to 700 nm light and responds to 5 ppm ammonia gas at room temperature. These enhancements are attributed to interface charge transfer and photogating effects. The ternary TiO2/MoS2/ZnO hetero-nanostructure is compatible with existing semiconductor fabrication technologies, making it feasible to integrate into flexible, lightweight semiconductor devices and circuits. These results may inspire new photodetectors and sensing devices based on two-dimensional (2D) layered materials for IoT applications.

CRYSTAL STRUCTURE CHANGE OF CELLULOSE DUE TO GASEOUS AMMONIA TREATMENT

Dissolving pulp was treated with ammonia gas at 20 °C at different pressure levels. The modified pulp was analysed with regard to the change in crystal structure from cellulose I to III. X-ray diffraction and Raman spectroscopy were used as analytical methods. It was found that the transformation of cellulose from cellulose I to III takes place above a defined pressure level, which could be recorded continuously as a function of pressure. Below the characteristic pressure level, the cellulose is still present as cellulose I after treatment. This pressure level is lowered by the presence of water. The ammonia gas is therefore able to swell the crystalline areas of the cellulose starting from a defined process intensity, causing the cellulose to recrystallize in a different structure. Finally, the cellulose III obtained was partially converted back into cellulose I by water boiling.

Study of doping effect of cd on ZrO2 nanostructures for gas sensing applications

Abstract Here, we enforced the conventional precipitation approach to yield pure and cadmium doped (3% and 8%) ZrO2 powder, to examine the gas sensing proficiency of Zirconium metal oxide. Drop casting mechanism is hired for the formation of pure and cadmium doped ZrO2 films. The X-ray diffraction (XRD) outcomes recommended that the prepared pure and cadmium doped ZrO2 powder samples are pure with no subordinate phase, but slight shift in peaks were detected. Scanning Electron Microscope (SEM) portrait substantiates the uniform spherical like morphology of the samples. The Current Voltage (I-V) study affirms the good conducting nature of the samples. The photoluminescence (PL) inspection, confirms that the oxygen vacant spots are present in the processed samples. The UV-Diffuse Reflectance Spectra validates the decrement of band gap of the prepared samples with rise in dopant concentration. The gas sensing capabilities of the drop casted samples were examined for different gas concentrations of reducing gases like ammonia, acetone, ethanol, formaldehyde and xylene. From the output data, we interpreted that the prepared samples show favorable response towards the target gas, explicitly the 8% cadmium doped sample shows 39% of an extreme response towards ammonia gas. Likewise, it also accomplishes an expeditious response time (RST) and recovery time (RCT) among all samples. Thus, we resolved that the inclusion of cadmium content stacks up the gas sensing adaptability of the zirconium metal oxide.

Enhanced sensing properties of optical ammonia sensor based on electrospun fibers containing Eosin-Y and silver nanoparticles

This study presents a highly sensitive fluorescence intensity-based gas sensor specifically designed to detect ammonia. Eosin-Y fluorescent dye and silver nanoparticles are incorporated into` cellulose acetate to fabricate fibers membrane using the electrospinning technique, which serves as the foundation for the optical ammonia sensors. Afterward, this sensor is illuminated by a 405 nm LED for monitoring purposes, resulting in changes to both intensity and wavelength. The sensitivity of the optical ammonia sensor is evaluated by comparing the fluorescence intensity recorded for pure nitrogen with that for 1000 ppm ammonia, expressed as the ratio I0/I1000 ppm. The sensor's ability to detect ammonia is evaluated based on the differences in fluorescence intensities between nitrogen and ammonia environments. The proposed optical ammonia gas sensor utilizes Eosin-Y molecules as indicator compounds. Notably, the sensor, constructed from an electrospun fiber membrane, demonstrates an exceptional response of 50.9 at 1000 ppm in an ammonia gas environment at room temperature, representing the highest response achieved to date in an ammonia gas sensor utilizing Eosin-Y molecules. Experimental findings highlight the enhanced sensitivity of the proposed Eosin-Y-containing electrospun fibers compared to traditional Eosin-Y-based dyes for optical ammonia sensing. The development of an optical ammonia sensor utilizing electrospun fibers embedded with fluorescent dye presents a promising opportunity, offering practical applicability due to its cost-effectiveness and straightforward manufacturing process. Finally, the innovative optical ammonia sensor approach can be applied across various fields, including environmental, industrial, and medical applications.

Flower-like nickel oxide nanostructures: Superior ammonia gas sensing and efficient dye removal behavior under UV–visible light illumination

In this study, we fabricated the NiO nanostructures using a straightforward solvothermal technique. The NiO nanoparticles were characterized using various analytical techniques. The FESEM images clearly show the flower-like structure of NiO nanoparticles. These nanostructures were then employed as a sensor to detect the presence of highly toxic ammonia (NH3) gas. The flower-shaped nanostructures of NiO played a vital role in improving sensing performance. Moreover, the NiO sensor displayed rapid response to 100 ppm ammonia at room temperature, with responses/recovery times of 40 s/44 s. This research holds promise as a viable approach for effectively sensing and detecting NH3 gas. The NiO exhibited excellent photocatalytic activity and degradation rates of 80% and 84.75% for Methyl orange (MO) and methylene blue dye (MB) respectively under UV-visible light irradiation. The NiO nanoflower remains unaffected after recycling MB dye degradation. This effective photocatalytic performance might be due to the formation of flower-like morphology. This underscores the potential of NiO as a promising candidate for applications in environmental and healthcare safety applications.

Biocompatible sensors for ammonia gas detection

In this work, three different dyes have been tested for the determination of gaseous ammonia. This gas is one of the products of microbial degradation and therefore its presence is an indicator of deterioration and could be used as a food freshness indicator.Three different sensors have been prepared and tested, two of them using the natural pigments curcumin and anthocyanin and the other one using bromothymol blue. All of them are biocompatible and therefore allowed to use in contact with food.Different compositions, materials for deposition, stability and reversibility for ammonia gas detection have been studied under high humidity conditions simulating real packaged food conditions. Colorimetry is the technique used to obtain the analytical parameter, the H coordinate of the HSV colour space, simply using a camera, avoiding the use of complex instrumentation.Sensibility, toxicity grade and stability found show that the sensor could be implemented in packaged food and form the basis of a freshness indicator for the food industry.