Addition Of Ammonia Research Articles

Control of nitrogen defects in carbon nanotubes for self-powered memristive systems

Recent studies show that the additional introduction of heteroatoms into the structure of CNTs makes it possible to change their electronic and physical properties [1]. Of great interest is the process of doping CNTs with nitrogen atoms [2]. The introduction of nitrogen defects into a lattice of carbon atoms makes it possible to modify the CNT structure up to the demonstration of anomalous properties that are not appropriate for this material [3]. It has been shown that multi-walled N-CNTs can exhibit memristive and piezoelectric properties [4]. The parameters of CNTs during synthesis can be controlled by the plasma enhanced chemical vapor deposition (PECVD) method. The addition of ammonia (NH3) to the carbonaceous gas in the PECVD process allows CNTs to be doped directly during growth. At the same time, the dopant concentration and the type of nitrogen defects have a significant effect on the properties of CNTs. The memristive properties of CNTs have already been sufficiently studied [5], however, for their application in self-powered systems, additional studies of the parameters of the piezoelectric module of N-CNTs are required. The aim of this work is to study the effect of ammonia flow on the concentration, type of nitrogen defects, and the value of the piezoelectric modulus during growth of CNTs by the PECVD. Silicon (100) substrates were used as samples with films of a buffer (Mo, 100 nm) sublayer and a catalytic layer (Ni, 15 nm). CNTs were grown at a temperature of 550 °C in an atmosphere of acetylene (C2H2, 35 sccm) and NH3. The C2H2 flow was kept constant, while the NH3 flow was changed in the C2H2:NH3 ratio from 1:1 to 1:10. Based on the obtained SEM images, it was found that with an increase in the ratio of C2H2:NH3 flowes, an increase in the density of nanotubes in the array were observed. This occurs due to more active growth of N-CNTs on small nickel catalytic centers due to the accelerated process of hydrogen desorption and its binding with ions in ammonia plasma, which leads to an increase in the growth rate of nanotubes on smaller catalytic centers. Thus, the area of the catalytic center is one of the limiting factors of the growth rate and allows one to control the aspect ratio and density of CNTs in the array. An analysis of the XPS spectra showed that with an increase in the ratio of C2H2:NH3 flows from 1:1 to 1:10, a nonlinear change in the concentration of the nitrogen dopant in N-CNTs from 8.4 to 12 at % is also observed. This led to a nonlinear change in the piezoelectric modulus of nanotubes from 8.7 to 20.6 pm/V and a change in their memristive properties. It has been established that an increase in the concentration of doping nitrogen leads to an increase in the piezoelectric modulus of N-CNTs, which is the source of the memristive effect. The obtained results can be used in the development of energy-efficient piezoelectric nanogenerators based on an array of vertically aligned N-CNTs for autonomous memristive systems.

Effects of NH3 and H2 addition on morphology, nanostructure and oxidation of soot in n-decane diffusion flames

The effects of ammonia and hydrogen addition on soot formation characteristics in n-decane laminar diffusion flames were studied. The addition of argon was specifically considered to identify the chemical effect of ammonia. The flame temperature, particle morphology, and oxidation characteristics were analyzed. Results showed that both ammonia and hydrogen addition increase the flame height and suppress soot formation, while the suppression effect of ammonia is more pronounced. The addition of argon or ammonia reduces the temperature of flame upstream and yields the similar flame temperature, while hydrogen addition increases the flame temperature. Compared to the flame with argon, the addition of ammonia delays particle nucleation, indicating that the soot nucleation and growth process are chemically inhibited. In contrast, doping hydrogen leads to an earlier nucleation process and aggregation phenomenon. Further analysis on particle nanostructure indicated that the addition of ammonia yields shorter lattice fringes, larger interlayer spacings and amorphous carbon contents, demonstrating a looser and higher disorder internal structure. The addition of hydrogen yields longer fringes and smaller interlayer spacings, showing the particles have a more compact internal structure and higher degree of graphitization. This indicates hydrogen addition reduces the oxidation activity of the particles, which is confirmed by thermogravimetric analysis.

Coupled interactive effects of ammonia and hydrogen additions on ethylene diffusion flames: A detailed kinetic study

Coupled interactive effects of ammonia and hydrogen additions on ethylene diffusion flames: A detailed kinetic study

Experimental and kinetic modeling study on ammonia/polyoxymethylene dimethyl ether 2 oxidation in a jet-stirred reactor

The oxidation of ammonia/polyoxymethylene dimethyl ether 2 (NH3/PODE2) was investigated in a jet-stirred reactor with ammonia addition of 10 %, 25 %, and 50 % in mole fraction. Atmospheric experiments were conducted at an equivalence ratio of 1.0, within the temperature range of 500–1100 K. The initial fuel mole fraction and residence time were fixed at 0.5 % and 2 s, respectively. PODE2 and NH3, along with other intermediates and products such as C1-C2 hydrocarbons and permanent gases, were analyzed using gas chromatography and Fourier transform infrared spectroscopy. The experimental results demonstrate that the addition of NH3 has little impact on the consumption of PODE2, primarily influencing the mole fraction of hydrocarbon intermediates. All three blends exhibited negative temperature coefficient (NTC) behaviors. However, NTC behavior was weakened as the NH3 blending ratios increased due to the competition for O2 at low temperatures. A detailed kinetic model for PODE2/NH3 blends was constructed, incorporating updated rate coefficients from the recent literature and analogy methods. The model also considers the interaction between PODE2 and NH3, which was investigated through reaction pathway analysis and sensitivity analysis. Simulated results show that the mole fraction profiles are reasonably predicted by this model at the test conditions. The interaction between PODE2 and NH3 is facilitated by CH3, NH2 radicals, and NO-NO2 cycle. The rapid reversible reaction between NO and NO2 alters the reaction pathway of radicals in the blends. At low temperatures, PODE2 in blend follows the same oxidation pathway as pure PODE2, while NH3 oxidation is affected by the introduction of additional HO2 and H from PODE2. New OH formation pathways involving NH2, NO, and NO2 occur, while the decomposition of H2O2 is inhibited, thereby affecting the oxidation of PODE2 at intermediate temperatures. Additionally, a notable decrease in the intermediates with carbon–carbon double bonds is observed, due to the consumption of CH3 through the reaction NO2 + CH3 = NO + CH3O. This important reaction also promotes the oxidation of CH3 and the NO-NO2 cycle, resulting in an improvement in system reactivity.

Aeration strategies and total nitrogen removal in a hybrid aerated treatment wetland

Abstract This study investigates the impact of aeration strategy on the performance of total nitrogen (TN) removal in a compact hybrid aerated treatment wetland (TW), called Rhizosph'air®. The system combines a single-stage French vertical flow wetland with an aerated horizontal-flow wetland, offering a unique and flexible approach for optimizing TN removal. In total, seven experimental conditions were tested, with different aeration modes, hydraulic loading rates and ammonium addition. The wetland system demonstrated high performance in terms of chemical oxygen demand removal (>85%) and solids removal (>90%), regardless of the experimental condition. However, TN removal was found to be directly impacted by operational changes. Increasing the hydraulic loading rate from 0.15 to 0.25 m/day led to an improvement in TN removal, achieving over 60%. Furthermore, when ammonium was added to the inlet and when the aeration timing was synced with the timing of the influent batch load, the environmental conditions facilitated the denitrification process, resulting in TN removal of approximately 70% and the lowest effluent NO3-N concentrations (8.70 ± 4.40 mg/L). In summary, the timing of the aeration strategy according to influent batch loading improved TN removal, suggesting its potential for optimization in future studies.

Effects of Ammonia Addition on the Sooting Characteristics of Ethylene Counterflow Diffusion Flames with Oscillating Strain Rates

Effects of Ammonia Addition on the Sooting Characteristics of Ethylene Counterflow Diffusion Flames with Oscillating Strain Rates

Effect of ammonia on the soot properties in a laminar ethylene flame

Ammonia, as a non-carbon fuel, has been regarded as an alternative fuel for combustion. In this investigation, the effect of ammonia on the soot properties such as morphology, nanostructure, graphitization degree, surface functional groups, and oxidation energy in a laminar ethylene flame has been studied using different detection techniques at 15 mm and 30 mm height above burner (HAB). The results show that the soot basically appears as a chain-like aggregate, which is composed of several tens of primary particles, and it also finds that the use of ammonia decreases diameters of primary particles, the diameter of A60 (ethylene with 60 ml/min ammonia) decreases by 28.0 % compared with that of A0 (ethylene without ammonia) at 30 mm HAB. Moreover, the addition of ammonia promotes the regularity degree of soot, slightly increases the mean separation distance at 30 mm HAB, and decreases the mean fringe tortuosity both of 15 mm and 30 mm HAB based on the results from high-resolution transmission electron microscope (HRTEM). Meanwhile, the ratio of ID1/IG, ID3/IG, and ID4/IG has been used to evaluate the degree of graphitization, it indicates that the use of ammonia increases the degree of graphitization, but both of the hybridization degree of sp3 and sp2 in amorphous carbon and carbon atoms decrease. Furthermore, the proportion of oxygenated functional groups decreases with the increase of ammonia. The highest content of C-OH functional group is about 9 % to 15 %, followed by C=O and O-C=O functional groups, which is about 3 % to 6 % and 2.5 % to 3.5 %, respectively. Eventually, the oxidation process of the particles has been analyzed, it is indicated that the use of ammonia decreases the oxidation activity, which is more difficult to oxidize.

Nitrogen addition drives changes in arbuscular mycorrhizal fungal richness through changes in plant species richness in revegetated alpine grassland

Nitrogen (N) addition not only promotes the restoration of degraded grasslands, but also threatens ecosystem functioning through the loss of species richness. Thus, a deep understanding of the effect of N addition on the richness of key organisms in restored grasslands is critical to sustainably restoring degraded grasslands. We conducted a 4-year N addition experiment to investigate the response of both plant and arbuscular mycorrhizal (AM) fungal richness to the combined addition of ammonium (Am) and nitrate (Ni) in a revegetated grassland rehabilitated (with a focus on restoration) on the Qinghai–Tibet Plateau. Both nitrogen forms were added at three levels: 0, 10, and 20 g N m−2 year−1. By itself, Ni addition of 20 g N m−2 year−1 (Ni20) reduced both plant and AM fungal richness, while Am addition of 20 g N m−2 year−1 (Am20) had no significant effect on them. However, when Ni and Am were combined, only Ni20 plus Am20 among all combinations reduced both plant and AM fungal richness. Both soil nitrate-N and plant species richness jointly drove changes in AM fungal richness, but plant species richness was the main factor affecting AM fungal richness under N addition. Our results suggest that minimizing the loss of AM fungi caused by plant species loss resulting from N addition is a key means to sustainably restore degraded grasslands.

Production of Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) from CO2 via pH-Stat Jar Cultivation of an Engineered Hydrogen-Oxidizing Bacterium Cupriavidus necator.

The copolyester of 3-hydroxybutyrate (3HB) and 3-hydoxyhexanoate (3HHx), PHBHHx, is a biodegradable plastic characterized by high flexibility, softness, a wide process window, and marine biodegradability. PHBHHx is usually produced from structurally related carbon sources, such as vegetable oils or fatty acids, but not from inexpensive carbon sources such as sugars. In previous studies, we demonstrated that engineered strains of a hydrogen-oxidizing bacterium, Cupriavidus necator, synthesized PHBHHx with a high cellular content not only from sugars but also from CO2 as the sole carbon source in the flask culture. In this study, the highly efficient production of PHBHHx from CO2 was investigated via pH-stat jar cultivation of recombinant C. necator strains while feeding the substrate gas mixture (H2/O2/CO2 = 80:10:10 v/v%) to a complete mineral medium in a recycled-gas, closed-circuit culture system. As a result, the dry cell mass and PHBHHx concentration with the strain MF01/pBPP-ccrMeJAc-emd reached up to 59.62 ± 3.18 g·L-1 and 49.31 ± 3.14 g·L-1, respectively, after 216 h of jar cultivation with limited addition of ammonia and phosphate solutions. The 3HHx composition was close to 10 mol%, which is suitable for practical applications. It is expected that the autotrophic cultivation of the recombinant C. necator can be feasible for the mass production of PHBHHx from CO2.

Chemodosimetric discriminative analysis of cyanide, ammonia, aliphatic amine, and hydrazine utilizing the diverse reaction types of the pyrylium salt

Pyrylium salts are well known to react with different nucleophiles to form many different types of products like pyridinium salt, pyridine, cyanodienone, thiopyrylium, isoxazoline, N-aminopyridinium salt or 1,2-diazepine, depending on the nucleophile used. This property of pyrylium salts could be used to develop a multi-analyte chemosensor for the species having nucleophilic character. On this idea, we synthesized a pyrylium compound (PyrSen) bearing auxochromes and studied its photophysical responses to different nucleophiles. Different absorption spectra were observed to emerge upon the separate addition of cyanide, propylamine, ammonia, and hydrazine to the aqueous solution of PyrSen (ethanol-water 5:1). In the solutions containing ammonia and hydrazine were also observed fluorescence at different wavelengths. The products responsible for these photophysical properties were isolated and characterized. The developed sensor was proved to be usable for the discrimination and quantification of these four species in aqueous solutions.

An environmentally friendly approach for the extraction and recovery of Mn from pyrolusite by ammonium sulfate roasting‐water leaching and ammonium carbonate precipitation

AbstractWith the growth of the new energy industry, the requirements for manganese have increased significantly. In this paper, the method of manganese extraction from pyrolusite using ammonium sulfate roasting and water leaching was presented. At the optimal process parameters: mass ratio of (NH4)2SO4 to pyrolusite of 2:1, the roasting temperature of 420°,C and duration of 120 min, the leaching efficiency of Mn and Fe was 94.55% and 54.38%, respectively. The mechanism analysis shows that MnO2 and Fe2O3 in pyrolusite were converted to (NH4)2Mn2(SO4)3, (NH4)3Fe(SO4)3, and NH4Fe(SO4)2 by roasting with ammonium sulfate. Iron was removed from the leaching solution with the addition of ammonia. Afterward, manganese carbonate products were prepared from iron‐free manganese sulfate solution by adding ammonium carbonate at a stirring duration of 60 min, a reaction temperature of 40°C, a pH of 7, and a molar ratio of ammonium carbonate to the manganese of 1.1:1, the precipitation efficiency of manganese could reach 99.8%, and the obtained manganese carbonate products were compliant with the industry standards. The ammonia released during the roasting process could be absorbed to regenerate (NH4)2SO4 and the final filtrate after evaporation and crystallization could be used to recycle (NH4)2SO4, both of which were used again into roasting process to reduce the consumption of raw material. In this process, the roasting temperature was only 420°C, which was significantly lower than the pyrometallurgical process suggested in earlier studies.

Effect of ammonia addition on combustion characteristics of hydrogen/air using passive turbulent jet ignition

Hydrogen (H2) and ammonia (NH3) are ideal carbon-free fuels, and the application of NH3/H2 in internal combustion engines offers the potential to reduce carbon emissions. And turbulent jet ignition (TJI) is an advanced ignition strategy that can effectively enhance the combustion. This work aims to experimentally investigate the effect of NH3 addition on the combustion characteristics of H2/air mixtures under passive TJI conditions. Combustion images and instantaneous pressure were collected for processing and analysis. The effect of NH3 substitution and equivalence ratio were investigated. The results indicate that the peak combustion pressure decreases with the addition of NH3, accompanied by longer combustion duration and ignition delay, as well as lower jet velocity and flame area growth rate. The hot jet will be quenched by the strong heat transfer, causing the change in the ignition mechanism as the NH3 substitution ratio increases. In addition, compared to lean conditions, the combustion appears to be less sensitive to the equivalence ratio on the rich side and always shows high jet velocity and flame propagation speed. However, a relatively small amount of NH3 addition changes the ignition mechanism on the rich combustion side compared with lean conditions, resulting in a longer ignition delay.

Study on combustion stability and flame development of ammonia/n-heptane dual fuel using multiple optical diagnostics and chemical kinetic analyses

Ammonia is considered as one of the most potential clean energy due to its carbon-free structure, which ensures the extensive decrease in global CO2 emissions. However, it has difficulty in using ammonia as a single fuel in actual apparatus due to the low reactivity and slow laminar flame speed. The dual fuel combustion of ammonia and high reactivity fuel is a potential solution, which is expected to address the issues raised by ammonia. Nevertheless, the investigations on the influence of boundary conditions on combustion stability and related mechanisms in dual fuel approach of ammonia and high reactivity fuel are still scarce at present. Therefore, in current study, n-heptane was used as the direct-injected fuel, and the investigations on combustion stability and relevant mechanisms of ammonia/n-heptane dual fuel approach were conducted by using optical diagnostics and chemical kinetic analyses. Results indicate that in n-heptane-only combustion, the premixed blue flames are found in the initial combustion stage. The auto-ignition sites dominated by orange chemiluminescence are generated near the combustion chamber wall in ammonia/n-heptane dual fuel combustion and then the flames develop towards the combustion chamber center. The addition of ammonia inhibits the combustion of n-heptane. The ammonia/n-heptane dual fuel combustion is more sensitive to the change of intake temperature compared with n-heptane-only combustion. The increase of directed-injection pressure from 300 bar to 600 bar and compression ratio from 11 to 14.5 favors the flame development speed. The increase of compression ratio is an effective mode to improve the ammonia/n-heptane dual fuel combustion stability compared with increasing intake temperature and modulating directed-injection strategies. The chemical kinetic analyses indicate that the ignition delay of dual fuel combustion of ammonia and n-heptane is more sensitive to the variations of ambient temperature compared with ambient pressure. Consequently, the changes of ambient temperature on the dual fuel combustion stability of ammonia and n-heptane play a dominant role. In a word, the dual fuel combustion stability of ammonia and n-heptane can be achieved through the collaborative optimization of multiple boundary conditions to reduce the dependence on single factor.

Combustion Behaviors and Unregular Emission Characteristics in an Ammonia–Diesel Engine

Ammonia is considered one of the attractive alternatives for fossil fuels to realize carbon neutralization. However, low chemical reactivity limits its use in compression ignition (CI) engines. This study investigated dual-fuel combustion, involving the use of ammonia for port fuel injection (PFI) and diesel for direct injection (DI) in a heavy-duty engine. Unregular emissions, specifically HCN, were studied for the first time in an ammonia–diesel engine. The combustion and emission performance of the engine with pure diesel mode was also studied to reveal the influence on ammonia addition. The engine was consistently operated at a fixed condition of 0.556 MPa IMEP and 800 r/min. The findings reveal the successful achievement of stable dual-fuel combustion in the tested engine. The addition of ammonia led to delayed ignition and an extended combustion duration. Implementing early pilot injection timing (SOI1) strategies significantly improved ammonia combustion efficiency, elevating it from 74% to 89%. This enhancement could be attributed to the diesel injected during pilot injection, which facilitated ammonia decomposition. However, early pilot injection had adverse effects on emissions, including CO, THC, NOx, N2O, and HCN. Advancing the main injection timing (SOI2) within the early SOI1 strategies accelerated the oxidation processes for CO, THC, N2O, and HCN. Nevertheless, this adjustment resulted in increased thermal NOx emissions. The highest HCN emission detected in this study was 9.2 ppm. Chemical kinetics analysis indicated that HCN production occurred within the temperature range of 1000 K to 1750 K under fuel-lean conditions. Furthermore, H2CN played a significant role in HCN formation as temperatures increased. More HCN was formed by H2CN as temperature rose. Strategies such as increasing pilot injection fuel quantity, raising premixed gas intake temperature, or advancing combustion phases close to TDC could potentially reduce HCN emissions.

Stopping of ammonia addition to the exit gas can stop global warming

Global warming is caused by the elimination of NOx. NOx elimination decrease CO2 assimilation, CO2 fix and heat absorption. Lack of N is caused by the elimination of NOx. Global warming will stop if developed countries stop the elimination of NOx. CO2 assimilation will be activated and global warming will stop. But developed countries hated NOx and are eliminating NOx by the reaction with ammonia Amount of NOx is much and amount of ammonia is much Much money is necessary to prepare ammonia. Much CH4 is necessary to prepare hydrogen. Toxity of NOx is almost zero and NOx is good fertilizer. NOx should be released without adding ammonia.

Activity standardisation of 32Si at IRA-METAS

This work explores the primary activity standardisation of 32Si as part of the SINCHRON project that aims at filling the geochronological dating gap by making a new precise measurement of the half-life of this nuclide. The stability of some of the radioactive test solutions, providing 32Si as hexafluorosilicic acid (H232SiF6), was monitored over long periods, pointing to the adequate sample composition and vial type to ensure stability. These solutions were standardised using liquid scintillation counting with the triple to double coincidence ratio (TDCR) technique and the CIEMAT-NIST efficiency tracing (CNET) method. Complementary backup measurements, using 4πβ-γ coincidence counting with 60Co as a tracer, were performed with both liquid and plastic scintillation for beta detection. While 60Co coincidence tracing with a liquid scintillator predicted activities in agreement with the TDCR and CNET determinations, using plastic scintillation turned out to be unfeasible as the addition of lanthanum nitrate and ammonia to fix the silicon during the drying process generated large crystals that compromised the linearity of the efficiency function.

Exploring the potential use of aluminium nitride nanoparticles in the delivery of flutamide anticancer drug

Aluminium nitride (ALN) is a widely studied material due to its unique physicochemical properties. In drug delivery, AlN is also important, because it is biocompatible and can be well-tolerated by living organisms. AlN nanoparticles can be utilized in controlled release mechanisms to achieve the desired therapeutic outcomes. In this study, we present a simple and cost-effective method to synthesize aluminium nitride nanoparticles, which were then characterized using various analytical techniques including SEM, TEM, FT-IR, XPS, and XRD. For this purpose, an equimolar ratio of aluminium chloride hexahydrate was treated with urea and, subsequently, addition of ammonia afforded a viscous gel and detailed thermal treatments in the required time led to the desired ALN nano-powder. Next, we investigated the potential of the fabricated ALN nanostructure for delivering of flutamide, a potent nonsteroidal antiandrogen in the treatment of hormone receptor-positive breast cancer in women. This study showed ∼67% drug loading and proved that release of flutamide is significantly influenced by both pH and release time. Therefore, the drug release was gradual under physiological conditions (pH 7.4, 28% release); whereas, the release rate was significantly accelerated in pH 6.0 (73% release) within 48 h. Furthermore, the in vitro cellular toxicity assay was conducted on human OVCAR-3 cancer cells to evaluate the efficacy and safety of ALN nanoparticles. The results of MTT assay confirmed that this material can be considered as a promising nano-vehicle for delivering of flutamide.

Toward Modeling the Growth of Large Atmospheric Sulfuric Acid-Ammonia Clusters.

Studying large atmospheric molecular clusters is needed to understand the transition between clusters and aerosol particles. In this work, we studied the (SA)n(AM)n clusters with n up to 30 and the (SA)m(AM)m±2 clusters, with m = 6-20. The cluster configurations are sampled using the ABCluster program, and the cluster geometries and thermochemical parameters are calculated using GFN1-xTB. The cluster binding energies are calculated using B97-3c. We find that the addition of sulfuric acid is preferred to the addition of ammonia. The addition free energies were found to have large uncertainties, which could potentially be attributed to errors in the applied level of theory. Based on DLPNO-CCSD(T0)/aug-cc-pVTZ benchmarks of the binding energies of the large (SA)8-9(AM)10 and (SA)10(AM)10-11 clusters, we find that ωB97X-D3BJ with a large basis set is required to yield accurate binding and addition energies. However, based on recalculations of the single-point energy at r2SCAN-3c and ωB97X-D3BJ/6-311++G(3df,3pd), we show that the single-point energy contribution is not the primary source of error. We hypothesize that a larger source of error might be present in the form of insufficient configurational sampling. Finally, we train Δ machine learning model on (SA)n(AM)n clusters with n up to 5 and show that we can predict the binding energies of clusters up to sizes of (SA)30(AM)30 with a binding energy error below 0.6 %. This is an encouraging approach for accurately modeling the binding energies of large acid-base clusters in the future.

Experimental characterization of ammonia, methane, and gasoline fuel mixtures in small scale spark ignited engines

In this study, gaseous anhydrous ammonia is blended with fuels like gasoline and methane and tested in an instrumented, low-technology single cylinder carbureted engine. In-cylinder pressure and emissions are monitored with the various mixtures and their performance is then compared with pure gasoline. With the addition of ammonia, the stability of combustion inside the combustion chamber was affected. But with the addition of a combustion modifier, the overall variability was reduced. At higher substitutions of ammonia, Initial results show an increase in indicated thermal efficiency of the engine. There is also a substantial decrease in the heat release rate (HRR) of the engine when substituting gasoline with ammonia. With the addition of methane, the change in the fuel reactivity helped improve HRR. Increasing ammonia substitution also resulted in an increase in indicated efficiency when compared to pure gasoline by approximately 12% with 50% substitution of ammonia in gasoline. Adding ammonia to the fuel mixtures also showed an initial reduction in unburnt hydrocarbon emission, followed by a sudden increase with further increasing concentration, suggesting incomplete combustion of the fuel mixture. The addition of methane with gasoline also showed a reduction in overall NOx emissions. Furthermore, methane was also tested as the main fuel with ammonia substitution of up to 50%. This ammonia and methane blend also showed comparable results to the gasoline, ammonia, and methane blends tested. From the emissions data, the catalyzing effects of ammonia were also seen with some cases showing varying trends with increasing ammonia substitution. Results from this study can be used to design small-scale engine based power generation systems that need very little modifications to accept ammonia based mixed fuels. Furthermore, this study lays the groundwork for using fuels blends with methane sourced using carbon neutral technologies and ammonia to power engine based systems.

The role of ammonia as an alternative fuel by mixing it into natural gas and satisfying the gas quality requirements

AbstractAmmonia as a carbon‐free e‐fuel has a good potential as a future energy vector to contribute to reducing greenhouse gas emissions. By mixing it into natural gas (NG), the carbon dioxide emissions are decreased when the mixture is burnt. To study the change in the gas properties of different NG compositions with and without added hydrogen, 0–20 mol% ammonia was mixed and various parameters were calculated. The results show that a higher content of ammonia decreases the compression factor, lower heating value, and Wobbe index (WI). Depending on the gas composition the relative density is either increasing, for NGs containing a high level of methane and/or hydrogen, or decreasing, for gases with larger quantities of higher hydrocarbons and/or inert gases. NGs with added hydrogen are more impacted by addition of ammonia, where the relative density can be improved by mixing the gas with ammonia to satisfy the gas quality requirements. However, taking the WI limits into account, more ammonia can be added into a NG without any hydrogen compared to one with hydrogen. The addition of ammonia into NG is possible considering the gas quality parameters, even in the case when the gas contains some hydrogen.