Papers by Keyword: Ammonia

Abstract: Production of ammonia required high capital energy intensive such as high temperatures (400 to 500 °C) and high pressure (15 to 30 MPa). We investigated a new way to produce green ammonia synthesis using new nanocatalyst and operate in room temperature and ambient pressure. The idea is to synthesize ammonia using Magnetic Induction Method (MIM) and Y₃Fe₅O₁₂ (YIG) as magnetic nanocatalyst. YIG was prepared by sol gel method and sintered at various temperatures 950 °C, 1050 °C, and 1150 °C. X-Ray Diffraction (XRD) result shows that the major peak at [420] plane. The balance composition of YIG resulted by Energy Dispersive X-Ray (EDX) is in the form of Y₃Fe₅O₁₂. Initial permeability results show, the highest value maximum permeability at 140 with the range of frequency 1Hz to100MHz obtained by 950 °C sample. The lowest value of relative loss factor obtained by 950 °C sample. YIG nanocatalyst and MIM method were successfully produce ammonia yield at 197 μmol, without MIM the yield was decreased by 14.28%.

Abstract: The processing of the light fraction formed during the separation of amines for components by rectification is investigated. The light fraction which is an aqueous solution with about 1% of ethylenediamine and 2% of ammonia is treated in an electrolyzer with ion-exchange membranes. It is shown that a concentrated product containing about 118 g/l of ethylenediamine, about 106 g/l of ammonia and purified water can be obtained in this case. The concentrated product can be used at the initial stage of amines production.

Abstract: Research in two-phase flow in heat exchanging devices plays an important part in today’s applications in miniaturization of engineering systems. The phase change process factors in the flow conditions and heat transfer in evaporators and condensers. Numerous studies in the past have looked at the predicted and measured frictional pressure drop of coolants as the vapor quality increases. This paper reports a preliminary attempt at modeling of the relationship between the frictional pressure drop and vapor quality in an ammonia-cooled and R22-cooled mini-channel of 1.5 mm diameter under optimized conditions using multi-objective genetic algorithm. R22 is a being phased-out due to its ozone-depleting characteristic and ammonia is being considered as its potential replacement. The properties of ammonia and R22 used have been obtained experimentally at the saturation temperature of 5°C and 10°C respectively. Modeling of the minimized pressure drop per unit tube length together with the Lockhart-Martinelli parameter was completed under optimized flow rate and vapor quality.The outcomes obtained are similar to those that have been reported experimentally with other coolants, increasing pressure drop with increasing vapor quality.

Abstract: Substantial research has been completed with more on-going on the flow pattern and heat transfer associated with two-phase flows. Discrepancies reported may have been as much as agreements, due to the different models, approaches, flow regimes, correlations, and new working fluids being utilized. This paper reports the outcome of a study to look at the effects of applying two different friction factor correlations on the simultaneous minimization of the pressure drop and Martinelli parameter under optimized flow rate and vapor quality, using genetic algorithm. The homogeneous model is assumed with ammonia as the working fluid, the coolant being environmentally friendly and having recently discovered as a potential replacement for the current refrigerants in micro and mini-channels. Results show that significant differences in the frictional pressure drop and Martinelli parameter arise due to the different correlations used, and this is only the outcome from two different correlations currently being considered by researchers in pressure drop analysis for two-phase flows in mini-channels. Thus, absolute agreement is indeed not possible between theoretical, experimental, and numerical work in view of the many different available correlations being utilized today with differences between 10 to 100 percent that has already been established.

Abstract: The effect of amines and ammonia vapour on luminescence of Eu (III) complexes immobilized in different matrices has been investigated. It has been revealed that interaction of Eu (III) tris-dibenzoylmethanate with analyte vapour results in the increase of the intensity of Eu (III) luminescence. The mechanism of the effect of ammonia and amines vapours on intensification of the Eu (III) luminescence has been suggested using the data of IR, luminescence spectroscopy and quantum chemistry calculations.

Abstract: Ammonia classified as one of the hazardous chemical to environment and human. Therefore, monitoring the ammonia in air is vital. Chitosan film was selected as a sensing material for ammonia detection in this study. Chitosan powder was dissolved in 2% of acetic acid to form chitosan solution gel. It was subsequently deposited on patterned electrode by using electrochemical deposition technique. The response of the chitosan sensor towards ammonia was tested via electrical testing by exposing different ammonia concentration ranging from 20 ppm, 100 ppm, 200 ppm, and 300 ppm using air exposure technique. The response of the chitosan sensor towards ammonia was recorded as output voltage. Sensor properties which include sensitivity, stability, recovery, and repeatability were studied. The electrical result showed that the response of chitosan sensor increases as the ammonia concentration increases. All the sensing properties were achieved. Finally, the structure characterization of the chitosan was studied using Fourier Transform Infrared Spectroscopy (FTIR). The appearance of N-H and O-H groups in FTIR spectrum of chitosan film provides evidence that the domain functional group exist in chitosan after it was processed into film.

Abstract: Porous polyvinylidene fluoride (PVDF) membranes were prepared from PVDF and N-methyl-2-pyrrolidone (NMP) solution system using immersion precipitation phase inversion technique with ammonia as an inert solvent additive. The effects of ammonia amount on pore size, surface morphology, crystallinity, hydrophobic property, oil uptake and water-oil separation performance of the membranes were investigated. It was found that all membranes had an interpenetrating porous structure. The increase of ammonia amount led to significant variations in morphology. Lots of tiny apophysis formed on the membrane surface, pore size deceased, and pore density increased with the increase of ammonia amount. The crystallinity decreased with increasing ammonia amount, and hydrophobic property was improved. The membrane showed high oil uptake and effective separation function of oil-water mixture.

Abstract: Benzene derivatives and Ammonia contamination in University Laboratories can cause great harm to the researcher’s health. To investigate the status of air quality in the laboratory, Benzene derivatives and ammonia were monitored in a water analysis laboratory. Besides, the results of monitoring were analyzed to provide reference on the improvement of laboratory.

Abstract: Toxic data of local fishes was very essential in the derivation of local water quality criteria. In this study, two local fishes (S.dabryi and P.parva) of Liao River were chosen to conduct 96-h acute toxic data under ammonia (total ammonia) whose pollution was proved to be serious in Liao River. 96 h LC50s of S.dabryi and P.parva under total ammonia were 35.36 mg/L (pH=7.50, T=20.00°C) and 30.35 mg/L (pH=7.50, T=20.00°C), respectively. These toxic values could be used to supply the local database which was the basement to formulate site-specific water quality criteria accordingly in Liao River.

Abstract: NH₃ was synthesized from H₂ and N₂ under normal temperature and pressure by microwave plasma. The effects of microwave input power, ratio of H₂/N₂, the amount of total material gas concentration and catalyst on the synthetic reaction were studied. The volume fraction of NH₃ can reach 0.58% under the optimal condition.