• KEPCO Journal on Electric Power and Energy
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• v.2 no.3
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• pp.437-445
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• 2016

This paper discussed the effect of ammonia concentration adsorbed on fly ash for the ammonia emission as AAFA (Ammonia Adsorbed Fly Ash) produced from coal fired plants due to operation of NOx reduction technologies was landfilled with distilled or sea water at closed and open systems, respectively. Ammonia bisulfate and sulfates adsorbed on fly ash is highly water soluble. The pH of ammonium bisulfate and sulfate solution had significant effect on ammonia odor emission. The effect of temperature on ammonia odor emission from mixture was less than pH, the rate of ammonia emission increased with increased temperature when the pH conditions were kept at constant. Since AAFA increases the pH of solution substantially, $NH_3$ in the ash can release the ammonia order unless it is present at low concentration. $NH_4{^+}$ ion is unstable in fly ash and water mixtures of high pH at open system, which is changed to nitrite or nitrate and then released as ammonia gas. The proper conditions for < 20 ppm of ammonia concentration released from the AAFAs landfilled in ash pond were explored using an open system with sea water. It was therefore proposed that optimal operation to collect AAFA of less than 168 ppm ammonia at the electrostatic precipitator were controlled to ammonia slip with less than 5 ppm at SCR/SNCR installations, and, ammonia odor released from mixture of fly ash of 168 ppm ammonia with sea water under open system has about 20 ppm.

• Membrane and Water Treatment
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• v.9 no.3
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• pp.189-194
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• 2018

Electrochemical reduction of nitrate was studied using Zn, Cu and (Ir+Ru)-Ti cathodes and Pt/Ti anode in a cell divided by an ion exchange membrane. During electrolysis, effects of the different cathode types on operating parameters (i.e., voltage, temperature and pH), nitrate removal efficiency and by-products (i.e., nitrite and ammonia) formation were investigated. Ammonia oxidation rate in the presence of NaCl was also determined using the different ratios of hypochlorous acid to ammonia. The operating parameter values were similar for all types of cathode materials and were maintained relatively constant. Nitrate was well reduced and converted mostly to ammonia using Zn and Cu cathodes. Ammonia, produced as a by-product of nitrate reduction, was oxidized in the presence of NaCl in the electrochemical process and the oxidation performance was enhanced upon increasing the hypochlorous acid-to-ammonia ratio to 1.09:1. Zn and Cu cathodes promoted the nitrate reduction to ammonia and the produced ammonia was finally removed from solution by reacting with hypochlorite ions. Using Zn or Cu cathodes, instead of noble metal cathodes, in the electrochemical process can be an alternative technology for nitrate-containing wastewater treatment.

• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.4
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• pp.113-119
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• 2001

Ammonia emissions during composting of hog manure mixed with sawdust were studied in four runs comprising a total of 22 pilot-scale reactor vessels. These four runs extended previous work and both verified and extended the previous conclusions. The pilot-scale vessels were 205 L insulated stainless steel drums that were aerated either continuously (high/low thermostatically controlled fans) or intermittently (5 min high fan 55 min off). Temperature ammonia emissions air flow rates carbon dioxide production and oxygen utilization moisture and dry matter reduction initial and final chemical compositions were measured. Ammonia emissions from the intermittently aerated vessels were only about 50% as great as those from the continuously aerated ones but this was found to be a result more related to total air flow than to aeration technique. All of the data for total result more related to total air flow were fitted with a linear regression line y=0.139x+29.835 where y is ammonia expressed as g of N and x is air flow in kg with $R^2$=0.6808. this general trend indicates that about 50% reduction in ammonia emissions can be achieved with 75% reduction in air flow. For the aeration techniques used the minimum oxygen level in te exhaust gas from the vessels was 5% and this is probably a resonable lower limit constraining air flow reduction. However within this constraint lower air flow now appears to be a technique that can reduce odorous ammonia emissions.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.6
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• pp.155-165
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• 2013

The effect of gaseous ammonia direct injection on the engine performance and exhaust emissions in gasoline-ammonia dual fueled spark-ignition engine was investigated in this study. Results show that based on the gasoline contribution engine power increases as the ammonia injection timing and duration is advanced and increased, respectively. However, as the initial amount of gasoline is increased the maximum power output contribution from ammonia is reduced. For gasoline-ammonia, the appropriate injection timing is found to range from 320 BTDC at low loads to 370 BTDC at high loads and the peak pressures are slightly lower than that for gasoline due to the slow flame speed of ammonia, resulting in the reduction of combustion efficiency. The brake specific energy consumption (BSEC) for gasoline-ammonia has little difference compared to the BSEC for gasoline only. Ammonia direct injection causes slight reduction of $CO_2$ and CO for all presented loads but significantly increases HC due to the low combustion efficiency of ammonia. Also, ammonia direct injection results in both increased ammonia and NOx in the exhaust due to formation of fuel NOx and ammonia slip.

• Environmental Engineering Research
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• v.23 no.2
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• pp.136-142
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• 2018

The river water source of Saidabad Surface Water Treatment Plant at Dhaka, Bangladesh, is deteriorated too much to be treated by conventional treatment process due to excessive ammonia pollution. In order to improve the raw water quality before it enters into the main treatment chain, a pilot study was conducted for pre-treatment of the raw water. The objective is to investigate the rate of reduction of ammonia using the Meteor pilot, a biological pretreatment system, which is a laboratory scale Moving Bed Biofilm Reactor with a nominal volume of hundred liters, filled with 50 L of Meteor 660 media. The reduction of ammonia was quite significant on average 73%, while the reduction of COD was in a range from 20 to 60%. The Meteor pilot was able to treat and nitrify the raw water and produce an effluent that respects the guarantee of ammonia < $4.0mg\;NH_3-N/L$ when the raw water ammonia concentration was < $15mg\;NH_3-N/L$. The study identified operating parameters necessary to achieve the desired goal of adequate ammonia removal. The study results would benefit a range of systems across the country by providing guidance on the design and operation of a biological pre-treatment system for ammonia removal.

• Journal of the Korean Electrochemical Society
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• v.22 no.1
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• pp.1-12
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• 2019

The reduction of nitrogen to produce ammonia has been attracting much attention as a renewable energy technology. Ammonia is the basis for many fertilizers and is also considered an energy carrier that can power internal combustion engines, diesel engines, gas turbines, and fuel cells. Traditionally, ammonia has been produced through the Haber-Bosch process, in which atmospheric nitrogen combines with hydrogen at high temperature ($350-550^{\circ}C$) and high pressure (150-300 bar). This process consumes 1-2% of current global energy production and relies on fossil fuels as an energy source. Reducing the energy input required for this process will reduce $CO_2$ emissions and the corresponding environmental impact. For this reason, developing electrochemical ammonia-production methods under ambient temperature and pressure conditions should significantly reduce the energy input required to produce ammonia. In this review, we introduce the electrochemical nitrogen reduction reaction at ambient condition. Numerical studies on the electrochemical nitrogen reduction mechanism have been carried out through the computation of density function theory. Electrodes such as nanowires and porous electrodes have been also actively studied for further participation in electrochemical reactions.

• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.7
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• pp.46-52
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• 2002

Manure compost biofilter for reducing ammonia emissions at the active stage of a semi air tight and agitated bed composting of hog manure amended with sawdust were evaluated in the practical composting plant(75 m 5 m $\times$1.4 m deep). During 55 days of composting and biofiltration process, the manure compost biofilter had a ammonia reduction of 91 to 98%. Results showed that the active stage of composting maintained temperatures between 40 and 7$0^{\circ}C$ and fluctuated greatly the ammonia concentrations between 100 and 300 ppm. Ammonia concentrations in manure compost biofiltration reached within a moderate range (2-18 ppm).

• Corrosion Science and Technology
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• v.21 no.6
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• pp.514-524
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• 2022

Carbon emissions from fuel consumption have been pointed by scientists as the cause of global warming. In particular, fossil fuels are known to emit more carbon when burned than other types of fuels. In this regard, International Maritime Organization has announced a regulation plan to reduce carbon dioxide emissions. Therefore, recently, Liquefied Natural Gas propulsion ships are responding to such carbon reduction regulation. However, from a long-term perspective, it is necessary to use carbon-free fuels such as hydrogen and ammonia. Nitrogen oxides might be generated during ammonia combustion. There is a possibility that incompletely burned ammonia is discharged. Therefore, rather than being used as a direct fuel, Ammonia is only used to reduce NO_X such as urea solution in diesel vehicle Selective Catalyst Reduction. Currently, LPG vehicle fuel feed system studies have evaluated the durability of combustion injectors and fuel tanks in ammonia environment. However, few studies have been conducted to apply ammonia as a ship fuel. Therefore, this study aims to evaluate corrosion damage that might occur when ammonia is used as a propulsion fuel on ships.

• KEPCO Journal on Electric Power and Energy
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• v.4 no.1
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• pp.39-45
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• 2018

Ammonia Adsorbed Fly Ash (AAFA) samples produced from coal fired plants equipped with SNCR (Selective Non-Catalytic Reduction) of nitrogen oxides with urea have been chemically analyzed, and their physical and dissolution properties have been investigated. XRD results for the ammonia component in AAFA ascertained that ABS (ammonium bisulfate) and AS (ammonium sulfate) were deposited on fly ash as $SO_3$ reacted with unreacted ammonia at SNCR. SEM and EDS images showed that fine ashes on large fly ash surface of sphere type were agglomerated, due to adhesive role of ammonium salts attached fly ashes. Dissolution test results of ammonium salts absorbed on AAFA in distilled water or sea water showed that the proportion of un-ionized $NH_3$ to $NH_4{^+}$ were primarily a function of pH and temperature. Increasing pH and temperature causes an increase in the fraction of un-ionized $NH_3$. At pHs of 9.6 and 10.7, un-ionized $NH_3$ and $NH_4{^+}$ ions are present in equal amounts at distilled water and sea water, respectively.

• Journal of Animal Environmental Science
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• v.12 no.2
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• pp.85-94
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• 2006

The effects of turning frequency of in-vessel composting on ammonia emissions during composting of separated solids from swine slurry/sawdust mixtures and performance of biofiltration using the chicken manure compost were investigated. Separated solids from swine manure amended with sawdust was composted in a 226 L laboratory-scale in-vessel reactors under various turning frequency and continuous airflow (0.6 L/min.kg.dm) for three weeks. Three laboratory-scale manure compost biofilters were built to treat effluent gas from the composting of separated solid from swine manure amened with sawdust process. These experiments were continued over a period of three weeks. The composting of separated solid swine manure amended with sawdust and manure compost biofiltration system were evaluated to determine the turning frequency type that would be adequate for the rate of decomposition and compost odour reduction. The compost odour cleaning was measured based on ammonia gas concentration before and after passing through the manure compost biofilter. The average ammonia odor reduction in the manure compost biofilter was 96.9 % at R1 (no turning), 99.4 % at R2(once a day turning) and 89.0 % at R3(twice a day turning), respectively. The efficiency of ammonia reduction was mainly influenced by the turning frequency.