10 kW 급 암모니아-수소 혼소엔진을 위한 암모니아 개질 촉매 및 반응기 설계에 관한 연구

이상호,최영,박철웅,김홍석,이영덕,김영상 한국수소및신에너지학회 2020 한국수소 및 신에너지학회논문집 Vol.31 No.4

Ammonia-hydrogen dual-fuel engine is a way to reduce greenhouse gas emission because ammonia and hydrogen are carbon-free fuels. In ammonia-hydrogen dual-fuel engine, hydrogen is supplied to improve the combustion characteristic of ammonia. In this study, an ammonia reformer was developed to supply hydrogen for 10 kW class ammonia-hydrogen dual-fuel engine. Thermodynamic characteristic and catalyst were investigated for ammonia reforming. Heat transfer was important for high ammonia conversion of ammonia reformer. 99% of ammonia conversion was obtained when 10 LPM of ammonia and 610℃ of hot gas were supplied to the ammonia reformer.

Ammonia as a marine fuel: likelihood of ammonia releases

문경태,Paul Davies,Louise Wright 한국마린엔지니어링학회 2023 한국마린엔지니어링학회지 Vol.47 No.6

The maritime industry is transitioning to low or zero carbon fuels and ammonia is one of the potential substitutes for con-ventional fuels. For safe use of ammonia as a fuel, risk assessment is necessary to address the hazards presented by ammonia and to provide insights where experience as a fuel does not exist. Therefore, it is important to estimate the likelihood of ammonia releases is important. However, there is a lack of applicable leak data within the maritime industry. This study examines applicability of leak data from oil and gas industry by comparing the historical ammonia leak frequency recorded in the LPG tankers carrying ammonia with leak frequency estimate derived from the oil and gas data. The analysis shows that the oil and gas data provide a more conservative estimate than the historical leak frequency, concluding that the oil and gas data can be considered as a useful starting point for estimating the likelihood of ammonia releases. In addition, the ammonia leakage frequency of an ammonia-fuelled LPG carrier is estimated using the oil and gas leak database. The estimated frequency is approximately 0.054 per year, suggesting that the vessel could experience more than one ammonia leaks during operation.

면양에 의한 암모니아-황산병용처리 볏짚의 반추위내 발효특성

문승식,유성오 진주산업대학교 농업기술연구소 1998 農業技術硏究所報 Vol.11 No.-

This study was carried out to investigate the effects of treatment of ammonia (NH_3)-sulfuric acid combination on feed value of rice straw as a ruminant feedstuff. Rice straw was treated with 3% ammonia (W/DM) for at least 45 days and further with sulfuric acid for overnight to complete the combination treatment. The treated rice straw was then sun-dried, and the chemical composition of the treated rice straw was analyzed. Also, three sheep (49.8 kg) were used to determine the fermentation characteristics in the rumen. The treatments included untreated, ammonia-treated, and ammonia·H_2SO_4 combination-treated rice straw. The results are as follows 1. Ruminal pH of sheep fed ammonia·H_2SO_4 combination-treated rice straw was slightly lower at all times after feeding, but no difference was observed among 1∼8 hours after feeding. 2. Ruminal ammonia nitrogen concentrations of sheep fed ammonia·H_2SO_4 combination-treated rice straw was significantly (P<0.05) higher than those of sheep fed untreated and ammonia-treated rice straw. 3. Ruminal total VFA concentration peaked at 1 hour after feeding, and was higher in ammonia-treated and ammonia·H_2SO_4 combination-treated rice straw than that of sheep fed untreated rice straw. 4. Ruminal acetic acid and propionic acid concentration of sheep fed ammonia-treated and ammonia·H_2SO_4 combination-treated rice straw were slightly higher than that of sheep fed untreated rice straw from 1 to 8 hours after feeding. 5. Ruminal acetic acid to propionic acid ratio of sheep fed ammonia-treated rice straw was slightly higher than those of sheep fed other treatments. 6. Ruminal butyric acid concentration of sheep fed untreated rice straw was lower than those of sheep fed other treatments from 1 to 8 hours after feeding.

암모니아-황산병용처리 볏짚의 in vitro 소화율 및 면양의 기호성

정현승,유성오 진주산업대학교 농업기술연구소 1998 農業技術硏究所報 Vol.11 No.-

This study was carried out to investigate the effects of treatment of ammonia(NH_3)-sulfuric acid combination on feed value of rice straw as a ruminant feedstuff. Rice straw was treated with 3% ammonia(W/DM) for at least 45 days and further with sulfuric acid for overnight to complete the combination treatment. The treated rice straw was then sun-dried, and the chemical composition and in vitro digestibility of the treated rice straw was analyzed. Also, three sheep (49.8 kg) were used to determine palatability. The treatments included untreated, ammonia-treated and ammonia·H_2SO_4 combination-treated rice straw. The results are as follows 1. Crude protein content was higher(P<0.05), in ammonia·H_2SO_4 combination-treated rice straw than those of other treatments, but NDF and ADF contents were lower (P<0.05) in ammonia·H_2SO_4 combination-treated rice straw than those of other treatments. 2. Total nitrogen and ammonia nitrogen contents were higher(P<0.05) in ammonia·H_2SO_4 combination-treated rice straw han those of other treatments. 3. In vitro dry matter and crude protein digestibilities were higher(P<0.05) in ammonia·H_2SO_4 combination-treated rice straw than those of other treatments. 4. For estimation of palatability, dry matter intake per metabolize body weight(BW^0.75) for 30 minutes was slightly higher in ammonia-treated and ammonia·H_2SO_4 combination-treated rice straw than that of untreated rice straw, although statistical differences were not observed.

Effects of acclimation and pH on ammonia inhibition for mesophilic methanogenic microflora

Park, Jong-Hun,Yoon, Jeong-Jun,Kumar, Gopalakrishnan,Jin, Yong-Su,Kim, Sang-Hyoun Elsevier 2018 waste management Vol.80 No.-

<P><B>Abstract</B></P> <P>This work evaluated the toxicity of ammonia toward mesophilic methanogenic microflora, with respect to the acclimation and pH. Microflora acclimated to total ammonia nitrogen (TAN) concentrations of 1.0–2.5 g N/L and neutral to alkaline pH, 7.5–8.0, were used for anaerobic toxicity assays (ATA) with TAN up to 6.1 and pH ranged from 7 to 8.2. The effect of ammonia on the specific methanogenic activity (SMA) and methane yield (MY) was described using a noncompetitive model. Acclimation increased the tolerance of the methanogenic microflora to ammonia over the acclimation range. There was no significant difference in the values of SMA and MY at each TAN concentration in the examined pH range, although free ammonia nitrogen (FAN) concentrations increased along with pH. It implied that TAN rather than FAN would be the useful criterion for ammonia inhibition. Propionate degradation was more inhibited compared to acetoclastic methanogenesis by ammonia. The half-maximal inhibitory concentrations (<I>IC</I> <SUB>50</SUB>) of TAN for the SMA from acetate, SMA from propionate, MY from acetate, and MY from propionate were 3.42–4.26, 3.14–3.91, 3.67–4.07, and 3.34–3.88 g N/L, respectively, at pH 7.4. 454-pyrosequencing analysis of the inoculum showed that the archaeal community was dominant of <I>Methanosarcinaceae</I> and <I>Methanobacteriaceae</I>, which were known as tolerant to ammonia inhibition.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Acclimation increased the tolerance to ammonia inhibition over the acclimated range. </LI> <LI> Total ammonia rather than free ammonia would be the direct inhibition criterion. </LI> <LI> Propionate degradation was more sensitive to NH<SUB>3</SUB> than acetoclastic methanogenesis. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

The feasibility of ammonia as marine fuel and its application on a medium-size LPG/ammonia carrier

Muammer Akturk,서정관 한국마린엔지니어링학회 2023 한국마린엔지니어링학회지 Vol.47 No.3

The study investigated the feasibility of using ammonia as a marine fuel and its application on a medium-size LPG/ammonia carrier. The study included a comprehensive literature review of existing research on ammonia as a marine fuel and further research on industrial developments in the field to gain insights into the practical challenges and opportunities associated with using ammonia as a marine fuel. The study found that ammonia has several advantages as a marine fuel, including its high energy density, low emis-sions profile, and potential for production from renewable sources. However, there are also significant technical, economic, and safety challenges associated with using ammonia, particularly in the design and operation of marine engines and fuel systems, particularly due to ammonia’s combustion characteristics. The study also demonstrated that the application of ammonia on a medium size LPG/Am-monia carrier is feasible but requires investment and technical expertise. The findings of this study have important implications for the shipping industry's efforts for decarbonization and suggest that ammonia could play a significant role in a carbon-free maritime future. In conclusion, the study provides a comprehensive analysis of the feasibility of ammonia as a marine fuel and highlights its potential application on a medium size LPG/Ammonia carrier.

NUTRITIVE VALUES AND GROWTH RESPONSE OF CATTLE FED AMMONIA TREATED RICE STRAW

Maeng, W.J.,Chung, T.Y. Asian Australasian Association of Animal Productio 1989 Animal Bioscience Vol.2 No.1

Nutritive values and fermentation rates of rice straw treated with 3% anhydrous and 3% aqueous ammonia were evaluated both in vitro and sheep metabolism trials. Daily gain, feed efficiency and feed cost per gain were also determined with growing Holstein bulls fed anhydrous and aqueous ammonia treated rice straw. Crude protein was increased 2.4 fold and NDF was decreased 6.5%, but ADF and cellulose were not different between untreated and ammonia treated rice straw. An average of 35.5% of total added ammonia-N retained in the rice straw and other 64.5% was not retained in the rice straw. Ammonia treatment increased in vitro DM, NDF, ADF and cellulose digestibilities by 44.8%, 43.3%, 49.4% and 42.4%, respectively, and fermentation rates by 63.3%, 132.4%, 49.4% and 42.4%, respectively. In sheep metabolism trials, DM digestibilities of rice straw treated with anhydrous and aqueous ammonia were increased 22% and 36%, respectively, and digestible DM intakes by 48% and 70%, respectively in sheep fed anhydrous and aqueous ammonia treated rice straw over untreated rice straw. Rumen ammonia and blood urea were considerably higher in sheep fed ammonia treated rice straw than sheep fed untreated rice straw. Daily gain of Holstein bulls was increased 20.8% and 29.9% and rice straw intakes were increased 28.4% and 44.3% in anhydrous and aqueous ammonia treated rice straw over untreated rice straw. Feed conversion was improved 9.5% and 10.3% and feed cost/gain was reduced 7.1% and 9.2% respectively in anhydrous and aqueous ammonia treated rice straw group as compared with untreated rice straw group.

Ammonia half-saturation constants of sludge with different community compositions of ammonia-oxidizing bacteria

Pantip Kayee,Chaiwat Rongsayamanont,Pattaraporn Kunapongkiti,Tawan Limpiyakorn 대한환경공학회 2016 Environmental Engineering Research Vol.21 No.2

Owing to the kinetic differences in ammonia oxidation among ammonia-oxidizing microorganisms (AOM), there is no standard set of kinetic values that can be used as a representative set for nitrifying wastewater treatment plant (WWTP) design. As a result, this study clarified a link between the half-saturation constants for ammonia oxidation (Ks) and the dominant ammonia-oxidizing bacterial (AOB) groups in sludge from full-scale WWTPs and laboratory-scale nitrifying reactors. Quantitative polymerase chain reaction analyses revealed that AOB affiliated with the Nitrosomonas oligotropha cluster were the dominant AOM groups in the sludge taken from the low-ammonia-level WWTPs, while AOB associate with the Nitrosomonas europaea cluster comprised the majority of AOM groups in the sludge taken from the high-ammonia-level WWTPs and nitrifying reactors. A respirometric assay demonstrated that the ammonia Ks values for the high-ammonia- level WWTPs and nitrifying reactors were higher than those of the low-ammonia-level plants. Using the Ks values of available AOM cultures as a reference, the Ks values of the analyzed sludge were mainly influenced by the dominant AOB species. These findings implied that.different sets of kinetic values may be required for WWTPs with different dominant AOM species for more accurate WWTP design and operations.

가솔린 엔진에서 가솔린-암모니아 혼합 연료의 연소 및 배기 특성

유경현(Kyunghyun Ryu) 한국자동차공학회 2013 한국 자동차공학회논문집 Vol.21 No.6

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 CO₂ 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.

연구보문 : 토양환경 ; 밭 토양에서 돈분 퇴비 시용방법에 따른 암모니아 휘산량 평가

윤홍배 ( Hong Bae Yun ),이연 ( Youn Lee ),이상민 ( Sang Min Lee ),김석철 ( Suk Chul Kim ),이용복 ( Yong Bok Lee ) 한국환경농학회 2009 한국환경농학회지 Vol.28 No.1

대기중으로 휘산되는 대부분의 암모니아는 농경지에서 시용하는 가축분뇨 퇴비와 질소비료에서 유래한다. 본 연구는 밭 토양에서 돈분 퇴비 시용방법에 따른 암모니아 휘산량을 소형원드터널 방법을 이용해서 정량적으로 평가하였다. 돈분 퇴비(20 Mg/ha) 표층살포(SA), 표층살포 후 즉시 경운(IRA), 표층 살포 3일 후 경운(RA-3d) 처리의 13일 동안 암모니아 휘산량은 각각 28.7, 8.7, 24.3 kg N/ha로 IRA 처리구는 SA 처리구에 비해 70% 저감효과를 가져왔다. 그리고 SA 처리구의 퇴비 처리 후 24시간 이내 휘산된 암모니아양은 총 휘산량의 61%로 대부분의 암모니아는 시용 초기 짧은 시간 내에 휘산됨을 알 수 있었다. 석회와 퇴비 혼용시용 후 교반(L+C mix), 퇴비표층 살포 3일 후 석회시용 교반(C+L3D), 석회시용 3일 후 퇴비시용 교반(L+C3D) 처리구의 22일 동안 총 암모니아 휘산량은 각각 40.1, 31.4, 27.7 kg/ha이었다 따라서 가축분 퇴비 시용시 석회를 혼용하는 것은 피해야 하며, 만일 동일 작기내 시용이 불가피할 경우는 퇴비시용에 앞서 석회를 먼저 충분한 일수를 앞두고 시용하는 것이 암모니아 휘산량을 저감시킬 수 있다는 결론을 얻었다. Ammonia in atmosphere has a negative effect on the natural ecosystems, such as soil acidification and eutrophication, by wet and dry deposition. Livestock manure, compost, and fertilizer applications to arable land have been recognised as a major source of atmospheric ammonia emissions. The objective of this study was to evaluate the efficiency of compost application techniques in reducing ammonia loss in upland soil. The reductions in ammonia emission were 70 and 15% for immediate rotary after application (IRA) and rotary at 3 day after application (RA-3d) in comparison with surface application (SA). Total ammonia emissions for 13 days, expressed as % ammonia-N applied with compost, were 42, 35.7, and 12.7% for SA, RA-3d, and IRA treatments, respectively. The ammonia emission rate fell rapidly 6 h after application and 61% of total ammonia emission occurred within the first 24 h following surface application. The lime application along with compost significantly enhanced the total ammonia emission. Total ammonia emission for 22 days were 40.1, 31.4, and 27.7 kg/ha for immediate incorporation in soil after lime and compost application, lime incorporation in soil following 3 days after compost surface application, and compost incorporation in soil following 3 days after lime surface application, respectively. Therefore, lime and livestock manure compost application at the same time was not recommended for abatement of ammonia emission in upland soil.