• Title/Summary/Keyword: gas production

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Anaerobic treatment of red-bean processing wastewater in a sludge bed reactor (슬러지반응기에서 팥가공폐수의 철기성 처리)

  • 안재동;금재우;홍종향
    • Journal of environmental and Sanitary engineering
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    • v.9 no.1
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    • pp.29-37
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    • 1994
  • Anaerobic treatment of wastewater of the red- bean processing industry was carried out and discussed an anaerobic sludge bed reactor( ASBR) as a preliminary study to evaluate applicability of given processes. The dimension of reactor were same as 0.09m- ID$\times $1.5m- height. The type of substrate and the hydraulic retention time( HRT) were considered as experimental variables. The synthetic wastewater with glucose in the laboratory, the wastewater from the red bean processing industry mixed with synthetic wastewater with variation of mixing percent were fed as substrate. The hydraulic retention time was changed from one day to five days. The gas production, the methane content in produced gas, efficiencies of COD removal and 55 removal were evaluated as principal characteristics. With synthetic wastewater as a substrate and at a hydraulic retention time of one day, characteristics of ASBR was the gas production(12$\ell$/day ), the methane content of produced gas(60%), the efficiency of COD removal(92%) and 55 removal(30%). With the real wastewater and at a hydraulic retention time of one day, the gas production and the efficiency of COD removal of the ASBR decreased with the proportion of real wastewater. The gas production and the efficiency of COD removal with real wastewater only was decreased to 70% and 87% of those with synthetic wastewater only, respectively. However, the methane content in produced gas and the efficiency of 55 removal with real wastewater only was increased significantly by 1.25 times and two times of those with synthetic wastewater only, respectively. However, the methane content in produced gas and the efficiency of 55 removal with real wastewater only was increased significantly by 1.25 times and two times of those with synthetic wastewater only, respectively. With real wastewater only as a substrate in the ASBR, the gas production was decreased with an increase of HRT, but the efficiency of COD removal increased with HRTI like the usual trend reported. As a conclusion, the wastewater of the red- bean Processing industry could be treated by anaerobic digestion successfully in the ASBR.Anaerobic treatment of wastewater of the red- bean processing industry was carried out and discussed an anaerobic sludge bed reactor( ASBR) as a preliminary study to evaluate applicability of given processes. The dimension of reactor were same as 0.09m- ID$\times $1.5m- height. The type of substrate and the hydraulic retention time( HRT) were considered as experimental variables. The synthetic wastewater with glucose in the laboratory, the wastewater from the red bean processing industry mixed with synthetic wastewater with variation of mixing percent were fed as substrate. The hydraulic retention time was changed from one day to five days. The gas production, the methane content in produced gas, efficiencies of COD removal and 55 removal were evaluated as principal characteristics. With synthetic wastewater as a substrate and at a hydraulic retention time of one day, characteristics of ASBR was the gas production(12$\ell$/day ), the methane content of produced gas(60%), the efficiency of COD removal(92%) and 55 removal(30%). With the real wastewater and at a hydraulic retention time of one day, the gas production and the efficiency of COD removal of the ASBR decreased with the proportion of real wastewater. The gas production and the efficiency of COD removal with real wastewater only was decreased to 70% and 87% of those with synthetic wastewater only, respectively. However, the methane content in produced gas and the efficiency of 55 removal with real wastewater only was increased significantly by 1.25 times and two times of those with synthetic wastewater only, respectively. However, the methane content in produced gas and the efficiency of 55 removal with real wastewater only was increased significantly by 1.25 times and two times of those with synthetic wastewater only, respectively. With real wastewater only as a substrate in the ASBR, the gas production was decreased with an increase of HRT, but the efficiency of COD removal increased with HRTI like the usual trend reported. As a conclusion, the wastewater of the red- bean Processing industry could be treated by anaerobic digestion successfully in the ASBR.

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High Efficient Metal Powder Production by Gas Atomisation Process

  • Unal, Rahmi;Aydin, Mehmet
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09a
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    • pp.14-15
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    • 2006
  • In this study, a new laval type nozzle was designed and manufactured. Using this nozzle tin powder was produced in close coupled system by using nitrogen gas at different operating conditions. The results showed that the increasing the gas pressure up to 1.47 MPa reduced the mean powder size down to 11.39 microns with a gas/melt mass flow rate ratio of 2.0. Powders are spherical in shape and have smooth surfaces.

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Comparison of Gayal (Bos frontalis) and Yunnan Yellow Cattle (Bos taurus): In vitro Dry Matter Digestibility and Gas Production for a Range of Forages

  • Xi, Dongmei;Wanapat, Metha;Deng, Weidong;He, Tianbao;Yang, Zhifang;Mao, Huaming
    • Asian-Australasian Journal of Animal Sciences
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    • v.20 no.8
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    • pp.1208-1214
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    • 2007
  • Three male Gayal, two years of age and with a mean live weight of $203{\pm}26$ kg, and three adult Yunnan Yellow Cattle, with a mean live weight of $338{\pm}18$ kg were fed a ration of pelleted lucerne hay and used to collect rumen fluid for in vitro measurements of digestibilities and gas production from fermentation of a range of forages. The forages were: bamboo stems, bamboo twigs, bamboo leaves, rice straw, barley straw, annual ryegrass hay, smooth vetch hay and pelleted lucerne hay. There were significant (p<0.05) effects of the source of rumen fluid on in vitro dry matter digestibility (IVDMD) and gas production during fermentation of forage. For the roughage of lowest quality (bamboo stems and rice straw), gas production during fermentation was higher (p<0.05) in the presence of rumen fluid from Gayal than Yunnan Yellow Cattle. Differences for these parameters were found for the better quality roughages with gas production being enhanced in the presence of rumen fluid from Yunnan Yellow Cattle. Moreover, the IVDMD of investigated roughages was significantly higher (p<0.05) in Gayal than Yunnan Yellow Cattle. The results offer an explanation for the positive live weight gains recorded for Gayal foraging in their natural environment where the normal diet consists of poor quality roughages.

Chemical Composition, Degradation Characteristics and Effect of Tannin on Digestibility of Some Browse Species from Kenya Harvested during the Wet Season

  • Osuga, I.M.;Abdulrazak, S.A.;Ichinohe, T.;Fujihara, T.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.1
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    • pp.54-60
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    • 2005
  • A study was conducted with the objective of evaluating the nutritive value of some browse species from Kenya. The species evaluated included: Bauhinia alba, Bauhinia variegata, Bridelia micrantha, Calliandra calothyrsus, Carisa edulis, Cratylia argentea, Gliricidia sepium, Lantana camara, Maerua angolensis, Sesbania micrantha and S. sesban. The browses were evaluated by their chemical composition including phenolics, in vitro gas production and tannin activity (tannin bioassay). All the species had high crude protein content (149-268 g/kg DM) and low NDF content (239-549 g/kg DM). The feeds had varying contents of total extractable tannins (TET) ranging from low (3-22 mg/g DM), moderate (42-58 mg/g DM) and high (77-152 mg/g DM). Calliandra calothyrsus had the highest tannin content. Significant (p<0.05) variation in gas production was recorded among the species. Sesbania micrantha had the highest (p<0.05) potential gas production while Gliricidia sepium had the highest (p<0.05) rate of gas production. Use of polyethylene glycol (PEG 6000), to assess the adverse affect of tannins, indicated that tannins in browse species with high tannin content had inhibitory effects on rumen microbial fermentation as indicated by the gas production. Estimated organic matter digestibility and metabolizable energy also increased with PEG addition. The results of this study indicate that such Kenyan browse species have the potential to be used as feed supplements for ruminant animals.

Effects of Cordyceps militaris Mycelia on In vitro Rumen Microbial Fermentation

  • Yeo, Joon Mo;Lee, Shin Ja;Lee, Sang Min;Shin, Sung Hwan;Lee, Sung Hoon;Ha, Jong K.;Kim, WanYoung;Lee, Sung Sill
    • Asian-Australasian Journal of Animal Sciences
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    • v.22 no.2
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    • pp.201-205
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    • 2009
  • Effects of Cordyceps militaris mycelia on rumen microbial fermentation were determined by measuring in vitro gas production, cellulose digestion and VFA concentrations. C. militaris mycelia was added to buffered rumen fluid with final concentrations of 0.00, 0.10, 0.15, 0.20, 0.25 and 0.30 g/L and incubation times were for 3, 6, 9, 12, 24, 36, 48 and 72 h. At all incubation times, the gas production showed a quadratic increase with the supplementation of C. militaris mycelia; maximum responses were seen with 0.25 g/L supplementation. However, the gas production was significantly lower for the 0.30 g/L supplementation than for the 0.25 g/L supplementation from 9 h to 72 h incubation. The cellulose filter paper (FP) digestion showed a quadratic increase, as did the gas production except at 3 h incubation. The concentration of total VFA was significantly increased by the supplementation of C. militaris mycelia compared with the control treatment; the highest response was also seen with 0.25 g/L supplementation. This was true for responses in the concentration of acetic and propionic acids. As opposed to other responses, the responses of pH to the supplementation of C. militaris mycelia showed a quadratic decrease from 3 h to 36 h incubation. In conclusion, C. militaris mycelia alter the mixed rumen microbial fermentation with increases in the production of gas and VFA, and cellulose FP digestion.

The Relationship between Korea Agricultural Productions and Greenhouse Gas Emissions Using Environmental Kuznets Curve (환경쿠즈네츠곡선을 이용한 한국의 농업 생산과 온실가스 배출의 관계 분석)

  • Kang, Hyun-Soo
    • Asia-Pacific Journal of Business
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    • v.12 no.1
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    • pp.209-223
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    • 2021
  • Purpose - The purpose of this study was to investigate the relationship between Korea agricultural productions and Greenhouse Gas (GHG) emissions based on Environmental Kuznets Curve (EKC) hypothesis. Design/methodology/approach - This study utilized time series data of economic growth, greenhouse gas, agricultural productions, trade dependency, and energy usages. In order to econometric procedure of EKC hypothesis, this study utilized unit root test and cointegration test to check staionarity of each variable and also adopted Vector Error Correction Model (VECM) and Ordinary Least Square (OLS) to analyze the short and long run relationships. Findings - In the short run, greenhouse gas emissions resulting from economic growth show an inverse U-shape relationship, and an increase in agricultural production and energy consumption led to increase in greenhouse gas emission. In the long run, total GHG emissions and CO2 emissions show an N-shaped relationship with economic growth, and an increase in agricultural production has resulted in a decrease in total GHG and CO2 emissions. However, methane (CH4) and nitrous oxide (N2O) emissions showed an inverse U-shape relationship with economic growth, which indicated the environment and production process of agricultural production. Research implications or Originality - Korea agricultural production has different effects on the GHG emission sources, and in particular, methane (CH4) and nitrous oxide (N2O) emissions show to increase as the agricultural production expansions, so policy or technological development in related sector is required. Especially, in the context of the 2030 GHG reduction road-map, if GHG-related reduction technologies or policies are spread, national GHG emission reduction targets can be achieved and this is possible to predict the decline in production in the sector and damage to the related industries.

THE EFFECT OF MATURITY OF ITALIAN RYEGRASS (Lolium multiflorum, L) ON IN VITRO RUMEN DIGESTION AND GAS PRODUCTION

  • Fariani, Armina;Warly, L.;Ichinohe, T.;Fujihara, T.;Harumoto, T.
    • Asian-Australasian Journal of Animal Sciences
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    • v.9 no.3
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    • pp.247-254
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    • 1996
  • Three stages of growth of Italian ryegrass (pre-blooming, P-B; early-blooming, E-B; and late-blooming, L-B) were used to evaluate the effect of maturity on in vitro digestion of dry matter, fiber components and gas production. The rumen digestibility and gas production values were obtained by incubation of each sample in the rumen fluid of sheep for 12, 24, 36, 48 and 72 hr, respectively. The results showed that digestibility of dry matter (DM) significantly reduced (p < 0.05) as advancing maturity of the grass. Similarly, the digestibility of neutral detergent fiber (NDF) and acid detergent fiber (ADF) also significantly decreased (p < 0.05) with advancing maturity at all incubation times. However, the effect of maturity on digestibility of cellulose and hemicellulose was only detected when the samples were incubated more than 36 hr, where L-B was lower than P-B and E-B. Potential digestibility of nutrients, the maximum digestibility attainable in the rumen theoretically, was also higher at P-B than those of E-B and L-B. The amount of gas produced by microbial fermentation was closely related to the extent of DM digestion, and it was negatively correlated with advancing maturity of the grass.

A Study on Methodology of Assessment for Hydrogen Explosion in Hydrogen Production Facility (수소생산시설에서의 수소폭발의 안전성평가 방법론 연구)

  • Jae, Moo-Sung;Jun, Gun-Hyo;Lee, Hyun-Woo;Lee, Won-Jae;Han, Seok-Jung
    • Transactions of the Korean hydrogen and new energy society
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    • v.19 no.3
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    • pp.239-247
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    • 2008
  • Hydrogen production facility using very high temperature gas cooled reactor lies in situation of high temperature and corrosion which makes hydrogen release easily. In that case of hydrogen release, there lies a danger of explosion. However, from the point of thermal-hydraulics view, the long distance of them makes lower efficiency result. In this study, therefore, outlines of hydrogen production using nuclear energy are researched. Several methods for analyzing the effects of hydrogen explosion upon high temperature gas cooled reactor are reviewed. Reliability physics model which is appropriate for assessment is used. Using this model, leakage probability, rupture probability and structure failure probability of very high temperature gas cooled reactor are evaluated and classified by detonation volume and distance. Also based on standard safety criteria which is value of $1{\times}10^{-6}$, safety distance between the very high temperature gas cooled reactor and the hydrogen production facility is calculated.

A Case Study of Test Production of Gas from Hydrate Bearing Sediments on Nankai Trough in Japan (일본 난카이 해구 가스하이드레이트 퇴적층으로부터의 가스 시험생산 사례분석)

  • Kim, A-Ram;Lee, Jong-Won;Kim, Hyung-Mok
    • Tunnel and Underground Space
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    • v.25 no.2
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    • pp.133-143
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    • 2015
  • Gas hydrate is a solid substance composed of natural gas constrained in water molecules under low temperature and high pressure conditions. The existence of hydrates has been reported to be world-widely distributed, mainly at permafrost and deep ocean floor. Test productions of small amount of natural gas from the on-shore permafrost have been accomplished in U.S.A and Canada, but, world-first and the only production case from off-shore hydrate bearing sediments was in Nankai trough, Japan. In this study, we introduce key technologies in gas production from hydrates by analyzing the Japanese off-shore gas production project in Nankai trough in terms of depressurization- induced dissociation so as to utilize planned domestic gas production test in Ulleung basin.

Effects of Powdered Activated Carbon on Anaerobic Digestion (염기성 소화에 대한 활성탄의 영향)

  • 김승현
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.32 no.3
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    • pp.102-115
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    • 1990
  • Importance of anaerobic digestion as an energy generating device has been increased as fuel shortage becomes serieous. Several modification methods on the conventional digesters including Powdered Activated Carbon (PAC) addition and two-phase digestion were studied to enhance the gas production. This study investigated the effects of PAC on anaerobic digestion of chicken manure in terms of gas production and sludge stabilization. As a first experiment, an optimum PAC dose for efficient gas production was determined in a batch test. In semi-continuous experiments, an optimum Sludge Retention Time (SRT) at that PAC concentration and an overall substate utilization rate coefficient were investigated. A portion of gas increased by PAC addition was estimated using a substrate utilization rate coefficient of microorganisms attached on PAC. This test was performed in batch experiments using acetic acid as a substrate. The digesters for all experiments were kept 35${\pm}$ 1˚C in a heated water bath. Mixing was performed manually once a day and the produced gas was collected for daily reading. The following conclusions were made for this study. 1. Cptimum PAC concentration was 5% total solids, where gas production rate was increased by 20 percents. 2. Optimum SRT was 7.5 days. 3. Substrate utilization rate coefficient of microorganisms attached on PAC was about twice as much as that of suspended ones.

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