• 한국환경농학회지
• /
• 제27권4호
• /
• pp.406-412
• /
• 2008

Biogas plant with anaerobic digestion is receiving high attention as a facility for both livestock waste treatment and electric power generation. Objective of this study was to perform life cycle assessment (LCA) of a biogas plant which incorporates swine and food waste (7:3) as source materials for biogas production. In addition, the biogas production process was compared with the prevalent composting method as a reference in the aspects of green house gas (GHG) reduction potential and environmental impact. The biogas method was capable of reducing 52 kg $CO_2$ eq. emission per ton of swine/food waste, but the composting process was estimated to emit 268 kg $CO_2$ eq. into air. The biogas method was evaluated as more beneficial to the environment by mitigating the impact on abiotic depletion potential (ADP), global warming potential (GWP), ozone depletion potential (ODP), eutrophication potential (EP), and photochemical ozone creation potential (POCP), but not to acidification potential (AP).

• 한국유체기계학회 논문집
• /
• 제14권2호
• /
• pp.35-40
• /
• 2011

This study analyzed the influence of firing biogas on the performance and operation of a gas turbine combined heat and power (CHP) system. A reference CHP system designed with natural gas fuel was set up and off-design simulation was made to investigate the impact of firing biogas in the system. Changes in critical operating parameters such as compressor surge margin and turbine blade temperature caused by firing biogas were examined, and a couple of operating schemes to mitigate their changes were simulated. Part load operation of the biogas-fired system was compared with that of natural-gas fired system, and it was found that as long as the two system produce the same electric power output, they exhibit nearly the same heat recovery.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2009년도 추계학술대회 논문집
• /
• pp.306-309
• /
• 2009

Concern for new and renewable energy is growing globally. Biogas is one of the alternative fuels and consists of methane and carbon dioxide. It is difficult to achieve efficient engine operation due to a lower heating value of biogas compared to that of natural gas. In order to improve generating efficiency, finding an optimum point of ignition timing and excess air ratio is important. From this fact, generating efficiency and pollutant emissions of 2300cc gas engine generator operated by biogas as functions of ignition timings and excess air ratios were investigated in this study. As a test result, the generating efficiency of the gas engine generator using biogas was 27.34 % in the condition of the BTDC of $16^{\circ}$ and the excess air ratio of 1.4.

• 한국폐기물자원순환학회지
• /
• 제35권7호
• /
• pp.571-586
• /
• 2018

The Malaysian biogas upgrading technologies and policies were examined. In Malaysia, the regulation of palm oil mill effluent (POME) has been enforced to reduce the biochemical oxygen demand to 20 ppm and the biogas capture in the palm oil mills have been recently enforced for renewable energy. A huge amount of organic waste is produced from POME, and 80 million tons from palm oil trees, every year. Due to the renewable energy trends, the Malaysian government is modifying the use of biogases as fuels in favor of their conversion into compressed natural gas (CNG) and other chemicals; various green policies are being promoted because of many advantages of the organic substances. The Korean policies for biogas are a good model for exporting environmental plants after upgrading the digestion and purification technologies. Therefore, this article introduces the current status of POME and biogas production in Malaysia, it could encourage creating a new market for biomethane.

• 한국물환경학회지
• /
• 제26권5호
• /
• pp.754-760
• /
• 2010

This study was carried out not only to evaluate optimal operating condition to increase biogas production, but also to estimate feasibility of renewable energy from anaerobic digester of sewage sludge. Semi- continuous Fed and Mixed Reactors (SCFMRs) were operated in various condition to quantify the reactor variables. The result of SCFMR operation showed that the biogas productivity and total volatile solids (TVS) removal of total solids (TS) 4% reactor at hydraulic retention time (HRT) 20 days with Organic Loading Rate (OLR) of $1.45kg/m^3-d$ were $0.39m^3/m^3-d$ and 26.7%, respectively which was two times higher than that of TS 2.5% reactor. Consequently the daily biogas production of $20,000m^3$ would be possible from the total volume of $52,000m^3$ of anaerobic digesters of the municipal wastewater treatment plant in D city. In feasibility study for the Biogas utilization, combined heat and power system (CHP) and CNG gasification were examined. In case of CHP, the withdrawal period of capital cost for gas-engine (GE) and micro gas-turbine (MGT) were 7.7 years and 9.1 years respectively. biogas utilization as Clean Natural Gas (CNG) shows lower capital cost and higher profit than that of CHP system. CNG gasificaion after biogas purification is likely the best alternative for Biogas utilization which have more economic potential than CHP system. The withdrawal period of capital cost appeared to be 2.3 years.

• Journal of Microbiology and Biotechnology
• /
• 제26권4호
• /
• pp.739-747
• /
• 2016

The rational utilization of crop straw as a raw material for natural gas production is of economic significance. In order to increase the efficiency of biogas production from agricultural straw, seasonal restrictions must be overcome. Therefore, the potential for biogas production via anaerobic straw digestion was assessed by exposing fresh, silage, and dry yellow corn straw to cow dung liquid extract as a nitrogen source. The characteristics of anaerobic corn straw digestion were comprehensively evaluated by measuring the pH, gas production, chemical oxygen demand, methane production, and volatile fatty acid content, as well as applying a modified Gompertz model and high-throughput sequencing technology to the resident microbial community. The efficiency of biogas production from fresh straw (433.8 ml/g) was higher than that of production from straw silage and dry yellow straw (46.55 ml/g and 68.75 ml/g, respectively). The cumulative biogas production from fresh straw, silage straw, and dry yellow straw was 365 l^-1 g^-1 VS, 322 l^-1 g^-1 VS, and 304 l^-1 g^-1 VS, respectively, whereas cumulative methane production was 1,426.33%, 1,351.35%, and 1,286.14%, respectively, and potential biogas production was 470.06 ml^-1 g^-1 VS, 461.73 ml^-1 g^-1 VS, and 451.76 ml^-1 g^-1 VS, respectively. Microbial community analysis showed that the corn straw was mainly metabolized by acetate-utilizing methanogens, with Methanosaeta as the dominant archaeal community. These findings provide important guidance to the biogas industry and farmers with respect to rational and efficient utilization of crop straw resources as material for biogas production.

• 한국수소및신에너지학회논문집
• /
• 제29권1호
• /
• pp.1-10
• /
• 2018

The amount of biogas increases as the amount of organic waste increases. Recently, biogas from organic waste have been made much efforts to utilize as a energy. In particular, the concentration of $CH_4$ and $CO_2$ generated from sewage sludge and livestock manure treatment are 60-70% and 30-35%, and $CH_4$ and $CO_2$ generated from food wastes are 60-80% and 20-40%. In case of landfill gas, $CH_4$ and $CO_2$ have a concentration of 40-60% and 40-60% respectively. Therefore, in order to use the biogas more widely, it is necessary to convert the biogas to methanol, LNG or DME. In this study, experiments were conducted to produce hydrogen and carbon monoxide through various biogas reforming reactions on $Ni/Ce-ZrO_2/Al2O3$ catalysts. The experiment of synthetic gas synthesis was carried out on a wide concentrations of methane and carbon dioxide, which were the major constituents of biogas from various organic wastes. The effect of $(O_2+CO_2)/CH_4$ (=R') on the yields of hydrogen and carbon monoxide, the conversion rate of methane and carbon dioxide was investigated. Also simulation for syngas synthesis on the $CO_2$ reforming of $CH_4$ was computed by employing total Gibbs free energy minimization method using PRO/II simulator, and compared with the experimental results on wet and dry reforming reaction of biogas.

• 에너지공학
• /
• 제24권1호
• /
• pp.51-57
• /
• 2015

본 연구에서는 바이오가스의 공급이 부족한 환경에서 5MW급 바이오 가스터빈을 운전하기 위한 바이오가스와 도시가스의 혼합용 혼합챔버의 성능에 대한 수치해석 및 실증 시험을 수행한 것이다. 혼합챔버의 성능에 대한 수치해석으로 혼합챔버 출구부분에서의 불균일도와 압력강하를 계산하였다. 그 결과, 불균일도는 최소 0.05%에서 최대 0.16%로 이는 99%이상 바이오가스와 도시가스가 혼합되는 것을 의미한다. 압력강하는 입구압력 5bar대비 최소 0.07%에서 0.17%로 0.2%미만으로 나타났다. 이를 통해 현장에서 실증 시험을 수행한 결과 외기온도 $15^{\circ}C$조건에서 바이오가스를 $20.0Nm^3/min$, 도시가스를 $12.0Nm^3/min$ 공급할 경우 5MW급 바이오 가스터빈의 정상적인 운전이 가능함을 확인하였다.

• Environmental Engineering Research
• /
• 제23권3호
• /
• pp.288-293
• /
• 2018

The main objective of this study is to investigate the influence of hydraulic retention time (HRT) on biogas production during leachate treatment using an anaerobic reactor type Upflow Anaerobic Sludge Blanket. For this purpose, four HRTs ranging from 12 to 48 h were experienced. The obtained results showed that higher amount of biogas could be produced during longer HRTs. However, HRTs longer than 48 h could not affect clearly the biogas generation and considered as unnecessary given the small additional amount of biogas produced during the degradation process. A volume of $0.434L/L_{leachate}/d$ was achieved during the treatment with a HRT of 48 h. The higher biogas production, the smaller chemical oxygen demand (COD) values achieved. Besides, COD removal and biogas production positively correlate, showing that the active biomass has degraded effectively the organic load to produce biogas. Moreover, all the analyzed physicochemical parameters have experienced a decrease after 48 h except for the pH, which increased to approximately neutral value. More precisely, a decrease of 93.8%, 89.7%, 95%, 70%, 77%, and 84.4% was recorded for COD, electrical conductivity, total suspended solid, turbidity, $NH_4{^+}-N$, and $NO_3{^-}-N$, respectively.

• Animal Bioscience
• /
• 제36권12호
• /
• pp.1918-1925
• /
• 2023

Objective: The objective of this study was to evaluate the effect of biogas slurry application on biomass production and the silage quality of corn. Methods: A field experiment was conducted in which corn was grown using different biogas slurry application rates. The effect of 25% to 500% biogas slurry nitrogen replacement (T1 to T14) on the yield and quality indices of corn were studied by field plot experiments. Results: The results revealed that biogas slurry application improved the stem diameter and relative feed value of corn silage in treatments T13 and T11. Moreover, the fermentation quality of corn silage was improved due to an increase in lactic acid content; in comparison with the chemical synthetic fertilizer (CF) group. The crude protein contents of corn silage had no obvious change with increasing biogas slurry application. However, the forage quality index of acid detergent fiber was decreased (p<0.05) in the T11 group compared with the CF group. In addition, higher (p<0.05) 30 h in vitro dry matter digestibility and 30 h in vitro neutral detergent fiber digestibility were observed in the T11 and T13 groups than in the CF group. Conclusion: Based on these results, it was concluded that the optimum biogas slurry application rate for corn was approximately 350% to 450% biogas slurry nitrogen replacement under the present experimental conditions.