• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.102.2-102.2
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• 2010

We are to evaluate the stabilization technology of actual biogas plant facilities, which is operating currently. It describes the traits of the consistent facilities of mesophilic anaerobic digestion using Unison Biogas plant Recovery system(UBR). Also the economical efficiency is examined with the electric power sales earnings and applying the deserted heating by generating electric power, which is generated by operated combined heat and power using biogas produced by mesophilic anaerobic digestion. We have generated the 481,113kw for electric power and 1,376Gcal for thermal energy simultaneously. If these electric power and thermal energy are converted into diesel, we can achieve savings equal to 114,300L, and 152,109L in the quantity of heat. Finally, if CDM, RPS, liquid fertilizer sales business, etc. is activated, the earnings will be expected to improve dramatically and is considered to contribute a drop of the greenhouse gas.

• Journal of Environmental Science International
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• v.20 no.10
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• pp.1233-1241
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• 2011

The main objective of this experimental investigation was $CH_4$ recovery from biogas generated in municipal and wastewater treatment plant. The polysulfone hollow fiber membrane was prepared in order to investigate the permeation properties of $CH_4$ and $CO_2$. Permeability of $CO_2$ in Polysulfone membrane was 11-fold higher than of $CH_4$ gas. A membrane pilot plant for upgrading biogas was constructed and operated at a municipal wastewater treatment plant. The raw biogas contained 66 ~ 68 Vol % $CH_4$, the balance being mainly $CO_2$. The effect of the operating pressure of feed and permeate side and feed flowrate on $CH_4$ recovery concentration and efficiency were investigated with double stage membrane pilot plant. The $CH_4$ concentration in the retentate stream was raised in these tests to 93 Vol % $CH_4$.

• Membrane Journal
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• v.28 no.4
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• pp.243-251
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• 2018

Methane is one of the important greenhouse gases and methane is the major component of the biogas. A multiple stage membrane process was developed and analysed with the numerical analysis so that the mole fraction of methane in the final product could be kept higher than 0.95 and simultaneously the recovery of methane was also maintained higher than 99% from the biogas using 3 polysulfone hollow fiber membrane modules which were properly connected. As the feed pressure of the biogas, the mole fraction of methane in the biogas and the membrane area in the membrane module are increased, the methane mole fraction of the final product are found to be increased. However, a proper membrane area in the module should be carefully selected in order to achieve the satisfactory goal of 0.95 mole fraction of methane and 99% recovery of methane from the biogas. Even if the multiple membrane process is utilized with the properly selected membrane modules, the limited operating ranges have to be applied in the following parameters : the feed pressure, the flow rate, the mole fraction of methane in the biogas to get both the target methane concentration and the recovery rate of methane.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11c
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• pp.670-675
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• 2000

The purpose of the study is development and investigation about basic performance of the system operation on a dual fueled cogeneration system(CGS), which is operated with biogas and gas oil. As often seen in dual fueled CGS performance, the electric generating efficiency was obtained about 26□. Methane contained in the biogas could not bum completely at lower load, and it was discharged into exhaust gas. Considerable amount of the methane burned in the exhaust pipe, and the heat recovery ratio was 42□ on heat balance. As a result, the total heat efficiency, which is a summation of generating efficiency and heat recovery efficiency reached to about 70□. The supply of biogas into the engine reduces smoke density and NOx concentration in exhaust gas. At lower load, methane burned slowly and large portion of it was discharged without burning. Therefore the measures are desirable that promotes combustion of methane at lower load.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.4
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• pp.281-286
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• 2011

The objective of this study is to optimize the four-bed six-step pressure swing adsorption(PSA) process for high purity $CH_4$ recovery from the biogas. The effects of P/F(purge to feed) ratio and cycle time on the process performance were evaluated. The cyclic steady-states of PSA process were reached after 12 cycles. The purity and recovery rate of product gas, pressure and temperature changes were constant as the cycle repeated. It was shown that the P/F ratio gave significant effect on the product recovery rate by increasing the amount of purge gas in purge and regeneration step. The optimal P/F ratio was found to be 0.08. As the cycle time increased, the product purity decreased by increasing the feed gas flow rate. It was found that the optimal operating conditions were P/F ratio of 0.08 and total cycle time of 1,440 seconds with the purity of 97%.

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.3
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• pp.236-242
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• 2012

This study has been carried out the experiment for the possibility of biogas reforming using waste heat. The source of this waste heat is the exhaust gas from a small-sized gas engine generator. For recovering the waste heat, Two-stage heat exchanger is manufactured. The two-stage heat exchanger is composed of a heat exchanger for the exhaust gas and a heat exchanger for the water. This two-stage heat exchanger is used for reforming the biogas by means of on-site hydrogen production at the small-sized gas engine generator. The two-stage heat exchanger is coupled with the biogas reformer which is a kind of catalytic reformer. To confirm a heat recovery efficiency of the two-stage heat exchanger, temperature differences of inlet and outlet locations are measured. Also, the variations of syngas concentrations with various biogas flow rates are investigated. As a result using manufactured two-stage heat exchanger, the biogas can be reformed from waste heat recovery. This experiment suggests that the exhaust gas heat exchanger is available for reforming the biogas.

• The KSFM Journal of Fluid Machinery
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• v.14 no.2
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• pp.35-40
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• 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.

• Environmental Engineering Research
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• v.8 no.3
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• pp.107-115
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• 2003

• Journal of Korean Society of Water and Wastewater
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• v.21 no.3
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• pp.315-322
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• 2007

The purpose of this study was to investigate the biodegradability and performance of organic removal and methane production rate when treating piggery wastewater using a granule of two-phase anaerobic process applied UASB. BMP test was conducted as simple means to monitor relative biodegradability of substrate and to determine methane production of an organic material. The two-phase anaerobic process is consisted of a continuous flow stirred-tank reactor (CFSTR) for the acidification phase and an Upflow Anaerobic Sludge Blanket reactor (UASB) for the methanogenesis. The acidogenic reactor played key roles in reducing the periodically applied shock-loading and in the acidification of the influent organics. A stable maximum biogas production rate was 400mL. The methane contents ranged from 73 to 80% during the experimental period. It is known that most of the removed organic matter was converted to methane gas, and the produced biogas might be high quality for its subsequent use.

• Journal of Environmental Science International
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• v.20 no.8
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• pp.1011-1019
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• 2011

The objective of this research is to evaluate optimal conditions of permeability and selectivity on the polysulfone membrane for efficiency of separation of $CH_4$ by checking four factors which are temperature, pressure, gas compositions and gas flow rates. When higher pressure was applied at the input, lower efficiency of recovery of $CH_4$ and higher efficiency of separation of $CH_4$ were shown. It has the tendency to show lower efficiency of recovery of $CH_4$ and higher efficiency of separation of $CH_4$ at the output as higher temperature at input. The lower flow rates make higher efficiency of recovery of $CH_4$ and lower efficiency of separation of $CH_4$. Finally, over 90% efficiency for $CH_4$ separation and recovery conditions are temperature ($-5^{\circ}C$), pressure (8 bar), gas composition rate (6:4) ($CH_4:CO_2$) and gas flow rate ($5\ell$/min). These conditions make higher separation and recovery efficiency such as 90.1% and 92.1%, respectively.