• Journal of the Korea Organic Resources Recycling Association
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• v.18 no.2
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• pp.71-75
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• 2010

Production of crude glycerol from biodiesel industry is expected to exceed the commercial demand for purified glycerol in the near future. This study aimed to evaluate the feasibility of co-digestion of crude glycerol with swine manure. Crude glycerol up to 13.8 g/L was regarded as a good co-substrate for swine manure digester. It improved methane production and productivity by 90% and 120%, respectively. Methane yield of crude glycerol at the condition was estimated to be 232 mL/g. However, it inhibited methanogenic activity at above 27.5 g/L. Optimum concentration of crude glycerol for co-digestion with swine manure would be near to 13.8 g/L.

• Korean Chemical Engineering Research
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• v.53 no.3
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• pp.295-301
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• 2015

A theoretical analysis was carried out to examine the concentration behavior of methane from a biogas using a polysulfone membrane. After the governing equations were derived for the cocurrent flow mode in a membrane module, the coupled nonlinear differential equations were numerically solved with the Compaq Visual Fortran 6.6 software. At the typical operating condition of mole fraction of 0.7 in a feed stream, the mole fraction of methane in the retentate increased to 0.76 while the normalized retentate flow rate to the feed flow rate decreased from 1 to 0.79. When either the mole fraction of methane in a feed increased or the pressure of the feed stream increased, the methane mole fraction in the retentate increased. On the other hand, it was found that as either the membrane area decreased or the ratio of the permeate pressure to the feed pressure increased, the methane mole fraction in the retentate decreased. In case that the stage cut increased, the methane mole fraction in the retentate increased while the recovery of methane slightly decreased.

• Proceedings of the Membrane Society of Korea Conference
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• 1994.10a
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• pp.24-25
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• 1994

고분자 분리막을 통한 메탄과 이산화탄소의 분리는 천연가스에서 불순물로 작용하는 이산화탄소를 분리시켜 천연가스의 순도를 향상시키는데 활용할 수 있으며, 바이오가스나 제철소 폐가스로부터의 이산화탄소의 분리, enhanced oil revovery 공정에서의 이산화탄소의 분리, 그리고 지구 온난화의 원인이 되는 대기중의 이산화탄소 농도의 감소등에서 활용될수 있다. 이러한 분리막 공정은 여러 혼합기체에 대해 단순하고 간편하며 에너지 소비가 적다는 장점에 의해 기체분리에 효과적이고 응용성있는 공정으로 대두되고 있는데, 그 중에서도 분리막의 투과도(Permeability)와 선택도(Selectivity)를 동시에 높일수 있는 새로운 막재료의 개발에 관한 연구가 활발히 진행되고 있다. 이를 위해 고분자 구조를 화학적으로 변화시키는데, 이 경우에는 고분자의 구조 변화와 투과특성간의 관계를 밝히는 것이 매우 중요하다.

• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.5
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• pp.81-88
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• 2015

바이오매스는 유망한 신재생 에너지이다. 바이오매스는 액체 및 기체 연료로 전 환 할 수 있고, 다양한 공정을 통해 열 및 전력을 생산시키는데 사용된다. 바이오매스 가스화 공정은 바이오매스를 일산화탄소, 이산화탄소, 수소 및 메탄으로 이루어진 합성 가스로 전환시키는 기술이다. 바이오매스를 이용한 합성 가스 생산 및 활용은 세계적으로 늘어나는 에너지 필요성을 충족시킬 수 있는 대체에너지이다. 현재, 바이오매스 가스화의 주요 원료는 목질계 우드 칩을 주로 사용하고 있지만, 일반적으로 우드칩의 경우 수분을 다량 함유하고 있기 때문에 가스화 공정을 위해서는 별도의 건조처리를 필요로 한다. 우드칩의 건조에는 많은 에너지가 소요되고, 다량의 우드칩 건조에는 시간과 기상 및 공간적인 환경에 영향을 받는다. 본 연구에서는 미건조 우드칩의 가스화 공정을 위하여 미건조 우드칩에 숯을 각각 10, 30, 50 % 비율로 혼합하여 실험을 수행하였고, 실험결과 생산된 합성가스의 CO 농도 는 숯의 비율에 따라 14.9 ~ 25.6 % 증가되는 경향을 나타내었지만, 반대로 $CO_2$ 및 $CH_4$ 농도는 감소하였다. 이에 따라 합성가스 생산을 위한 미건조 우드칩과 숯의 최적혼합비율은 약 30 %로 판단되며, 발열량은 $1285.7kcal/Nm^3$, Gas yield는 $2.3Nm^3/kg$ 로 나타났다. 이에 적절한 숯의 혼합사용은 미건조 우드칩의 직접적인 가스화에 도움이 될 것으로 사료되며, 바이오매스 건조 공정에 필요한 에너지를 절약할 수 있을 것으로 판단된다.

• Journal of the Korea Organic Resources Recycling Association
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• v.19 no.4
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• pp.66-73
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• 2011

Objective of this study was to investigate the effect of biogas production to different systems and feeding stocks. For the biogas production through operating the temperature phase anaerobic digestion(TPAD) with different feeding stocks, the stage state of biogas production with 70% of methane concentration in the thermophilic digestion tank with co-digestion of food waste and swine manure(40 : 60) was delayed at 3.5 times, but its mesophilic tank was short for 5 days as relative to the swine manure. The cumulative methane production in the thermophilic digestion tank with co-digestion of food waste and swine manure was started with greater than its swine manure at 60 days after digestion periods. However, its mesophilic tank with swine manure was great at 3 days after digestion periods. For aspect of anaerobic digestion processes with swine manure, it was appeared that the stage state of biogas production rate in TPAD was shorter than the two phase anaerobic digestion system.

• Applied Chemistry for Engineering
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• v.34 no.4
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• pp.404-411
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• 2023

For the direct reforming of biogas, a three-phase gliding arc plasma reformer was designed to expand the plasma discharge region, and the operation conditions of the plasma reformer, such as the S/C ratio, the gas flow rate, and the plasma input power, were optimized. The H₂ production efficiency is increased at a lower specific plasma input energy density, but byproducts such as C_XH_Y and carbon soot are generated along with the increase in H₂ production efficiency. The formation of byproducts is decreased at higher specific plasma input energy densities and S/C ratios. The optimized operation conditions are 5.5 ~ 6.0 kJ/L for the specific plasma input energy density and 3 for the S/C ratio, considering the conversion efficiency, H₂ production, and byproduct formation. It is expected that the H₂ production efficiency will improve with the decrease in fuel consumption in biogas burners because the heat generated from plasma discharge heats up the feed gas to over 500 ℃.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.3
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• pp.356-362
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• 2010

This research studied the bio-methane potential of several waste biomass materials as alternative sources for biogas production, and the laboratory procedure for measuring the biochemical methane potential was described. The wastes from four agro-industries (sewage, livestock, food wastewater treatment sludge and cattle rumen substance generating in slaughter house) were evaluated as substrates for the assay of biochemical methane potential. In order to estimate the ultimate methane yield, two empirical equations (modified Gompertz equation and exponential equation) was investigated. The ultimate methane yield of sewage, livestock, food sludge and lumen substance estimated by the modified Gompertz equation were 0.086, 0.147, 0.146, and 0.121 L $CH_{4}\;g^{-1}\;VS_{added}$, respectively. The ultimate methane yield estimated by the exponential equation were 0.109, 0.246 and 0.174 L $CH_{4}\;g^{-1}\;VS_{added}$ in sewage, livestock sludge and lumen substance. And the ultimate methane yield estimated by the exponential equation showed more high values in the range of 26.7 ~67.3% than the ultimate methane yield estimated by the modified Gompertz equation.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.4
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• pp.62-71
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• 2013

This study was carried out to develope a pre-treatment technology for anaerobic digestion. Breaking down large particles into smaller particles enhances the performance of anaerobic digestion by increasing the hydrolysis of particles. A degree of hydrolysis is the most important factor determining the overall efficiency of methane production. Three types of pre-treatment devices (blade-type crusher, ozonization system, cavitation system) were set up and operated to crush solids in pig slurry in order to enhance biodegradability. The effect of pre-treatment on decreasing granular size within pig slurry by three experimental devices were compared. The highest performance of granulization of pig slurry was attained in a combination of blade-type crusher and ozonization system. In batch experiment, there was an improvement of the methane potential by combined pretreatment with crusher and cavitation. In case of pre-treated slurry, biogas and methane production were 325.9 L and 59.7% respectively, while, in untreated slurry, the production were lower; 298.8 L and 55.7%, respectively. These results indicate that higher anaerobic digestion efficiency of pig slurry can be obtained through the pre-treatment.

• Membrane Journal
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• v.24 no.3
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• pp.223-230
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• 2014

A numerical analysis was performed for concentration of methane from the biogas using a polysulfone hollow fiber membrane permeator. Governing equations were derived for the countercurrent flow and numerically solved by using the Compaq Visual Fortran 6.6 software. When the methane mole fraction of feed was 0.5, the mole fraction of retentate increased from 0.5 to 0.8; the normalized retentate flow rate to the feed flow rate decreased from 1.0 to 0.57 at the given typical operating condition as the feed gas flowed from the inlet to the outlet of the membrane. As the methane mole fraction of feed was changed to 0.9, the methane mole fraction of retentate became 0.93 and the normalized retentate flow rate was changed to 0.91. When the pressure ratio of the permeate to the feed was varied from 0.33 to 0.17, there was a little difference in the methane mole fraction of retentate for the low stage cut of 0.1, whereas there was an significant increment for the high stage cut of 0.3. The retentate methane mole fraction remained relatively high despite the change of a stage cut as the area of the membrane increased from $1.14m^2$ to $2.57m^2$.

• Journal of the Korea Organic Resources Recycling Association
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• v.26 no.2
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• pp.85-93
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• 2018

Semi-dry anaerobic digestion experiment using dairy cattle manure collected from dairy cattle house was conducted to analyze efficiency of biogas production. As a first experiment, Biochemical Methane Potential (BMP) test was carried out according to certain ratio of sample mixtures: dairy cattle manure, pig slurry, and mixture of dairy cattle manure and pig slurry. The amount of methane accumulated during BMP test period was high in the experimental groups containing dairy cattle manure. As a second experiment, semi-dry anaerobic digestion experiment was carried out using only the dairy cattle manure collected from floor of the dairy cattle house. Judging from the experimental results, the optimum hydraulic retention time (HRT) of semi-dry anaerobic digestion for dairy cattle manure containing 13% of TS was 25 days. The amount biogas generated from the semi-dry anaerobic digestor with the TS of 13% of the dairy cattle manure ranged from 1.36~1.50v/v-d and the average was 1.44v/v-d. The optimum HRT of the semi-dry anaerobic digestor for dairy cattle manure containing TS of 15% and the semi-dry anaerobic digestor for dairy cattle manure containing TS of 17% was the same as 30 days. The amount biogas generated from the semi-dry anaerobic digestor with the TS of 15% of the dairy cattle manure ranged from 1.42~1.52v/v-d and the average was 1.47v/v-d. The amount biogas generated from the semi-dry anaerobic digestor with the TS of 17% of the dairy cattle manure ranged from 1.50~1.61v/v-d and the average was 1.55v/v-d.