• Journal of the Korea Organic Resources Recycling Association
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• v.15 no.3
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• pp.113-120
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• 2007

Anaerobic batch tests were performed to evaluate the characteristics of methane production from piggery manure such as the ultimate methane yield (UMY), the kinetic constant and the maximum methane production rate. The kinetic behavior of anaerobic degradation of piggery manure was assumed as a first order reaction. The UMY, the first order kinetic constant and the maximum methane production rate were 0.27~0.44L $CH_4/gVS$, $0.161{\sim}0.280d^{-1}$ and 0.043~0.120L $CH_4/d$, respectively. Reactor of piggery manure as the self-seed source of anaerobic digestion resulted in longer acclimation time than reactors seeded with anaerobic digested sludge (ADS). But there was no little difference in the UMY between the two seed materials. The anaerobic digestion can be effective for the treatment of piggery manure containing high concentration of solids, the two-stage anaerobic digestion is, however, thought to be more effective than the traditional single one.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.1
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• pp.62-68
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• 2013

The effect of organic substance on its degradation rate in burial site was investigated using batch tests. Substrate were swine and cattle with the initial concentrations of 2, 4, 6, 8, and 10 g VS(volatile solids)/L, respectively. The highest methane production rates of swine and cattle were found at 2 g VS/L as 46.3 and 48.4 ml CH4/g VS.d, respectively. As substrate concentration increased, the methane production rate decreased. The inhibition constants were n and m that were estimated using nonlinear inhibition model. The values of n and m were inhibition constants of methane production rate and ultimate methane yield, respectively. The values of n and m were 4.9 and 0.6 on swine and 1.1 and 0.4 on cattle. The methane production rate was responded sensitively by increase and decrease of substrate concentration, whereas ultimate methane yield do not relatively. From a relation between n and m, inhibitory effect of substrate concentration was confirmed as uncompetitive inhibition.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.6B
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• pp.399-406
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• 2012

The objective of this research is to develop greenhouse gas generation models and estimation method of their parameters for solid waste landfills. Two models obtained by differentiating the Modified Gompertz and Logistic models were employed to evaluate two parameters of a first-order decay model, methane generation potential ($L_0$) and methane generation rate constant (k). The parameters were determined by the statistical comparison of predicted gas generation rate data using the two models and actual landfill gas collection data. The values of r-square obtained from regression analysis between two data showed that one model by differentiating the Modified Gompetz was 0.92 and the other model by differentiating the Logistic was 0.94. From this result, the estimation methods showed that $L_0$ and k values can be determined by regression analysis if landfill gas collection data are available. Also, new models based on two models obtained by differentiating the Modified Gompertz and Logistic models were developed to predict greenhouse gas generation from solid waste landfills that actual landfill generation data could not be available. They showed better prediction than LandGEM model. Frequency distribution of the ratio of Qcs (LFG collection system) to Q (prediction value) was used to evaluate the accuracy of the models. The new models showed higher accuracy than LandGEM model. Thus, it is concluded that the models developed in this research are suitable for the prediction of greenhouse gas generation from solid waste landfills.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2008.04a
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• pp.268-270
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• 2008

• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.1
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• pp.21-29
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• 2016

We mix food waste leachate and sewage sludge by the proportion of 1:9, 3:7 and 5:5. It turns out that they produced 233, 298 and 344 $CH_4{\cdot}mL/g{\cdot}VS$ of methane gas. The result suggests that as the mixing rate of food waste leachate rises, the methane gas productions increases as well. And more methane gas is made when co-digesting sewage sludge and food waste leachate based on the mixing ratio, rather than digesting only sewage sludge alone. Modified Gompertz and Exponential Model describe the BMP test results that show how methane gas are produced from organic waste. According to the test, higher the mixing rate of food waste leachate is, higher the methane gas productions is. The mixing ratio of food waste leachate that produces the largest volume of methane gas is 3:7. Modified Gompertz model and Exponential model describe the test results very well. The correlation values($R^2$) that show how the results of model prediction and experiment are close is 0.92 to 0.98.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2010.04a
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• pp.685-686
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• 2010

• Journal of the Korean GEO-environmental Society
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• v.15 no.5
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• pp.5-11
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• 2014

In this study, greenhouse gas emission for small scale landfill (H and Y landfill) was investigated to deduce special the methane generation rate constant(k). To achieve the purpose, the data of physical composition was collected and amount of LFG emission was calculated by using FOD method suggested in 2006 IPCC GL. Also, amount of LFG emission was directly measured in the active landfill sites. By comparing the results, the methane generation rate constant(k), which was used as input variable in FOD method suggested in 2006 IPCC GL, was deduced. From the results on the physical composition, it was shown that the ranges of DOC per year in H (1997~2011) and Y (1994~2011) landfill sites were 13.16 %~23.79 % ($16.52{\pm}3.84%$) and 7.24 %~34.67 % ($14.56{\pm}7.30%$), respectively. The DOC results showed the differences with the suggested values (= 18 %) in 2006 IPCC GL. The average values of methane generation rate constant(k) from each landfill site were $0.0413yr^{-1}$ and $0.0117yr^{-1}$. The results of methane generation rate constant(k) was shown big difference with 2006 IPCC GL defualt value (k = 0.09). It was confirmed that calculation results of greenhouse gas emission using default value in 2006 IPCC GL show excessive output.

• Journal of the Korea Organic Resources Recycling Association
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• v.6 no.1
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• pp.31-42
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• 1998

A fundamental study on methane conversion for the collection organic wastes of agriculture, forestry and fishers was performed in a laboratory scale. As a result, selected Run B sample were obtained 18.41 C/N Ratio and 168.96 mg/L TCOD; Under the biochemical methane potential test, theoretical and actual methane generation was 313.6 mg/L VS added and 234.2 mg/L VS added, respectively; However, methane conversion from Run B were occurred 74% by anaerobic digestion. By the first order reaction kinetics, kinetic constant were $0.2476d^{-1}$ for Run B. Three steps fill-up filter reactor was evaluated methane content 16% up to promote than blank reactor; TCOD and SCOD have reduced 44.7% and 44.2%, respectively.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.2
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• pp.130-139
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• 2000

Serial basic tests were conducted for the determination of fundamental kinetics and for the actual application of kinetic parameter to food waste digestion with precise measurement of methane production under a thermophilic condition. The effects of food particle size, sodium ion concentration, and volatile solid (VS) loading rate on the anaerobic thermophilic food waste digestion process were investigated. Results of serial test for the determination of fundamental kinetic coefficients showed the value of k (maximum substrate utilization rate coefficient) and KS (half-saturation coefficient) as $0.24hr^{-1}$ and $700mg/{\ell}$, respectively, for non-inhibiting organic loading range. No inhibition effect was shown until $5g/{\ell}$ of sodium ion concentration was applied to a serum bottle reactor. However, the volume of methane gas was decreased gradually when the concentrations of more than $5g/{\ell}$ of sodium ion applied. All sizes of food waste particle showed the same constants (A : 0.45) but the maximum substrate utilization rate constant ($k_{HA}$) was inversely proportional to particle size. As an average particle size increased from 1.02 mm to 2.14 mm, $k_{HA}$ decreased from $0.0033hr^{-1}$ to $0.0015hr^{-1}$. The result reveals that particle size is one of the most important factors in anaerobic food waste digestion. There was no inhibition effect of sodium ion when VS loading rate was $30g/{\ell}$. And maximum injection concentration of VS loading rate was determined about $40g/{\ell}$.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.261.1-261.1
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• 2014

지구상에 존재하는 모든 생물에 의해 배출되는 이산화탄소는 온실가스로써 산업혁명 이후 급격한 농도 증가로 인해 지구 온난화 등의 다양한 환경문제를 초래하고 있다. 지구 온난화의 가시화로 인한 각종 기후 협약 및 탄소배출권 등에 규제로 온실가스 감축의무부과가 확실해져 탈 석유기반 사회로 전환을 위한 이산화탄소를 처리하는 다양한 연구가 각국에서 활발히 진행 중이다. 본 연구에서 마이크로웨이브 플라즈마 토치를 이산화탄소 분해에 이용하게 되었고 그 목적은 이산화탄소가스를 마이크로웨이브로 가열하여 순수한 이산화탄소 플라즈마 토치를 발생함으로서 지구 온난화의 주범인 이산화탄소를 생산적으로 이용하기 위한 것으로 전자파를 발진하는 마그네트론으로는 3kW, 2.45GHz의 주파수를 사용한다. 마이크로웨이브 플라즈마 토치를 이용한 이산화탄소의 분해 시 생성되는 물질을 확인하기 위하여 이산화탄소의 열역학적 평형을 계산하였으며 또한 이산화탄소의 분해 반응의 준 평형상태에서의 속도상수를 이용하여 각 분해반응생성물들의 밀도비율을 계산하였고, 이를 일반화시켜 도시하였다. 위 과정을 통해 고온의 이산화탄소 토치는 탄화수소 연료를 1기압에서 개질할 수 있음을 알 수 있다. 예를 들어 메탄개질은 $CO_2+CH_4{\rightarrow}2CO+2H_2$의 반응식이 된다. 이때 엔탈피와 엔트로피 변화는 각 각 ${\Delta}H=247kJ/mole$과 ${\Delta}S=257J/mole/deg.$이며 이 반응에 대한 gibbs 자유에너지는 $G={\Delta}H-T{\Delta}S$로서 개질 자발반응이 일어나는 온도는 $T={\Delta}H/{\Delta}S=961K$가 된다. 그리고 탄화수소 개질에 참여하는 산소와 CO 라디칼의 밀도가 대단히 높다. 따라서 메탄개질은 이산화탄소 토치를 통하여 1기압에서 쉽게 이루어진다.