• Magazine of the Korean Society of Agricultural Engineers
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• v.40 no.2
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• pp.18-28
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• 1998

현재의 가축분뇨처리 형태와 축종별 적용대상은 표 3과 같이 분류되며, 축분 퇴비화 뇨오수 정화방식의 고액분리 형태에서 분뇨혼합물의 동시처리 즉, 깔감축사(소, 돼지), 슬러리 발효 퇴비화를 통한 무방류 시스템으로 변화되는 추세이다. 이러한 현상은 최근의 방류수질 규제강화에 따른 무방류화 저비용 단순화를 지향하고 있으며, 무방류화의 가장 큰 걸림돌은 톱밥과 같은 수분조절재 부족이라 할 수 있다. 현재 이용되고 있는 주요 시스템별 개선안은 다음과 같다. $\square$ 주요 처리 시스템 적용의 문제제기 $\circ$ 축분발효시설 - 톱밥 등 부자재 무이용을 위한 축분의 예비 건조시설 이용 - 교반식 발효기의 악취확산방지를 위하여 밀폐형 하우스 및 강제환기 장치 설치에 의한 악취 포집 및 탈취 - 중소규모 발효시설 개발 $\circ$ 화력건조 - 예비건조를 통한 톱밥, 연료비용 절감 - 악취방치 장치부착 의무화 $\circ$ 활성오니 정화시설 - 시설 운전관리 단순화 - 1차 고액분리를 통한 유입수 오염부하량 감소 및 균일화 $\circ$ 깔감축사 - 경제적으로 흡수를 극대화할 수 있는 수분조절재의 조합비 결정 및 혼합물을 깔감으로 재이용 기술개발 $\circ$ 슬러리 발효퇴비화 시설 - 톱밥 등 수분조절재 사용량 절감기술 - 증발량 극대화 기술개발 및 소요에너지 최소화기술개발 우리나라는 사계절이 뚜렷하여 외기상에 따라 편차가 심하며, 고밀도 사육 및 지역적 편중성, 경지면적 협소, 고비용 시장구조 등의 축산환경을 고려한다면 근원적으로 가축분뇨문제 해결한다는 것은 결코 쉬운 일이 아니다. 이는 저공해 사료개발에서부터 분뇨가 발생단계에서 분리, 수거할 수 있는 수거시설, 고효율 분뇨처리시스템의 정립, 액비 및 퇴비의 가공, 토양환원되었을 때 작물생장장애, 액비, 퇴비의 유통, 가축분뇨처리 정책 및 규제법 등의 각 분야에서 복합적 노력이 필요하다.

• Korean Journal of Poultry Science
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• v.20 no.3
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• pp.141-149
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• 1993

In order to develop a poultry manure dryer, a pilot dryer was designed and drying experiments were conducted to investigate the drying characteristics of poultry manure. According to the results, the pilot dryer could be operated without any air pollution problems. When poultry manure was dried from 79.2%(w.b. basis) moisture content, the final moisture content ranged from 38.7% to 57.9% depending upon the drying conditions. The drying results showed that drying rate was 189.8~198.0 kg/h and moisture evaporation rate was 124.0~125.4kg-$H_2$O/L. For this drying, electricity requirement was 9.5~19.3 Wh/kg and fuel consumption rate was 6.9~9.3 kg-$H_2$O/L with 50.2~65.1% thermal efficiency.

• Journal of Energy Engineering
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• v.19 no.4
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• pp.240-245
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• 2010

In this study, characteristics of wood pellet gasification was studied using a Two Stage Gasifier which is consisted of pyrolysis reactor and ultra high temperature reformer. The average yields of $H_2$, $CH_4$, CO, $CO_2$ were 16.7, 11.3, 37.2, 26.6 L/mim, conversion rate from biomass to gas was 65% in pyrolysis reactor and gas yields in reformer were 55.4, 0.8, 120.8, 56.8 L/mim, respectively. The hydrogen flow rate from reformer is obtained 360.1 L/hr. The most of $CH_4$ was decomposed from 12.3 to 0.3 vol.% while $H_2$ is from 18.2 to 23.7 vol.% in reformer by methane dry reforming, Boudouard reaction, oxidation and/or steam reforming. The amount of $H_2O$ generated by hydration reaction from reformer was 1111.8 g, its accelerated conversion of $CH_4$ to other products. The conversion rate from $CH_4$ to other Compounds was 97.2%. Cold gas efficiency was 53.2%.

• Journal of the Korean Institute of Gas
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• v.17 no.5
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• pp.1-7
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• 2013

In this study, simulation work of HCNG refueling system was performed. The hydrogen was produced from steam reforming process by natural gas. The conversion of natural gas is increased as SCR is increased. but it was no significant difference more than 3 of SCR and fuel throughput is increased as GHSV is increased. Both conversion and fuel throughput levels was optimized when the $1700h^{-1}$ of GHSV. CNG was compressed from low pressure natural gas. For the mixing of $H_2$ and CNG is mixed with the high pressure conditions such as 400bar of $H_2$ and 250bar of natural gas. Single-stage compression was required more power than multi stage. So, multi stage compression was suggested for high pressure compression. We calculated the intermediate pressure to minimize total required power of compressors. The intermediate pressure for $H_2$ and natural gas were derived at 61 and 65 bar, respectively.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.8
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• pp.1552-1565
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• 1992

Three dimensional numerical calculations were carried out for two different combustion chambers with the offset valve in order to investigate the swirl and the squish effects on the flow fields. The modified K-.epsilon. turbulence model considering the change of the density under the condition of the rapid compression and expansion of the pistion was used. During the compression process, it was found that the squish flow which controls the subsequent combustion process was produced due to the piston bowl in the bowl piston type combustion chambers but not for the flat piston type. The swirl velocity close to the solid body rotation was maintained in the flat piston type combustion chambers, but for the bowl piston type a resulting from the change of the solid body rotation was generated in the radial-circumferential plane. For the swirl ratio effect, as the swirl ratio increases, it was found that a large and strong vortex was generated in the radial-circumferential plane of bowl piston type combustion chambers because of the strong inward flows from the combustion chamber wall. These computational results were compared with the results of LDA measurement.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.12
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• pp.3761-3767
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• 2009

This study was investigated to determine the combustion characteristics, decomposition efficiency, and the flue gas concentrations after combustion in the high temperature reactor($1,250{\sim}1,400^{\circ}C$, 1 atm) for the liquid wastes(waste oil and waste solvent) generated from the industrial complex. The concentration of nitrogen oxide(NOx) is decreased and the synthetic gas is increased when the mass ratio of $O_2$/waste is about 1.53 because the reaction condition was changed to reduction state. And BTEXs(benzene, toluene, ethylbenzene, xylene) are decomposed more than 99.99%. If the highly concentrated liquid waste (waste oil and waste solvent) is treated under the operating conditions suggested by this study, our treatment method for the liquid waste was found to be proper because of the contaminants emission concentration is very low. In addition, the synthetic gas after combustion can be used as an alternative fuel.

• Journal of Energy Engineering
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• v.8 no.1
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• pp.189-201
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• 1999

범용 열가소성 플라스틱(polyethylene(PE), polypropylene(PP), polystyrene(PS), polyethylene-terephthalate(PET), acrylonitrile-butandiene-styrene(ABS))과 폐윤활유의 동시처리 열분해반응 실험을 수행하였다. 반응실험은 40$m\ell$ 용량의 회분식 미분반응기(microreactor)를 이용한 실험과 1리터 용량의 autoclave를 이용한 실험의 두 가지로 구분하여 행하였다. 전자의 경우는 통계적 실험적계획법(statistical experimental design)의 하나인 회전계획실험(rotatable design experiments)으로서 오각형 실험계획(pentagonal experimental design)에 의거한 반응변수 실험을 수행한 후 반응표면(response surface)을 회기분석법에 의하여 분석함으로써 최대의 오일 수율을 얻을 수 있는 최적 반응조건을 추적, 결정하였다. Autoclave 반응실험의 기본적인 목적은 실제 연속공정에 있어서 열분해 반응기 거동을 모사하기 위한 전초단계로서 충분한 시료의 확보를 통하여 이 때 생성된 연로유의 체계적인 분석(비등점분포특성, 진공증류, 기체분석, 원소분석, 발열량, 비중 등)을 행함으로써 연료유 수율 및 품질을 모사하고자 하였다. 미분반응기 실험에 있어서 주 범용열가소성수지인 PE, PP 그리고 PS는 각각의 최적반응조건하에서 거의 100%에 가깝게 오일로 전환되었지만 응축수지인 PET와 그래프트공중합수지인 ABS의 오일수율은 각기 78% 및 90%로서 상대적으로 낮게 나타났다. Autoclave를 이용한 실험의 경우 혼합플라스틱을 폐유에 대하여 40wt% 혼합하여 열분해하였을 때, 80wt% 오일, 15wt% 코우크, 그리고 나머지 5wt%는 탄화수소기체(C1-C6)로 전환되었다. 진공증류(252$^{\circ}C$,2 torr) 결과, 기/액-분리도는 3으로서 이는 생성오일의 75wt%가 경질연료유(가솔린, 등유, 경유)로 회수 가능하였다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.spc1
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• pp.104-107
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• 2005

This survey was conducted to know the post-harvest bulk treatment system for barley, The tendency of barley-bulk treatment in 4 RPC was gradually increased up to 4,458 ton in 2001, but after that time, the amounts was decreased 1,0731on in 2003. There was the big difference on the circulated and the continued systems that was the kinds of drying system they use. The barleys, the harvest and the conveyance method was different on RPCs. Naked barley was only treated, and $90\%$ barley was harvested by the consignment in J RPC, otherwise unhulled barley was treated, and there did not used the consignment in S RPC. Small and mulit combine was used to harvest, and the ratio of bulk was up to $90\%$ in J RPC, but small combine was only used and ratio of bulk was at most $5\%$ in S RPC. It was sell by 1kg in polished and 40kg unpolished barley around year in J RPC, but it was sell by bulk to september in S RPC.

• Korean Chemical Engineering Research
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• v.54 no.2
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• pp.248-254
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• 2016

Efficacious wastewater treatment is essential for increasing sewage sludge volume and implementing strict environmental regulations. The operation cost of sludge treatment amounts up to 50% of the total costs for wastewater treatment plants, therefore, an economical sludge destruction method is crucially needed. Amid several destruction methods, wet air oxidation (WAO) can efficiently treat wastewater containing organic pollutants. It can be used not only for sludge destruction but also for useful by-product production. Volatile fatty acids (VFAs), one of many byproducts, is considered to be an important precursor of biofuel and chemical materials. Its high reaction condition has instituted the study of gravity pressure reactor (GPR) for an economical process of WAO to reduce operation cost. Simulation of subcritical condition was conducted using Aspen Plus with predictive Soave-Redlich-Kwong (PSRK) equation of state. Conjointly, simulation analysis for GPR depth, oxidizer type, sludge flow rate and oxidizer injection position was carried out. At GPR depth of 1000m and flow rate of 2 ton/h, the conversion and yield of VFAs were 92.02% and 0.17g/g, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.2
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• pp.181-187
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• 2014

Polycyclic aromatic hydrocarbons (PAHs) are a group of ubiquitous hazardous pollutants derived from fossil fuel, various combustion sources and pyrolysis of a wide range of plastics. Because PAHs can be uptake into crop plants, the inhibitory effects on rice and soybean plants were examined in greenhouse and growth chamber experiment. Soil-applied PAHs (phenanthrene of 0, 10, 30, 100 ppm) slightly reduced the plant height and dry weight both in transplanted rice and soybean plant. The inhibitory effect on growth was greater in soybean than rice. Plant height of soybean plants treated by 100 ppm was 58.9 cm and this value was 87.2% of untreated plant. In rice plant, the plant height was less inhibited (96.0% of untreated plant) by 100 ppm at 80 days after treatment (DAT). However, leaf chlorophyll content and chlorophyll fluorescence were less inhibited by PAHs at late growth stage (after heading) although the photosynthesis-related parameters were slightly inhibited from 20 DAT to 70 DAT. In agar medium experiment with infant seedlings, inhibition of seedling length and fresh weight by phenanthrene at 100 ppm were greater as compared to the experiment with adult plant in pot. Seedling length and fresh weight were reduced by 54.2% and 33.3% for rice and 27.9% and 13.2% for soybean, respectively. The results reflected that PAHs were more inhibitory during juvenile stage than adult stage and more inhibitory to rice plant than soybean for juvenile stage.