• 제목/요약/키워드: gaseous reduction

검색결과 124건 처리시간 0.026초

마그네슘환원에 의한 C/N 조성제어 초미립 TiCxNy 분말 합성 (Preparation of Ultrafine C/N Controled TiCxNy Powders by Magnesium Reduction)

  • 이동원;김병기;윤중열;유지훈;김용진
    • 한국분말재료학회지
    • /
    • 제17권2호
    • /
    • pp.142-147
    • /
    • 2010
  • The ultrafine titanium carbonitride ($TiC_xN_y$) particles below 100 nm in mean size, including various carbon and nitrogen contents (x=0.55~0.9, y=0.1~0.5), were successfully synthesized by new Mg-thermal reduction process. Nanostructured sub-stoichiometric titanium carbide ($TiC_x$) particles were initially produced by the magnesium reduction of gaseous $TiCl_4+x/2C_2Cl_4$ at $890^{\circ}C$ and post heat treatments in vacuum were performed for 2 hrs to remove residual magnesium and magnesium chloride mixed with $TiC_x$. Finally, well C/N-controled $TiC_xN_y$ phases were successfully produced by nitrification heat treatment under normal $N_2$ gas atmosphere at $1150^{\circ}C$ for 2 hrs. The values of purity, mean particle size and oxygen content of produced particles were about 99.3%, 100 nm and 0.2 wt.%, respectively.

가스계 소화시스템용 소화약제 저장용기 누설 검출 무선 시스템 개발 (Development of Monitoring RF System on Leakage of Gas Cylinder in Gaseous Fire Extinguishing System)

  • 소수현;오주환;차철웅;이대근
    • 한국화재소방학회:학술대회논문집
    • /
    • 한국화재소방학회 2008년도 추계학술논문발표회 논문집
    • /
    • pp.7-10
    • /
    • 2008
  • In our study, Monitoring RF System in real-time on leakage of gas cylinder is developed. The system is consisted of Pressure Transmitting part, Main Controller and Operating program. The pressure data of gas cylinder are transmitted to the modem of main controller part by RF module of Pressure Transmitting part and the data received through the modem are recorded in real-time and showed the situation of gas cylinder on the PC monitor. Through the test on the case of the artificial pressure-reduction, the detecting performance. of the developed system is conformed.

  • PDF

2단 연소방법에 의한 미분탄 연소기의 특성에 관한 이론적 연구 (Theoretical Study on the Characteristics of Pulverized Coal Combustor with 2 Stage Combustion)

  • 주남로;최상일;김호영
    • 한국연소학회:학술대회논문집
    • /
    • 한국연소학회 1997년도 제15회 KOSCO SYMPOSIUM 논문집
    • /
    • pp.103-112
    • /
    • 1997
  • In the combustion of the pulverized coal compared with that of liquid fuel or gaseous fuel, serious pollutants such as ash, $NO_x$ and $SO_x$ are released to surroundings. The objective of this study is the reduction of such pollutants in the combustion process. The modeling of cyclone combustor which uses the method of two stage combustion was carried out. The main burner length, scattering angle and air/fuel ratio were considered as parameters. The results show that the shorter the main burner length is, the less the amounts of coals which exit the combustor directly are, but the scattered input of coal is required anyway in order to collect all ashes. It is recommended that the shorter the main burner length is, the less the scattering angle is. And in the case of the scattered input compared with no scattering, the temperature in the combustor is more uniform and the amount of volatile is more reduced.

  • PDF

디이젤機關의 黑煙防止에 관한 考察 (Some considerations for reducing black smoke in the exhaust gas from a diesel engine)

  • 방중철
    • 대한기계학회논문집
    • /
    • 제11권6호
    • /
    • pp.963-970
    • /
    • 1987
  • 본 연구에서는 LPG와 같은 기체연료를 디이젤기관의 흡기관에 소량 흡입시키 는 방법을 이용해서 비교적 간단히 흑연을 저감시킬 수 있는 대안을 검토한 것으로서, 기관사용자에게는 열효율이 향상되고 연료소비율이 저하되는 등의 이점이 있다. 또 이 방법을 기관의 부하나 회전속도의 변동에 따라 유효하게 이용할 수 있는 수법과 문 제점에 대해서도 검토하여 보았다.

TiO2 담지 세라믹 필터를 활용한 아세톤 제어에 관한 연구 (Reduction of Gaseous Acetone by using TiO2 Coated Woven Filters)

  • 윤정호;박덕신;이주열;조영민
    • 한국대기환경학회지
    • /
    • 제19권1호
    • /
    • pp.85-92
    • /
    • 2003
  • A new type of catalytic filers has been developed in this work. A porous photocatalytic filter was prepared by coating the titania (anatase phase) powder onto the woven metal mesh. The coating sol was prepared with unique cera-mic binder, and would assist drying condition and enhance the mechanical strength of the final ceramic filers. As a result of the test for acetone decomposition, it was found to be quite effective for the photocatalytic reaction as good at conventional glass reactors which were coated inside. The present filter type reactor is expected as one of plausible devices for the simultaneous treatment of gas - particulate materials.

Biodegradation Capacity Utilization as a New Index for Evaluating Biodegradation Rate of Methane

  • Kim, Tae Gwan;Yi, Taewoo;Yun, Jeonghee;Ryu, Hee Wook;Cho, Kyung-Suk
    • Journal of Microbiology and Biotechnology
    • /
    • 제23권5호
    • /
    • pp.715-718
    • /
    • 2013
  • Density of catalytic organisms can determine the biodegradation capacity and specific biodegradation rate (SBR). A new index, biodegradation capacity utilization (BCU, %), was developed for estimating the extent of actual biodegradation of a gas compound over the full capacity. Three methanotrophic cultures were serially diluted (1-1/25), and methane SBR and BCU were measured. Consistently, biomass reduction increased the SBR and decreased the BCU. Linearity (p < 0.05, r > 0.97) between the BCU and cell density indicated the reflection of biodegradation capacity by BCU. Therefore, BCU is indicative of whether the density of catalytic organisms is pertinent for SBR evaluation of low-soluble gaseous compounds.

콩의 오존처리가 두부의 저장성에 미치는 영향 (Shelf-Life of Soybean Curd Prepared with Ozone-treated Soybeans)

  • 김일두;박미자
    • 한국식품저장유통학회지
    • /
    • 제5권1호
    • /
    • pp.73-80
    • /
    • 1998
  • Shelf-life of soybean curd prepared with ozone-treated soybeans investigated on pH, acidity, sour taste, slime formation during storage at 3$0^{\circ}C$. Total Plate counts of raw soybeans showed about log 7.0 CFU/g before ozone treatment. The sterilization efficiency of raw soybeans showed the most effective in 0.5ppm of aqueous ozone treatment at 4$^{\circ}C$ for 90 minutes. Raw soybeans were treated with ozone by different methods; (1) Ozone treatment for 90 + 90 minutes (first 3.5~5 hours and later 8.5~10 hours) of 10 hours during soaking in aqueous solutions at 4$^{\circ}C$ (OW). (2) Ozone treatment by exposure first to 30ppm of gaseous ozone for 90 minutes and then allied to OW method (GO+OW). The log reduction of raw soybeans treated by OW and GO+OW methods showed 3.72 and 4.15, respectively. Soybean curd prepared with OW and GO+OW-treated soybeans kept the shelf-life of 4 and 5.5 days at 3$0^{\circ}C$, respectively, but, that without ozone treatment spoiled at me day.

  • PDF

디젤기관차의 출력과 배기가스 배출특성의 상관관계 연구 (Relationships between Characteristics of Emission Gases and Engine Load Condition of Diesel Locomotive Engine)

  • 조영민;권순박;박덕신;박은영;임인권
    • 한국철도학회:학술대회논문집
    • /
    • 한국철도학회 2007년도 춘계학술대회 논문집
    • /
    • pp.1558-1563
    • /
    • 2007
  • The air pollution by the diesel locomotives has become serious environmental concern because the emission gases are exhausted without any further treatment. Recently, the public interest on the air pollutants emission reduction technology is increasing due to the establishment of 'Metropolitan Air Quality Preservative Law' and the regulation of local governments on the urban air quality. In this study, we measured the concentration of particulate matters and gaseous pollutants by using a scanning mobility particle sizer, a dust spectrometer, and a stack sampler upon various engine load condition. The results show that the amount of emitted air pollutants increased upon the increase of engine power. The development of new technology to reduce the air pollutants emission is urgently required.

  • PDF

대형디젤기관에서 DOC에 의한 배출가스 저감에 관한 연구 (A study on Emission Reduction by DOC on Heavy Duty Diesel Engine)

  • 한영출;류정호;오용석
    • 한국자동차공학회논문집
    • /
    • 제7권5호
    • /
    • pp.16-21
    • /
    • 1999
  • The diesel vehicle is relatively superior to gasoline vehicle on the fuel consumption, durability and combustion efficiency. However, exhaust emission from diesel vehicle are known to be harmful to human health and environment. The treatment technologies for the diesel exhaust gases are classified as replacement of fuel, quality control of diesel fuel, improvement of engine and aftertreatment system. The most effective for the treatment technology is known to be aftertreatment system, and this research is continuously conducted by many groups. The DOC system has many advantages of reducing particulates and harmful gaseous substances such as CO. HC. Moreover, it is simple in device structure, relatively low cost, and easy to install witout retrofitting the vehicle. In this study, experiment were conducted to analyze the effects on factors of oxidation characteristics and conversion efficiency of DOC. In experiment, test was conducted to estimate engine emission in 11,000cc diesel engine which was equipped with DOC.

  • PDF

미생물 종균제(KMT-199)를 이용한 퇴비제조 공정의 악취제거 (Prevention and Control of composting Odors Using Microbial Inocula, KMT-199)

  • 남이;김국진;성기철;박기돈;김진만
    • 한국토양환경학회지
    • /
    • 제4권3호
    • /
    • pp.57-65
    • /
    • 1999
  • 퇴비 제조장에서 발생하는 여러 가지 악취원 중 가장 문제가 되는 암모니아가스의 발생량을 감소시키기 위하여 (주)인바이오넷에서 유용미생물을 제제화 하여 개발한 미생물종균제, KMT-199(상품명: 콤포백)를 사용하여 현장시험을 수행하였다. KMT-199를 첨가한 경우 퇴비화 초기단계에서의 중온성, 고온성 미생물밀도가 무처리구에 비하여 10배 이상 증가되었으며, 발효 초기의 퇴비 내 온도와 pH의 증가 폭이 크게 나타났다. 온도는 KMT-199가 첨가된 처리구에서 발효 9일째, $75^{\circ}C$로 가장 높게 측정되어 무처리구에 비하여 퇴비의 최고 발열 시간을 3일 앞당겼으며, 최고 온도는 $4^{\circ}C$높았다. pH는 퇴비화가 진행되면서 지속적으로 증가되었는데, KMT-199가 첨가된 처리구에서는 발효 15일 째 이후에는 더 이상 증가하지 않고 감소되는 경향을 보였으나, 무처리구에서는 발효 38일째 까지 지속적으로 증가하는 경향을 나타내었다. 교반식 퇴비화 공정에 KMT-199를 투여한 결과 암모니아 가스의 발생량을 무처리구에 비하여 29%감소시킬 수 있었다. KMT-199를 사용하여 제조된 퇴비의 경우 대조구에 비하여 무 종자의 발아율이 증가하는 것으로 나타났다. 이것은 퇴비화 과정에서 미생물 생태를 변화시켜 줌으로서 퇴비화 과정에서 발생되는 유기물의 분해 촉진, 퇴비의 온도상승, 화학적변화의 촉진으로 퇴비의 부숙도 증가와 암모니아 가스 발생량이 감소된다는 것을 나타낸다.

  • PDF