• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2006년도 제32회 KOSCO SYMPOSIUM 논문집
• /
• pp.69-74
• /
• 2006

An Experimental study was conducted on $CO_2$ recycle combustion heating system using pure oxygen instead of conventional air as an oxidant, which is thereby producing a flue gas of mostly $CO_2$ and water vapor($H_2O$) and resulting in higher $CO_2$ concentration. The advantages of the system are not only the ability to control high temperatures characteristic of oxygen combustion with recycling $CO_2$. but also the possibility to reduce NOx emission in the flue gas. A small scale industrial reheating furnace simulator and specially designed variable flame burner were used to characterize the $CO_2$ recycle oxy-fuel combustion, such as the variations of furnace pressure, temperature and composition in the flue gas during recycle. It was found that $CO_2$ concentration in the flue gas was about 80% without $CO_2$ recycle, but increased to $90{\sim}95%$ with $CO_2$ recycle. The furnace temperature and pressure was decreased due to recycle and the NOx emission was also reduced to maintain under 100ppm.

• 한국연소학회지
• /
• 제18권2호
• /
• pp.17-22
• /
• 2013

In this study, we tested the absorption of $CO_2$ in combustion gas into an alkaline wastewater to simultaneously control $CO_2$ and wastewater. During the experiment, we investigated the effects of operating parameters on neutralization characteristics of the wastewater by using $CO_2$ in a bench-scale semi-batch jet loop reactor (0.1 m diameter and 1.0 m in height). The operating parameters investigated in the study are gas flow rate of 1.0-2.0 L/min, liquid recirculation flow rate of 4-32 L/min, and liquid temperature of $20-25^{\circ}C$. It was shown that the initial pH of wastewater rapidly decreased with increased gas flow rate for a given liquid recirculation flow rate. This was due to the increase in the gas holdup and the interfacial area at higher gas flow rate in the reactor. At constant gas flow rate, the time required to neutralize the wastewater initial pH of 10.1 decreased with liquid recirculation flow rate ($Q_L$), reached a minimum value in the range of $Q_L$ = 16-24 L/min, and then increased with further increase in $Q_L$. Further, the time required to neutralize the wastewater was shortened at higher temperatures.

• 에너지공학
• /
• 제28권2호
• /
• pp.55-62
• /
• 2019

본 연구는 가스가마를 사용하여 청자를 소성 할 경우 최적의 소성조건을 구하고자 하였다. 특히 환원분위기와 산화 분위기 등의 소성분위기를 가마내의 CO 농도로 명확하게 정의하였다. $1250^{\circ}C$로 청자유약을 소성한 경우, 가마 안의 일산화탄소 양이 0~4,500PPM에서는 산화 4,500~25,000PPM에서는 중성, 25,000PPM 이상에서는 환원분위기가 됨을 관찰 할 수 있었다. 가스 가마 안의 소성분위기와 소성온도를 균일하게 하면서 가스소모량과 소성시간을 줄이기 위해서는 가마 안의 연돌을 일부 막은 후 댐퍼로 조절하면 된다. 이와 같은 조절방법으로 가스량은 40%, 소성시간은 1시간을 절약할 수 있다.

• 한국수소및신에너지학회논문집
• /
• 제26권5호
• /
• pp.445-452
• /
• 2015

A tubular packed bed reactor for the steam-$CO_2$ combined reforming of natural gas to produce the synthesis gas of a target $H_2/CO$ ratio 2.0 was simulated. The effects of the reactor dimension, the feed gas composition, and the gas feeding temperature upon the possibility of coke formation across the catalyst bed were investigated. For this purpose, 2-dimensional heterogeneous reactor model was used to determine the local gas concentrations and temperatures over the catalyst bed. The thermodynamic potential distribution of coke formation was determined by comparing the extent of reaction with the equilibrium constant given by the reaction, $CH_4+2CO{\Leftrightarrow}3C+2H_2O$. The simulation showed that catalysts packed in the central region nearer the entrance of the reactor were more prone to coking because of the regional characteristics of lower temperature, lower concentration of $H_2O$, and higher concentration of CO. With the higher feeding temperature, the feed gas composition of the increased $H_2O$ and correspondingly decreased $CO_2$, or the decrease in the reactor diameter, the volume fraction of the catalyst bed subsequent to coking could be diminished. Throughout the simulation, reactor dimension and reaction condition for coking-free operation were suggested.

• 대한공업교육학회지
• /
• 제33권1호
• /
• pp.282-296
• /
• 2008

기존의 자동차 부품 로봇 용접방법은 노즐을 통하여 $CO_2$ 가스가 확산되는 구조로 되어있어 용접대상물에 노즐간섭으로 인하여 로봇 용접이 불가능한 부위가 많고, 공간이 좁은 부분의 용접은 2차 수작업으로 완성하고 있어 생산성 향상에 걸림돌이었다. 따라서 본 연구에서는 이러한 용접과정을 분석하여 $CO_2$ 가스 소모량을 절약하고, 좁은 공간 부위를 로봇 용접할 수 있는 새로운 특수 용접 노즐을 개발하여 생산성을 향상시키고자 하였다. 본 연구개발에서 설계 제작된 협대역 자동차 부품 로봇 용접용 특수 용접 팁은 2단 구조로서 중단부에 직경 3mm의 구멍을 8개소로 제작하고 $CO_2$ 가스 소모량을 47%이상 절약한 형태로서 용접 결함율이 비교적 낮은 개발품이다. 본 연구의 결과는 국내 자동차 업계에서 사용되는 구형 용접 팁을 중간부에 구멍이 뚫린 2단 구조의 노즐로 대체하면 생산원가를 절감할 수 있다고 판단된다.

• Elastomers and Composites
• /
• 제33권1호
• /
• pp.37-43
• /
• 1998

The permeation of gas through polymer membrane at temperatures above its glass transition, generally occurs by a solution-diffusion mechanism. This mechanism is performed by the affinity difference between polymeric materials and gas molecules, and various technologies, such as copolymerization, impregnation and so on, have been researched to improve the affinity of polymeric material for the gases. In this study, permeability and selectivity for some gases were obtained from steady-state rates of gas permeation through silicone rubber membrane which is prepared by supercritical fluid extraction method. The permeability was measured by the volumetric method proposed by Barrer. Permeability was increased generally with temperature and permeation pressure. Silicone rubber membrane shows a higher permeability to $CO_2$ than to $O_2$, $N_2$. This results probably reflect the relatively high solubility of CO_2 in silicone rubber membrane, which is due to the affinity of $CO_2$ molecules. Since separation powers of $CO_2/N_2$, $CO_2/O_2$ were more than 200, and 100, respectively, it is able to separate $CO_2$ from the air, and the optimum temperature and pres-sure was 328.15 K, 60 cmHg respectively. In future, it is possible that the silicone rubber membrane can be used for separation or concentration of $CO_2$ through experiment for mixed gas separation.

• 전기학회논문지
• /
• 제59권7호
• /
• pp.1302-1308
• /
• 2010

In this study, Zigbee Sensor Node to transmit harmful gases CO and $CO_2$ information using wireless communication within the ground and underground structures were developed. Wireless communication protocol was used Zigbee Stack included IEEE 802. 15.4 MAC protocol. For wireless transmission of detected harmful gas signal from ADC of MCU was implemented Zigbee Sensor Node that was developed protocol using Serial-Port-Profile(SPP) here. The proposed Zigbee Sensor Node was verified transmission distance from experiments. Transmission distance was into 90m in experiments. Distance experiments were measured at 10m intervals using sine & pulse wave input signal at indoors. The proposed Route Sensor Node was applied mesh routing protocol. When built up USN(Ubiquitous Sensor Network)using Route Sensor Node, transmission distance was not limited. On the experimental results, harmful gas values between direct measurements and USN measurements were consistent. The semiconductor CO sensor and N-DIR $CO_2$ sensor module as a harmful sensor was used. Therefore, the proposed Zigbee Sensor Node was verified about reliability and validity to build USN for transmission of harmful gas information.

• 한국수소및신에너지학회논문집
• /
• 제22권6호
• /
• pp.925-933
• /
• 2011

The traditional feedstock for dimethyl ether (DME) has been natural gas obtained by pipeline from a nearby natural gas or oil field. This report focuses on other feedstock: Coal bed methane (CBM). The resource availability and suitability of CBM for DME manufacturing have been investigated. CBM in a short time has become an important industry, providing an abundant clean-burning fuel and also suggesting as a feedstock for gas industry. The use of CBM will have very little impact on the KOGAS' DME process design and economics up to 50 vol% of $CO_2$ in the CBM source. Many of the CBM sources in Asia are high in $CO_2$, but pose no difficulties for the KOGAS' DME plant. Since tri-reformer requires substantial $CO_2$ in its feed, no $CO_2$ removal from the CBM feed is needed. The $CO_2$ in the CBM means that less $CO_2$ needs to be recycled from the downstream in the process.

• 신재생에너지
• /
• 제5권2호
• /
• pp.15-24
• /
• 2009

As new small scale LFG (landfill gas) energy project model which can improve economic feasibility limited due to the economy of scale, LFG-Microturbine combined heat and power system with $CO_2$ fertilization into greenhouses was proposed and investigated including basic design process prior to the system installation at Gwang-ju metro sanitary landfill. The system features $CH_4$ enrichment for stable microturbine operation, reduction of compressor power consumption and low CO emission, and $CO_2$ supplement into greenhouse for enhancement plant growth. From many other researches, high $CO_2$ concentration was found to enhance $CO_2$ assimilation (also known as photosynthesis reaction) which converts $CO_2$ and $H_2O$ to sugar using light energy. For small scale landfills which produce LFG under $3\;m^3$/min, among currently available prime movers, microturbine is the most suitable power generation system and its low electric efficiency can be improved with heat recovery. Besides, since its exhaust gas contains very low level of harmful contaminants to plant growth such as NOx, CO and SOx, microturbine exhaust gas is a suitable and economically advantageous $CO_2$ source for $CO_2$ fertilization in greenhouse. The LFG-Microturbine combined heat and power generation system with $CO_2$ fertilization into greenhouse gas to enhance plant growth is technologically and economically feasible and improves economical feasibility compared to other small scale LFG energy project model.

• 신재생에너지
• /
• 제5권4호
• /
• pp.46-51
• /
• 2009

The purpose of this study is to investigate selective adsorption of $CO_2$ from LFG (Landfill gas) by using commercialized NaX-type zeolite adsorbent under the ambient temperature and pressure. The experiment of $CO_2$ adsorption was carried out by using simulated LFG. The $CO_2$ adsorption capacity and separation efficiency of NaX-type adsorbent were investigated by analyzing gas flow rate and gas composition at inlet and outlet of the adsorption reactor. The adsorbed $CO_2$ were desorbed under decompression condition which 0.5 Torr or by air purge. Through the result to use simulated LFG, when the method of VSA was used, 73.2~75.3 mg of $CO_2$ was adsorbed per 1 g commercial adsorbent, when the method of air purge was used, 78.4~83.2 mg of $CO_2$ was adsorbed per 1 g of commercial adsorbent.