• Title/Summary/Keyword: Flue-gas

Search Result 609, Processing Time 0.027 seconds

The Effect of HCl Gas on Selective Catalytic Reduction of Nitrogen Oxide (질소산화물의 선택적 환원 제거시 염화수소기체가 촉매에 미치는 영향)

  • Choung, Jin-Woo;Choi, Kwang-Ho;Seong, Hee-Je;Chai, Ho-Jung;Nam, In-Sik
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.22 no.4
    • /
    • pp.609-617
    • /
    • 2000
  • This study is aimed at investigating an effect of HCl gas on selective reduction of NOx over a CuHM and $V_2O_5-WO_3/TiO_2$ catalyst. SCR process is the most effective method to remove NOx, but catalyst can be deactivated by the acidic gas such as HCl gas which is also included in flue gas from the incinerator. In dry condition of flue gas, the CuHM catalyst treated by HCl gas has shown higher NO removal activity than the fresh catalyst. The activity of the catalyst can be restored by treating at $500^{\circ}C$. On the contrary. $V_2O_5-WO_3/TiO_2$ catalyst is obviously deactivated by HCl and the deactivation increases in proportion to the concentration of HCl gas. The deactivated catalyst is not restored to it's original activity by heat treatment for regeneration. In wet flue gas stream, the CuHM catalyst has shown lower activity than fresh catalyst and $V_2O_5-WO_3/TiO_2$ catalyst was severely deactivated by HCl treatment. The activity loss of catalysts are mainly due to the decrease of Br$\ddot{o}$nsted acid site on the catalyst surface by $NH_3$ TPD. The change of BET surface area of CuHM catalyst after the reaction isn't observed but $V_2O_5-WO_3/TiO_2$ catalyst is observed. The amount of $Cu^{{+}{+}}$ and $V_2O_5$ is decreased after the reaction. From these results, it is expected that CuHM catalyst should be better than $V_2O_5-WO_3/TiO_2$ catalyst for its application to the incineration of flue gas.

  • PDF

Improvement of the $SO_{x}$ Removal by Adding Dibasic Acids into the JBR FGD Process

  • Lee, Byeong-Kyu;Jeon, Sang-Ki;Cho, Seong-Won
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.17 no.E4
    • /
    • pp.157-162
    • /
    • 2001
  • Jet Bubbling Reactors(JBRs) were operated for the removal of SO$_{x}$ in flue gases produced from many electric power plants. However, many JBR flue gas desulfurization (FGD) facility faced a decrease of SO$_{x}$ removal efficiency and an increase of scale problems with continuous operations. We increased alkalinity of the SO$_{2}$ absorbing medium by adding the dibasic acids (DBAs) to solve these problems more effectively. The SO$_{2}$ removal efficiency, the purity of CaCO$_{3}$ and COD of the wastewater was measured to identify the addition effects of DBAs (150, 200, 250, and 400 ppm) for 2hr in a day into the JBR attached to the large-scale power plants (400 MW$\times$3). Addition of the DBAs resulted in the improvement of the SO$_{2}$ removal efficiency from 2 to 5% and the purity of the gypsum from 1 to 2%; these improvement were due to the alkalinity increase of the absorbing medium and the reduction of a proportion of un-reacted CaCO$_{3}$, respectively. Also, the scale problems formed by un-reacted CaCO$_{3}$ inside the reaction zone of the JBR were substantially reduced. Even though the effluent COD of the wastewater slightly increased from 10~15 to 18~36 mg/l and the erosion problems in the injection pump and duct occurred, this method of increasing SO$_{2}$ removal efficiency by adding the DBAs could be considered as a profitable approach.ach.

  • PDF

The Risk Assessment of Carbon Monoxide Poisoning by Gas Boiler Exhaust System and Development of Fundamental Preventive Technology (가스보일러 CO중독 위험성 예측 및 근원적 예방기술 개발)

  • Park, Chan Il;Yoo, Kee-Youn
    • Journal of the Korean Institute of Gas
    • /
    • v.25 no.3
    • /
    • pp.27-38
    • /
    • 2021
  • We devised the system to automatically shutdown the boiler and to fundamentally block the harmful gases, including carbon monoxide, into the indoor when the exhaust system swerves: (1) The discharge pressure of the exhaust gas decreases when the exhaust pipe is disconnected. The monitoring system of the exhaust pipe is implemented by measuring the output voltage of APS(Air Pressure Sensor) installed to control the amount of combustion air. (2) The operating software was modified so that when the system recognizes the fault condition of a flue pipe, the boiler control unit displays the fault status on the indoor regulator while shutting down the boiler. In accordance with the ventilation facility standards in the "Rules for Building Equipment Standards" by the Ministry of Land, Infrastructure and Transport, experiments were conducted to ventilate indoor air. When carbon monoxide leaked in worst-case scenario, it was possible to prevent poisoning accidents. However, since 2013, the number of indoor air exchange times has been mitigated from 0.7 to 0.5 times per hour. We observed the concentration exceeding TWA 30 ppm occasionally and thus recommend to reinforce this criterion. In conclusion, if the flue pipe fault detection and the indoor air ventilation system are introduced, carbon monoxide poisoning accidents are expected to decrease significantly. Also when the manufacturing and inspection steps, the correct installation and repair are supplemented with the user's attention in missing flue, it will be served to prevent human casualties from carbon monoxide poisoning.

A Study on the Generation of Oxygen-Free Gas Using Catalytic Combustion for Industrial Applications (촉매연소를 이용한 무 산소 가스 생성에 관한 연구)

  • Jeong, Nam-Jo;Kang, Sung-Kyu;Song, Kwang-Sup;Cho, Sung-June;Yu, Sang-Phil;Ryou, In-Su
    • 한국연소학회:학술대회논문집
    • /
    • 2001.06a
    • /
    • pp.46-52
    • /
    • 2001
  • In this study, the generation of oxygen-free gas using catalytic combustion for industrial applications is explained ; heat treatment and copper annealing. For the experiment, Pd catalysts were determined by testing their catalytic activities over LPG in a micro-reactor. Combustion characteristics for the generation of oxygen-free atmospheric gas and the effect of flue gas upon surface oxidation were estimated form this experiment. As a result of the experimental investigation, we can state that the catalytic combustion could generate oxygen-free atmospheric gas suitable for industrial applications, but vapor produced by combustion process must be carefully considered as a new factor of surface oxidation.

  • PDF

The Studies on the Thermal Resistant Properties of $WO_3/TiO_2$ and $V_2O_5-WO_3/TiO_2$ Catalysts for NOx Reduction of Flue Gases from Industrial Boiler and on Catalyst Surface Acid Characteristics (産業用 보일러의 燃燒 排가스 中 NOx 處理를 위한 SCR 用 $WO_3/TiO_2$$V_2O_5/TiO_2$ 觸媒들의 耐熱特性과 表面 酸特性에 關한 硏究)

  • 이중범;임상윤;정석진;성준용
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.6 no.1
    • /
    • pp.31-42
    • /
    • 1990
  • In order to suggest an efficient catalyst systems for NOx reduction of flue gases from industrial boilers, $TiO_2$ supported $WO_3-V_2O_5, V_2O_5$ and $WS_2$ catalysts were tested for the performances of NOx reduction at high reactin temperature range (250-500$^\circ$C) using a simulated flue gas system. It was found that while the proposed $WO_3/TiO_2$ and $WO_3-V_2O_5/TiO_2$ catalysts showed a significant high NOx reduction efficiency at about 350-400$^\circ$C, the conventional commercial catalyst of $V_2O_5/TiO_2$ showed a significant drop in NOx reduction efficiency due to the excessive $NH_3$ oxidation. From the measurement of surface acidities of those catalysts, it was found that the acidity are well correlated with the activities of NOx reduction. The reason of high activity of $WO_3$ series catalysts at high reaction temperature seems due to the low value of surface excess oxygen compared with that of $V_2O_5/TiO_2$ seems equivalent to the acid site of that catalyst.

  • PDF

Part Load Performance Characteristics of Domestic Wood Pellet Boiler (가정용 목재 펠릿 보일러에 대한 부분부하 운전 특성)

  • Kang, Sae Byul;Kim, Jong Jin;Kim, Hyouck Ju;Park, Hwa Choon;Choi, Kyu Sung;Sim, Bong Seok
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 2010.11a
    • /
    • pp.103.1-103.1
    • /
    • 2010
  • Recently domestic wood pellet boilers are installed in rural and forestry houses. The fuel price per lower heating value of wood pellet is about 20 % lower than that of heating oil on July 2010. In spite of lower price of wood pellet, a few user of wood pellet boiler complain expensive fuel cost. One of this reason is inaccurate or improper air-fuel ratio setting of wood pellet boiler. O2 concentration of flue gas of domestic wood pellet boiler is about 9.7 % and there are few domestic wood pellet boiler which can control air-fuel ratio automatically. We tested a domestic wood pellet boiler in changing boiler thermal output and air-fuel ratio. The nominal boiler thermal output is 25 kW (21 500 kcal/h). We measured thermal efficiency and flue gas concentrations such as CO and NOx at each boiler thermal load with various air-fuel ratio. The results show that if air flow rate is the same as full load and part load, thermal efficiency of part load of 40 % drops about 7.7 %p compared to boiler full load case.

  • PDF