• 제목/요약/키워드: electrolysis

검색결과 811건 처리시간 0.031초

Performance Assessment of Electrolysis Using Copper and Catalyzed Electrodes for Enhanced Nutrient Removal from Wastewater

  • Kim, Woo-Yeol;Son, Dong-Jin;Yun, Chan-Young;Kim, Dae-Gun;Chang, Duk;Sunwoo, Young;Hong, Ki-Ho
    • Journal of Electrochemical Science and Technology
    • /
    • 제8권2호
    • /
    • pp.124-132
    • /
    • 2017
  • The performance of electrolytic processes using copper and catalyzed electrodes for enhanced nutrient removal with various catalyzers and combinations of electrodes was evaluated. The catalyzed electrodes removed more ammonia nitrogen than the copper electrode, but higher ammonia removal was achieved using a Pt/Ti anode. On the other hand, electrolysis using the Pt/Cu anode consumed less energy and cost less. During electroreduction, nitrate was better removed by a pair of copper electrodes than by the catalyzed electrodes. During electrolysis of synthetic wastewater, ammonia removal not only increased owing to direct oxidation at the anode, but was also influenced by indirect oxidation at the cathode. Platinum-coated copper and titanium cathodes actively produced oxidizers and thus removed more ammonia than a pure metal cathode. Although phosphorus was removable irrespective of the type of catalyzer, electrocoagulation using the copper electrode achieved complete removal of phosphorus in a period of less than 10 min.

Applications of Scanning Electrochemical Microscopy (SECM) Coupled to Atomic Force Microscopy with Sub-Micrometer Spatial Resolution to the Development and Discovery of Electrocatalysts

  • Park, Hyun S.;Jang, Jong Hyun
    • Journal of Electrochemical Science and Technology
    • /
    • 제7권4호
    • /
    • pp.316-326
    • /
    • 2016
  • Development and discovery of efficient, cost-effective, and robust electrocatalysts are imperative for practical and widespread implementation of water electrolysis and fuel cell techniques in the anticipated hydrogen economy. The electrochemical reactions involved in water electrolysis, i.e., hydrogen and oxygen evolution reactions, are complex inner-sphere reactions with slow multi-electron transfer kinetics. To develop active electrocatalysts for water electrolysis, the physicochemical properties of the electrode surfaces in electrolyte solutions should be investigated and understood in detail. When electrocatalysis is conducted using nanoparticles with large surface areas and active surface states, analytical techniques with sub-nanometer resolution are required, along with material development. Scanning electrochemical microscopy (SECM) is an electrochemical technique for studying the surface reactions and properties of various types of electrodes using a very small tip electrode. Recently, the morphological and chemical characteristics of single nanoparticles and bio-enzymes for catalytic reactions were studied with nanometer resolution by combining SECM with atomic force microscopy (AFM). Herein, SECM techniques are briefly reviewed, including the AFM-SECM technique, to facilitate further development and discovery of highly active, cost-effective, and robust electrode materials for efficient electrolysis and photolysis.

Long-Term Stability for Co-Electrolysis of CO2/Steam Assisted by Catalyst-Infiltrated Solid Oxide Cells

  • Jeong, Hyeon-Ye;Yoon, Kyung Joong;Lee, Jong-Ho;Chung, Yong-Chae;Hong, Jongsup
    • 한국세라믹학회지
    • /
    • 제55권1호
    • /
    • pp.50-54
    • /
    • 2018
  • This study investigated the long-term durability of catalyst(Pd or Fe)-infiltrated solid oxide cells for $CO_2$/steam co-electrolysis. Fuel-electrode supported solid oxide cells with dimensions of $5{\times}5cm^2$ were fabricated, and palladium or iron was subsequently introduced via wet infiltration (as a form of PdO or FeO solution). The metallic catalysts were employed in the fuel-electrode to promote $CO_2$ reduction via reverse water gas shift reactions. The metal-precursor particles were well-dispersed on the fuel-electrode substrate, which formed a bimetallic alloy with Ni embedded on the substrate during high-temperature reduction processes. These planar cells were tested using a mixture of $H_2O$ and $CO_2$ to measure the electrochemical and gas-production stabilities during 350 h of co-electrolysis operations. The results confirmed that compared to the Fe-infiltrated cell, the Pd-infiltrated cell had higher stabilities for both electrochemical reactions and gas-production given its resistance to carbon deposition.

양방향수전해 기반 수소제조용 초고온스팀 생산시스템의 엑서지 분석 (Exergy Analysis on the System of Superheated Steam (700℃, 3 atm) Production for the Reversible Electrolysis: Based Hydrogen Production)

  • 한단비;박성룡;조종표;백영순
    • 한국수소및신에너지학회논문집
    • /
    • 제29권3호
    • /
    • pp.235-242
    • /
    • 2018
  • Hydrogen can be produced by reforming reaction of natural gas (NG) and biogas, or by water electrolysis. In this study, hydrogen production through water-electrolysis needs superheated steam above $700^{\circ}C$ for high efficiency. The production method of hydrogen like this was recommended for the 4-type processes for superheated steam ($700^{\circ}C$, 3 atm) by Bio-SRF combustion furnace. The 4-type processes to produce superheated steam at $700^{\circ}C$ from the heat source of SRF combustion furnace was simulated using PRO II. The optimum process was selected through exergy analysis. The difference of process 1 and 2 is to the order of depressure and heating process to change $180^{\circ}C$ and 7 atm to $700^{\circ}C$ and 3 atm. Process 3 and 4 is to utilize 25% of steam to generate superheated steam and remaining to use for the power generation by steam generator.

마그네사이트 광석으로부터 용융염전해법에 의한 마그네슘 제조 (Preparation of Magnesium from Magnesite using Fused Salt Electrolysis)

  • 박형규;강정신;이진영
    • 자원리싸이클링
    • /
    • 제26권3호
    • /
    • pp.69-78
    • /
    • 2017
  • 최근 국내 자동차부품 및 전자기기 산업에서 마그네슘 금속의 수요가 증가하고 있다. 마그네슘 제련은 크게 용융염전해법과 열환원법 두 가지로 대별할 수 있는데, 본 고에서는 마그네슘 금속 제련에 관하여 원료 광석인 마그네사이트로부터 무수염화마그네슘 제조를 거쳐 용융염전해법에 의한 금속 마그네슘 제조까지 실험실 규모로 전해 마그네슘을 제조한 내용을 요약 보고하였다.

전기분해법에 의한 해수내의 암모니아성 질소 제거 (Ammonia-nitrogen Removal in Sea Water by Using Electrolysis)

  • 이병헌;이제근;길대수;곽순열
    • 한국양식학회지
    • /
    • 제10권4호
    • /
    • pp.435-438
    • /
    • 1997
  • 전기분해를 이용한 해수의 암모니아성 질소 및 대장균 제거에 효과적이었다. 암모니아의 제거효율은 전류의 세기가 클수록, 반응 시간이 길수록, 극판간격이 좁을수록 증가하였다. 해수내 250/100 m\ell$의 대장균은 모든 실험 조건에서 검출되지 않아, 살균 목적으로 전기분해가 매우 효과적이었다. 암모니아의 제거 효율은 잔류 염소의 농도에 따라 증가하였다. 암모니아의 제거 효율과 잔류 염소와의 관계는 다음과 같다.$NH_4^+-N(%)=4cdotlog[Residual\;chlorine(mg/\ell)+28(r=0.892)$

  • PDF

펄스전원에 의한 수산화가스 발생기에 관한 연구 (A Study on Analysis of the Hydrogen-Oxygen Gas Generator Using Pulse Power Supply)

  • 이정민;강병희;목형수;최규하
    • 전력전자학회논문지
    • /
    • 제6권5호
    • /
    • pp.377-385
    • /
    • 2001
  • 물을 전기분해하여 얻은 일정 부피비를 갖는 수소와 산소 혼합가스를 수산화가스로 명명하며, 이를 역반응시켜서 열 에너지원으로 사용하고 있다. 수산화가스는 경제성, 안전성 및 환경친화적인 고유한 특성을 지니고 있어서 현재 가스용접기에 적용하고 있으며 여러 가지 응용분야에 적용할 수 있도록 연구 중에 있다. 본 논문에서는 수산화가스의 특성에 관하여 고찰하고 발생기용 전원에 대하여 소개하고 이 중에서 아직까지 적용되지 않은 펄스전원을 적용하여 여러 가지 운전주파수에서 비교분석 하였다.

  • PDF

기질에 따른 미생물 전해 전지-혐기성 소화의 미생물 군집 특성 (Effect of Substrates on the Microbial Communities in a Microbial Electrolysis Cell and Anaerobic Digestion Coupled System)

  • 이채영;한선기
    • 한국수소및신에너지학회논문집
    • /
    • 제30권3호
    • /
    • pp.269-275
    • /
    • 2019
  • This study was conducted to evaluate the microbial communities in coupled system of a microbial electrolysis cell and an anaerobic digestion. Glucose, butyric acid, propionic acid and acetic acid were used as substrates. The maximum methane production and methane production rate of propionic acid respectively were $327.9{\pm}6.7mL\;CH_4/g\;COD$ and $28.3{\pm}3.1mL\;CH_4/g\;COD{\cdot}d$, which were higher than others. Microbial communities' analyses indicated that acetoclastic methangens were predominant in all systems. But the proportion of hydrogenotrophic methanogens was higher in the system using propionic acid as a substrate when compared to others. In coupled system of a microbial electrolysis cell and anaerobic digestion, the methane production was higher as the distribution of hydrogen, which was generated by substrate degradation, and proportion of hydrogenotrophic methanogens was higher.

Copper Recovery from Printed Circuit Boards Waste Sludge: Multi-step Current Electrolysis and Modeling

  • Nguyen, Huyen T.T.;Pham, Huy K.;Nguyen, Vu A.;Mai, Tung T.;Le, Hang T.T.;Hoang, Thuy T.B.
    • Journal of Electrochemical Science and Technology
    • /
    • 제13권2호
    • /
    • pp.186-198
    • /
    • 2022
  • Heavy metals recovery from Printed Circuit Boards industrial wastewater is crucial because of its cost effectiveness and environmental friendliness. In this study, a copper recovery route combining the sequential processes of acid leaching and LIX 984N extracting with an electrowinning technique from Printed Circuit Boards production's sludge was performed. The used residual sludge was originated from Hanoi Urban Environment One Member Limited Company (URENCO). The extracted solution from the printed circuit boards waste sludge containing a high copper concentration of 19.2 g/L and a small amount of iron (0.575 ppm) was used as electrolyte for the subsequent electrolysis process. By using a simulation model for multi-step current electrolysis, the reasonable current densities for an electrolysis time interval of 30 minutes were determined, to optimize the specific consumption energy for the copper recovery. The mathematical simulation model was built to calculate the important parameters of this process.

Pt포일 양극을 이용한 전기화학적 암모니아 수전해 특성 연구 (Characterization of Electrochemical Ammonia Electrolysis Using a Platinum Electrode for Anodic Reaction)

  • 최정민;김학덕;송주헌
    • 한국수소및신에너지학회논문집
    • /
    • 제33권4호
    • /
    • pp.337-342
    • /
    • 2022
  • In this study, a water electrolysis was studied to investigate the effect of ammonia on current density and H2 gas production. A H type cell with three electrodes was used and KOH solution was used as electrolyte. The conventional platinum foil was used for working electrode, whereas nickel foam was used for counter electrode. CV experiment was performed to see the activity of ammonia oxidation reaction. In addition, CP experiment was done to examine the dependence of Faraday efficiency of hydrogen on current density and NH3 concentration. The CV result shows the 0.5M NH3 concentration required for highest current density and reliable operation. The CP result shows the increased current density leads to higher H2 generation. The higher H2 production and subsequent energy efficiency was observed for 0.5M NH3 using a Pt/13%Rh coil for a cathode as compared to those in water electrolysis.