Editor’s Choice
486
… NICE, 제39권 제4호, 2021Korean Journal of Chemical Engineering, Vol.38, No.5, 885-898, 2021
Recent applications of the liquid phase plasma process Kim SC, Park YK, Jung SC
Abstract - In this paper, the principle and application of plasma are briefly described, and in particular, the principle and practical application for plasma generated in liquid are introduced. Also, the research results of water treatment, synthesis of metal nanoparticle, synthesis of visible light-responsive photocatalyst, synthesis of energy material, and hydrogen gas production, which were tested using liquid phase plasma, are introduced. Various water pollutants were treated and hydrogen gas was produced using the strong chemical oxidizing species and ultraviolet rays in the plasma field generated in the reactant aqueous solution during the liquid phase plasma (LPP) process. The effects of plasma discharge conditions, dissolved oxygen concentration, pH value, photocatalytic behavior, as well as the properties of organic solutions on the LPP reaction were investigated experimentally and reported. Based on these previous studies, metal nanoparticles were synthesized using hydrogen atom radicals as well as the numerous electrons in the plasma field generated during the LPP process. Additionally, these studies indicate that visible light-responsive photocatalysts can be obtained when metal nanoparticles are precipitated in TiO2. They also provide evidence that metal nanoparticles can be precipitated in various carbon materials for application as electrodes in secondary batteries and supercapacitors. Therefore, the LPP process has been successfully applied in various fields given that it can be easily and conveniently used, and presently it is being applied in several new fields and many possibilities for its future application are expected.
Korean Journal of Chemical Engineering, Vol.38, No.5, 938-944, 2021
Life cycle assessment of LPG and diesel vehicles in Korea Kim MJ, Lee EJ, Kim CJ, Hong UG, Park DS, Shin HB, Lee KY
Abstract - With LPG automobile deregulation in 2019, the demand for LPG automobiles has increased in Korea; therefore, a comparison of the eco-friendliness of LPG and other petroleum-based vehicles has become necessary. We conducted a well- to-wheels (WTW) analysis of diesel and LPG fuel in Korea. GREET, PRELIM, and GHGenius models were utilized to calculate and appropriately allocate the energy use and greenhouse gas (GHG) emission in the life cycle process of diesel and LPG fuel. In the well-to-tank (WTT) step, the GHG emissions of LPG were lower than that of diesel because of the lower energy consumption of LPG in fuel production. For the WTW comparison, we selected four automobiles currently sold in Korea and a 1,500 kg curb weight model. The WTW GHG emissions of the LPG automobiles were lower than those of the diesel SUV and the 1 ton truck. On the other hand, the WTW GHG emissions of diesel automobiles were lower in the sedans and in the 1,500 kg model. Finally, it was verified that LPG automobiles were advantageous in terms of GHG emission in the SUV and one-ton truck, although the GHG emissions of diesel and LPG vehicles can vary depending on the fuel economy of the vehicles.
Korean Journal of Chemical Engineering, Vol.38, No.5, 952-965, 2021
Facile synthesis and characterization of WO
3/CuWO
4nanocomposites for the removal of toxic methylene blue dye
Thiyagarajan T, Deivasigamani V, Raj M, Joseph C, Dheivasigamani T, Palanivel B, Hamdy MS, Shkir M
Abstract - Pure tungsten oxide (WO
3) nanoparticles (NPs) and WO
3/copper tungstate (CuWO
4) nanocomposites (NCs) were
prepared by varying copper content from (5-20 wt%) via the co-precipitation process. XRD results reveal that the structural
parameters of WO
3/CuWO
4NCs have been strongly affected via Cu doping. Morphology of synthesized WO
3was noticed to
be distinct and particle size was significantly reduced through Cu doping confirmed by employing HRTEM studies. Elemental
purity of as synthesized products, elucidated from EDX and XPS analyses, reveals that WO
3/CuWO
4nanocomposites contain
W, O and Cu elements only. Also, FT-IR spectra and its corresponding assignments indicate the existence of WO
3/CuWO
4.
UV-Visible study shows that WO
3/CuWO
4composites have narrow bandgap compared to pure WO
3. Photoluminescence
spectral peaks intensity of NCs displays a decreasing trend, which supports the enhanced photocatalytic activity. The results
clearly show that 20 wt% Cu incorporated WO
3sample exhibits better photocatalytic nature than that of pure WO
3and will be
more applicable in purify the water.
Editor’s Choice
NEWS & INFORMATION FOR CHEMICAL ENGINEERS, Vol. 39, No. 4, 2021 …
487 Korean Journal of Chemical Engineering,
Vol.38, No.6, 1087-1103, 2021
A review on the recent developments of ruthenium and nickel catalysts for COx-free H
2generation by ammonia decomposition
Le TA, Do QC, Kim YM, Kim TW, Chae HJ
Abstract - The emerging H2 economy faces storage and transport challenges, and the use of ammonia (NH3) as a COx-free source of H2 via NH3 decomposition has recently attracted attention. Noble Ru-based catalysts are considered the best choice for highly efficient NH3 decomposition; however, their high cost and limited availability are disadvantages in large-scale applications. Otherwise, among non-noble metal-based catalysts, Ni-based catalysts are the most active, and Ni is considered a good alternative candidate material for NH3 decomposition because of its low cost. At present, some challenges remain in efforts to improve the efficiency of both Ru- and Ni-based systems. This review covers recent developments regarding these catalysts and can serve as a comprehensive work for evaluating effective long-term strategies.
Korean Journal of Chemical Engineering, Vol.38, No.6, 1104-1116, 2021
A review of synthesis strategies for MOF-derived single atom catalysts Hwang JK
Abstract - Single atom catalysts (SACs) have attracted great attention as promising catalysts that integrate the benefits of both heterogeneous and homogeneous catalysts. SACs exhibit unique properties that are otherwise difficult to achieve, such as high atom utilization efficiency, unprecedentedly high catalytic activity and selectivity. However, it still remains a great challenge to prepare stable SACs without particle aggregation and sintering. Among the various fabrication methods for SACs, metal- organic framework (MOF)-derived synthesis routes have shown great potential by taking advantage of MOFs’high structural/
chemical tunability, large surface area and high porosity. In this review, the synthesis strategies for MOF-derived SACs are comprehensively summarized and classified into five classes, metal node modification, ligand modification, guest encapsulation, migration and trapping, and others. The current challenges and future opportunities of MOF-derived SACs are further discussed. This review will be useful for the rational design of MOF-derived SACs for various catalytic reactions.
Korean Journal of Chemical Engineering, Vol.38, No.6, 1117-1128, 2021
Recent progress on Al distribution over zeolite frameworks:Linking theories and experiments Kwak SJ, Kim HS, Park NJ, Park MJ, Lee WB
Abstract - The location and distribution of aluminum in zeolites is considered important in determining various properties,
such as acidity and reactivity. Controlling the placement of aluminum substitution has therefore been of significant interest,
and a number of studies have been conducted, including synthesis methods using either different organic structure-directing
agents (OSDAs) or cationic species, and the application of dealumination as post-processing. In addition to experimental
developments, computational methods have emerged as a useful tool for analyzing the effects of different types of aluminum
siting on catalytic properties, especially by incorporating statistical methods. A review of recent developments and findings
related to aluminum siting and its effects is presented in this work. Analysis of the thermodynamic distribution of aluminum,
as well as synthetically altered distribution in different zeolite frameworks, has been discussed. Computational studies have
revealed that catalytic properties are sensitive to adsorbate-dependent properties such as the size of rings and voids for the
residence of aluminum, the relative distribution of acid sites, and the adsorption properties of molecules in different framework
motifs. Along with the atomic scale evaluation of synthetic treatments in positioning the aluminum, cases of instrumental
analysis methods and their verification with simulations is discussed, demonstrating how theories have complemented and,
sometimes modified, experimental perspectives. Lastly, recent progress in incorporating machine learning techiques, its
application to zeolites, and directions for future work are introduced.
Editor’s Choice
488
… NICE, 제39권 제4호, 2021Korean Chemical Engineering Research, Vol.59, No.3, 393-398, 2021
리튬이온전지의 사이클 수명 모델링
Modeling to Estimate the Cycle Life of a Lithium-ion Battery 이재우, 이동철, 신치범, 이소연, 오승미, 우중제, 장일찬
Abstract - 리튬이온전지의 성능을 최적화하기 위해서는 여러 열화 요소들을 고려한 성능 예측 모델링 기술이 필요하다.
본 연구에서는 리튬이온전지의 사이클 노화로 인한 방전 거동 및 사이클 수명 변화를 수학적으로 모델링하였다.
모델링의 신뢰성을 검증하기 위해 0.25C로 사이클 시험을 진행했으며, 30 사이클 간격으로 진행한 RPT (Reference performance test)를 통해 전기적 거동을 파악하였다. 기존의 리튬이온전지의 사이클 수명 예측 모델에 BOL (Beginning of life)에서 일어나는 현상 중 하나인 Break-in 메커니즘을 반영하여 수명예측 정확도를 개선시켰다. 모델에 근거하여 예측된 사이클 수명 변화는 실제 시험 결과와 잘 일치하였다.
Korean Chemical Engineering Research, Vol.59, No.3, 417-428, 2021
0.1MWth 급 순환유동층에서의 무연탄 연소 전산유체역학 모사
Anthracite Oxygen Combustion Simulation in 0.1MWth Circulating Fluidized Bed 고은솔, 국진우, 서광원, 서수빈, 김형우, 강서영, 이시훈
Abstract - 낮은 반응성으로 인해 복잡한 공정이 필요한 무연탄은 순환유동층 내의 동적 거동을 통해 연소 특성이 고찰되어야 한다. Pilot 규모의 0.1MWth 급 순산소 순환유동층 연소로에서의 무연탄 연소 특성을 고찰하기 위하여 본 연구에서는 전산유체해석 기법을 이용하였다. 순산소 순환유동층 보일러는 연소로(0.15 m l.D., 10 m High), 싸이클론, 재순환부 등으로 구성되었고 동일한 크기의 3D 모델 반응기를 구축하였다.실험에 사용한 무연탄은 평균 입도 1,070 μm, 밀도 2,326 kg/m3이다. 공기 연소에서 순산소 연소로의 연소 환경 변화에 따른 반응기 내부의 기-고 흐름 패턴을 고찰하였다. 이때, 공기 연소와 순산소 연소에서 온도 분포는 비슷한 양상을 보이지만 압력 분포는 순산소 연소에서 더 낮음을 알 수 있었다. 더불어 공기 연소에 비해 순산소 연소에서 더 높은 CO2 농도를 가지므로 이산화탄소 포집이 활발히 이루어질 것을 예상해 볼 수 있다. 결과적으로 본 연구를 통해 무연탄 활용 시 순환유동층 반응기의 최적화된 설계 및 운전에 기여할 수 있음을 확인하였다.
Korean Chemical Engineering Research, Vol.59, No.3, 443-449, 2021
전분-구연산을 기반으로 한 생분해성 비산방지용 소재의 제조 및 특성 분석
