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건식 개질 기반 청록 수소 생산을 위한 Ni-Cu 촉매 합성 최적화
최지환(Ji Hwan Choi),박상욱(Sangwook Park) 대한기계학회 2022 대한기계학회 춘추학술대회 Vol.2022 No.11
The dry reforming method is attracting great attention because it can produce hydrogen using carbon dioxide and methane, which are greenhouse gases. Although several dry reforming studies have been conducted using bimetallic alloys, additional studies are needed to ensure the high efficiency and high stability required for the industrial level. In this paper, we proceed with dry reforming by solvothermal synthesis using Nickel acetylacetonate and Copper acetylacetonate which have the same face-centered cubic(fcc) structure in nanoparticles. Using three solvents, (1) Ethanol (2) DMF(N, Ndimethylformamide) (3) Ethanol : Acetone (vol 50 : 50), we check which solvent has the highest CO2 and CH4 conversion rate and yield rate. Furthermore, by confirming that there is no change in the rate at 700°C for 24 hours, we show excellent catalytic stability when synthesizing elements with the same crystal structure.
건식 개질 기반 청록 수소 생산을 위한 Ni-Cu 촉매 합성 최적화
최지환(Ji Hwan Choi),박상욱(Sangwook Park) 대한기계학회 2022 대한기계학회 춘추학술대회 Vol.2022 No.11
The dry reforming method is attracting great attention because it can produce hydrogen using carbon dioxide and methane, which are greenhouse gases. Although several dry reforming studies have been conducted using bimetallic alloys, additional studies are needed to ensure the high efficiency and high stability required for the industrial level. In this paper, we proceed with dry reforming by solvothermal synthesis using Nickel acetylacetonate and Copper acetylacetonate which have the same face-centered cubic(fcc) structure in nanoparticles. Using three solvents, (1) Ethanol (2) DMF(N, Ndimethylformamide) (3) Ethanol : Acetone (vol 50 : 50), we check which solvent has the highest CO2 and CH4 conversion rate and yield rate. Furthermore, by confirming that there is no change in the rate at 700°C for 24 hours, we show excellent catalytic stability when synthesizing elements with the same crystal structure.
복합공구대 디스크임계돌출거리와 절삭력과의 관계에 관한 연구
최지환(Ji-Hwan Choi),김재실(Chae-Sil Kim),조수용(Su-Yong Cho) 한국기계가공학회 2013 한국기계가공학회지 Vol.12 No.1
Curvic coupling of mill turret should maintain disk weight and the cutting resistance which occurs the machining operation and must also have power transmission function. In order to improve machining operation range, the ejecting distance from curvic coupling to the disk must increase as much as possible. But moment is increased by the lack of capacity of the curvic coupling. Increase of moment is the cause of vibration/noise and degradation of machining performance not only stability problem. The manufacturer of mill turret has no the design information between the ejecting distance and the cutting resistance with safety of curvic coupling. Therefore this study describes a finite element analysis model of mill turret using ANSYS workbench. The structural analyses and modal analyses with varying of the ejecting distances and cutting resistances are performed. Finally the equation for relationship between the critical ejecting distance and the cutting resistance is defined under 5 of the safety factor for the maximum von-Mises stress at the curvic coupling.