• Title, Summary, Keyword: Clean Process

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Development of Treatment Process for Residual Coal from Biosolubilization

  • Rifella, Archi;Shaur, Ahmad;Chun, Dong Hyuk;Kim, Sangdo;Rhim, Young Joon;Yoo, Jiho;Choi, Hokyung;Lim, Jeonghwan;Lee, Sihyun;Rhee, Youngwoo
    • Clean Technology
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    • v.24 no.2
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    • pp.119-126
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    • 2018
  • This study introduced a treatment process that was developed to treat Indonesian low-rank coal with high-ash content, which has the same characteristics as residual coal from the biosolubilization process. The treatment process includes separation of ash, solid-liquid separation, pelletizing, and drying. To reduce the ash content, flotation was performed using 4-methyl-2-pentanol (MIBC) as frother, and kerosene, waste oil, and cashew nut shell liquid (CNSL) as collectors. The increasing amount of collector had an effect on combustible coal recovery and ash reduction. After flotation, a filter press, extruder, and an oven drier were used to make a dried coal pellet. Then another coal pellet was made using asphalt as a binder. The compressive strength and friability of the coal pellets were tested and compared.

Development of a Process for Clean-Washed Rice Processing (I) - Mass Balance Analysis - (씻지 않은 쌀의 가공 공정 개발 (I) - 질량수지 분석 -)

  • 장동일;한우석;김동철;이상효
    • Journal of Biosystems Engineering
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    • v.24 no.4
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    • pp.317-324
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    • 1999
  • This study was conducted to decide several design criterion for clean-washed rice processing system development. A Computer simulation was used to predict and analyze the mass balances and moisture changes of the process of clean-washed rice processing system. The following results were obtained from this study. 1. In order to attain the processing capacity of 1,000kg/h of the clean-washed rice processing system, that of the system was designed as 1,400kg/h which was based on the safety factor of 40% and handling capability of mass variations occurred during processing. 2. It was analyzed that the proper time required for aqueous cleaning process should be within one minute. 2. It was analyzed that the proper time required for aqueous cleaning process should be within one minute. 3. The final moisture content of clean-washed rice was controlled being 15%(w.b.) for the sake of safe storage. 4. It was proven that the optimum drying time was three minutes for the clean-washed rice dried by a rotary dryer.

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One-step aldol condensation of ethyl acetate with formaldehyde over Ce and P modified cesium supported alumina catalyst

  • Sararuk, Chidchon;Yang, Dan;Zhang, Guoliang;Li, Chunshan;Zhang, Suojiang
    • Journal of Industrial and Engineering Chemistry
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    • v.46
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    • pp.342-349
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    • 2017
  • Ethyl acrylate (EA) is synthesized by ethyl acetate (EtOAc) with formaldehyde (FA) through aldol condensation with fixed-bed reactor, and a series of $Ce-P-Cs/{\gamma}-Al_2O-3$ catalyst was developed. The catalysts were characterized with XRD, XPS, SEM-EDS, $NH_3-$ and $CO_2-TPD$, BET, and pyridine FTIR. The influence of acidity and basicity on activity was discussed. Catalytic performances were further improved by the addition of small amounts of Ce. Key reaction parameters, such as amount of metal loading, space velocity and reaction temperature, were also optimized. The optimum condition demonstrated a maximum EA yield of 31.38% and 60.03% selectivity toward EA.

One-step and in-situ catalytic synthesis of acrylates from acetates (or propionates) and trioxane at room temperature

  • Wang, Gang;Wang, Hui;Li, Chunshan;Zuo, Cuncun;Li, Zengxi;Zhang, Suojiang
    • Journal of Industrial and Engineering Chemistry
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    • v.55
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    • pp.173-182
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    • 2017
  • One-step synthesis of acrylates from acetates and trioxane via aldol reaction at 623 K-653 K was reported. But proceeding this process at room temperature is still a challenge due to ester activation and trioxane decomposition. Herein, series of acrylates were firstly achieved, with the one-step and in-situ catalytic strategy, from acetates (or propionates) and trioxane at 293 K. Selectivity of product reaches up to 94.4% with a 80.8% yield. $^1H$ NMR confirmed the soft enolization of ester, the decomposition of trioxane was catalyzed by TMSOTf, and the generated ionic liquid has catalytic performance on aldol condensation step.

A modified heteropoly acid catalyst with cetyltrimethylammonium bromide for methacrolein to methacrylic acid

  • Cao, Yun-Li;Wang, Lei;Zhou, Li-Long;Xu, Bao-Hua;Diao, Yan-Yan;Zhang, Suo-Jiang
    • Journal of Industrial and Engineering Chemistry
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    • v.65
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    • pp.254-263
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    • 2018
  • A novel type of heteropolyacids, $CTAB-CsH_3PMo_{11}VO_{40}$ (CTA-CsPAV), was developed by a method of emulsion synthesis using cetyltrimethyl ammonium bromide (CTAB) as the structure promoter, which was applied as a catalyst in the oxidation of methacrolein (MAL) to methacrylic acid (MAA) with fixed-bed reactor. The structure and property of CTA-CsPAV were characterized by FT-IR, XRD, nitrogen adsorption-desorption, $NH_3-TPD$, SEM, XPS, and so on. The structure-performance relationship of CTA-CsPAV was systematically studied, wherein the influence of surface area, acidity, redox property of CTA-CsPAV were focused and discussed. Importantly, the long-term performance of CTA-CsPAV was also investigated.

Nitrate Removal and Recycling Technique (질산 제거 및 재이용 기술)

  • Sim, Sang Jun;Lee, Kyung Hee;Cho, Young Sang
    • Clean Technology
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    • v.3 no.2
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    • pp.31-33
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    • 1997
  • Nitrate contamination in surface water and ground water have increased in Korea. This trend has raised concern because nitrates caused methemoglobinemia in infants. To remove nitrates from waters, various purification processes including ion-exchange, biological denitrification, and chemical denitrification are currently in use for the treatment of water. However, little economically advantageous process exists for the industrial scale treatment of effluents highly polluted with nitrates. A new process has been developed for nitrate and other salts removal from polluted waters. Alumina cement and lime served as precipitating agents to remove nitrate with stirring at basic pH. Decreasing alumina content in alumina cement result in a increasing in nitrate removal yield. Stable removal of nitrate(1000mg/L) was readily achieved by two-stage removal process.

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Analysis of Greenhouse Gas Emission associated with Clean Energy Agriculture System Development (청정에너지농업시스템 개발에 따른 실증단지의 온실가스배출량 분석)

  • Kim, Tae-Hoon;Yoon, Sung-Yee
    • Korean Journal of Organic Agriculture
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    • v.23 no.4
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    • pp.643-658
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    • 2015
  • This study presents detailed emission of greenhouse gases of using Clean Energy Agriculture System according to a cradle-to-gate life-cycle assessment, including emission from energy use and leak of Biogas. Calculations were done with the PASS software and the covered gases are $CH_4$, $N_2O$ and $CO_2$, Total GHG fluxes of amount to $1719.03kgCO_2/day$, $39.63kgCO_2/day$ (2.31%) are from facility house process, $0.19kgCO_2/day$ (0.01%) are from transport process, $696.72kgCO_2/day$ (40.53%) are from Anaerobic digestion process, $846.61kgCO_2/day$ (49.25%) are from Heating and cooling system, $135.88kgCO_2/day$ (7.90%) are from Fertigation production process. The results suggest that for effective reduction of GHG emissions from Facility house using clean energy. Reduction targets should address both the production process as defined by IPCC sectors and the consumption process. An LCA assessment as presented here could be a basis for such efforts.

Reduce on the Cost of Photovoltaic Power Generation for Polycrystalline Silicon Solar Cells by Double Printing of Ag/Cu Front Contact Layer

  • Peng, Zhuoyin;Liu, Zhou;Chen, Jianlin;Liao, Lida;Chen, Jian;Li, Cong;Li, Wei
    • Electronic Materials Letters
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    • v.14 no.6
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    • pp.718-724
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    • 2018
  • With the development of photovoltaic industry, the cost of photovoltaic power generation has become the significant issue. And the metallization process has decided the cost of original materials and photovoltaic efficiency of the solar cells. Nowadays, double printing process has been introduced instead of one-step printing process for front contact of polycrystalline silicon solar cells, which can effectively improve the photovoltaic conversion efficiency of silicon solar cells. Here, the relative cheap Cu paste has replaced the expensive Ag paste to form Ag/Cu composite front contact of silicon solar cells. The photovoltaic performance and the cost of photovoltaic power generation have been investigated. With the optimization on structure and height of Cu finger layer for Ag/Cu composite double-printed front contact, the silicon solar cells have exhibited a photovoltaic conversion efficiency of 18.41%, which has reduced 3.42 cent per Watt for the cost of photovoltaic power generation.

Selection of Cutting Fluids for Environmentally Clean Machining (청정 절삭 가공을 위한 절삭유제의 선택)

  • Chang, Yoonsang
    • Clean Technology
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    • v.2 no.2
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    • pp.165-175
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    • 1996
  • Cutting fluids in machining process are one of the parameters which have serious effects on the environment. A simple method to accomplish the environmentally clean process is to evaluate the effects of cutting fluids and select one which has the least environmental load. In this research, a process planning to select the best cutting fluid is suggested considering both machinability and environmental effects. The selection criteria and evaluation method named AHP are introduced. The planning process is illustrated with drilling characterized as a heavy-duty and low-speed process. Five standard fluids are compared with respect to five environmental attributes. Compounded cutting oils are superior to water-soluble oils in both machinability and environmental effects.

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