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Kwon, Hweeung,Tak, Kyungjae,Cho, Jae Hyun,Kim, Jiyong,Moon, Il American Chemical Society 2017 INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH - Vol.56 No.5
<P>Using an optimization technique, this study proposes a new decision support system to improve the economics of petrochemical industries. In achieving the goal, we first develop two optimization models to support the decisions on (1) the hedge trade by minimizing purchase costs of raw materials, and (2) the production planning by maximizing profits from product sales. We then integrated these two models into a single decision support system using a recursive two-stage programming framework. On the basis of the integrated framework, we systematically identify the optimal solution, that is, the maximum profit, by simultaneously determining timing, amount, and price of raw materials to purchase, and the strategies for facility operation and product sales. To illustrate the capability of the proposed system, it was then applied to the business model of the petrochemical company in Korea. As a result, compared to the base case, it is revealed that the profitability of the petrochemical company could be improved by up to 4.82% by optimized hedging trades and 4.30% by optimizing the production plan.</P>
Web-based multi-dimensional education system for the simulated moving bed process
Hweeung Kwon,문일,탁경재,이인규,Jinsuk Lee 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.10
This paper describes the development of an operator-education program for a simulated moving bed (SMB)pilot plant that separates para-xylene isomer from mixed xylenes. The education program was motivated from reliableand safe operations for a newly developed SMB technology, in particular, a priori education on preventing accidentssuch as explosion, fire and toxic material release, most of which result from the lack of understanding of the processesbeing operated. This SMB process education program has overall SMB process description, sixteen operating screenand response procedure for accident of leak and explosion. The proposed system was implemented based on client/server architecture in company-wise LAN environment and applied previously operator heuristics. In addition, it featuresmulti-dimensional animation for virtual reality of process flow, using multi-media techniques. Operators are expected tobenefit from education that is free of time and space constraints. The education system for the pilot plant will contributeto keeping the full scale SMB operation workforce performing at a high level of proficiency as well as refreshing theoperational skills of senior operators.
Analysis of air blast effect for explosives in a large scale detonation
Kwon, Hweeung,Tak, Kyungjae,Maken, Sanjeev,Kim, Hyounsoo,Park, Jungsu,Moon, Il Springer-Verlag 2017 Korean Journal of Chemical Engineering Vol.34 No.12
<P>Open Burning/Open Detonation (OB/OD) has been widely used for demilitarization of expired explosives. However, OB/OD effects a variety of hazardous damages to environment. Therefore, using incinerators to treat expired explosives is required instead of OB/OD. To guarantee the safety of these demilitarization methods, the blast wave of the explosives should be previously recognized to evaluate the impact of detonations. Although various materials are used to produce explosives, most researches have focused on trinitrotoluene (TNT). Other representative explosives such as research department explosives (RDX) and high melting explosives (HMX) are seldom studied in the literature. Therefore, our aim was to understand the blast wave of three materials under different geometry throughout simulations. To improve accuracy and reduce computational time, a zoning technique with Euler-Lagrange coupling method was used. Due to limitations and difficulties of detonation experiments, simulations were verified by theoretical models. In case of semi-confined bunker, the simulation results were compared with experimental data, showing a close match. As a result, cylinder type is the safest incinerator among semi-confined bunker, cylinder, and cube incinerators, in terms of the blast wave.</P>
Comparison of Multistage Compression Configurations for Single Mixed Refrigerant Processes
Tak, Kyungjae,Lee, Inkyu,Kwon, Hweeung,Kim, Junghwan,Ko, Daeho,Moon, Il American Chemical Society 2015 INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH - Vol.54 No.41
<P>This study investigates the effects of multistage compression on single mixed refrigerant processes in terms of specific work. Comparison of specific work published in the literature is not straightforward due to the variety of compression configurations and the design bases. Therefore, four configurations (two-, three-, and four-stage and pump-added three-stage compressions) along with three natural gas compositions were considered. To compare with the simulation and optimization results in the literature, these 12 cases, having the same design basis, were optimized by adjusting the optimization variables such as the flow rate and composition of the refrigerant, the compression ratio of each compressor, the inlet pressure of the first compressor, and the outlet temperatures of the hot and cold refrigerant streams. There were two important findings: (1) adding a pump reduces specific work more than adding a compressor or decreasing the minimum temperature difference value in the compressors; (2) among the four configurations, the refrigerant composition does not significantly change, although it greatly affects the efficiency. The former results from the compressor constraint of the gaseous inlet and the latter from the minimum temperature constraint of the multistream heat exchanger. Furthermore, direct comparisons to other studies were also performed showing the importance of optimization and the effect of the design basis.</P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ie5b00936'>ACS Electronic Supporting Info</A></P>