Multiobjective design of calorific value adjustment process using process simulators / Hosoo Kim in Industrial & engineering chemistry research, Vol. 49 N° 6 (Mars 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 6 (Mars 2010) . - pp. 2841–2848 Titre : Multiobjective design of calorific value adjustment process using process simulators Type de document : texte imprimé Auteurs : Hosoo Kim, Auteur ; Ik Hyun Kim, Auteur ; En Sup Yoon, Auteur Année de publication : 2010 Article en page(s) : pp. 2841–2848 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Multiobjective  Calorific  Value  Adjustment  Simulators Résumé : In this work, we present a solution procedure for design of a chemical process for effectively adjusting calorific values in an offshore regasification terminal. To tackle the technical and commercial issue in the liquefied natural gas (LNG) industry caused by differences of LNG calorific values between importing countries, many methods and configurations are being studied. This design problem is defined in two parts: a generalized disjunctive programming (GDP) problem with one objective and a multiobjective problem for minimizing the operating costs and the performance of natural gas liquids (NGLs). First, the GDP problem has been mathematically reformulated as a mixed-integer nonlinear programming (MINLP) problems, and the MINLP technique incorporated into the process simulator using its own optimization capabilities has been suggested. For solving the resulting bicriterion problem with the MINLP problem, we have suggested the heuristic procedure that reduces the number of discrete solutions which are necessary for complete Pareto optimal sets. The complete Pareto optimal sets for a new calorific value adjustment process under three feedstock scenarios are generated. Note de contenu : Bibiogr. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901685m [article] Multiobjective design of calorific value adjustment process using process simulators [texte imprimé] / Hosoo Kim, Auteur ; Ik Hyun Kim, Auteur ; En Sup Yoon, Auteur . - 2010 . - pp. 2841–2848. Industrial Chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 6 (Mars 2010) . - pp. 2841–2848 Mots-clés : Multiobjective  Calorific  Value  Adjustment  Simulators Résumé : In this work, we present a solution procedure for design of a chemical process for effectively adjusting calorific values in an offshore regasification terminal. To tackle the technical and commercial issue in the liquefied natural gas (LNG) industry caused by differences of LNG calorific values between importing countries, many methods and configurations are being studied. This design problem is defined in two parts: a generalized disjunctive programming (GDP) problem with one objective and a multiobjective problem for minimizing the operating costs and the performance of natural gas liquids (NGLs). First, the GDP problem has been mathematically reformulated as a mixed-integer nonlinear programming (MINLP) problems, and the MINLP technique incorporated into the process simulator using its own optimization capabilities has been suggested. For solving the resulting bicriterion problem with the MINLP problem, we have suggested the heuristic procedure that reduces the number of discrete solutions which are necessary for complete Pareto optimal sets. The complete Pareto optimal sets for a new calorific value adjustment process under three feedstock scenarios are generated. Note de contenu : Bibiogr. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901685m

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Real-time end-point detection using modified principal component analysis for small open area SiO2 plasma etching / Kyounghoon Han in Industrial & engineering chemistry research, Vol. 47 n°11 (Juin 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 n°11 (Juin 2008) . - p. 3907–3911 Titre : Real-time end-point detection using modified principal component analysis for small open area SiO2 plasma etching Type de document : texte imprimé Auteurs : Kyounghoon Han, Auteur ; En Sup Yoon, Auteur Année de publication : 2008 Article en page(s) : p. 3907–3911 Note générale : Bibliogr. p. 3911 Langues : Anglais (eng) Mots-clés : PCA algorithm  End-point detection  SiO2 etching Résumé : Principal component analysis (PCA) was modified for real-time applications and applied to the end-point detection of small open area SiO2 plasma etching. Typically, the end point of plasma etching is determined from a few manually selected wavelengths. Determining the end point of the plasma etching using this approach is quite a challenge when the exposed open area is less than several percent. To increase the sensitivity, information was extracted from the entire spectra of 2755 signals in the range of 200−1100 nm, using a PCA algorithm. In this study, the PCA algorithm was modified to allow real-time applications of end-point detection. The loading vector was determined from the model wafer, and the score vector was determined using the real-time data of the target wafer to reduce the processing time. This algorithm was tested for the small open area of SiO2 etching of a 200 ms sampling period, using the entire optical emission spectra, through a comparison with a defined signal-to-noise ratio. The results were compared with the conventional single wavelength signals of SiF (440.2 nm), CO (482.5 nm), and Si (505.6 nm). The end-point detection of 0.4%−0.8% SiO2 open area was achieved using the suggested algorithm, while the single wavelength showed limitations in the open areas above a few percent. The sensitivity was also increased by a factor of 2.15, compared to the signal-to-noise ratio of the single wavelength method. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie070930s [article] Real-time end-point detection using modified principal component analysis for small open area SiO2 plasma etching [texte imprimé] / Kyounghoon Han, Auteur ; En Sup Yoon, Auteur . - 2008 . - p. 3907–3911. Bibliogr. p. 3911 Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°11 (Juin 2008) . - p. 3907–3911 Mots-clés : PCA algorithm  End-point detection  SiO2 etching Résumé : Principal component analysis (PCA) was modified for real-time applications and applied to the end-point detection of small open area SiO2 plasma etching. Typically, the end point of plasma etching is determined from a few manually selected wavelengths. Determining the end point of the plasma etching using this approach is quite a challenge when the exposed open area is less than several percent. To increase the sensitivity, information was extracted from the entire spectra of 2755 signals in the range of 200−1100 nm, using a PCA algorithm. In this study, the PCA algorithm was modified to allow real-time applications of end-point detection. The loading vector was determined from the model wafer, and the score vector was determined using the real-time data of the target wafer to reduce the processing time. This algorithm was tested for the small open area of SiO2 etching of a 200 ms sampling period, using the entire optical emission spectra, through a comparison with a defined signal-to-noise ratio. The results were compared with the conventional single wavelength signals of SiF (440.2 nm), CO (482.5 nm), and Si (505.6 nm). The end-point detection of 0.4%−0.8% SiO2 open area was achieved using the suggested algorithm, while the single wavelength showed limitations in the open areas above a few percent. The sensitivity was also increased by a factor of 2.15, compared to the signal-to-noise ratio of the single wavelength method. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie070930s

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire