Documents disponibles écrits par cet auteur

Crystallization of RDX by drowning - out combined with fines dissolution and cooling process / Jun-Woo Kim in Industrial & engineering chemistry research, Vol. 51 N° 9 (Mars 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 9 (Mars 2012) . - pp. 3758–3765 Titre : Crystallization of RDX by drowning - out combined with fines dissolution and cooling process Type de document : texte imprimé Auteurs : Jun-Woo Kim, Auteur ; Dhan Bee Park, Auteur ; Hong-Min Shim, Auteur Année de publication : 2012 Article en page(s) : pp. 3758–3765 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Crystallization Résumé : A new process of drowning-out combined with fines dissolution and cooling crystallization (the DFC process) was proposed to recover 1,3,5-trinitro-1,3,5-triazinane (RDX) from RDX/γ-butyrolactone solution with relatively large crystal size and high yield. In this process, fine crystals induced by drowning-out are dissolved into the solution by heating so that the dissolved solute can contribute to grow seed crystals by cooling. The DFC process is repeated to reach the desired yield. Estimation of the amount of antisolvent for drowning-out is made by a simple mass balance model in which the mass of fine particles produced by drowning-out equals to that dissolved. Considering dissolution of seeds at the fines dissolution stage, an empirical parameter α which is smaller than 1 was employed for the estimation of the optimum amount of antisolvent added. α = 1 indicates that effect of dissolution of seeds is negligible. In the present work, initial seeds were prepared by rapid injection of 15 g of water into a saturated RDX/γ-butyrolactone solution of 30 °C. Heating temperature for fines dissolution and cooling temperature for further crystal growth were 40 and 20 °C, respectively. In those operating conditions with α = 0.8, the average crystal size of RDX with the yield of 90% was 67.6 μm, which was a remarkably improved result when compared with that of 40.4 μm by drowning-out only. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202562u [article] Crystallization of RDX by drowning - out combined with fines dissolution and cooling process [texte imprimé] / Jun-Woo Kim, Auteur ; Dhan Bee Park, Auteur ; Hong-Min Shim, Auteur . - 2012 . - pp. 3758–3765. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 9 (Mars 2012) . - pp. 3758–3765 Mots-clés : Crystallization Résumé : A new process of drowning-out combined with fines dissolution and cooling crystallization (the DFC process) was proposed to recover 1,3,5-trinitro-1,3,5-triazinane (RDX) from RDX/γ-butyrolactone solution with relatively large crystal size and high yield. In this process, fine crystals induced by drowning-out are dissolved into the solution by heating so that the dissolved solute can contribute to grow seed crystals by cooling. The DFC process is repeated to reach the desired yield. Estimation of the amount of antisolvent for drowning-out is made by a simple mass balance model in which the mass of fine particles produced by drowning-out equals to that dissolved. Considering dissolution of seeds at the fines dissolution stage, an empirical parameter α which is smaller than 1 was employed for the estimation of the optimum amount of antisolvent added. α = 1 indicates that effect of dissolution of seeds is negligible. In the present work, initial seeds were prepared by rapid injection of 15 g of water into a saturated RDX/γ-butyrolactone solution of 30 °C. Heating temperature for fines dissolution and cooling temperature for further crystal growth were 40 and 20 °C, respectively. In those operating conditions with α = 0.8, the average crystal size of RDX with the yield of 90% was 67.6 μm, which was a remarkably improved result when compared with that of 40.4 μm by drowning-out only. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202562u

Evaporation crystallization of RDX by ultrasonic spray / Jun-Woo Kim in Industrial & engineering chemistry research, Vol. 50 N° 21 (Novembre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12186-12193 Titre : Evaporation crystallization of RDX by ultrasonic spray Type de document : texte imprimé Auteurs : Jun-Woo Kim, Auteur ; Moon-Soo Shin, Auteur ; Jae-Kyeong Kim, Auteur Année de publication : 2011 Article en page(s) : pp. 12186-12193 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Crystallization  Evaporation Résumé : Cyclotrimethylene trinitramine (RDX) with size of 0.8 to 2.6 μm was produced by evaporation crystallization of RDX with ultrasonic spray. In the experimental range of the present work, the size of RDX crystals was found to be strongly affected by operating parameters including RDX concentration and furnace temperature. The size of RDX crystals was reduced as RDX concentration decreased and furnace temperature increased. The formation of random-shaped RDX particles due to agglomeration could be explained by coalescence between a crystal-containing droplet and a crystal or a crystal-containing droplet. In the present work, agglomeration was found to be controlled with injection of additives into starting solution: polyvinylpyrrolidone (PVP), which acted as a strong nucleation inhibitor in the crystallization of RDX from acetone, was very effective on the formation of spherical RDX particles. However, when the nucleation promoters such as polyoxyethylene 10 oleoyl ether (Brij 97) and oleylamine were added, highly agglomerated and random-shaped RDX particles were produced. Therefore, it can be concluded that the controlling onset time of nucleation is an important factor to improve crystal shape in evaporation crystallization by ultrasonic spray. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697536 [article] Evaporation crystallization of RDX by ultrasonic spray [texte imprimé] / Jun-Woo Kim, Auteur ; Moon-Soo Shin, Auteur ; Jae-Kyeong Kim, Auteur . - 2011 . - pp. 12186-12193. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12186-12193 Mots-clés : Crystallization  Evaporation Résumé : Cyclotrimethylene trinitramine (RDX) with size of 0.8 to 2.6 μm was produced by evaporation crystallization of RDX with ultrasonic spray. In the experimental range of the present work, the size of RDX crystals was found to be strongly affected by operating parameters including RDX concentration and furnace temperature. The size of RDX crystals was reduced as RDX concentration decreased and furnace temperature increased. The formation of random-shaped RDX particles due to agglomeration could be explained by coalescence between a crystal-containing droplet and a crystal or a crystal-containing droplet. In the present work, agglomeration was found to be controlled with injection of additives into starting solution: polyvinylpyrrolidone (PVP), which acted as a strong nucleation inhibitor in the crystallization of RDX from acetone, was very effective on the formation of spherical RDX particles. However, when the nucleation promoters such as polyoxyethylene 10 oleoyl ether (Brij 97) and oleylamine were added, highly agglomerated and random-shaped RDX particles were produced. Therefore, it can be concluded that the controlling onset time of nucleation is an important factor to improve crystal shape in evaporation crystallization by ultrasonic spray. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697536