848 … NICE, 제31권 제6호, 2013 Korean Journal of Chemical Engineering, Vol.30, No.11, 1973-1984, 2013
Catalytic applications of immobilized ionic liquids for synthesis of cyclic carbonates from carbon dioxide and epoxides
Kim DW, Roshan R, Tharun J, Cherian A, Park DW
Abstract - The catalytic applicability of ionic liquids immobilized on various support materials such as silica, polystyrene and biopolymers in the cycloaddition of carbon dioxide with epoxides is reviewed in this work. Comparisons of the catalytic efficiency of these various catalysts have been done from the aspect of turnover number and reusability. The studies revealed that ionic liquids or support materials possessing hydrogen bonding capable groups exhibited enhanced catalytic activity towards cyclic carbonate synthesis. Moreover, the increased quest towards environmentally benign materials has renewed the search for biocompatible materials as support for ionic liquids.
Korean Journal of Chemical Engineering, Vol.30, No.11, 1990-1996, 2013
Robust PI controller design for integrator plus dead-time process with stochastic uncertainties using operational matrix
Duong PLT, Lee MY
Abstract - To increase the precision and reliability of process control, random uncertainty factors affecting the control system must be accounted for. We propose a novel approach based on the operational matrix technique for robust PI controller design for dead-time processes with stochastic uncertainties in both process parameters and inputs. The use of the operational matrix drastically reduces computational time in controller design and statistical analysis with a desired accuracy over that of the traditional Monte-Carlo method. Examples with deterministic and stochastic inputs were considered to demonstrate the validity of the proposed method. The computational effectiveness of the proposed method was shown by comparison with the Monte-Carlo method. The proposed approach was mainly derived based on the integrator plus dead-time process, but can be easily extended to other types of more complex stochastic systems with dead- time, such as a first-order plus dead-time or a second-order plus dead-time system.
Korean Journal of Chemical Engineering, Vol.30, No.11, 2012-2016, 2013
Preparation of α -MnO
2nanowires and its application in low temperature CO oxidation Sadeghinia M, Rezaei M, Amini E
Abstract - α -MnO
2nanowires were synthesized through a simple hydrothermal route and employed as support to obtain CuO/ α -MnO
2catalysts in low temperature CO oxidation. The prepared samples were characterized by X-ray diffraction (XRD), N
2adsorption (BET), temperature programmed reduction (TPR), thermal gravimetric/differential thermal analysis (TGA/DTA), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. The results showed that the prepared samples have nanowire morphology with a size about 30-40 nm in diameter. The obtained results revealed a remarkably high activity for the prepared catalysts in low temperature CO oxidation.
Korean Journal of Chemical Engineering, Vol.30, No.12, 2127-2141, 2013
Characterization of crystalline cellulose in biomass:
Basic principles, applications, and limitations of XRD, NMR, IR, Raman, and SFG Seong H. Kim, Christopher M. Lee, Kabindra Kafle
Editor’s Choice
NEWS & INFORMATION FOR CHEMICAL ENGINEERS, Vol. 31, No. 6, 2013 … 849 Abstract - Cellulose is among the most important and abundant biopolymers in biosphere. It is the main structural component of a vast number of plants that carries vital functions for plant growth. Cellulose-based materials have been used in a variety of human activities ranging from papers and fabrics to engineering applications including production of biofuels. However, our understanding of the cellulose structure in its native form is quite limited because the current experimental methods often require separation or purification processes and provide only partial information of the cellulose structure. This paper aims at providing a brief background of the cellulose structure and reviewing the basic principles, capabilities and limitations of the cellulose characterization methods that are widely used by engineers dealing with biomass. The analytical techniques covered in this paper include x-ray diffraction, nuclear magnetic resonance, and vibrational spectroscopy (infrared, Raman, and sum-frequency-generation). The scope of the paper is restricted to the application of these techniques to the structural analysis of cellulose.
Korean Journal of Chemical Engineering, Vol.30, No.12, 2142-2150, 2013
A facile approach to preparing palladium nanoparticles-embedded polyvinylpyrrolidone (PVP) heterogeneous hybrid nanofibers mats by electrospinning
Liping Guo, Jie Bai, Haiou Liang, Tong Xu, Chunping Li, Qingrun Meng, Huan Liu, Yarong Huang
Abstract - Well-dispersed palladium nanoparticles (Pd NPs) were prepared under the condition that trisodium citrate was the reduction agent and polyvinylpyrrolidone (PVP) was the stabilizing agent via sol-gel process. By making good use of the advanced electrospinning technology we obtained Pd NPs/PVP composite nanofibers films. Optical properties were examined by UV-visible absorbance spectra (UV-vis) and Fourier transform infrared spectroscopy (FTIR). The morphology and distribution of Pd NPs in/on PVP matrix were characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM). The results showed that Pd NPs presented as spherical spots and distributed in/on PVP nanofibers uniformly; their diameter was 4-10 nm and decreased with the increase of PVP. The as-prepared Pd NPs/PVP hybrid mats possess catalytic activity, stability and reusability, as verified by performance in Heck reaction.
Korean Journal of Chemical Engineering, Vol.30, No.12, 2223-2227, 2013
Production of polyhydroxyalkanoates by Ralstonia eutropha from volatile fatty acids Jung Hyun Yun, Shailesh S. Sawant, Beom Soo Kim
Abstract - Polyhydroxyalkanoates (PHAs) are biodegradable and biocompatible thermoplastics that can be synthesized in various microorganisms. Volatile fatty acids (VFAs) are produced by anaerobic treatment of organic wastes that can be utilized as inexpensive substrates for PHA synthesis. In this study, several Ralstonia eutropha strains were grown on the mixture of VFAs (acetic, propionic, and butyric acid) as its carbon and energy source for growth and PHA synthesis. R.
eutropha KCTC 2658 accumulated PHAs up to 50% of dry cell weight from total 5 g/L of mixed VFAs (acetic acid : propionic acid : butyric acid=1 : 2 : 2). In batch culture of R. eutropha KCTC2658 in a 5 L fermentor, a homopolymer of poly(3-hydroxybutyrate) [P(3HB)] was produced from 20 g/L glucose as a sole carbon source with dry cell weight of 8.4 g/L and PHA content of 30%. In fed-batch culture, two feeding strategies, pulse or pH-stat, were applied to add VFAs to the fermentor. When VFAs were fed using pH-stat feeding strategy after 40 h, a copolymer of poly(3-hydroxybutyrate-co- 3-hydroxyvalerate) [P(3HB-co-3HV)] was produced with dry cell weight of 8.1 g/L, PHA content of 50%, and 3HV fraction of 20 mol%.
Korean Chemical Engineering Research,
Vol.51, No.5, 597-601, 2013
850 … NICE, 제31권 제6호, 2013
마이크로채널 내 이중유화 액적 형성을 통한 마이크로캡슐 제조