• Title/Summary/Keyword: Chemical process industry

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Preparation and Characterization of Sisal Fiber-based Activated Carbon by Chemical Activation with Zinc Chloride

  • Lu, Xincheng;Jiang, Jianchun;Sun, Kang;Xie, Xinping
    • Bulletin of the Korean Chemical Society
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    • v.35 no.1
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    • pp.103-110
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    • 2014
  • Sisal fiber, an agricultural resource abundantly available in china, has been used as raw material to prepare activated carbon with high surface area and huge pore volume by chemical activation with zinc chloride. The orthogonal test was designed to investigate the influence of zinc chloride concentration, impregnation ratio, activation temperature and activation time on preparation of activated carbon. Scanning electron micrograph, Thermo-gravimetric, $N_2$-adsorption isotherm, mathematical models such as t-plot, H-K equation, D-R equation and BJH methods were used to characterize the properties of the prepared carbons and the activation mechanism was discussed. The results showed that $ZnCl_2$ changed the pyrolysis process of sisal fiber. Characteristics of activated carbon are: BET surface area was $1628m^2/g$, total pore volume was $1.316m^3/g$ and ratio of mesopore volume to total pore volume up to 94.3%. These results suggest that sisal fiber is an attractive source to prepare mesoporous high-capacity activated carbon by chemical activation with zinc chloride.

Advances in Food Irradiation and It's Potential Roles in Korea (한국에 있어서 식품조사 기술의 진보와 식품산업에서의 역할)

  • 권중호
    • Proceedings of the Korean Society of Food Hygiene and Safety Conference
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    • 1994.03a
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    • pp.35-49
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    • 1994
  • Based on the safety of irradiated foods which was demonstrated from the toxicological, microbiological and nutritional points of view, irradiation has been identified as a viable technology for food preservation and processing, having a potential both of reducing storage losses by controlling spoilage organisms, sprouting and ripening, and of improving hygienic quality of raw and processed products. Research and development over decades in the field of food irradiation have led to the regulatory approval in 37 countries and of them 25 countries including Korea are commercially utilizing food irradiation process. Although progress towards acceptance of food irradiation by the industry is slow, actual market trials have shown that once consumers have understood this technology, they are willing to buy irradiated foods. Considering recent advances in food irradiation and restrictions in the use of chemical fumigants, it is expected that food irradiation is in the process of "taking off". This paper deals with up-to-date progress in food irradiation with particular reference to domestic activities in legislation, consumer perception, commercialization, and potential applications in the food industry.

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Development of Amphoteric Polyacrylamide Retention System for ONP Recycled Pulp

  • Son, Dong-Jin;Kim, Bong-Yong
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.42 no.5
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    • pp.24-30
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    • 2010
  • Papermaking technology has drastically improved over the last 20 years to face new challenges. Because environmental regulations have become increasingly strict, papermaking systems have had to accommodate elevated recycled pulp content and an increased use of recycled process water. Process water in papermaking systems has become more dirtier and reduced polymer efficiency. Amphoteric PAM demonstrated a higher degree of stability in a high conductivity environment compared to cationic PAM. This was illustrated by the improved retention performance, particularly the ash retention. This amphoteric polymer can be used for board or newsprint production using recycled pulp, especially for the systems where polymer dissolving water is high in conductivity and degradation of cationic functional groups of cationic PAM can occur.

An Overview of Biopulping Research: Discovery and Engineering

  • Scott, Gary M.;Akhtar, Masood;Lentz, Michael J.;Horn, Eric;Swaney, Ross E.;Kirk, T.Kent
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.30 no.4
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    • pp.18-27
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    • 1998
  • Biopulping is defined as the treatment of wood chips with lignin-degrading fungi prior to pulping. Fungal pretreatment prior to mechanical pulping reduces electrical energy requirements during refining or increases mill throughput, improves paper strength, reduces the pitch content, and reduces the environmental impact of pulping. Our recent work involved scaling up the biopulping process towards the industrial level, investigating both the engineering and economic feasibility. We envision the process to be done in either a chip-pile or silo-based system for which several factors need to be considered: the degree of decontamination, a hospitable environment for the fungus, and the overall process economics. Currently, treatment of the chips with low-pressure steam is sufficient for decontamination and a simple, forced ventilation system maintains the proper temperature, humidity, and moisture conditions, thus promoting uniform growth of the fungus. The pilot-scale trial resulted in the successful treatment of 4 tons of wood chips (dry weight basis) with results comparable to those on a laboratory. Larger, 40-ton trials were also successful, with energy savings and paper properties comparable with the laboratory scale. The overall economics of the process also look very favorable and can result in significant annual savings to the mill. Although the current research has focused on biopulping for mechanical pulping, it is also beneficial for sulfite chemical pulping and some applications to recycled fiber have been investigated.

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Creation of System Dynamics in an Uncertain and Complex Market: The Case of Korea's Evolving Biopharmaceutical Industry

  • Lee, Jeong Hyop;Kim, Jaewon;Hyeon, Byung-Hwan
    • Asian Journal of Innovation and Policy
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    • v.8 no.2
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    • pp.180-207
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    • 2019
  • This article explores the historical evolutionary process of the biopharmaceutical industry of Korea, and how intentional and unintentional policy interventions have triggered the creation of the industry's system dynamics and paved the way for the generation of a few global leading products, including biosimilar, as well as next-generation therapeutics of gene and cell. The policies cover the simple technology transfer of API synthesis to overcome the endemic parasitic disease, new substance patent adoption and new drug development consortia, human resource development, various national initiatives influenced by the Human Genome Project, and venture promotion schemes. The scope and implementation tools under these policies have been aligned and refined to transform traditional fine chemical-based pharmaceuticals, to stimulate large companies' participation and to create technology-based venture companies in the biopharma business of Korea.

Design of Reformate Fractionation Process with Thermally Coupled Distillation Column (Reformate 분리공정에서의 열복합 증류탑 설계)

  • Lee, Ju-Yeong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.5
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    • pp.2445-2450
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    • 2011
  • Design of reformate fractionation process using a fully thermally coupled distillation is conducted with commercial design software Aspen HYSYS. Detailed procedure of the design is explained, and the performance of the process is compared with that of a conventional system. The design outcome indicates that the procedure is simple and efficient. The performance of the new process indicates that an energy saving of 12.2% is obtained compared with the conventional process while total number of trays maintains at the same.

In-Vitro Refolding of PEGylated Lipase (PEGylation된 Lipase의 In-Vitro 재접힘)

  • Kim, Min-Young;Kwon, Jin-Sook;Lee, Eun-Kyu
    • KSBB Journal
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    • v.20 no.5 s.94
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    • pp.338-340
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    • 2005
  • Covalent modification of a protein with polyethylene glycol (PEG) has become one of the most widely used and well established drug enhancement strategies in the biopharmaceutical industry. The general benefits enjoyed by PEGylation, such as prolonged serum half-lives or reduced immunogenicity in vivo, are well known. By now the PEGylation process has been performed with purified proteins, and it is required to recover the desired PEGylate by a multi-step purification process. The ultimate aim of our research is to develop an integrated process of PEGylation and in vitro refolding starting with inclusion body material. For this, we investigated the feasibility that a protein could be PEGylated under a denaturing condition and also the PEGylated proteins could be refolded correctly. Using lipase as a model protein, we found that it was PEGylated in the presence of 8M urea and that the PEG molecules covalently attached to lipase did not appear to hinder its refolding.

Characteristic of heat storage/release in chemical heat pump using the calcined dolomite (소성 Dolomite를 이용한 화학열펌프내의 축·방열특성)

  • Hong, Min-Hyuk;Lee, Young-Sei;Choi, Hyun-Kuk;Park, Young-Hea;Kim, Jong-Shik
    • Journal of the Korean Society of Industry Convergence
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    • v.8 no.4
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    • pp.191-196
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    • 2005
  • This study was carried out to investigate the heat storage/release characteristics of the thermochemical reaction of the calcined dolomite with the packed bed shape experimental apparatus for development of chemical heat pump system. In the present study, it was found that MgO of the calcined dolomite was not hydrated during the hydration process under the experimental conditions. Therefore, the MgO of the calcined dolomite can be regard as an inert material. As a result, it was found that all of CaO packed kept the reaction temperature of about $510^{\circ}C$ through the entire part of the bed. The dehydration reaction was incurred first at the wall side area as the supplied heat was transferred through the wall side into the packed bed. As a result of the temperature and concentration spread, the reaction was completed at the wall side progressed into the center.

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Morphology control in PVDF membranes using PEG/PVP additives and mixed solvents

  • Rajabi, Shima;Khodadadi, Foroogh;Mohammadi, Toraj;Tavakolmoghadam, Maryam;Rekabdar, Fatemeh
    • Membrane and Water Treatment
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    • v.11 no.4
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    • pp.237-245
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    • 2020
  • The effects of the mixed two solvents, Dimethylacetamide (DMAc) and Dimethylformamide (DMF), and Polyethylene glycol (PEG) and Polyvinylpyrrolidone (PVP) as additives on performance of Polyvinylidene fluoride (PVDF) membranes were studied. Initially, PEG200 was used as a primary additive at fixed percentage of 5% wt. PVP was then blended with PEG200 in different concentrations. PVDF and DMAc were used as polymer and solvent in the casting solutions, respectively. To control the diffusion rate of PVP in the presence of PEG200 and PVP blend, mixtures of DMAc and DMF were used as the mixed solvent in the casting solutions. Asymmetric PVDF membranes were prepared via phase inversion process in a water bath and the effects of two additives and two solvents on the membrane morphology, pure water flux (PWF), hydrophilicity and rejection (R) were investigated. Attenuated Total Reflection Fourier Transform Infrared Spectra (ATR-FTIR) analysis was used to show the residual PVP on the surface of the membranes. Atomic Force Microscopy (AFM) was utilized to determine roughness of membrane surface. The use of mixed solvents in the casting solution resulted in reduction of PVP diffusion rate and increment of PEG diffusion rate. Eventually, PWF and R values reduced, while porosity and hydrophilicity increased.

Application of Enzymatic Hydrolysis for the Yield Optimization in Froth-Flotation of ONP

  • Ryu, Jeong-Yong;Song, Bong-Keun;Song, Jae-Kwang
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2006.06a
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    • pp.129-136
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    • 2006
  • Although cleaner and cheaper deinking of ONP could be performed at the neutral or low alkaline condition excessive loss from froth-flotation is unavoidable and so reduction of alkali or caustic soda dosage sacrifices recycling yield. Now the new trade-off regarding alkali dosage versus flotation yield is urgently required in order to set the optimized neutral or low alkaline deinking process of ONP. Lipase from Thermomyces Lanuginosus has an effect on desizing and deacetylation reaction and it could be applied to the stock of pre flotation secondary stage in order to reduce the flotation reject without the sacrifice of optical properties of flotation accepts. Instead of inorganic base, lipase could be applied as a biochemical catalyst for the selective modification of valuable hydrophobic particles in deinking stock, for example cellulose fines and inorganic fillers covered by hydrophobic additives or contaminants. When the enzymatic hydrolysis of ester bond could be made on the surface of hydrophobic particulates, unwanted float of fine particles could be prevented. Now the enhancement of flotation selectivity or the modification of the hydrophobicity of deinking stock is expected to be promoted by the enzymatic pre treatment. And the reduction of recycling cost with the saves of raw material, recovered paper would be possible as a result.

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