• Title, Summary, Keyword: CSTR

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The Kinetics of Radical Copolymerization of Styrene with Alkyl Methacrylate in a CSTR (연속반응기에서 스티렌과 메타크릴산 알킬의 라디칼 공중합 반응속도론)

  • Kim, Nam Seok;Seul, Soo Duk;Cheong, Young Eon;Park, Keun Ho;Choi, Jong jueng
    • Applied Chemistry for Engineering
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    • v.10 no.5
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    • pp.796-803
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    • 1999
  • Solution copolymerization of styrene(St.) with methyl methacrylate(MMA), ethyl methacrylate(EMA) and n-butyl methacrylate(BMA) was carried out with benzoylperoxide(BPO) as an initiator in toluene at $80^{\circ}C$ in a continuous stirred tank reactor. Reaction volume and residence time were 0.6 liters and 3hours, respectively. The monomer reactivity ratios, $r_1(St.)$ and $r_2(RMA)$ determined by both the Kelen-Tudos method and the Fineman-Ross method were $r_1(St.)=0.60(0.61),\;r_2(MMA)=0.59(0.60);\;r_1(St.)=0.65(0.62),\;r_2(EMA)=0.55(0.52);\;r_1(St.)=0.75(0.67),\;r_2(BMA)=0.63(0.56)$. The cross-termination factor $\Phi$ of the copolymer over the entire St. compositions ranged from 0.26 to 0.96. The $\Phi$ factors of St.-RMA copolymer were increased with increasing St. content. The simulated conversions and copolymerization rates were compared with the experimental results. The average time to reach dynamic steady-state was three times and half of the residence time.

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Continuous Bio-hydrogen Production from Food Waste and Waste Activated Sludge (음식물 쓰레기와 폐활성 슬러지를 이용한 생물학적 수소생산 및 수소생산 미생물 군집분석)

  • Kim, Dong-Kun;Lee, Yun-Jie;Kim, Dong-Im;Kim, Ji-Seong;Yu, Myong-Jin;Pak, Dae-Won;Kim, Mi-Sun;Sang, Byoung-In
    • KSBB Journal
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    • v.20 no.6
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    • pp.438-442
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    • 2005
  • Batch experiments were performed to investigate the effects of volumetric mixing ratio(v/v) of two substrates, food wastes(FW) and waste activated sludge(WAS). In batch experiments, optimum mixing ratio for hydrogen production was found at $10{\sim}20$ v/v % addition of WAS. CSTR(Continuous Stirred tank reactor) was operated to investigate the hydrogen productivity and the microbial community under various HRTs and volumetric mixing ratio(v/v) of two substrates. The maximum yield of specific hydrogen production, 140 mL/g VSS, was found at HRT of 2 day and the volumetric mixing ratio of 20:80(WAS:FW). The spatial distribution of hydrogen producing bacteria was observed in anaerobic fermentative reactor using fluorescent in situ hybridization(FISH) method.

Production of Pyruvate Dehydrogenase Complex-E2 Specific Human Monoclonal Antibody in Fed-batch Culture Systems with High Cell Density Recombinant Escherichia coli (고농도 재조합 대장균의 Fed-batch 배양 시스템을 이용한 Pyruvate Dehydrogenase Complex-E2 특이성 인간 모노클론 항체의 생산)

  • 이미숙;전주미;차상훈;정연호
    • KSBB Journal
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    • v.15 no.5
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    • pp.489-496
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    • 2000
  • Several culture systems including batch, two-stage CSTR, semi-fed batch, and two-stage cyclic fed-batch were investigated for the efficient production of the Fab fraction of PDC-E2 specific human monoclonal antibody using high cell density recombinant E. coli. A two-phase batch system and a two-stage continuous system were examined to overcome plasmid instability problems, by separating the growth and the production stages. The cell density and productivity of the two-stage continuous culture was better than that of the two-phase batch fermentation. In the two-stage continuous culture system with DO-stat, the cell growth and the productivity were superior to those of the system without the DO control. Also, almost total plasmid stability was maintained in the two-stage continuous culture system. Modified M9 medium was selected as an optimum feeding medium for the fed-batch process, and the optimum C/N ratio determined to be 2:3. The optimum feeding rate was $0.6g/\ell/hr$ for a constant feeding strategy in semi-fed batch system. When the feeding medium was fed by pulsing, it was observed that more frequent pulsing resulted in improved cell growth. The linear feeding method was the most efficient of the various feeding methods tested. Finally, high cell density culture using a two-stage cyclic fed batch system with pH-stat was tried because the linear feeding method showed limitations in terms of obtaining high cell densities, and a cell density of $54 g/\ell$ was achieved. It was concluded that the two-stage cyclic fed batch system was the most efficient system for high cell density culture of the systems tested. However, productivity improvements were lower than expected due to the extremely high accumulations of acetate, although the low levels of residual glucose were maintained.

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A Study on Establishment of Technical Guideline of the Installation and Operation for the Efficient Bio-gasification Facility of Pig Manure and Food Waste(II): - Results of the Precision Monitoring - (가축분뇨 병합처리 바이오가스화를 위한 설계 및 운전 기술지침 마련 연구(II) - 정밀모니터링 결과 중심으로 -)

  • Lee, Dongjin;Moon, HeeSung;Son, Jihwan;Bae, Jisu
    • Journal of the Korea Organic Resources Recycling Association
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    • v.25 no.3
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    • pp.91-98
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    • 2017
  • The purpose of this study is to provide a design and operation technical guideline for meeting the appropriate design criteria to bio-gasification facilities treating organic wastes. 9 anaerobic digestion facilities which is normally operated during the field survey and 14 livestock manure farms were selected for precision investigation. the physicochemical analysis was performed on the moisture and organic contents, nutrients composition (carbohydrate, fat, protein), volatile fatty acids (VFAs), and nitrogen, etc. Volatile solids (VS) of organic wastes brought into the bio-gasification facilities were 2.81 % (animal manure only) and 5.92 % (animal manure+food waste), respectively. Total solids (TS) reults of samples from livestock farms were 5.6 % in piglets and 11~13 % in other kinds of breeding pigs. The actual methane yield based on nutrients contents was estimated to $0.36Sm^3CH_4/kgVS$ which is equivalent to 72 % of theoretical methane yield value. The optimum mixing ratio depending on the effect of the combined bio-gasification was obtained through the continuous stirred-tank reactor (CSTR) which is operated at different mixing ratio of swine manure and food waste leachate. The range of swine manure and food waste leachate from 60:40 to 40:60 were adequate to the appropriate conditions of anaerobic digestion; less than 100 gTS/, more than alkalinity of 1 gCaCO3/L, C/N ratio 12.0~30.0, etc.