CO2 회수를 위한 2단계 PSA 공정의 경제성 평가

원왕연,이광순 제어로봇시스템학회 2010 제어로봇시스템학회 국내학술대회 논문집 Vol.2010 No.5

노인 정신질환 약물치료

원왕연,이창욱 대한의사협회 2010 대한의사협회지 Vol.53 No.11

Psychiatric disturbances in the elderly are complicated. Dementia and depression are serious causes of global impairment in the elderly. Aging is characterized by a progressive functional impairment of multiple organs, a reduction of homeostatic mechanisms, and a changed sensitivity or capacity of neurotransmitter receptors. Understanding the influence of age-dependent changes in the composition and function of the body on the pharmacokinetics and pharmacodynamics of drugs is important before prescribing drugs to elderly patients. However, there is little clinical pharmacological information available to guide pharmacotherapy for late-life psychiatric disorders. Treatment of dementia is based on the cognitive decline and behavioral symptoms that accompany dementia. Currently prescribed antidepressants have similar efficacies but the side effect profiles vary. Comprehension of the normal aging process and understanding the characteristics of each of the psychotropics are essential in geriatric psychopharmacology. Up to the present, most studies are confirmations or reproductions of previous results on efficacy or safety. Future directions for psychopharmacological research should include discovering newer drugs,treatment of resistance or nonresponders, and combination or adjunctive therapies. This review focused on the geriatric pharmacokinetic/pharmacodynamic changes and clinical information regarding currently prescribed psychotropic medications.

Parameter Estimation and Dynamic Control Analysis of Central Carbon Metabolism in Escherichia coli

원왕연,Changhun Park,Changhun Park,이상엽,이광순,이진원 한국생물공학회 2011 Biotechnology and Bioprocess Engineering Vol.16 No.2

The central carbon metabolic pathway is the most important among metabolic pathways in all microorganisms since it produces energy and precursors for biosynthesis. In this study, a dynamic model for central carbon metabolism in Escherichia coli (E. coli) consisting of the phosphotransferase (PTS) system, glycolysis,pentose-phosphate pathway (PPP), and storage materials was obtained by ameliorating the model proposed by Chassagnole et al. (2002). In order to improve the performance of the model, principal parameters were estimated through the experimental measurements of intracellular concentrations of metabolites under transient conditions. Through dynamic metabolic control analysis (MCA), the tendencies of the metabolic fluxes at branch points were investigated, and the key parameters and enzyme kinetics that most dominantly affected the productivity of the desired metabolites were determined.

CO₂회수용 PSA 공정의 적응 격자 배열 기반 비선형 관측자 시스템

원왕연,이광순 제어로봇시스템학회 2012 제어로봇시스템학회 국내학술대회 논문집 Vol.2012 No.4

Current trends for the floating liquefied natural gas (FLNG) technologies

원왕연,Yongchai Kwon,Sun Keun Lee,Kwangho Choi 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.5

Natural gas (NG) and liquefied NG (LNG), which is one trade type of NG, have attracted great attentionbecause their use may alleviate rising concerns about environmental pollution produced by classical fossil fuels andnuclear power plants. However, when gas reserves are located in stranded areas and a portion of the offshore reserves isa significant amount of the total gas reserves, LNG is not suitable because (i) installation of pipelines for the transferof NG to onshore LNG facilities is expensive and difficult, and (ii) it still has environmental and security problems. As a result, there are many efforts to excavate and monetize these stranded and offshore reserves with floating facilitieswhere offshore liquefaction of NG is possible. Therefore, the development of floating LNG (FLNG) technology is becomingimportant. Although the FLNG technologies have advantages over conventional LNG technologies, there arestill several roadblocks. To overcome the challenges, modular designs related to the main and typical stages of the FLNGprocess – gas pretreatment, liquefaction and regasification topsides, hulls, mooring, and transfer systems should beenhanced. Regarding FLNG ongoing operations and future plans, there are six nations (Argentina, Brazil, Kuwait, UAE,UK, and USA) operating FLNG, and a variety of FLNG liquefaction projects will be finished soon. Shell and Petrobrasare making rapid strides to build FLNG facilities, and Flex LNG, Hoegh LNG, SBM Linde, MODEC, and Saipem arealso building their FLNGs. In this review paper, we initially review the LNG concept and compare it with FLNG. Inturn, new and typical FLNG technologies are introduced and the main challenges are also explained with insight intohow these challenges are overcome. The main market drivers for FLNG industry are also considered.

Combined run-to-run and LQG control of a 12-inch RTP equipment

원왕연,Sang Hyun Ji,Byung-Cheol Na,Woohyun Yun,이광순 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.6

A combined run-to-run (R2R) and LQG control method has been proposed for rapid thermal processing (RTP) equipment for run-wise improvement and real-time multivariable control of the temperature uniformity over the wafer surface. The standard LQG objective was modified to include a quadratic penalty term for input deviation from bias values which are updated by an R2R control law. The proposed method has been applied to commercial 12- inch rotating RTP equipment with four pyrometers and ten circular groups of tungsten-halogen lamps for measurements and manipulation of wafer temperatures. The performance of LQG control was evaluated under wafer rotation and found to show quite accurate tracking. For evaluation of the combined control technique, a wafer with seven thermocouples (TC’s) attached along the radial direction has been employed for the TC measurements to be used for R2R control, whereas the pyrometer measurements are fed back for real-time LQG control. It was observed that the temperature uniformity is improved as the run number increases.

열병합 발전소의 응축순환공정에 대한 모델예측제어 : 제어기 설계와 수치적 적용

원왕연,이광순,이봉국,이승주,이석영 제어로봇시스템학회 2006 제어로봇시스템학회 국내학술대회 논문집 Vol.2006 No.6

배가스 CO2 포집을 위한 압력변동 흡착공정 최적화

원왕연,이승훈,이광순 제어로봇시스템학회 2011 제어로봇시스템학회 국내학술대회 논문집 Vol.2011 No.5

The PSA process is one of the viable technologies for CO2 capture from large CO2 generating sources. It is generally known that a two-stage PSA process is required to recover 99% CO2 from flue gas containing 10-15% CO2. The aim of this research is placed in re-evaluating the economy of the two-stage PSA process for CO2 capture using zeolite 13X as adsorbent through numerical simulation and optimization. The performance curves of commercial vacuum pumps were used for realistic calculation of the operating cost. In addition, parameters such as mass transfer coefficients that have significant effects on the process behavior but whose values are only ambiguously known were estimated through the experiments. For numerically stable calculation, a novel numerical procedure using gradient-directed adaptive predictive collocation with a cubic spline interpolation function and far-side boundary conditions were adopted. Economy of the PSA process was evaluated for the optimized process conditions as a function of CO2 contents of the inlet flue gas and CO2 recovery rate.

바이오리파이너리 구현을 위한 공정합성 및 기술경제성 분석

원왕연 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.0

We develop an integrated strategy for the production of ethanol from lignocellulosic biomass. Cellulose and hemicellulose fractions are first hydrolyzed into sugars using a mixture of γ-valerolactone (GVL), water, and toluene as a solvent containing dilute sulfuric acid as a catalyst, and the sugars are then co-fermented into ethanol over engineered yeast strains. Separation subsystems are designed to effectively recover GVL and toluene for reuse in biomass hydrolysis, and to recover lignin and humins for heat and power generation. We also develop an alternative process, in which we recover sugars and GVL from the residual biomass. To minimize utility requirements, we conduct heat integration, which allows us to meet all heating requirement using biomass residues. Finally, we perform a range of system-level analyses to identify the major cost and technological drivers. The proposed strategy is shown to be cost-competitive with other strategies.

Production of Bioplastics: Process Synthesis and Evaluation

원왕연 한국공업화학회 2020 한국공업화학회 연구논문 초록집 Vol.2020 No.-

2,5-Furandicarboxylic acid (FDCA) has attracted considerable attention as a building block for renewable polymers, as it can substitute conventional petroleum-derived terephthalic acid as a monomer for the synthesis of polyethylene terephthalate. In this study, we develop a new process for the co-production of FDCA, furfural, and activated carbon from lignocellulosic biomass to make the production of renewable plastics cost-competitive by generating high-value chemicals at the same time. Pinch analysis was conducted to form a heat exchanger network for reducing utility requirements. We conducted an uncertainty analysis using the Monte-Carlo simulation method for the minimum selling price of FDCA to quantify the risks of the proposed process and provide a more realistic estimation to decision makers. Furthermore, the sustainability of the proposed process was demonstrated via life-cycle assessment.