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.

배가스 CO2 포집을 위한 압력변동 흡착공정 최적화

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

수소 생산 공정에서 CO₂ 포집을 위한 PSA 공정 개발

원왕연 한국공업화학회 2021 한국공업화학회 연구논문 초록집 Vol.2021 No.1

촉매 전환 공정의 경제성/환경성 평가

원왕연 한국공업화학회 2022 한국공업화학회 연구논문 초록집 Vol.2022 No.1

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.

CO2 회수를 위한 2단계 PSA 공정의 경제성 평가

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

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.

CO₂회수용 PSA 공정의 적응 격자 배열 기반 비선형 관측자 시스템

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

Changes of Plasma Adiponectin Levels after Smoking Cessation

원왕연,김대진,이창욱,채정호,김정진,이철 대한신경정신의학회 2014 PSYCHIATRY INVESTIGATION Vol.11 No.2

Objective Cigarette smoking is associated with a variety of health problems including cardiovascular, pulmonary, neoplasms, endocrinopathies including diabetes, the metabolic syndrome, and chronic inflammation. Adiponectin is an adipocyte-derived plasma protein that is closely associated with insulin sensitivity and the metabolic syndrome. The aim of this study was to evaluate the changes of plasma adiponectin levels after smoking cessation. Methods Thirty seven smokers that wanted to stop smoking without any nicotine replacement therapy or medication were recruited for this study. Fifteen smokers succeeded in stopping smoking (validated by urine cotinine levels ≤50 ng/mL) and 22 smokers failed. Therefore, only the 15 that succeeded were included in the analysis. The plasma adiponectin levels were determined using a commercially available enzyme-linked immunosorbent assay. Results The mean age of the successful 15 was 35±9.3 years old. They were all males. The daily smoking habit was a mean of 13.5±5.4 cigarettes per day. The mean Nicotine Dependence Syndrome Scale (NDSS) and Fagerstrom Test for Nicotine Dependence (FTND) scores were 55.6±9.6 and 2.9±1.9. During the study period of three months, the mean body mass index (BMI), body fat mass (BFM), waist-hip ratio (WHR) and body weight increased by 1.1 kg/m2, 3.0%, 0.02%, and 2.9 kg, respectively. The baseline mean adiponectin level in the subjects was 11.9±5.2 mg/L. The mean adiponectin levels measured at one and three months were 16.0±5.1 mg/L and 14.7±4.5 mg/L respectively. The mean plasma adiponectin levels of the successful group was significantly increased after four weeks when compared to the baseline (z=-2.401, p=0.016). However, the decrease in plasma adiponectin levels at one and three months was not statistically significant. Conclusion Even though the decrease over the next two months was not significant, these findings, the increase of plasma level of adiponectin after smoking cessation, provide preliminary data for future research on the possible mechanisms associated with smoking cessation and changes in body metabolism.

Process Synthesis and Technoeconomic Analysis

원왕연 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.1

We propose an integrated strategy for the production of 2,5-furandicarboxylic acid (FDCA) from fructose. In this process, fructose is first dehydrated to hydroxymethylfurfural (HMF) at high yield (70%) using a gamma-valerolactone (GVL)/H₂O solvent system. HMF is then oxidized to FDCA over a Pt/C catalyst with 93% yield. The advantage of our system is the higher solubility of FDCA in GVL/H₂O, which allows oxidation at high concentrations using a heterogeneous catalyst that eliminates the need for a homogeneous base. Our process eliminates the use of corrosive acids, because FDCA is an effective catalyst for fructose dehydration, leading to improved economic and environmental impact of the process. Our technoeconomic model indicates that the overall process is economic and environmental impact of the process. Our technoeconomic model indicates that the overall process is economically competitive with current terephthalic acid processes.