Performance analysis of an eight-layered bed PSA process for H₂ recovery from IGCC with pre-combustion carbon capture

Moon, Dong-Kyu,Park, Yongha,Oh, Hyun-Taek,Kim, Shin-Hyuk,Oh, Min,Lee, Chang-Ha Elsevier 2018 Energy conversion and management Vol.156 No.-

<P><B>Abstract</B></P> <P>Integrated gasification combined cycle (IGCC) plants that are also capable of CO<SUB>2</SUB> capture have received significant attention as the next generation of coal-based power plants for the co-production of H<SUB>2</SUB> and electrical power. Accordingly, for a cost-effective and environmentally friendly poly-generation IGCC process, efficient techniques need to be developed to recover H<SUB>2</SUB> from the syngas of an IGCC plant with carbon capture.</P> <P>In this study, an eight-layered bed pressure swing adsorption (PSA) process using activated carbon and zeolite simultaneously was developed to produce high purity H<SUB>2</SUB> from the H<SUB>2</SUB>-rich syngas of an IGCC plant. As a first step, the separation performance was compared between four-and eight-layered bed PSA processes. The eight-layered bed PSA process led to higher recovery of H<SUB>2</SUB> at the condition of a similar H<SUB>2</SUB> purity owing to a greater number of pressure equalization steps in the operational step configuration. It is noteworthy that the productivity could be greatly improved as the purge gas was replaced from the product gas to residual gas in a bed. When the adsorption bed was purged by using the residual gas after the first pressure equalization step, recovery improved by about 3 ∼ 6% at the condition of 99.99+mol% H<SUB>2</SUB> purity in comparison with the product-purge PSA configuration. On the other hand, the highest H<SUB>2</SUB> recovery that could be obtained for the requirement of 99.99mol% H<SUB>2</SUB> purity, was ∼ 89.7% from the eight-layered bed H<SUB>2</SUB> PSA process when the purge gas was provided from the residual gas of the adsorption bed after the last depressurization pressure equalization step. However, as the concentration of CO in the desired H<SUB>2</SUB> product was higher in the PSA configuration when using residual gas compared to the product gas, the operational configuration of PSA needed to be decided by the desired H<SUB>2</SUB> purity and impurity constraints for application. Furthermore, the tail gas from the PSA contained 45–66mol% of H<SUB>2</SUB> and CO, depending on the applied PSA configurations, and could be used to drive a gas turbine without any loss of the syngas, even though the recompression energy loss required evaluation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> An eight-bed PSA process was developed for H<SUB>2</SUB> recovery from H<SUB>2</SUB>-rich IGCC syngas. </LI> <LI> The PSA using bed residual gas produced 89.7% recovery at 99.99+mol% H<SUB>2</SUB> purity. </LI> <LI> H<SUB>2</SUB> product with trace amount of CO can be used for the application of fuel cell. </LI> <LI> Tail-gas has been utilized to generate additional net power from a gas turbine. </LI> </UL> </P>

전시공간의 시각구조에 따른 동선 특성에 관한 기초적 고찰

이종숙,최준혁 한국문화공간건축학회 2009 한국문화공간건축학회논문집 Vol.- No.25

The circulations of visitors are predicted by analyzing the circulation axes of room-to-room exhibition spaces, and the existing types of exhibition space are classified of art museums in Europe. The purposes of this study are to predict the movement of visitors depending on the spatial composition and visual configuration; and to compare the predicted movement and the actual movement of visitors. From the analysis of circulation axes, the exhibition space is classified into four types: cyclical loop type, non-cyclical linear type, non-cyclical branch type, and combination type. In exhibition space with the non-cyclical circulation axis, the values of agent counts, visual connectivity, and isovist area are found to be all correlated with each other. Compared with exhibition space with the cyclical circulation axis, exhibition space with the non-cyclical circulation axis is shown to have a more distinct visual configuration suggesting visitors' directionality and circulation.

전동식 니켈 티타늄 파일의 표면 결함 및 단면 형태가 반복응력 하에서 피로 파절에 미치는 영향

신유미,김의성,김광만,금기연 大韓齒科保存學會 2004 Restorative Dentistry & Endodontics Vol.29 No.3

The purpose of this in vitro study was to evaluate the effect of surface defects and cross-sectional configuration of NiTi rotary files on the fatigue life under cyclic loading. Three NiTi rotary files (K3^(TM), ProFile®, and HERO 642®) with #30/.04 taper were evaluated. Each rotary file was divided into 2 subgroups: control (no surface defects) and experimental group (artificial surface defects). A total of six groups of each 10 were tested. The NiTi rotary files were rotated at 300rpm using the apparatus which simulated curved canal (40 degree of curvature) until they fracture. The number of cycles to fracture was calculated and the fractured surfaces were observed with a scanning electron microscope. The data were analyzed statistically. The results showed that experimental groups with surface defects had lower number of cycles to fracture than control group but there was only a statistical significance between control and experimental group in the K3^(TM) (p〈0.05). There was no strong correlation between the cross-sectional configuration area and fracture resistance under experimental conditions. Several of fractured files demonstrated characteristic patterns of brittle fracture consistent with the propagation of pre-existing cracks. This data indicate that surface defects of NiTi rotary files may significantly decrease fatigue life and it may be one possible factor for early fracture of NiTi rotary files in clinical practice.

Characterizing the Cyclic Behavior of Stiffened SPSWs

O. Haddad,N.H. Ramli Sulong,Z. Ibrahim 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.4

To enhance the behavior of steel plate shear walls, stiffeners are attached on the infill plate. The various researches on the stiffened Steel Plate Shear Walls (SPSWs) with Low Yield Point (LYP) infill steel plate have approved excellent capacity of this system. In those studies, the researcher focused on the specific type on stiffeners and in some cases, different results was reported. To cover different aspects, to provide comprehensive necessary data for structure designers and, to study the post-buckling and performance factors, this research is conducted. Using the validated Finite Element (FE) models with experimental test results, an analytical study of a single story SPSWs conducted to determine the influence of the selected parameters on the strength, stiffness, energy absorption and seismic performance factors. The variant parameters include the stiffeners pattern, stiffeners thickness, one-side or double-sides stiffeners and the slenderness of the stiffened infill plates. The results showed that cross-stiffened pattern is preferable in the one-side stiffening method while, diagonal pattern in double-side shape. Finally, the value of seismic performance factors is proposed for stiffened SPSWs.

경복궁 자경전 십장생 굴뚝 문양(紋樣)에 대한 재고(再考)

노재현 한국전통문화대학교 전통문화연구소 2022 한국전통문화연구 Vol.29 No.-

The traditional patterns engraved in the palace are representative Korean traditional cultural contents that have infinite expressive potential and are very easy to reproduce and reconstruct. However, if there is an understanding of the source data or uncertainty about the material, it may fall into simple form imitation and distortion. Under this recognition, this study tried to reveal the identity of the pattern material through a comparative analysis of the chimney flower wall pattern of Gyeongbokgung Palace Jagyeongjeon chimney flower wall, which is a representative flower wall pattern in Korea, through literature review, field photo observation, comparative analysis with detailed images drawn based on actual survey design and advice from plant experts. Also, based on the results, an attempt was made to elucidate the compositional characteristics of this icon. The results of this study are as follows. The pattern of ‘Ten longevity symbols part’ is divided into two distinct areas, and among them, three species of birds observed in pairs in the ‘Non-ten longevity symbols part’ are a duck swimming on the water, a kingfisher aiming for a lotus rice, and a two little cuckoo flying in the sky to ‘unite yin and yang (陰阳合一)’ was emphasized. The plant patterns independently expressed in the ‘Ten longevity Symbols part’ are presumed to be Peony, and the other patterns expressed as cloud gates are also judged to be floor plans that are repeatedly expressed using the Peonies as a material. On the other hand, in addition to the previously known lotuses and grapes, the patterns of creeping thistle (Jobaengi), azalea, and horsetail were confirmed for the first time in this study. These patterns are plants with strong vitality and fertility, and they are placed together with lotuses and grapes, which symbolize ‘prosperity of offspring', and can be seen as symbolizing ‘longevity'. On the other hand, the addition of the genitalia of the creeping thistle and the horsetail is a humorous element introduced into the solemn and feminine space. In the Jagyeongjeon’s chimney pattern, there is the sun, clouds, stones, cranes, deer, turtles, pine trees, bamboo, and yeongji (herb of eternal youth). In addition to the nine longevity symbols, the number of patterns was confirmed to be 19. Plant-based patterns such as chrysanthemum, peony, lotus, grape, azalea, creeping thistle, and horsetails and three birds-type patterns such as ducks, little cuckoo and common kingfishers were additionally identified. Gyeongbokgung Palace Jagyeongjeon’s ten long-lived chimney pattern has a strong folklore character, showing nine long-lived chimneys and three pairs of birds of non-seven long-lived chrysanthemums, chrysanthemums and peonies, grapes, kites, and rhododendrons, horsetails, and azaleas. Similarities to <Jangsaenghwajodo> are also found. 궁궐에 새겨진 전통 문양은 무한한 표현 가능성과 재현 및 재구성이 매우 쉬운 대표적인 한국의 전통문화 콘텐츠이다. 그러나 원천 자료에 대한 이해나 소재 불확실성이 크다면 단순한 형태 모방과 왜곡에 빠질 수 있다. 이러한 인식 아래 본 연구는 국내 대표적 꽃담 문양으로 알려진 경복궁 자경전 십장생굴뚝 문양을 대상으로 문헌고찰과 현장사진 고찰 그리고 실측설계를 바탕으로 작도된 상세 이미지와의 비교분석 그리고 식물전문가의 자문을 통해 문양 도상(圖像)의 정체성과 그 구성상의 특성을 밝히고자 한 것이다. 본 연구의 결론은 다음과 같다. 십장생굴뚝 문양은 분명한 ‘십장생부’와 ‘비십장생부’의 2개 영역으로 구분되며 그중 비십장생부에서 관찰되는 조류은 물 위를 유영하는 오리와 연밥을 노리는 물총새 그리고 하늘을 비상하는 두견이로, 3종의 날짐승을 쌍(雙)으로 배치하여 음양합일(陰陽合一)을 강조하였다. 십장생부에 독립되어 표현된 식물 문양은 모란으로 추정되며 이 밖에 구름문으로 표현된 문양 또한 모란을 소재로 표현된 평면도안으로 판단된다. 한편 비십장생부에는 기존에 알려진 연과 포도 이외에 조뱅이·진달래·쇠뜨기 문양이 본 연구를 통해 처음으로 확인되었다. 이 문양들은 강한 생명력과 번식력을 갖는 식물로 ‘자손 번창’을 상징하는 연과 포도와 함께 배치되어 ‘장수 희구’를 상징화한 것으로 볼 수 있다. 한편 조뱅이와 쇠뜨기의 생식경(生殖莖)을 추가한 것은 근엄하고 여성 중심 공간에 도입된 해학적 요소가 아닐 수 없다. 자경전 십장생굴뚝에서는 해(日)·구름(雲)·돌(石)·학(鶴)·사슴(鹿)·거북(龜,)·소나무(松)·대나무(竹)·영지(靈芝, 不老草) 등 9종류의 십장생 이외에 국화, 모란, 연, 포도, 진달래, 조뱅이, 쇠뜨기 등의 식물계 문양과 오리, 물총새, 두견이 3종류의 동물계 문양이 추가로 확인됨에 따라 전체 문양의 소재 수는 총 19종으로 늘어났다. 경복궁 자경전 십장생굴뚝 문양은 띠처럼 연결되어 순환하는 구성을 보이는 민화적 성격이 강한 <장생화조도(長生花鳥圖)>의 일면이 드러나는바, 이 부분은 향후 연구과제로 돌리기로 한다.

Optimizing Anode Arrangement for Enhanced Performance in Microbial Fuel Cells: A Comparative Study of Vertical and Horizontal Configurations

Jonghyeon YU,Sokhee JUNG 한국생물공학회 2024 한국생물공학회 학술대회 Vol.2024 No.4