Modeling for simple process analysis in a dry-feeding entrained bed coal gasifier건식 분류층 석탄 가스화기의 운전 조건에 따른 단순 공정 해석 모델

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A dry-feeding entrained bed coal gasifier was numerically modeled to analyze the process in this thesis. The Shell type up-flow gasifier was modeled in the view of reverse engineering and by simultaneously solving the rate equations for the solid and gas phases. It was modeled considering own reactivity of a case of coal introduced into the gasifier. According to the heterogeneous characteristics of coal, this model describes the simplified physical and chemical processes occurring in the entrained bed coal gasifier. The gasification phenomena can be separated into devolatilization, gas phase, and solid phase reactions by difference of reaction time of coal. The coal gasifier shape is also simplified to 1-D PFR and pseudo 2-D reactor models for simple analysis. As an indicator of the gasifier performance, carbon conversion and cold gas efficiency (CGE) are determined. Oxygen/coal mass ratio, steam/coal mass ratio, and pressure are selected as operating parameters. As a result of simulation, carbon conversion, CGE, gas composition, temperature, and velocity distributions are obtained along with the reactor. The oxygen/coal ratio at which maximum CGE was achieved ranged from 0.5 to 0.6 kg/kg. However, the higher oxygen/coal ratio is, the higher carbon conversion rate is. Therefore, proper operating conditions are changeable on operating objectives. For validation, the results are compared with data obtained in Shell gasifier and it shows a little difference for CGE. That is because the kinetic data applied in this research is to incorporate the incoherent rate constants from different experimental conditions and coal type. In addition, this model does not consider the physical phenomena such as turbulence and radiative heat transfer. The model prediction may be best used to evaluate trends in process analysis of the Shell gasifier and may give useful information for the designing and operation of the coal gasifier.
Advisors
Choi, Sang-Minresearcher최상민researcher
Description
한국과학기술원 : 기계공학전공,
Publisher
한국과학기술원
Issue Date
2010
Identifier
419004/325007  / 020083435
Language
eng
Description

학위논문(석사) - 한국과학기술원 : 기계공학전공, 2010.2, [ xi, 122 p. ]

Keywords

Process analysis; Entrained bed coal gasifier; Coal gasification; Chemical kinetics; 화학 반응 카이네틱스; 공정 해석; 분류층 석탄 가스화기; 석탄 가스화

URI
http://hdl.handle.net/10203/45802
Link
http://library.kaist.ac.kr/search/detail/view.do?bibCtrlNo=419004&flag=dissertation
Appears in Collection
ME-Theses_Master(석사논문)
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