A Kinetic Assessment of Entrained Flow Gasification Modeling

2018 ◽  
Vol 140 (9) ◽  
Author(s):  
A. Rakhshi ◽  
T. Wiltowski
Keyword(s):  
Coal Gasification ◽  
Heterogeneous Reaction ◽  
Bulk Diffusion ◽  
Pilot Scale ◽  
Factors Affecting ◽  
Entrained Flow ◽  
Reaction Matrix ◽  
Kinetic Assessment ◽  
Value Decomposition ◽  
Homogeneous Reactions

A kinetics assessment of the quasi-global homogeneous and heterogeneous reaction mechanisms is carried out for entrained flow coal gasification modeling. Accurate closure of the chemical source term in gasification modeling necessitates a detailed study of turbulence-chemistry interaction. Toward this end, a time-scale analysis of the homogeneous reactions is discussed using eigenvalue analysis of the reaction rate Jacobian matrix. A singular value decomposition (SVD) of the stoichiometric reaction matrix is performed to assess the behavior of the homogeneous reactions in a reduced species vector space. The significant factors affecting the heterogeneous char reactions are assessed, and the relative importance of bulk diffusion and inherent char kinetics is analyzed in a gasifier. The overall study is carried out using numerical and experimental results of an actual pilot scale gasifier.

Linking laboratory data with pilot scale entrained flow coal gasification performance. Part 2: Pilot scale testing

2012 ◽  
Vol 94 (1) ◽  
pp. 26-33 ◽  
Author(s):  
Daniel G. Roberts ◽  
David J. Harris ◽  
Alexander Tremel ◽  
Alexander Y. Ilyushechkin
Keyword(s):  
Coal Gasification ◽  
Laboratory Data ◽  
Pilot Scale ◽  
Entrained Flow

Performance of an entrained-flow gasification technology of pulverized coal in pilot-scale plant

2007 ◽  
Vol 88 (5) ◽  
pp. 451-459 ◽  
Author(s):  
Xiaolei Guo ◽  
Zhenghua Dai ◽  
Xin Gong ◽  
Xueli Chen ◽  
Haifeng Liu ◽  
...  
Keyword(s):  
Pilot Scale ◽  
Pulverized Coal ◽  
Entrained Flow ◽  
Entrained Flow Gasification ◽  
Gasification Technology

scholarly journals Investigation of the Coal Gasification Process Under Various Operating Conditions Inside a Two-Stage Entrained Flow Gasifier

2012 ◽  
Vol 4 (2) ◽  
Author(s):  
Armin Silaen ◽  
Ting Wang
Keyword(s):  
Coal Gasification ◽  
Operating Conditions ◽  
Coal Slurry ◽  
Two Stage ◽  
Heating Value ◽  
Fuel Distribution ◽  
Entrained Flow ◽  
One Stage ◽  
Gasification Process ◽  
Entrained Flow Gasifier

Numerical simulations of the coal gasification process inside a generic 2-stage entrained-flow gasifier fed with Indonesian coal at approximately 2000 metric ton/day are carried out. The 3D Navier–Stokes equations and eight species transport equations are solved with three heterogeneous global reactions, three homogeneous reactions, and two-step thermal cracking equation of volatiles. The chemical percolation devolatilization (CPD) model is used for the devolatilization process. This study is conducted to investigate the effects of different operation parameters on the gasification process including coal mixture (dry versus slurry), oxidant (oxygen-blown versus air-blown), and different coal distribution between two stages. In the two-stage coal-slurry feed operation, the dominant reactions are intense char combustion in the first stage and enhanced gasification reactions in the second stage. The gas temperature in the first stage for the dry-fed case is about 800 K higher than the slurry-fed case. This calls for attention of additional refractory maintenance in the dry-fed case. One-stage operation yields higher H2, CO and CH4 combined than if a two-stage operation is used, but with a lower syngas heating value. The higher heating value (HHV) of syngas for the one-stage operation is 7.68 MJ/kg, compared with 8.24 MJ/kg for two-stage operation with 75%–25% fuel distribution and 9.03 MJ/kg for two-stage operation with 50%–50% fuel distribution. Carbon conversion efficiency of the air-blown case is 77.3%, which is much lower than that of the oxygen-blown case (99.4%). The syngas heating value for the air-blown case is 4.40 MJ/kg, which is almost half of the heating value of the oxygen-blown case (8.24 MJ/kg).

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