SENSITIVITY ANALYSIS OF COAL GASIFICATION IN TWO-STAGE ENTRAINED-FLOW GASIFIER: SYNGAS AND CARBON CONVERSION PREDICTION

Year 2017, , 1574 - 1587, 04.10.2017

J. Fukai

https://doi.org/10.18186/journal-of-thermal-engineering.353727

Cited By: 1

Abstract

The energy production from coal-fired power plant is increasing day
by day, which result in increased CO₂ emission from the existing
power plant. However, CO₂ emission from coal gasification can be
reduced if an efficient CO₂/O₂/N₂ coal
gasification is implemented in IGCC system. Numerical simulations of coal
gasification under CO₂/O₂/N₂ gasification
condition are carried out with the aim of describing the effects of model parameters, char reaction rates,
operating conditions and heat losses to increase the syngas heating value and
carbon conversion in a two stage entrained flow coal gasification process. The Eulerian–Lagrangian approach is
applied to solve the Navier–Stokes equation and the particle dynamics. Finite
rate/eddy dissipation model is used to calculate the rate of nine homogeneous
gas-to-gas phase reactions. While only finite rate is used for the
heterogeneous solid-to-gas phase reactions. It is found
that the carbon conversions of combustor coal lie in the ranges from 97 wt% to
99 wt% for most of the calculated conditions. On the other hand, the carbon
conversion of reductor coals varies from 45 wt% to 57 wt%. A noticeable change
is obtained when the gasification occurs under a high-temperature condition.
Remarkable outlet results of about 32 wt% CO, 0.58 wt% H₂ and 89 wt%
overall carbon conversion are predicted if a high temperature of 1673K is
maintained in the reductor. On the other hand, a reduced soot concentration is
predicted if the O₂ concentration and/or the reductor gas
temperature increase(s) in the gasifier.

Keywords

Sensitivity Analysis, Two-stage Gasifier, Syngas Heating Value, CO2-blown

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