Comparative Study of the Gasification of Coal and Its Macerals and Prediction of the Synergistic Effects Under Typical Entrained-Bed Pulverized Coal Gasification Conditions

Peng Jiang,Tao Wu,Dengting Guo,Xiang Luo,Mengxia Xu

doi:10.1115/1.4044552

Abstract

Abstract This research is focused on the gasification performance of coal and its corresponding macerals as well as on the interactions among macerals under typical gasification conditions by Aspen Plus modeling. The synergistic coefficient was employed to show the degree of interactions, while the performance indicators including specific oxygen consumption (SOC), specific coal consumption (SCC), cold gas efficiency (CGE), and effective syngas (CO + H2) content were used to evaluate the gasification process. Sensitivity analyses showed that the parent coal and its macerals exhibited different gasification behaviors at the same operating conditions, such as the SOC and SCC decreased in the order of inertinite > vitrinite > liptinite, whereas CGE changed in the order of liptinite > vitrinite > inertinite. The synergistic coefficients of SOC and SCC for the simulated coals were in the range of 0.94–0.97, whereas the synergistic coefficient of CGE was 1.05–1.13. Moreover, it was found that synergistic coefficients of gasification indicators correlated well with maceral contents. In addition, the increase in temperature was found to promote the synergistic coefficients slightly, whilst at an oxygen to coal mass ratio of 0.8 and a steam to coal mass ratio of 0.8, the highest synergistic coefficient was obtained.

Highlights

According to IEA report 2017, coal constitutes approximately 27% of the global energy mix
The indicators of specific oxygen consumption (SOC) and specific coal consumption (SCC) illustrate that the parent coal consumes the most amount of oxygen and fuel to produce the same amount of syngas, while the pure Liptinite and Vitrinite require the least amount of oxygen and fuel to produce the same amount of syngas
The lower heating value (LHV) value of the syngas derived from the Inertinite is greater than that of syngas derived from parent coal from Table 5, the LHV value of Inertinite feedstock is greater than that of the parent coal resulting in a relatively smaller cold gas efficiency (CGE) of the Inertinite

Summary

Introduction

According to IEA report 2017, coal constitutes approximately 27% of the global energy mix. There are three major types of gasifier that have been commercially used worldwide, i.e., fixed-bed gasifier, fluidized-bed gasifier and entrained-bed gasifier. Their unique characteristics are summarized in the literature [7]. Entrained-bed gasifiers have the advantages of dealing with any type of coals with high carbon conversion and high throughput [8, 9]. Shell entertained-bed gasifier is one of the representative gasification technologies and takes up a significant portion of installed capacities in the world [7, 8]

Methods

Results

Conclusion