Clean Technology for Resource, Energy and Environment

Vol. 2 (2026)
Articles

Study on the Circulating Fluidized Bed Co-Combustion of Coal Gasification Slag and Coal Coking Dedusting Ash

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  • Jianping Kuang,
  • Zhanxiang Song,
  • Ping Zhang,
  • Weiqiang Zeng,
  • Wei Li,
  • Mengxiang Fang,
  • Wei Guo,
  • Qinghui Wang,
  • Feng Li,
  • Jiashuo Zhang,
  • Lebo Ma,
  • Yaning Zhang,
  • Hongling Liu,
  • Yanlong Luo
Jianping Kuang
Ningxia Shenyao Technology Co., Ltd, Yinchuan, 750000, China
Zhanxiang Song
State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, 310018, China
Ping Zhang
Anhui Tanxin Technology Co., Ltd., Huaibei, 235000, China
Weiqiang Zeng
State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, 310018, China
Wei Li
Anhui Tanxin Technology Co., Ltd., Huaibei, 235000, China
Mengxiang Fang
State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, 310018, China
Wei Guo
Lusai Environmental Protection (Ningxia) Technology Co., Ltd, Yinchuan, 750000, China
Qinghui Wang
State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, 310018, China
Feng Li
Anhui Tanxin Technology Co., Ltd., Huaibei, 235000, China
Jiashuo Zhang
Ningxia Shenyao Technology Co., Ltd, Yinchuan, 750000, China
Lebo Ma
Lusai Environmental Protection (Ningxia) Technology Co., Ltd, Yinchuan, 750000, China
Yaning Zhang
Ningxia Shenyao Technology Co., Ltd, Yinchuan, 750000, China
Hongling Liu
Ningxia Shenyao Technology Co., Ltd, Yinchuan, 750000, China
Yanlong Luo
Lusai Environmental Protection (Ningxia) Technology Co., Ltd, Yinchuan, 750000, China

Published 2026-10-23

Keywords

  • Waste utilization,
  • Coal gasification slag,
  • Coal coking dedusting ash,
  • Circulating fluidized bed,
  • Combustion efficiency,
  • Coal conversion,
  • NOx, SO2 and CO emissions
    • ...More
    Less

How to Cite

Study on the Circulating Fluidized Bed Co-Combustion of Coal Gasification Slag and Coal Coking Dedusting Ash . (2026). Clean Technology for Resource, Energy and Environment, 2, 31-48. https://doi.org/10.65638/2979-2746.2026.02.03

Abstract

Coal-based chemical industries generate large amounts of coal gasification slag (CGS), including coarse slag (CGCS) and fine slag (CGFS), and coal coking dedusting ash (CCDA). CGFS is wet, fine, carbon-rich but difficult to ignite; CGCS has low carbon and calorific value; CCDA is high-carbon and anthracite-like but too fine for metallurgical use. This study proposes and validates circulating fluidized bed (CFB) co-firing of CGS and CCDA. Three cases were tested: Case I, CGFS alone; Case II, CGCS + CCDA (≈1800 kcal·kg⁻¹); and Case III, CGFS (≈30% moisture) + CGCS + CCDA (≈1800 kcal·kg⁻¹). A 2 MWh CFB pilot platform was used to evaluate operational stability, ash characteristics, emissions, and combustion efficiency. The ternary blend showed a potential synergistic effect: its apparent activation energy was only 95.8 kJ·mol-1, lower than 157.7 kJ·mol-1 for CGFS and 115.1 kJ·mol-1 for CGCS + CCDA. All cases achieved stable feeding, unobstructed circulation, and uniform temperature distribution, with fluctuations within 50°C for Case I and 20°C for Cases II and III. Raw flue-gas concentrations were NOx 20–60 ppm, SO2 70–180 ppm, and CO 500–850 ppm; after normalization to 6% O2, SO2 was 255.5–492.0 mg/Nm3 and NOx (as NO2) 56.5–108.8 mg/Nm3, exceeding regulatory limits, so flue-gas cleaning is required. Combustion efficiencies reached 83.86–92.53%, and fly-ash carbon/ash ratios were 0.047, 0.061, and 0.035. The innovation lies in using high-carbon CCDA to compensate for low-calorific CGCS and difficult ignition of CGFS, while high-reactivity CGFS and ternary blending improve burnout. Preliminary scheme-level TEA for Case III (400,000 t·a-1, 8,000 h·a-1) estimates ~9.3×104 tce·a-1 saved, 7.8×105–8.3×105 t·a-1 steam, direct CO2 2.52×105 t·a-1, avoided CO2 2.71×105 t·a-1, and net reduction ~1.9×104 t·a-1; ash mineralization potential is 0.9×104–3.0×104 t CO2·a-1. Estimated revenue is CNY 110–200 million·a-1 with a 4–7-year payback. CFB co-firing is therefore a feasible and promising route for CGS and CCDA utilization.

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