High‐temperature pyrolysis and CO₂ gasification of Victorian brown coal and Rhenish lignite in an entrained flow reactor

Abstract

The low rank coals from Victoria, Australia, and Rhineland, Germany are of interest for use in entrained flow gasification applications. Therefore, a high temperature, electrically heated, entrained flow apparatus has been designed to address the shortage of fundamental data. A Victorian brown coal and a Rhenish lignite were subjected to rapid, entrained flow pyrolysis between 1100 and 14008C to generate high surface area chars, which were subsequently gasified at the same temperatures under CO 2 in N 2 between 10 and 80 vol %. The Victorian coal was more reactive than the Rhenish coal, and peak char reactivity was observed at 12008C. Char conversion and syngas yield increased with increasing temperature and plateaued at high CO 2 concentration. Ammonia and tar species were negligible and HCN and H 2 S were present in parts per million (volume) concentrations in the cooled, filtered syngas.

Modeling the influence of changes in aliphatic structure on char surface area during coal pyrolysis

“…The Zhundong subbituminous char specific surface area slightly increases from 15 to 37 m 2 /g with temperature increasing from 500 to 600°C, then decreases to 15 m 2 /g with temperature further increasing to 800°C, and finally rapidly increases to 78 m 2 /g at 1,000°C . However, for various coals, a decreasing char surface area with increase of temperature during slow pyrolysis is observed at temperatures above 1,200 K …”

Chemical fractionation of inorganic constituents in entrained flow gasification of slurry from straw pyrolysis

“…In this study, CO/CO 2 and K as main fragment of potassium species was qualitatively and semi-quantitatively measured. The reduction of CO 2 by the glycol and carbon of the char during the reaction results in the formation of CO [23]. Thus, the start and the end of reaction of the glycol and char can be identified.…”

Effect of reactant types (steam, CO 2 and steam + CO 2 ) on the gasification performance of coal using entrained flow gasifier

“…3,10,11 An estimated 22% higher thermal efficiency and 25% lower CO 2 emission is reported using black coal in an integrated gasification combined cycle (IGCC) power plant, resulting in the lower CO 2 emission of 370 kg/MWh e . 7,12 Numerous studies [13][14][15][16][17][18][19] have been conducted to investigate the entrained flow gasification of coal and biomass using air, oxygen, steam and CO 2 . The results of CO 2 gasification showed that the yield of CO increases whereas H 2 decreases with increasing CO 2 -to-coal ratio.…”

“…Numerous studies 13‐19 have been conducted to investigate the entrained flow gasification of coal and biomass using air, oxygen, steam and CO 2 . The results of CO 2 gasification showed that the yield of CO increases whereas H 2 decreases with increasing CO 2 ‐to‐coal ratio.…”

“…The yield of CH 4 in steam gasification was approximately eight vol.% higher than that of CO 2 gasification, decreasing gradually with increasing reactant concentrations under both gasification conditions. 14,28 On the other hand, under mixed-reactant condition, the yield of H 2 , CO and CH 4 were increased by 56%, 106% and 35% compared to that of pure CO 2 gasification.…”