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Potassium‐catalyzed steam gasification of ash‐free lignite coal with CO 2 capture
Author(s) -
Rasi Negar Manafi,
Mostafavi Ehsan,
Retuta Maria Angelica,
Rahman Moshfiqur M.,
Gupta Raj,
Mahinpey Nader
Publication year - 2018
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.22883
Subject(s) - catalysis , chemistry , coal , sorbent , hydrogen production , coal gasification , carbon fibers , waste management , hydrogen , chemical engineering , potassium , raw material , materials science , organic chemistry , adsorption , composite number , engineering , composite material
The purpose of this research was to study steam gasification of ash‐free coal integrated with CO 2 capture in the presence of a K 2 O catalyst for enhancement of the key water‐gas shift reaction and promotion of hydrogen production. To achieve this goal, gasification experiments on ash‐free coal (AFC) were carried out at varying temperatures (600, 650, 675, 700, and 750 °C) with a sorbent‐to‐carbon (CaO/C) ratio of 2 and a catalyst (K 2 O) loading of 0.2 g/g (20 weight percent (wt%)) in a fixed‐bed reactor equipped with a gas chromatography analyzer. The sorbent‐to‐carbon (CaO/C) ratio of 2 is based on dry and ash‐free basis. The CaO/C ratio and K 2 O wt% were chosen to maximize hydrogen production based on our previously determined optimal values. The AFC was originally extracted from raw lignite coal using organic solvents, which allowed the sorption‐enhanced gasification to be conducted with minimal ash‐catalyst interactions. The effect of temperature on the yield and the initial reaction rate were investigated. The optimal reaction temperature of 675 °C was determined. Carbon balance and final carbon conversions were calculated based on the residue analysis. Activation energy was also calculated using intrinsic kinetics of the reaction. In this study, using AFC offered the potential advantage of operating the gasification process with catalyst recycle.