Open AccessInfluence of coal properties on the CO 2 adsorption capacity of coal gasification residues
Author(s) -
Sripada Pramod,
Khan Md M.,
Ramasamy Shanmuganathan,
Trivedi Japan,
Gupta Rajender
Publication year - 2018
Publication title -
energy science and engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.638
H-Index - 29
ISSN - 2050-0505
DOI - 10.1002/ese3.201
Subject(s) - coal , adsorption , char , bituminous coal , environmental science , chemical engineering , carbon fibers , waste management , raw material , specific surface area , carbon dioxide , materials science , chemistry , mineralogy , engineering , organic chemistry , composite material , catalysis , composite number
Post‐underground coal gasification ( UCG ) sites hold attractive prospects for geological storage of carbon dioxide. For the successful commercial implementation of UCG with carbon capture and storage ( CCS ), site‐selection is crucial, and a careful techno‐economic feasibility analysis is essential to systematically assess the site related parameters aside from evaluating the environmental risk. This study is related to one of the important aspects of site selection‐ the coal type. Specifically, this work investigates the influence of coal properties and gasification conditions on the adsorption capacities of CO 2 on gasified coal chars. For this purpose, four coals of diverse ranks varying from lignite to bituminous were selected and subjected to CO 2 gasification at atmospheric pressure for 10 min at 800, 900, and 1000°C under a low heating rate of 5°C/min. Subsequently, the gasified chars, as well as the raw coals, were tested for their adsorption capacity in a purpose built volumetric adsorption apparatus at 45.5°C and pressures up to 90 bar. Also, complementary coal and char analysis were carried out for determining the surface area, pore size distribution, and surface morphology. The CO 2 storage capacity was observed to be a strong function of the coal properties and gasification conditions. Among the samples examined, the highest adsorption capacity was observed for chars of the sub‐bituminous coals. The CO 2 adsorption capacity at 80 bar and 45.5°C on the sub‐bituminous char samples was 2.08, 2.43, and 1.95 mmole/g that were prepared at 800, 900, and 1000°C, respectively. The experimental adsorption isotherms were fitted to the Dubinin‐Radushkevic ( DR ) and the Dubinin‐Astakhov ( DA ) models.