TY - JOUR
T1 - The hydrogen adsorption behavior of Mechano-Chemically activated carbon from Indonesian low-rank coal
T2 - Coupled Langmuir and Dubinin-Astakhov Isotherm model analysis
AU - Harjanto, Sri
AU - Fatriansyah, Jaka Fajar
AU - Noviana, Latifa Nuraini
AU - Yunior, Stefanno Widy
N1 - Funding Information:
The publication of this article is supported by the United States Agency for International Development (USAID) through the Sustainable Higher Education Research Alliance (SHERA) Program for the Universitas Indonesia Scientific Modeling, Application, Research and Training for City-centered Innovation and Technology (SMART CITY) Project, Grant #AID-497-A-1600004, Sub Grant #IIE-00000078-UI-1. Comprehensive discussions with and comments from Dr.-Ing. Nasruddin of the Department of Mechanical Engineering, Universitas Indonesia, are very much appreciated.
Publisher Copyright:
© IJTech 2018.
PY - 2018
Y1 - 2018
N2 - This study aims to produce activated carbon from low-rank coal from East Kalimantan, Indonesia by a mechano-chemical method and to determine its adsorption parameters: hydrogen uptake/capacity, activation energy, the structural heterogeneity parameter, and the isosteric heat of adsorption. The hydrogen uptake/capacity of the coal was determined by a volumetric adsorption test using constant-volume-variable-pressure (CVVP). The characteristic adsorption parameters, such as hydrogen uptake, characteristic energy and heterogeneity structure factor, were determined using the coupled Langmuir and Dubinin-Astakhov (D-A) isotherm models, with the assumption that the hydrogen uptake value would be similar, irrespective of the model used. We found that the mechano-chemical method significantly reduced the particle size of the activated carbon relative to the untreated control, by approximately 60%. In addition, the activation process yielded a higher surface area for the activated carbon (390 m2/g) compared to the untreated control (90 m2/g). We also found that greater surface area led to a greater uptake of hydrogen by the activated carbon (40.17±1.56)×10-3 kg/kg than by the untreated control (7.94±1.56)×10-3 kg/kg. We also found that the heterogeneity factor of the activated carbon was 3.73±0.23, lower than the untreated control 4.65±0.56, which reflects the more heterogeneous pore diameter sizes for the activated carbon compared to the untreated control. Lastly, using the obtained adsorption parameters, we observed that the hydrogen uptake-dependent isosteric heat of adsorption on the activated carbon changed rapidly in the initial and final stages compared to the untreated control due to the adsorption of hydrogen by smaller pores which reside inside larger ones.
AB - This study aims to produce activated carbon from low-rank coal from East Kalimantan, Indonesia by a mechano-chemical method and to determine its adsorption parameters: hydrogen uptake/capacity, activation energy, the structural heterogeneity parameter, and the isosteric heat of adsorption. The hydrogen uptake/capacity of the coal was determined by a volumetric adsorption test using constant-volume-variable-pressure (CVVP). The characteristic adsorption parameters, such as hydrogen uptake, characteristic energy and heterogeneity structure factor, were determined using the coupled Langmuir and Dubinin-Astakhov (D-A) isotherm models, with the assumption that the hydrogen uptake value would be similar, irrespective of the model used. We found that the mechano-chemical method significantly reduced the particle size of the activated carbon relative to the untreated control, by approximately 60%. In addition, the activation process yielded a higher surface area for the activated carbon (390 m2/g) compared to the untreated control (90 m2/g). We also found that greater surface area led to a greater uptake of hydrogen by the activated carbon (40.17±1.56)×10-3 kg/kg than by the untreated control (7.94±1.56)×10-3 kg/kg. We also found that the heterogeneity factor of the activated carbon was 3.73±0.23, lower than the untreated control 4.65±0.56, which reflects the more heterogeneous pore diameter sizes for the activated carbon compared to the untreated control. Lastly, using the obtained adsorption parameters, we observed that the hydrogen uptake-dependent isosteric heat of adsorption on the activated carbon changed rapidly in the initial and final stages compared to the untreated control due to the adsorption of hydrogen by smaller pores which reside inside larger ones.
KW - Activated carbon
KW - Adsorption isotherms
KW - Heterogeneity
KW - Planetary ball mill
KW - Sub-bituminous coal
UR - http://www.scopus.com/inward/record.url?scp=85055555145&partnerID=8YFLogxK
U2 - 10.14716/ijtech.v9i5.2031
DO - 10.14716/ijtech.v9i5.2031
M3 - Article
AN - SCOPUS:85055555145
SN - 2086-9614
VL - 9
SP - 993
EP - 1005
JO - International Journal of Technology
JF - International Journal of Technology
IS - 5
ER -