Abstract
Calcium-based sorbents, such as limestone and dolomite are viable candidates for capturing pollutants in an in-situ coal gasification/desulphurisation process. Recently, scallop shell is also used as a Ca-based sorbent. However, the ability in capturing pollutants varies from one type to another and it also depends on the process involved. In this study, two types of limestone, scallop shell and dolomite were characterized and studied for H₂S absorption ability under the coal gasification conditions. The characterizations were done using Scanning Electron Microscope (SEM), X-ray Diffraction (XRD), Thermal analysis and Surface Area analysis. All of the samples showed a porous structure, and in addition, the column structure was found in the scallop shell sample. The calcination temperature for all the sorbents was found to be in the range of between 783–803°C. The surface area of the scallop shell was slightly higher than the two limestone samples and dolomite showed the lowest surface area. H₂S absorption ability was studied by using a tubular flow reactor. The H₂S absorption ability for the two limestones was found to be almost the same at 900°C and about 1800 ppm of H₂S. Their absorption ability was also higher than the scallop shell and dolomite. Studies were also conducted under different reaction temperatures and H₂S concentration. The temperature was found to have a very small effect on H₂S absorption ability. On the other hand, the ability increased with H₂S concentration. Furthermore, the complete H₂S absorption time was found to be longer at low H₂S concentration.
Recommended Citation
Katalambula, H. (2002). Comparative Analysis of H₂S Removal Ability of Different Calcium-Based Absorbents under Coal Gasification Conditions. Tanzania Journal of Engineering and Technology (TJET), 25(1), 78-85. https://doi.org/https://doi.org/10.52339/tjet.v25i1.319
Publisher Name
University of Dar es Salaam