Gas desulfurization adsorption technology

Adsorption technologies used for gas desulfurization are a widespread technique which, due to its relative simplicity, are widely used to the purification smaller volumes of gas. However, for their trouble-free and economical use, it is necessary to respect several basic requirements for the selection of suitable types of adsorbents with respect to the specific composition of the purified gas. The article provides a brief overview of the history of the development of adsorption technologies and also provides several different examples of the operational use of this technology for the purification of gases containing high concentrations of sulfur substances. Furthermore, the principles of correct selection of a suitable adsorbent for specific application cases are also specified here. Iron oxide adsorbents were used in the early times of the operation of the technology, which were inexpensive but had a relatively low sorption capacity for sulfur compounds. Therefore, sorbents based on iron oxides have been gradually replaced by more powerful, but also more expensive sorbents based on activated carbon. Initially, activated carbon without impregnation was used, the production of which took place in the Czech Republic on an industrial scale. By the further development of impregnated types of activated carbon and their introduction into industrial production, these adsorbents have been also used in adsorption technologies intended for gas desulfurization. Their sorption capacity is much higher in comparison with non-impregnated types of activated carbon, because the impregnants used convert sulfur compounds from gas into non-volatile substances (elemental sulfur, sulfides, polysulfides). This ensures a long service life of the adsorbent and high efficiency of gas purification from sul-fur substances.