• Journal Article

Attrition-resistant zinc titanate sorbent for sulfur

Citation

Swisher, J. H., Yang, J., & Gupta, R. (1995). Attrition-resistant zinc titanate sorbent for sulfur. Industrial & Engineering Chemistry Research, 34(12), 4463-4471. DOI: 10.1021/ie00039a037

Abstract

For new coal gasification systems, zinc titanate sorbents are being developed to remove sulfur
from the hot product gas prior to its use in combined cycle turbines and high-temperature fuel
cells. The properties of zinc titanate for this application are very attractive. However, there is
still a concern about durability over many sulfidation-regeneration cycles. The approach to the
problem taken in this project was to contain the zinc titanate in a structural matrix of excess
titania. Fifteen sorbent formulations were evaluated in a screening study to obtain a good
compromise between mechanical properties and chemical reactivity. Then, the two best
formulations were evaluated in ten-cycle fluidized bed and fixed bed tests. One of these was
shown to be outstanding in resistance to attrition and decrepitation during the tests. It had
the composition 33.5% zinc oxide and 66.5% titania, was prepared from 2 pm powders, and was
sintered at 1000 "C. The crush strength of this sorbent was approximately a factor of 10 higher
than values reported by other investigators. Its chemical reactivity was good, and improvement
should be possible with minor changes in preparation procedures. The results of complementary
research on improving sorbent regeneration procedures and on activation pretreatments are
reported, also.