Testing of Functionalized Sorbents for Mercury Control

University of Kentucky (UK), Department of Chemical Engineering have been working on various projects (funded by U.S. EPA, and also by NSF-IGERT program) dealing with development of high capacity sorbents for toxic metal capture. The attachment of polyligands (containing COOH and thiol groups) on various supports such as, silica, composite membranes has led to new sorbent developments with high capacity. The work in this area has led to publications in Langmuir, Env. ScL and Tech., Ion Exchange book, AICHE Proc, etc. On the other hand, the use of sorbent materials for mercury capture (such as, from power plant gases near 70 to 100 oC) require the use of materials with high accessibility and adequate sorption at low contact times. The overall goal will be to do joint research work with the University of Cincinnati (UC) which will lead to the efficient adsorbent development relating to power plant Hg capture issues. Through EPA work UK has developed silica based - sorbents for mercury capture from solution phase/gas phase, and has also tested in batch and Hg vapor + nitrogen streams. Further refinement will be necessary after results are obtained (with UK materials) from UC involving the use of realistic flue gases. The proposed tasks will involve development of silica and potentially alumina based materials containing sulfur (thiols and polythiols) groups for Hg vapor capture at temperatures between 70 and 110 DC; supply the functionalized adsorbent materials (including modified commercial materials for comparison) in gram quantities (2 to 10 gram) to UC to establish rate of sorption with and without the presence of C02, S02, NOx ; evaluate results to establish extent of utilization of sorption sites, role of sorbent particle size, and correlate results as a function of temperature; and comparison of sorption behavior between open structured silica materials and highly porous alumina (thiol functionalized) materials.