Optimization of In-Situ Capture by Sorbents of Toxic Metals in Combustion ProcessesEPA Grant Number: R825389
Title: Optimization of In-Situ Capture by Sorbents of Toxic Metals in Combustion Processes
Investigators: Wendt, Jost O.L.
Institution: University of Arizona
EPA Project Officer: Shapiro, Paul
Project Period: October 1, 1996 through September 30, 1999
Project Amount: $293,068
RFA: Exploratory Research - Air Engineering (1996) RFA Text | Recipients Lists
Research Category: Land and Waste Management , Air , Engineering and Environmental Chemistry
The proposed research is concerned with the generic problem of managing the fate of toxic and heavy metals in high temperature, combustion processes. Combustion processes currently comprise a major source of toxic and heavy metal emissions into the environment, and the isolation of heavy and toxic metals from the environment is an issue of great concern. The overall objective of this research is to develop quantitative models that can be used to predict how sorbents and toxic metal vapors interact at high combustion temperatures and to extend these results to allow optimization in the use of new, multi-functional, designer sorbents for the simultaneous isolation of more than one metal in the presence of chlorine and sulfur.
The research involves systematic experimental studies and mathematical modeling. Experiments involve a 17kW downflow combustor, which has certain attributes of practical systems, but is sufficiently well defined to allow the extraction of rates and mechanisms. Well controlled clean systems will be investigated, where the primary fuel is natural gas, and surrogate toxic metals (Pb, Cd, As and Hg), additives and sorbents are added in controlled amounts. Data consist of exhaust and time resolved particulate samples, isokinetically withdrawn from the furnace, collected on Anderson impactors, and subsequently analyzed by AA, ICP/MS, Auger Microscopy, and SEM/EDX as required. Kinetic mechanisms uncovered from examination of the data, will be modeled, as has been recently done for sodium/kaolinite reactions. These models will be used to optimize sorbent utilization for practical combustion systems.