BENMOL sorbents have been purported to be reactive with sulfur dioxide (SO{sub 2}) in flue gas at post-air-preheater temperatures (350{degrees}F and below), thus making them possible candidates for dry sorbent injection desulfurization processes. As an initial step to determine the reactivity of these sorbents, microbalance studies were conducted at the Pittsburgh Energy Technology Center (PETC) under the Cooperative Research and Development Agreement (CRADA) program. Initial reactivity rates and total absorption capacities were determined and compared to those obtained with hydrated lime, which is the chosen sorbent for most duct injection flue gas desulfurization processes.