Chemical Composition and Engineering Properties of Solid By-products Collected from the Ohio State Carbonation and Ash Reactivation (OSCAR) Process

摘要

Ohio state carbonation and ash reactivation (OSCAR) process was installed as a slip-stream at the McCracken Power Plant located on the Ohio State University main campus to test the efficiency of a new dry FGD system to remove SO2. In this study, the chemical composition including heavy metals and polycyclic aromatic hydrocarbons (PAHs), leaching characteristics, and physical and engineering properties of solid by-product samples collected during the testing of the OSCAR process were examined to assess potential re-use opportunities for this material. Generally, trace element (I.e., arsenic, selenium, and mercury) concentrations were detected in mg/kg level. Measurement results for polycyclic aromatic hydrocarbons (PAHs) on selected cyclone and baghouse samples showed low concentrations (e.g. μg/kg). From the results, trace element concentrations in OSCAR samples were enriched compared to LSD ash. However leachate results indicated that ashes collected from the cyclone were not hazardous material. Arsenic concentration in cyclone ash was as much as 95 mg/kg, which is above the limit at 75 mg/kg for land application (EPA 503 Rule). For baghouse ash, arsenic and selenium concentrations were above the land application limits especially arsenic which was as high as 673 mg/kg. Bulk chemical and engineering properties indicated that OSCAR ash can be utilized in construction, agricultural and other civil engineering applications. .