REACTIVITY OF OIL SHALE ASHES
TOWARDS SULFUR DIOXIDE
1. ACTIVATION OF HIGH-TEMPERATURE ASHES
T. KALJUVEE
A. TRIKKEL
R. KUUSIK
Tallinn Technical University
Department of Chemistry
Tallinn, Estonia
| Initial and activated by different methods ashes formed at
the Baltic Thermal Power Plant (TPP) during high-temperature combustion (1100-1200 °C) of
powdered Estonian oil shale, and some samples of mud from sediment ponds of the hydraulic ash
separation system at the Baltic TPP as sorbents for SO2 were studied in the
temperature range of 700-950 °C by means of SO2 -air mix- ture (pSO2 =190 mm Hg) and a thermogravimetric equipment. It was determined that the SO2- -binding capacity for the initial samples of high-temperature ashes at a two-minute contact was in the range of 7.3-13.1 mg SO2 per 100 mg sample. Dry grinding increased the SO2 -binding capa- city of the initial ashes 1.15-1.25 times, wet grinding 1.3-1.6, hydration 1.3-1.7, the combination of grinding and hydration 1.9-2.1 times. Using preliminary activation of the oil shale ashes it was possible to diminish the difference in their SO2 capturing ability, compared to samples of natural Estonian limestones and dolomites, from 3-4 times to 1.6-2 times. The SO2 -binding capacity of the samples of mud from the sediment ponds was on the same level as that of natural limestone and dolomites. |