SO - Rheinkalk

Incinerator
Spray dry adsorption Bag house filter
Milk of lime & water
Spongiacal ® + Active carbon
Graph 6: Application example of the MCD process
ca. 170°C
Clean gas
Reaction products
In one application, the operating trials are used to check the performance of the MCD
process with regard to the removal of the acid-forming pollutants HCl and SO2 as well
as Hg. Combinations of spray and dry sorption with a lime milk suspension and
Spongiacal ® with active carbon were used. This plant is operated in the dry sorption
stage at approx. 170 °C. During the measuring period, the concentrations of HCl in
the raw gas lay between 500 and 1200 mg/m³N.tr., while the concentrations of SO2 in
the raw gas were 200 – 500 mg/m³N.tr.. The average removal efficiencies attained
were > 99 % for HCl and > 94 % for SO2. These values were obtained with a
stoichiometric ratio of 2.0 - 2.5. An important factor was also the adjustability of the
dry sorption stage with regard to the minimum dosage. The specific consumption of
lime-based products in these trials was approx. 15.7 kg/t waste † .
In addition to the overall mass balances some tests with high HCl and SO2
concentrations were carried out. In one case the HCl concentrations on the raw gas
side increased from 1.500 mg/m³N.tr. to app. 6.000 mg/m³N.tr.. The injection of
Spongiacal was activated and it was possible even under these unfavourable
conditions to fulfil the requirements regarding HCl reduction (< 10 mg/m³N.dry )
† Burnt lime + Spongiacal ®
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