Fuel gases with low calorific value for firing PFR lime shaft kilns - borderline case studies and realisation

摘要

Due to the progressive reduction of the production of coke oven gas in iron mills, fuel gases with low calorific value resulting from the production of pig iron and steel are now to be used for firing PFR lime kilns. Within the framework of this article it is described in detail to what extent gases with low calorific value can be used for the operation of PFR lime kilns. The process data are demonstrated by the example of a 500 tpd PFR lime kiln. Fuel gases with a calorific value of 7.5 MJ/m~3_n have successfully been used in PFR lime kilns so far. It will be shown that even fuel gases with a calorific value of only 4.3 MJ/m~3_n can be used. This will lead to marked changes in the process conditions, which, however, can be technically controlled. An essential advantage of these gases is that only very little sulphur is introduced into the process.