This is not my line of expertise but I provide replies nonetheless, not guaranteeing the engineering contents or the exactitude of the terminology and the interpretation of the information Lukoil has provided in the Bulgarian and the Russian languages. I apologize for any discrepancies or errors my replies might contain.
The Lukoil Refinery at Bulgaria's Burgas port on the Black Sea, the biggest one in the Balkans and one of the most modern in the whole of Europe, applies the following processes and technologies:
Gas sulphur - 4 Installation is used to process hydrogen sulphur (if this is the correct term), which comes as a result of the thermocatalytic processes used while "softening" the oil fractions of granulated sulphur, the rate of extraction of the sulphur being no less than 99.98%;
A new utility cauldron (holder) P-401 has been built at the catalytic cracking installation, and a new filtering system, DAHLMANN-produced, has been mounted;
Two furnaces, F-101 and F-201, have been fitted with purifying (flushing) exhaust gases systems, produced by the Hamon company. These systems contain DeNOx-nodes for purifying (flushing) nitric oxides, electric filters, DeSOx nodes for purifying (or flushing) sulphur oxides. These improvements have led to a reduction of the annual SOx emissions by 210 tonnes, NOx emissions by 90 tonnes; and 70 tonnes of dust.