Lurgi process, residues from

G. Klamp and D. Wanner, Removal of Arsenic from Washing Acid by the Sachtleben-Lurgi Process, in Residues and Effluents Processing and Environmental Considerations, R. G. Reddy, W. P. Imrie, and P. B. Queneau (eds.), TMS, Warrendale, PA, 1992, pp. 833-837. 

Concat A process for removing residual sulfur-containing gases from the off-gases from the Claus process, by oxidation to sulfur trioxide and hot condensation to sulfuric acid. Developed by Lurgi and first operated at Port Sulfur, LA, in 1974. 

Lucas [Lurgi-Claus-Abgas-Schwefelgewinnung] A process for removing residual sulfur compounds from the tail gases from the Claus process. The gases are incinerated and then passed over a bed of hot coke, which converts all the sulfur to sulfur dioxide. This is absorbed in aqueous sodium phosphate, which releases it on heating ... 

Tail gas emissions are controlled by improving the S02 conversion efficiency and by scrubbing the tail gas. In a double absorption process plant, a five-bed converter has 0.3 percent unconverted S02, as compared with 0.5 percent for a four-bed converter. A Lurgi Peracidox scrubber may be used to remove up to 90 percent of the residual S02 in the tail gas from a double absorption plant. Hydrogen peroxide or electrolytically produced peroxymonosulfuric acid is used to convert the S02 to H2S04 in the Lurgi scrubber. 

The LURGI Concat Process offers itself to produce sulfuric acid of up to 93 % concentration from low-sulfur gases. The process tolerates both gases containing the sulfur mainly in the form of H2S and COS and others which contain almost exclusively SO2 with only little residual H2S. As the gas leaving a Concat unit does not contain more than small quantities of SO2, the process can be used also for tailgas treatment downstream of Claus units. 

---