Zero waste disposal of sulfur-alkaline effluents

66EN
Process Description
Feedstock – sulfur-alkali effluents are contacted in the upper section of column 5 with oxidation gas supplied from reactor 2 through cooler 3, and then with circulating mixture of flue gas and air supplied from cooler 4. The treated effluents are discharged from the bottom of column 5, and the sour gas from the top of column 5 is fed to heater 1, to which air and fuel are also forced. The flue gas is removed from the heater 1, cooled by mixing with air and divided into two parts. The first part of the flue gas-air mixture is directed to reactor 2, where most of the sulfur dioxide is oxidized to sulfur trioxide. The resulting oxidation gas is cooled in cooler 3 and sent to column 2 between the first and second sections. The second part of the flue gas-air mixture is cooled in cooler 4 and is divided into two streams. The first one is discharged from the unit as off-gas, and the second one, circulating, is fed to the lower part of column 5.

Process features
  • Free from use of third party chemicals
  • Production of low-toxic salt effluents

Technical Specification
  • Feedstock - alkaline effluents with a pH of up to 13.5
  • Feedstock capacity: up to 100 t/h⁻¹
  • Product - neutralized treated saline drains
  • The content of sulfide ions in treated effluents: no more than 30 mg/dm³
  • pH of treated effluents is 7.5-9.5

Patents of the Russian Federation No.
2791257, 2795605

Development level, industrial application
  • Developed design concepts