Sulfuric acid is a dense clear liquid, it is used for making fertilizers, leaching metallic ores, refining petroleum, and for manufacturing a myriad of chemicals and materials, worldwide, about 180 million tonnes of sulfuric acid are consumed per year (Kitto, 2004).
The raw material for sulfuric acid is SO2 gas, which is obtained by:
- Burning elemental sulfur with air
- Smelting and roasting metal sulfide minerals
- Decomposing contaminated (spent) sulfuric acid catalyst.
Our project will adopt double conversion double absorption as the manufacturing technique. Since 1980s, with large scale of sulfuric plants imported from developed countries the Chinese government had contributed a lot of support for scientific research in designing and manufacturing of equipment for producing sulfuric acid, the technology has been dramatically improved and China has achieved leading position in this field around the world.
About 70% of sulfuric acid is made from elemental sulfur which is obtained as a byproduct from refining natural gas and petroleum. Sulfuric acid manufacturing from solid sulfur has several advantages such as simpler production flow, lower investment, higher thermal recycle efficiency, and environment-friendly, furthermore the implementation period for such sulfuric acid plant will be shorter, the management and operation will also be easier.
SO2 in metallurgical smelting and roasting gas accounts for about 20% of sulfuric acid production. The SO2 is ready for sulfuric acid manufacture, but the gas is dusty, therefore the dust in the off-gas from smelting and roasting must be removed by different treatment before going to catalytic SO2 oxidation.
A major use of sulfuric acid is as catalyst for petroleum refining and polymer manufacture, the acid becomes contaminated with water, hydrocarbons and other compounds during this use, the spent acid will be sprayed into a hot furnace, where the acid decomposes to SO2, O2 and H2O(gaseous), such mixed off-gas will be cleaned and dried before catalytic oxidation to SO3. About 10% of sulfuric acid is made in this way, virtually all the product is re-sued for petroleum refining and polymer manufacture.
According to the national standard GB/T 534-2014, the final product can reach first grade and premium grade according to client's requirement.
The plant has one central controlling room for operation of the whole production, monitoring of main equipment, start and stop of the production etc. The main production parameters will be monitored, alarmed, recorded, and computed within the Distributed Control System. Engineers and operators can monitor the real-time manufacturing process via different display, trending record, various reports, diagnosis report and so on, in order to stabilize technique parameters, ensure product quality, reduce work intensity, and guarantee the manufacturing safety etc.