The sulfuric acid sensor
Measuring accuracy: 0.03 m%
Measuring range: 80 - 100 m% H2SO4
No cleaning necessary
Plug 'n' Play solution
Sulfuric acid is one of the most important basic chemicals. The constant demand is constantly increasing as the properties of sulfuric acid are useful for the production of many different products.
Some examples of important applications for measuring the concentration of sulfuric acid and oleum with the LiquiSonic® measuring systems:
- Sulfuric acid and oleum production
- Synthesis gas drying in chemistry and petrochemistry
- Etching and pickling agents in the steel industry
- Ore extraction in mining
- Starting material for sulfate fertilizer
- Basic chemical for various chemical products
The two main production processes are the double contact double absorption process (DCDA), a process that provides a vanadium pentoxide (V2O5) catalyst to produce highly concentrated sulfuric acid and oleum, and the wet sulfuric acid process (WSA), which removes sulfur from various process gases. The LiquiSonic® Measuring system can be very easily integrated into the various process stages of both processes mentioned above. The fast, robust sensor technology improves system utilization, process reliability and product yield.
Double contact process
The double contact process (DCDA) uses a number of starting materials, which synthesize sulfur dioxide in various reactions. Initially SO flows2-containing gas into the drying tower, where water is removed from it. The gas then meets the catalyst, the SO, in the converter2 to SO3 oxidized.
2 SO2 + O2 → 2 SO3
Next comes the SO3 into the intermediate absorber. Although the absorption of sulfur trioxide in an aqueous solution is possible, such a highly exothermic reaction could attack and destroy the system. The SO3 reacts with 98% sulfuric acid, forming highly concentrated acid.
SO3 + H2O → H2SO4
In order to reduce environmental pollution, the SO flows2-containing exhaust gases from the intermediate absorber into the converter again. There they are used to prepare the sulfur trioxide for processing into sulfuric acid in the final absorber. An intermediate product in the double contact process is oleum, which consists of 100% sulfuric acid enriched with SO3, consists.
The possible applications include:
- Production of highly concentrated sulfuric acid
- Production of caprolactam and nylon
- Nitration process in combination with nitric acid
Oleum is formed by the absorption of SO3 in an oleum absorption tower. The LiquiSonic® Sensors provide excellent process control in oleum at concentrations between 20 – 30 m% and 50 – 60 m%. The sensors are ideally installed in the inlet and return lines of the absorption towers and after the dilution unit.
Contact procedure
The contact process (WSA) was originally developed to remove sulfur components from exhaust gases from various industrial manufacturing processes. In contrast to the double contact process, the water vapor remains in the resulting SO2. Thanks to a special vanadium-containing catalyst, the gas has no negative effects on the catalytic oxidation of SO2 to SO3 in the converter.
Finally, during the contact process, the sulfur trioxide enters the condenser, where water vapor condenses and SO3 in H2SO4 converted. A concentration of 98 m% is typical. In order to measure the concentration directly in the line, an installation is required LiquiSonic®-Sensors required at the end of the condenser and dilution unit.
