Sulfuric Acid is manufactured by oxidizing SO2 gas to SO3 in a converter through a catalytic oxidation process.
The most common sources of SO2 are:
- Burning elemental Sulfur
- SO2 off-gas from a primary process such as a copper smelter
- Decomposition of H2SO2 in a spent acid regeneration process
The SO2 gas as produced above is passed over a catalyst in the presence of Oxygen to oxidize it to SO3. The SO3 gas is then is absorbed into 97–98% H2SO4 to form oleum (H2S2O7), also known as fuming sulfuric acid. The oleum is then diluted with water to form concentrated sulfuric acid.
It is critical to avoid the formation of weak sulfuric acid at any point in the process to avoid corrosion in the process. Weak sulfuric acid is formed when the SO3 gas reacts with moisture (H2O). The Sulfuric Acid manufacturing process includes several stages of heat removal (see process flow diagram below), namely the waste heat boiler and economizers.
The potential sources of moisture ingress in the process are:
- Drying Tower Malfunction
- Moisture in Feed
- Waste Heat Boiler Tube leaks
- Economizer Tube Leaks
- Cleaning System Malfunctions
Moisture leak detection in the Sulfuric Acid process is highly desirable to minimize equipment corrosion, process downtime and H2 safety hazards. When moisture leaks into the process, the acid dewpoint of the flue gas rises and is therefore a leading indicator of moisture leaks. Therefore, a measurement device that can measure acid dewpoint as an early moisture leak detection system can provide benefits to the process.
The Breen AbSensor-ADM-SA, Sulfuric Acid dewpoint measurement system is ideally suited for this application. This system was specifically developed for this challenging environment to provide an early warning for moisture leaks in the system.
In addition to the acid dewpoint measurement system, Breen also provides the TrueFire line of combustion ignition products for sulfur burners and other combustion systems in the Sulfuric Acid manufacturing process. These include the TrueFire NFPA 85 continuous duty gas igniters and the TrueFire High Energy Spark Igniter (HESI).