Sulphonation technology and how screw blowers play an important part

Sulphonation is a chemical process that involves introducing a sulphonate group (–SO3H) into an organic compound. This process is widely used in the production of various chemicals, including detergents, surfactants, dyes, and pharmaceuticals. Sulphonation is a critical process in the production of surfactants, detergents, and various other chemicals. Sulfonate or Sulphate: Methyl Esters, Olefins, Alkyl Benzene, Alcohols / Ethoxylates, Fatty Acids, and Petroleum Alkylates & custom designed plants for asphalt and alkyl aryl alkylates.

• Sulphur trioxide (SO3): SO3 is used in its gaseous form or dissolved in a solvent. It is a highly reactive and efficient sulphonating agent.
• Oleum: Liquid-phase sulphonation: Oleum is a solution of SO3 in sulfuric acid, commonly used for liquid-phase sulphonation due to its high reactivity.
• Concentrated H2SO4: Versatile agent: Concentrated sulfuric acid can act as both a sulphonating agent and a catalyst in the sulphonation reaction.

Continuous air + SO3 sulfonation (To get constant flow with variation in back pressure, required effectively for sulphur burning application). The blower requirements are quite specific due to the demanding nature of the process. Here are some technical characteristics of air demand to consider: 

• Air flow rate: The required air flow rate typically ranges from 500 to 15 ,000 m³/h, depending on the scale of the operation.
• Pressure requirements: Blowers must provide a consistent pressure, usually between 0.5 to 1.5 bar, to ensure the correct operation of the sulphonation process.

• Temperature control: The blowers should be capable of operating at elevated temperatures, as sulphonation reactions are exothermic. This may require blowers with integrated cooling systems.
• Material compatibility: The blowers must be constructed from materials that can withstand the corrosive nature of sulphonating agents, such as stainless steel or other corrosion-resistant alloys.
• Reliability and maintenance: Given the continuous nature of sulphonation processes, blowers should have low maintenance requirements and high reliability to minimize downtime. Features such as oil-free operation and robust design contribute to this.
• Control systems: Advanced control systems can help in optimizing the blower performance in real-time, ensuring that the airflow and pressure are maintained as per the process requirements.

Screw blower provide wide range of flow rates ranging from 500- 15,000 m3/hr with wrt to constant output pressure with the help of VFD/VSD which is critical for maintaining steady operating conditions in sulphonation processes v/s in case of turbo blowers pressure fluctuation with varying flow rates leads to instability. 

As shown in the graph, a pressure vs flow curve for a screw blower. With increase in pressure, the flow remains same or unchanged for screw blowers, which suits the process air demand for this application. This is the main advantage of screw blowers in this application. 

Unlike screw blowers which serve a wide range of flow requirement, the turbo blower flow significantly drops as the pressure increases which does not support the process air demand & leads to risk of surging in turbo blowers. This is a typical turbo curve, as you can see with increase in pressure the flow reduces considerably, which affects the process.

Our esteemed customer well known in the field of manufacturing of items like soap, detergent and cosmetic products. They had a set up for sulphur burning & process air. Their sulphonating set up faced challenges in getting constant flow as variations in back pressure were required for the sulphur burning application.

• Blower controlling through DCS and Monitoring parameters.
• Manage two different applications with dedicated 2 Pressure bands of 0.7 Barg & 0.3 Barg respectively

Sight insight:

1. Design flow: Constant 1200 m3/hr flow at varying back pressure w.r.t major concern to have constant kg/hr of O2, i.e. air demand on various pressure band at all seasons. Operating pressure ranging from 0.5 -  0.89 barg.
2. Existing – high speed, turbo blower with air foil bearings à existing problems – no constant flow (reduced flow) with change in pressure and ambient conditions.

The proposed schematic shows that the Atlas Copco Screw blower provided continuous flow based on the closed loop circuit ensuring accurate flow and optimum power consumption by continuously adjusting based on feedback getting from connection build with PLC—PLC here Receives the set point for oxygen (O2) and controls the operation connected with 4-20mA which is directly connect to our latest Neos Drive (VSD/VFD) . The VFD blowers running based on DCS meter feedback. This set up serves most energy-efficient solution when compared to any fixed-speed blowers, resulting in significant energy savings & control to critical operations.

Due to this set up our customer were able to get the significant result of 2700 m3/hr @ 0.5 Barg operating with best in class Specific Energy Requirement (SER ) of 0.06 kW/m3/hr. VFD built-in technology helped them to serve Constant flow throughout season with varying pressure. Along with that no special arrangement needed to be provided for an ambient temperature 46°C..