Sulfonated surfactants reactors

There are four main sulfonation reactor configurations applied worldwide to produce all kinds of top quality anionic surfactants from sulfur-based S03/air as the sulfonating agent. All these systems have proven and documented experience ... 

The Chemithon Corporation has patented a novel venture reactor.34,35 The organic to be sul-fonated is injected into a stream of gas containing S03 at a venture. The reaction mixture is quenched and recycled downstream until sulfonation is complete. The reactor design can be used for highly viscous, high molecular weight specialty surfactants for industrial applications such as lubrication oil additives. 

At times, it is necessary to add a quantity of material all at once to a reactor in which an emulsion is already polymerising. For example, a relatively small amount of functional monomer could be added to a latex near the end of the polymerisation to produce a functionalised particle surface. Such a process is known at the shot-growth method (283). This method is often used in emulsifier-free polymerisations (69, 360) that contain no surfactant (but do use highly water-soluble, surface-active, functional monomers instead). During the early stages of emulsifier-free polymerisation, the particle size is determined primarily by the amount and type of initiator (such as potassium persulfate) and functional monomer (such as sodium styrene sulfonate). Latexes made in this manner tend to be narrow in size distribution. At high conversion (approximately 90%) an additional quantity or shot of functional monomer is added, and it chemically binds at the surface of the... 

FIGURE 7.5 Flowchart of the light-water sulfoxidation process. Photoreactor (1), separators (2,5,8,9), SOj stripper (3), evaporating column (4), neutralization reactor (6), evaporator (7), exhaust gas (10), fresh paraffin (11), sulfonic acid (12), recycle paraffin (13), recycle gas (14), acid phase (15), air (Oj) (16), back paraffin (17). (After Falbe, J., ed., Surfactants in Consumer Products Theory, Technology and Application, Springer, Berlin, 1986. With permission.)... 

The production uses a different method than the more common sulfonation systems such as chlorosulfonic acid, sulfur trioxide, pyrosulfate, or oleum. The Streckerization reaction utilizes a mixture of sulfite and bisulfite salts to sulfonate the ether intermediates into the final surfactant. The most commonly used process for the production of these surfactants is a multistep batch system, where each reaction step is performed in separate reactor. This prevents contamination of one step to the next as well as the introduction of certain species, which are a benefit to one step but a detriment to another—specifically water. The batch system s agitation allows for good mixing between two immiscible liquids, which is a common theme throughout the production. Although batch systems are the most common, the process can be adapted for continuous production. 

The reaction is therefore characterized as a single-pass, short-reaction-time process. Different systems are used to form the film and to generate turbulence by the mixing of the two reactants during sulfonation. The best-known systems are the Stepan [49], Allied Chemical Corporation [50], and Chem-ithon reactors [51]. The reactor heads of the three systems are illustrated by Kapur et al. [46]. Lion Corporation modified these reactors in order to improve the reaction conditions. A dry-air stream is introduced between the diluted SO3 gas stream and the organic thin film so that the diffusion of the surfactant agent could be better controlled and a mild sulfonation reaction achieved [38]. 

At approximately the same time, a further process for the manufacture of anionic surfactants of the sulfonate type, namely the olefinesulfonates, became of interest. This process starts from a-olefines obtained by cracking of higher hydrocarbons. In this process, the olefine is reacted with SO3 for a short time in a thin-layer reactor. Alkenesulfonates and hydroxyalkanesulfonates are formed [18]. 

---