Ballestra CSTR system

In the Ballestra CSTR system the flow of SOj/air is reduced in each successive reactor i.e. achievement of conversion is biased to the early reactors in the train. However, the quantity of gas that can be fed to a reactor is limited to that at which flooding of the turbine impeller occurs which results in severe entrainment of the organic liquid with the reaction gas. The maximum superficial gas velocity is in the region of 1 m/s, based on the free cross-sectional area of the reactor. Because of this limitation, Ballestra CSTR plants tend to operate with relatively high SOj-in-air concentrations (6 to 7% by volume). 

The Ballestra CSTR system, because of its back-mixing characteristics long residence time and residence time distribution, can expose the organic material to by-product formation by side rea dom.- (see 5.5.1.) This can prove disadvantageous for sensitive materials such as primary alcohols, alcohol ethoxylates and alpha-olefins. Thgefore> the Ballestra CSTR system is predominantly used for branched and linear alkylbenzenes and fatty acid methyl ester (FAMEl SUlplLQUation. 

The pure falling-film reactors will have the shortest residence time, order of magnitude 30 seconds. The Chemithon FFR and Jet Impact Reactor, both with quench loop, could have an organic liquid residence time of about 2 to 5 minutes, depending on the liquid level in the de-gassing tank. Finally the Ballestra CSTR system shows a total residence time for the organic liquid of the order of 60 minutes. 

The Ballestra Sulphurex CSTR system is relatively simple in its mechanical construction. The same can be said about the Chemithon Jet Impact Reactor. Film reactors are mechanically more sophisticated constructions, notably the organic liquid distribution systems. The delicate FFRs can not always be recommended for countries where the level of technology and maintenance is low. 

There are seven main sulphonation reactor systems used world-wide for SOs/air sulphonation for which there is proven practical and documented experience The Ballestra Sulphurex continuous stirred tank reactor (CSTR) cascade, the Ballestra Sulphurex F (a multitube falling-film reactor (MT-FFR)) the Chemithon falling-film reactor (FFR), the Chemithon Jet Impact Reactor, the MM falling-film reactor (FFR), the Mazzoni Sulpho film reactor (a multitube falling-film reactor) and the Japanese T-0 FFR reactor system. 

Table 20 Final product specification for Ballestra Sulphurex CSTR sulphonation system... 

Final product specification for Ballestra sulphurex CSTR sulphonation system Final product specification for Ballestra multi-tube falling-film reactor (MT-FFR) Final product specification for Chemithon falling-film reactor system (FFR)... 

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