Page 17 - 81Sulfonation-Sulfation Processing Technology for Anionic Surfactant Manufacture_opt

284 Advances in Chemical Engineering

Fig. 17. Reactions in the aging step (adapted from Roberts, 2001)
 B 
  
k  Ae  T  (20)

k f, (s -1 ) k s, (s -1 )
LogA 12,10 11,52
B 12,060 12,130
Table 4. Values for equation 20 on aging stage (Roberts, 2008)

The overall conversion as function of time and mole ratio M of SO 3/ME is given by:
 1   f k t 
% conversion  100M    0.25e  0.167e s k t (21)
 M 100 

M 100 is mole ratio for a conversion at 100%, after a delayed aging M 100 = 1,2. These equations,
for aging in a batch reactor system or in a plug flow systems, can be used as guidelines
when setting initial conditions before fine-tuning plant operation to meet a required
specification (Roberts, 1998). Methyl esters are less active than aromatic compounds to
sulfonating due to the less electronic density of the aliphatic chains. The methyl ester
sulfonation include a neutralization step to obtain monosodium salts of -sulfo methyl
esters as desire products (Kapur et al. 1978). If neutralization is immediate disodium salt is
formed (see Figure 18a). However, if neutralization of the acid is delayed, the sulfo ester
monodisodium salt is obtained as final product (see Figure 18b).

Fig. 18. Neutralization chemistry of SME (Torres et al., 2009b)

www.intechopen.com