SULFOCHLORINATION WITH SULFURYL CHLORIDE : AN ALTERNATIVE PROCESS FOR THE MANUFACTURE OF SECONDARY ALKANESULFONATES / SULFOCHLORATION PAR LE CHLORURE DE SULFURYLE : UN PROCEDE ALTERNATIF POUR LA FABRICATION D ALCANESULFONATES SECONDAIRES.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

Secondary alkanesulfonates (SAS) are biodegradable surfactants largely used as active matter in detergent formulations and as emulsifying agents. SAS are manufactured by photosulfoxidation or photosulfochlorination of linear paraffin cuts. The photosulfochlorination process usually involves the reaction of a gas mixture (SO 2 + Cl 2) on alkanes, but recent work showed that sulfuryl chloride (SO 2 Cl 2) can advantageously replace the two gases in this reaction. Our goal was the search for optimal conditions of sulfochlorides preparation in pure phase, the kinetic study of this reaction and the design of the possible ways leading to its industrial application. Using experimental design, several parameters were varied: temperature, mode of addition of SO 2 Cl 2, reaction time, luminous flux, catalyst concentration. The results obtained enabled us to determine the optimal conditions to carry out the reaction. Kinetic experiments were carried out and the BATCHMOD software was used to determine a chemical kinetic model describing the transformation. The models agree very well with experimental data. For the treatment of the reaction mixture, two ways were considered: either the extraction of sulfonyl chlorides by acetonitrile and a posterior distillation of the mixture n-dodecane/1-chlorododecane in order to recycle the alkane or the direct saponification of the whole mixture followed by above-mentioned processing of the organic phase. Consequently, a thermodynamic study of phase equilibria of this liquid-liquid system was carried out. In addition, the vapour-liquid equilibrium of the system n-dodecane/1-chlorododecane was predicted by UNIFAC and simulated by the PROPHY PLUS software. An initial approach to the design of extraction and distillation columns for the treatment of the sulfochlorination mixture was also carried out. In the photosulfochlorination of n-dodecane with sulfuryl chloride the RSO2C1/RC1 (0,93) and secondary-to-primary isomer (4,9) ratios are close to those obtained with SO2/Cl2 mixtures.

ASSUNTO(S)

chlorure de sulfuryle photosulfochloration alcanesulfonates engenharia quimica photosulfochlorination sulfuryl chloride alkanesulfonates process procédé cinétique plan d optimisation kinetics experimental design

ACESSO AO ARTIGO

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