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Kinetics and reactor design aspects of the synthesis of ionic liquids--Experimental and theoretical studies for ethylmethylimidazole ethylsulfate
Chemical Engineering Science, 62 (6): 1760-1769 (2007)ss.
Аннотация
Ionic liquids (ILs) are promising new solvents, e.g. for catalysis
and separation processes. Currently, ILs are produced in batch reactors
at comparatively high prices. So improved and continuous reactors
are probably provitable. Reaction engineering aspects of the exothermic
IL-synthesis are exemplarily discussed for ethylmethylimidazole ethylsulfate
(EMIMEtSO4), formed by liquid phase alkylation of methylimidazole
with diethylsulfate. Simulations based on the experimentally determined
kinetic data show that an adiabatic loop reactor with an external
heat exchange is the best choice, e.g. compared to expensive multi-tubular
reactors, which are cooled intensively to avoid a runaway. The unfavourable
dilution of the reactants in the loop reactor is outbalanced by the
higher inlet temperature, which leads to a higher mean reaction rate
(compared to multi-tubular reactors) and a much smaller reactor without
exceeding the maximum temperature of (coloration of IL; long-term
thermal stability). In addition, the design and operation of a loop
reactor is straightforward and less complex. Compared to batch reactors,
the hold-up is by a factor of 1000 lower, which is particularly advantageous
for toxic reactants (here diethylsulfate). The results are beyond
synthesis of EMIMEtSO4 instructive for other ILs, and probably
also for other exothermic reactions with a temperature limit.
