Alkoxylations are commonly performed in industry for the production of surfactants and polyglycols by means of a simple semi-batch liquid-stirred reactor. More recent processes use semi-batch Venturi Loop Reactors (VCR) or Spray Tower Loop Reactors (SLR), where liquid phase is dispersed into the gaseous oxides through recirculation loops. In this article, a risk analysis is made on the recirculation loops to compare these three reactor types. More specifically, the analysis of consequences for the ethoxylation of dodecanol with different ethylene oxide partial pressures and process temperatures are studied. The atmospheric wind velocity was varied for a range of releases from the recirculation loop or from small releases from flanges and valves along the same pipeline. This article shows that the risks of the VLR and SLR are lower than the semi-batch reactor. The higher risks for recirculation loops are only related to toxicity in the proximity of reactor. Explosions give high overpressures only in the case of near-instantaneous releases of the reactor contents (large releases). Although this analysis was specifically made for alkoxylation reactors, the methods and conclusions can also be used for comparing the risks of other semi-batch reactors to loop reactors.
The evaluation of risks of ethoxylation reactors
Salzano E;
2007
Abstract
Alkoxylations are commonly performed in industry for the production of surfactants and polyglycols by means of a simple semi-batch liquid-stirred reactor. More recent processes use semi-batch Venturi Loop Reactors (VCR) or Spray Tower Loop Reactors (SLR), where liquid phase is dispersed into the gaseous oxides through recirculation loops. In this article, a risk analysis is made on the recirculation loops to compare these three reactor types. More specifically, the analysis of consequences for the ethoxylation of dodecanol with different ethylene oxide partial pressures and process temperatures are studied. The atmospheric wind velocity was varied for a range of releases from the recirculation loop or from small releases from flanges and valves along the same pipeline. This article shows that the risks of the VLR and SLR are lower than the semi-batch reactor. The higher risks for recirculation loops are only related to toxicity in the proximity of reactor. Explosions give high overpressures only in the case of near-instantaneous releases of the reactor contents (large releases). Although this analysis was specifically made for alkoxylation reactors, the methods and conclusions can also be used for comparing the risks of other semi-batch reactors to loop reactors.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
