Reactive System Screening Tool RSST

Reactive System Screening Tool (RSST) The RSST is a calorimeter that quickly and safely determines reactive chemical hazards. It approaches the ease of use of the DSC with the accuracy of the VSP. The apparatus measures sample temperature and pressure within a sample containment vessel. Tne RSST determines the potential for runaway reactions and measures the rate of temperature and pressure rise (for gassy reactions) to allow determinations of the energy and gas release rates. This information can be combined with simplified methods to assess reac tor safety system relief vent reqiiire-ments. It is especially useful when there is a need to screen a large number of different chemicals and processes. 

Reactive Systems Screening Tool (RSST ) Temperature history of runaway reaction, rates of temperature and pressure rise (for gas producing reactions)... 

Figure 12-14. Reactive system screening tool (RSST) apparatus. (Source Fauskes Associates Inc.)...

The Fauske and Associates Reactive System. Screening Tool (RSST) w as developed as a result of the DIERS studies and allow s rapid evaluadon of the potential for runaway reactions. It measures the rate of energy and gas release during the runaway and is valuable for screening various process s)stems before commercial designs are completed (see Figure 7-61). 

Several commercial calorimeters are available to characterize runaway reactions. These include the accelerating rate calorimeter (ARC), the reactive system screening tool (RSST), the automatic pressure-tracking adiabatic calorimeter (APTAC), and the vent sizing package (VSP). Each calorimeter has a different sample size, container design, data acquisition hardware, and data sensitivity. 

The Reactive System Screening Tool (RSST), marketed by Fauske and Associates, is a relatively new type of apparatus for process hazard calorimetry [192, 196-198]. The equipment is designed to determine the potential for runaway reactions and to determine the (quasi) adiabatic rates of temperature and pressure rise during a runaway as a function of the process, vessel, and other parameters. 

The Reactive System Screening Tool (RSST) was described in Section 33.2.7. This apparatus is a relatively recent development. Therefore, only limited literature data are available regarding the application of results from this equipment for direct scale-up of reactor systems. The Vent Size Package (VSP) is discussed further in Section 3.3.2.6. 

The pseudo-adiabatic Reactive System Screening Tool (RSST, ARSST)... 

The simpler and most reliable approach to the use of the DIERS methodology is the use of FAUSKY s reactive system screening tool (RSST). It is an experimental autoclave which simulates actual situations that may arise in industrial systems. The RSST runs as a differential scanning calorimeter that may operate as a vent-sizing unit where data can readily be obtained and can be applied to full-scale process conditions. The unit is computerized and records plots of pressure vs. temperature, temperature vs. time, pressure vs. time, and the rates of temperature rise and pressure rise vs. the inverse of temperature. From these data it determines the potential for runaway reactions and measures the rates of temperature and pressure increases to allow reliable determinations of the energy and gas release rates. This information can be combined with simplified analytical tools to assess reactor vent size requirements. The cost of setting up a unit of this kind is close to 15,000. 

Fauske, H. K., The Reactive System Screen Tool (RSST) An Easy, Inexpensive Approach to the DIERS Procedure, Int. Symp. on Runaway Reaction, Pressure Relief Design, and Effluent Handling, AIChE, pp. 51-63, March 11-13, 1998. 

The stability of the Ishikawa reagent itself [(I) in Scheme 2] was examined in our reactive system screening tool (RSST) this equipment was used, since, by design, it allowed us to test the effects of heat in a pressure vessel. The reactor and contents were heated at a rate of l°C/min under a pressure of 200 psi. 

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