(557h) Optimize Reactor Networks Using Gate and Highway Reactors and Neon

Gate Reactor: Determination of Optimal CSTR and PFR arrangement is known only for single isothermal reaction. Using geometric arguments it can be shown that a CSTR is a tangent to an isothermal PFR trajectory in the space of concentration variables. It follows that an extremal tangent should be an inflection tangent. The inflection point of an isothermal PFR trajectory is termed as Gate, since it is possible to find a more desirable trajectory once a Gate is reached from the feed trajectory. After the Gate reactors are identified the Optimal Isothermal Reactor Network can be determined, as shown for five reaction schemes including the single isothermal reaction.

Highway Reactor: Using the case of van de Vusse reaction, it is proposed that the Optimal Nonisothermal reactor network consists of Optimal isothermal networks at the constraint temperatures, connected by a single nonisothermal PFR called here as Highway Reactor. Thus it is suggested that there are optimal paths or Highways through the nonisothermal space. Highways can be determined in general using Pontryagin Maximum Principle. However, sometimes algebraic calculations are sufficient as demonstrated for van de Vusse reaction.

NEON: Implementing Optimal Temperature Profile (OTP) for nonisothermal PFR has not been discussed in the literature. Corresponding problem for the Batch reactor is easy as a single optimal heat exchanger can implement OTP closely. However the PFR would require infinitely many small heat exchangers along the length of the reactor. The gain in the performance of the PFR using OTP has been established for (m, n) series reactions (m and n are the orders of the two consecutive reactions). Using analogy with numerical integration schemes, easily constructed cascades of PFRs are proposed as NEar Optimal Networks (NEON) for approaching the performance of a PFR based on OTP. For (1, 1) reactions, a 3-stage PFR cascade can give 80% of the differential improvement offered by an OTP based PFR.