Q2. What are the future works mentioned in the paper "Optimal temperature profiles for tubular reactors implemented through a flow reversal strategy" ?
Future work may evolve in several directions. 05. 027 sented proof of feasibility, both the classic jacketed tubular and the jacketed RFR configuration can be compared quantitatively for the case studied by Smets et al. ( 2002 ) and Logist et al. ( 2006 ). Second, a further validation can be performed through the use of more rigourous and complex models ( e. g., 2D and/or heterogeneous ) and/or through an experimental set-up.
Q3. What is the energy cost of an ignited reactor?
For all ignited operation regimes, the conversion cost J ′1 increases with increasing switching times due to lower averaged temperatures, the energy cost J ′2 exhibits a minimum, whereas a monotonous increase is observed for the energy cost J ′3.
Q4. What is the heat transfer coefficient in the jacketed zone?
The value of this heat transfer coefficient is constant and positive in the jacketed zone, i.e., [L/2−Lj/2, L/2+Lj/2] with Lj [m] the jacket length, and zero in the insulated zones.
Q5. What is the maximum temperature of the jacketed tubular reactor?
Once the minimal length has been exceeded (i.e., Lj ≥ 0.4 m), symmetric profiles are obtained and the maximum temperature is hardly affected by the jacket length.
Q6. What is the way to determine the maximum reactor temperature?
As the jacket fluid temperature has the largest influence on the maximum reactor temperature, bounds on the jacket fluid temperature can be selected depending on the constant temperature level envisioned.
Q7. What are the important variables which influence the maximum temperature value?
The most important variables which influence this maximum temperature value are the heat transfer coefficient and the jacket fluid temperature.
Q8. What is the effect of the extended high temperature plateau on the energy cost of the reactor?
The decrease in energy cost J ′3 is easily explained by the fact that the extended high temperature plateau induces less deviations from the desired reference temperature Tref,2, whereas the decrease in energy cost J ′2 is related to the sharper gradients at the outlet causing the optimal switching time to shift towards lower values, i.e., closer to the here used fixed value of 100 s.
Q9. What is the important parameter to be determined in practice?
From a cost point of view, the most important parameters to be determined in practice are the jacket temperature (i.e., to minimise mainly the conversion cost J ′1 and the energy cost J ′3) and the switching time and jacket length (i.e., to minimise mainly the energy cost J ′2).
Q10. What is the simulated time of the gas reversal?
After 1500 s, during which the gas enters at high temperature (873 K), the feed temperature is decreased to 293 K and periodic flow reversals every 100 s are started.
Q11. How many s are the corresponding optimal values for the jacket fluid temperature T w?
The corresponding optimal values for the jacket fluid temperature T ∗w and the switching time τ∗ are 846.9 K and 169.1 s, respectively.
Q12. What is the difference between a conversion and an energy cost part?
These criteria both consist of a trade-off between a conversion and an energy cost part, reflecting the current trend in process industry towards process integration and intensification, which relates to enhancing the over all plant performance by (i) optimising the performance of existing reactors or by (ii) adopting novel reactor types, which combine several unit operations into one, and by (iii) interconnecting material and energy streams plantwide.
Q13. What is the way to achieve the optimal temperature profiles for tubular reactors?
For classic jacketed tubular reactors where an exothermic first-order reaction takes place, optimal steady-state temperature profiles have∗
Q14. What is the maximum value of the jacket fluid temperature?
For a grid of jacket lengths, i.e., from 0.4 to 1 m in steps of 0.1 m, continuous optimisations are performed with the jacket fluid temperature and the switching time as decision variables.
Q15. What is the optimisation strategy for the jacket fluid temperature?
the following optimisation strategy is proposed, which combines discrete grid search and continuous optimisation procedures.