Comparative design of flow reactors for the production of 100,000 tons per year of cumene from the catalytic alkylation of propylene and benzene

Abstract

This research is driven by the need to ensure effective, economic and sustainable processes for cumene production from the catalytic alkylation of propylene and benzene in flow reactors. The flow reactors are the continuous stirred tank reactor (CSTR) and the plug flow reactor (PFR) where the alkylation reaction occurred. The reactors were designed by exploring the conservation principle of mass and energy over the reactors. The performance model of the reactors were simulated using MATLAB at the same initial feed and operating temperature of 481.1k and 483k with fractional conversion changes within the range of X_A  at an interval of 0.05. The comparative analysis of the flow reactors design was based on the target product yield (cumene yield) and the energy efficiency of the process. The cumene yield is dependent on the reactor volume while the energy efficiency of the process depends on the quantity of heat generated per unit volume of the reactor. At maximum fractional conversion of 0.95, the volume of the CSTR and the PFR design were 52.296m³ and 19.771m³ with a percentage difference of 22.6% while the quantity of heat generated per unit volume of the CSTR and PFR were 0.013j/sm³ and 0.035j/sm³ with a percentage difference of 22.9%.  The above comparative design analysis showed that in terms of cumene yield, the CSTR displayed a better performance characteristics as indicated by the reactor volume while in terms of energy efficiency, the PFR showed a better performance characteristics as indicated by the quantity of heat generated per unit volume of the reactor. This article has shown that both the CSTR and the PFR are suitable for cumene production and the choice of reactor depends on the designer’s primary need.

This research is driven by the need to ensure effective, economic and sustainable processes for cumene production from the catalytic alkylation of propylene and benzene in flow reactors. The flow reactors are the continuous stirred tank reactor (CSTR) and the plug flow reactor (PFR) where the alkylation reaction occurred. The reactors were designed by exploring the conservation principle of mass and energy over the reactors. The performance model of the reactors were simulated using MATLAB at the same initial feed and operating temperature of 481.1k and 483k with fractional conversion changes within the range of X_A  at an interval of 0.05. The comparative analysis of the flow reactors design was based on the target product yield (cumene yield) and the energy efficiency of the process. The cumene yield is dependent on the reactor volume while the energy efficiency of the process depends on the quantity of heat generated per unit volume of the reactor. At maximum fractional conversion of 0.95, the volume of the CSTR and the PFR design were 52.296m³ and 19.771m³ with a percentage difference of 22.6% while the quantity of heat generated per unit volume of the CSTR and PFR were 0.013j/sm³ and 0.035j/sm³ with a percentage difference of 22.9%.  The above comparative design analysis showed that in terms of cumene yield, the CSTR displayed better performance characteristics as indicated by the reactor volume while in terms of energy efficiency, the PFR showed better performance characteristics as indicated by the quantity of heat generated per unit volume of the reactor. This article has shown that both the CSTR and the PFR are suitable for cumene production and the choice of reactor depends on the designer’s primary need.