(442a) Intensification Options for Different Hierarchical Process Levels Illustrated in the Conceptual Design of a Novel Cyclohexanol Production Process

A chemical production process can be decomposed into a multi-scale structure of four hierarchical levels [1,2]. The most detailed level is the molecular level, at which phenomena on the scale of individual molecules are investigated. At the next level, molecule populations that build up a thermodynamical phase (phase level) are considered. In the process, the thermodynamical phase(s) are embedded into apparatuses, or ? more abstract ? into individual process spaces. This is the process unit level. Usually, the process consists of several such process units. The interconnection between the individual process units and thus the overall process flowsheet can finally be analyzed at the superordinated plant level. Options for process intensification arise from all of these levels.

In this contribution, the conceptual design of a novel reactive distillation process for the production of cyclohexanol from cyclohexene via indirect hydration is presented and compared to state-of-the-art processes. It is exemplarily illustrated that a certain measure for process intensification ? here the use of a reactive entrainer as reaction partner ? has an impact on all levels of the process: on the molecular level (new reaction route, new catalyst), on the phase level (eliminate the problem of limited solubilities), on the process unit level (use of a different reactor type with structured internals) and on the plant level (integration of reaction and separation leads to a reduced number of process units and thus to a simplified process flow scheme).

The process development performed includes the experimental identification of thermodynamic and kinetic data, feasibility studies by means of reactive residue curve map analysis [3], rigorous process simulations [4] and experimental validation via mini plant experiments [5]. It is demonstrated that the new process scheme features a very promising performance, i.e. high conversion in combination with high selectivity (nearly 100% conversion of cyclohexene and more than 99 mole-% purity of cyclohexanol based on rigorous process simulations).

[1] H. Freund, K. Sundmacher, Chem. Eng. Process. 47 (2008) 2051. [2] H. Freund, K. Sundmacher, Process Intensification, In: Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH: Weinheim, (2010) accepted. [3] F. Steyer, H. Freund, K. Sundmacher, Ind. Eng. Chem. Res. 47 (2008) 9581. [4] A. Katariya, H. Freund, K. Sundmacher, Ind. Eng. Chem. Res. 48 (2009) 9534. [5] R. Kumar, A. Katariya, H. Freund, K. Sundmacher, Appl. Catal. A-Gen. (2010) submitted.