Work package 2.5 - Studies on the reaction of isobutane to TBHP

Principal Investigator: Dr. H. Kryk (Helmholtz-Zentrum Dresden-Rossendorf)

Scientist: Dr. T. Willms (HZDR)

Main Scientific Goals:

The work package aims on the enhancement of yield and selectivity of radical partial oxidation processes exemplified by the partial oxidation of isobutane to tert-butyl hydroperoxide (TBHP). The goal shall be achieved by carrying out the reaction in a capillary micro reactor as a two-phase flow process in Taylor flow regime.

In particular, the application of new process windows (regarding temperatures, pressures, concentrations) as well as the influences of initiators and additives on reaction mechanism, yield and selectivity are in the focus of the studies.

Particular tasks:

• Literature study regarding reaction mechanism and kinetics for derivation of simplified mechanistic reaction models based on existing data
• Identification of levers to enhance selectivity and yield of the oxidation process
• Design, construction and setup of a modular capillary reactor
• Development and adaption of methods for chemical quantitative analysis of reaction mixtures (educts, products, intermediates, by-products)
• Thermal analysis for testing the stability of products mixtures against materials and by-products using DSC (differential scanning calorimetry) and TAM (thermal active monitoring)
• Non-reactive investigations on flow pattern in Taylor flow regime
• Testing and proof of methods to enhance selectivity and yield by reactive studies varying temperatures, pressures, concentrations, initiators and additives

Simplified reaction scheme

Fig. 1: Simplified Mechanism of the oxidation of isobutane to TBHP (decomposition of TBHP not considered)

Modular capillary reactor for partial oxidation processes in Taylor flow regime

Fig 2a: P&ID scheme of the capillary reactor	Fig. 2b: Photo of the capillary reactor

Analysis of the reaction mixtures by GC-MS (liquid phase) and GC-TCD (gas Phase)

     Fig. 3: Analysis of the reaction mixtures 

Publications:

• T. Willms: Partialoxidation von Isobutan. Neue Analysenmethode mittels GC, SHIMDAZU NEWS 03 (2014), 8 – 9.
• T. Willms, H. Kryk, M. Wiezorek, U. Hampel: Development of a micro reactor for the isobutane oxidation as a multiphase process, 4th European Conference on Microfluidics, 10.-12.12.2014, Limerick, Ireland (accepted as presentation).