Assembly and initial operation of a particle heated lab reactor for the decomposition of sulphuric acid

Kurzfassung

A kinetic study of the sulphur trioxide decomposition in the particle heated lab reactor for the research projects PEGASUS and BaSiS is carried out. The reactor is developed for the use of hot ceramic particles to evaporate sulphuric acid and dissociation into sulphur trioxide and water and further decompose sulphur trioxide into sulphur dioxide and oxygen in the framework of a sulphur based thermochemical energy storage cycle (TCES) for CSP plants. The kinetic study is separated into two parts. In the first part, a literature research is conducted on available kinetic models which describe the sulphur trioxide decomposition and they are evaluated. The kinetic models showed to be strongly limited regarding their application range and several influencing factors such as active catalyst surface area, catalyst loading, operating pressure and equilibrium effects are not considered by the kinetic models. In the second part the kinetic models are implemented in a discretized model of the sulphur trioxide decomposition section of the particle heated lab reactor. The simulation results are used to evaluate the reactor design, to find favorable operating conditions for the upcoming experiments and to develop the evaluation method for the experiments. The influence of parameters like the gas temperatures at the catalyst inlet, the temperature difference between the particles and the gas, and the mass flow in the decomposer on the sulphur trioxide decomposition are varied and the conversions are calculated. With the simulation results initial test plans for the upcoming experiments with the PEGASUS reactor are developed. Furthermore, the evaluation method for the experiments is defined based on the model equations for the decomposer. The evaluation method is subsequently implemented in LabVIEW sub-VIs to prepare the interface of the evaluation method to the overall measurement and control software.