Publishable summary: The objective of D5.1 is the development of models for the main processes at QSr’s facilities at Escombreras Industrial Area near Cartagena, in southeast Spain. The IS solution to be implemented at QSr´s will cover a new process for the production of potassium nitrate (KNO3) to replace the imported raw materials (hydrochloric acid – HCl and calcium carbonate – CaCO3), use CO2 from surrounding industries and reduce wastewater discharge and water consumption. Two main sections comprehend the IS to be implemented: the production of KNO3 and the recovery of HCl.
In the case of the KNO, the complexity of such process makes it nearly impossible or very difficult to simulate with off-the-shelf specialist process simulation software, as a higher degree of control over the system is required that the one normally offered through the interfaces of such software. Accordingly, a completely tailored simulation algorithm based on the resolution of the appropriate partial differential equations (PDEs) was developed using python and the FVM library FiPy. This required a comprehensive literature review on the topic as well as the mathematical development necessary to provide the required PDE system in a suitable form before the implementation of a finite volume method (FVM) in a dynamic loop that considers all process variables.
Graphic representation of the solutions is provided during the algorithm’s execution, as well as reporting on the errors, number of resin transfers, simulation status and others through python’s console. Furthermore, an alternative implementation including parallelization was written that is able to run up to 20 different simulations of the system at the same time, which is expected to greatly impact the quality of the RoM models expected later on in the project.
For the HCl recovery section, the approach taken has been with standard process simulation software and only at the time of the submission of this delivery for the denitrification section. The Escombreras group is about to finalize the complete definition of HCl process and the model of the whole section will be done. The main parameters that define the behavior of the denitrification system such as input volume of HCl and Nitrates concentration, residence time, temperature and number of cycles that the catalyst is used have been concluded from previous experimental tests. A batch continuous stirred tank reactor (CSTR) will be used to model denitrification reactor where conversion efficiency upcoming experimental results will be used to calculate product composition.
This deliverable is a first report of the final reduced order model (RoM) of the plant to be submitted under Deliverable 5.2. in a later stage of project.