I have a petroleum hydro-processing unit that requires a robust reactor model built from the ground up. My immediate priority is model creation rather than plant-wide optimisation, and the focus is strictly on the reactor section handling petroleum-based feedstock. Here is what I need: • A first-principles or data-driven reactor model that captures hydrogen consumption, sulfur/nitrogen removal and catalyst performance under typical HDS/Hydro-cracking conditions. • Calibration against operating data I will provide (feed assays, reactor temperatures, pressures and product qualities). • Well-documented equations or code (Python, MATLAB, gPROMS, Aspen Custom Modeler—whichever you prefer) plus a short validation report comparing predictions with plant data. If you are comfortable extending the work later toward process optimisation or adding kinetic or catalyst-deactivation sub-models, great—flexibility for future phases is a plus, though not required for this first milestone. Deliver the runnable model files and accompanying documentation; once results align with the plant data within an agreed error band, the task is complete.