Studio sperimentale e simulazione numerica del processo WGSR di conversione del CO in CO2 per l’arricchimento in H2 di syngas da gassificazione del carbone e reforming di combustibili fossili

The water gas shift reaction (WGSR) is an important chemical process for enhancing the conversion of syngas carbon monoxide content into hydrogen by means of steam in coal gasification power plants integrated with Carbon Capture and Storage (CCS) technologies. This paper concerns an experimental investigation and numerical simulation on carbon monoxide conversion and hydrogen generation from WGSR using a small scale experimental apparatus designed and built at the Department of Mechanical Engineering, University of Cagliari. The laboratory test rig is based on two packed-bed catalytic reactors in series to be operated at different temperatures. It is designed for testing WGSR processes using different catalysts at varying syngas temperatures (from 300 to 500°C for the high temperature reactor and from 180 to 250°C for the low temperature reactor) and initial syngas compositions (up to 100% of dry CO fraction).The system is instrumented for temperature, flow rate and gas composition measurements, and can operate both in a two-stage or single-stage mode. This paper investigates the performance of the WGSR affected by various and important parameters, such as catalyst type (Fe/Cr or Pt/Al for high temperature and Cu/Zn or Pt/Al for low temperature), operating mixture composition, residence time of reactants in the catalyst bed, reaction temperature and H2O/CO ratio. The experimental results are supported by numerical analyses based on equilibrium and kinetic models for WGSR simulations