Thermodynamic Analyses of Tri-reforming Reactions To Produce Syngas

Thermodynamic analysis of tri-reforming reactions to produce synthesis gas has been conducted by total Gibbs energy minimization to understand the effects of process variables, such as temperature (200–1000 °C), pressure (1–20 atm), and inlet O2/CH4 (0–1.0), H2O/CH4 (0–3.0), and CO2/CH4 (0–3.0) mole ratios on the product distribution. The results reveal that high temperature and low pressure are favorable to achieve high H2 production and CO2 conversion. In addition, excessive additions of H2O, O2, and CO2 bring about lower H2 yield and CO2 conversion, while low concentrations of H2O, O2, and CO2 result in more intense carbon formation. To attain the maximum H2 yield and high CO2 conversion coupled with a desired synthesis gas (H2/CO) ratio for the downstream methanol production and effective elimination of carbon formation, the corresponding optimum feed ratio in tri-reforming process is identified to be CH4/CO2/H2O/O2 = 1:0.291:0.576:0.088.