Thermodynamic Analyses of Tri-reforming Reactions To Produce Syngas

Abstract

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 O 2 /CH 4 (0–1.0), H 2 O/CH 4 (0–3.0), and CO 2 /CH 4 (0–3.0) mole ratios on the product distribution. The results reveal that high temperature and low pressure are favorable to achieve high H 2 production and CO 2 conversion. In addition, excessive additions of H 2 O, O 2, and CO 2 bring about lower H 2 yield and CO 2 conversion, while low concentrations of H 2 O, O 2, and CO 2 result in more intense carbon formation. To attain the maximum H 2 yield and high CO 2 conversion coupled with a desired synthesis gas (H 2 /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 CH 4 /CO 2 /H 2 O/O 2 = 1:0.291:0.576:0.088.