Experimental Modeling, Analysis, and Solution of Ethanol Coupling for C4 Olefin Production Based on Cubic Spline Interpolation Algorithm

This paper presents an analysis of ethanol coupling to prepare C4 olefins based on the cubic spline interpolation algorithm. Firstly, the cubic spline interpolation was utilized to fit and plot the trends of temperature, catalyst combination, ethanol conversion rate, and C4 olefin selectivity. Additionally, a polynomial fitting model was established to determine the functional relationships of ethanol conversion rate and C4 olefin selectivity with different catalysts and temperatures, thereby identifying their dependencies on temperature. Subsequently, interpolation fitting was conducted for the variables over time. As the reaction is reversible, a dynamic equilibrium was observed after 273 minutes, allowing for predictive function modeling. Discrepancy analysis between predicted values and experimental data revealed prediction errors of 4.19% and 2.11% for A8 and B7 ethanol conversion rates, and 0.03% and 4.48% for A2 and A3 C4 olefin selectivity, respectively. Combining these errors led to the inference of the catalyst in Appendix II as 200mg1wt%Co/SiO2-200mgHAP with an ethanol concentration of 0.9ml/min.