CO2 to green fuel: photocatalytic process optimization study

Abstract

Over the years, the world has been battling global warming issues caused by excess carbon dioxide (CO2) in the atmosphere. There is a need to reduce, convert and utilize the emitted CO2 to the atmosphere. One of the efficient approaches is to convert CO2 to fuel through photocatalysis. The present work concentrates on process modeling and simulation of CO2 conversion to methanol using Cu/TiO2 photocatalyst. Design expert 11.1.2.0. Response Surface Methodology was implemented to study the effect of process parameters, including temperature, pressure, and feed flow rate. 3D surface plots were used to analyze the impact of parameters. P-value <0.0001 showed that the model is significant. The optimized conditions of 350°C temperature, the pressure of 100 kPa, and the H2O/CO2 molar ratio of 5 are obtained through response surface methodology and the desirability function. With the desirability of 1.000, the optimized conditions reported the predicted conversion and yield of 48.496% and 54.071%, respectively. The simulated conversion and yield obtained are 48.99% and 54.42%, respectively. The energy analysis found that the electricity, cooling water, and steam generation costs were 65,772.886 USD yr-1, 2,674.944 USD yr-1, and 18,43,556.2 USD yr-1 respectively. The agreement between the simulated and predicted value supports mathematical modeling to predict CO2 conversion and methanol yield.