Multiobjective Bayesian Optimization Framework for the Synthesis of Methanol from Syngas Using Interpretable Gaussian Process Models

Abstract

Methanol production has gained considerable interest on the laboratory and industrial scale as it is a renewable fuel and an excellent hydrogen energy storehouse. The formation of synthesis gas (CO/H 2 ) and the conversion of synthesis gas to methanol are the two basic catalytic processes used in methanol production. Machine learning (ML) approaches have recently emerged as powerful tools in reaction informatics. Inspired by these, we employ Gaussian process regression (GPR) to the model conversion of carbon monoxide (CO) and selectivity of the methanol product using data sets obtained from experimental investigations to capture uncertainty in prediction values. The results indicate that the proposed GPR model can accurately predict CO conversion and methanol selectivity as compared to other ML models. Further, the factors that influence the predictions are identified from the best GPR model employing "Shapley Additive exPlanations" (SHAP). After interpretation, the essential input features are found to be the inlet mole fraction of CO (Y(CO, in)) and the net inlet flow rate (Fin(nL/min)) for our best prediction GPR models, irrespective of our data sets. These interpretable models are employed for Bayesian optimization in a weighted multiobjective framework to obtain the optimal operating points, namely, maximization of both selectivity and conversion.

Bayesian optimization of radical polymerization reactions in a flow synthesis system

“…This process would correspond to a so-called multi-objective BO and has been previously applied to the design of various materials and been shown to be effective. [65][66][67][68][69] We propose that the aforementioned challenges could be addressed through empirical validation using multiobjective BO.…”

Bayesian optimization of radical polymerization reactions in a flow synthesis system

“…This process would correspond to a so-called multi-objective BO and has been previously applied to the design of various materials and been shown to be effective. [65][66][67][68][69] We propose that the aforementioned challenges could be addressed through empirical validation using multiobjective BO.…”

Balancing computational chemistry's potential with its environmental impact

“…Similarly, Iwama et al 92 utilized BO to optimize the conversion of CO 2 to CO via the reverse water–gas shift reaction. BO also helped to optimize the reaction conditions for biocatalytic C–C bond formation reactions, 93 synthesis of methanol from syngas, 94 and the CO 2 to methanol conversion using heterogeneous catalysis. 95 Several other studies show the reduction of the number of run experiments to achieve more optimal reaction conditions in also digital chemistry experiments, e.g.…”