Stochastic economic evaluation of different production pathways for renewable propylene glycol production via catalytic hydrogenolysis of glycerol

Hydrogenolysis of crude glycerol is perceived as an alternative route for the production of propylene glycol owing to the environmental challenges and declining petroleum sources. However, the source of hydrogen is still a concern for the implementation of this technology. In this study, we investigated the economic viability of three different renewable propylene glycol (RPG) production pathways. The goal of this study is to determine whether the method used to produce hydrogen affects how economically feasible and environmentally friendly it is to produce RPG from the catalytic hydrogenolysis of glycerol. Furthermore, we developed a mathematical model using a stochastic approach based on Monte Carlo simulation to estimate the minimum selling price of RPG. The model considers uncertainties and future price trends. The results showed that scenario 1, with a net present value (NPV) of 3.2m US$, is more economical compared to scenarios 2 and 3, which have lower NPV values of 0.2m US$ and −1.9m US$, respectively. The stochastic mean minimum selling price (MSP) of propylene glycol for all three scenarios is also similar to the deterministic values (2.9 US$ per kg for scenario 1, 6.3 US$ per kg for scenario 2 and 7.6 US$ per kg for scenario 3). In terms of the GHG emissions, the direct emissions for scenario 2 (0.23 Mtons CO2 eq. per y) are greater than those for scenarios 1 and 3, while scenario 1 has the highest amount of indirect CO2 emissions, almost twice that of scenario 3 and 9.35 times more than scenario 1. The growing body of knowledge on the production of renewable propylene glycol will be strengthened by this study.