Exergoenvironmental analysis of hydrogen production through glycerol steam reforming

The increase in biodiesel production is leading to a scenario in which more glycerol, which is a by-product of this biofuel production, is generated each day. Among the many potential applications for this substance, steam reforming is emerging as an alternative for solving the glycerol utilization problem, while also providing a new and potentially green source of fuel. In this study, an exergoenvironmental analysis of this process for high-purity hydrogen production was carried out based on data obtained from an Aspen HYSYS (R) V11 process simulation. Three different scenarios regarding reform gas processing were evaluated from both technical and environmental points of view. Despite the high concentration of water and CO2 in the residual gas obtained after H-2 purification, recycling this flow was found to maximize glycerol reforming capacity, while also increasing the system's overall exergy efficiency. For all of the scenarios evaluated through exergy analysis, the environmental impact associated to hydrogen production through glycerol steam reforming was found to be lower than the values reported for methane, indicating that this by-product may be a suitable feedstock for decreasing the environmental impact caused by the use of fossil fuels for hydrogen production. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

The study found that by recycling the residual gas with high concentration of water and CO2, the glycerol reforming capacity can be maximized while increasing the system's overall exergy efficiency. This process was evaluated in three different scenarios regarding reform gas processing from technical and environmental perspectives.