Effect of Operating Conditions on the Performance of Rh/TiO2 Catalyst for the Reaction of LPG Steam Reforming

Aliki Kokka,Theodora Ramantani,Paraskevi Panagiotopoulou

doi:10.3390/catal11030374

Aliki Kokka, Theodora Ramantani + Show 1 more

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https://doi.org/10.3390/catal11030374

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Abstract

The catalytic performance of Rh/TiO2 catalyst was investigated for the reaction of Liquefied Petroleum Gas (LPG) steam reforming with respect to the operating conditions employed. The impacts of reaction temperature, steam/C ratio, Gas Hourly Space Velocity (GHSV), and time were examined and discussed both in the absence and presence of butane in the feed. It was found that the catalytic performance is improved by increasing the reaction temperature, steam content in the feed, and/or by decreasing GHSV. In the presence of butane in the feed, the effect of H2O/C ratio on catalytic performance is prominent, whereas the opposite was observed for the effect of GHSV. The propane conversion curve decreases by adding butane in the feed, indicating that the presence of butane retards propane steam reforming. The investigation of the dynamic response of Rh/TiO2 catalyst to variations of H2O/C ratio showed that neither catalytic activity nor product selectivity is varied with time following abrupt changes of the steam/C ratio between 2 and 7. The catalyst exhibited excellent stability with time-on-stream at 500 and 650 °C. However, a reversible catalyst deactivation seems to be operable when the reaction occurs at 600 °C, resulting in a progressive decrease of propane conversion, which, however, can be completely restored by increasing the temperature to 650 °C in He flow, respectively. The long-term stability of Rh/TiO2 catalyst in the form of pellets showed that this catalyst is not only active and selective but also stable, and therefore, it is a promising catalyst for the reaction of LPG steam reforming.

Highlights

During the last decades, hydrogen (H2 ) has attracted a lot of interest as a clean alternative energy source for the production of electricity via its electrochemical conversion in fuel cells, offering a viable alternative to fossil fuels [1,2,3,4,5,6,7,8]
The novelty of the present study lies in the development of an active, selective, and stable Rh/TiO2 catalyst of high durability in variations of operating condition and suitable for use in H2 production via Liquefied Petroleum Gas (LPG) steam reforming for fuel cell applications
In order to investigate the effect of Gas Hourly Space Velocity (GHSV) on the catalytic performance for propane steam reforming reaction, experiments were conducted by varying this parameter in the range of 16,800–78,200 h−1 over 0.5%Rh/TiO2 catalyst using a steam/C ratio equal to 3.25

Summary

Introduction

Hydrogen (H2 ) has attracted a lot of interest as a clean alternative energy source for the production of electricity via its electrochemical conversion in fuel cells, offering a viable alternative to fossil fuels [1,2,3,4,5,6,7,8]. LPG is of special interest and is considered a suitable route for power generation via the intermediate production of H2 , especially in remote areas, where the existing power grids address serious problems (e.g., lack of natural gas infrastructure, high cost of modifying the existing infrastructure) [2,3,16,17]. LPG typically consists of propane (C3 H8 ) and butane (C4 H10 ). States and Canada, LPG consists of at least 95% propane [18], whereas the composition of LPG in Australia varies between a 40:60 mixture of propane/butane to 100% of propane [19].

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