Abstract
The present review focuses on the production of renewable hydrogen through the catalytic steam reforming of bio-oil, the liquid product of the fast pyrolysis of biomass. Although in theory the process is capable of producing high yields of hydrogen, in practice, certain technological issues require radical improvements before its commercialization. Herein, we illustrate the fundamental knowledge behind the technology of the steam reforming of bio-oil and critically discuss the major factors influencing the reforming process such as the feedstock composition, the reactor design, the reaction temperature and pressure, the steam to carbon ratio and the hour space velocity. We also emphasize the latest research for the best suited reforming catalysts among the specific groups of noble metal, transition metal, bimetallic and perovskite type catalysts. The effect of the catalyst preparation method and the technological obstacle of catalytic deactivation due to coke deposition, metal sintering, metal oxidation and sulfur poisoning are addressed. Finally, various novel modified steam reforming techniques which are under development are discussed, such as the in-line two-stage pyrolysis and steam reforming, the sorption enhanced steam reforming (SESR) and the chemical looping steam reforming (CLSR). Moreover, we argue that while the majority of research studies examine hydrogen generation using different model compounds, much work must be done to optimally treat the raw or aqueous bio-oil mixtures for efficient practical use. Moreover, further research is also required on the reaction mechanisms and kinetics of the process, as these have not yet been fully understood.
Highlights
The decarbonization of our global energy market and the exploitation of renewable energy sources (RES) are widely considered as the most important policies which can bring our planet into a secure sustainable future [1,2,3]
Raw bio-oil cannot be completely vaporized and when heated leads to the formation of residual solids which accelerate catalyst poisoning at rates much higher than the usually examined model compounds
The choice of support has a crucial role on the properties of the catalytic system, as it affects the dispersion of the active phase over the surface of the carrier, the stability shown by the catalytic system through the degree of interaction achieved between metal and support
Summary
The decarbonization of our global energy market and the exploitation of renewable energy sources (RES) are widely considered as the most important policies which can bring our planet into a secure sustainable future [1,2,3] Renewable energy, such as solar, wind, tidal and geothermal, will inevitably play a decisive role in the decades, but clean and effective technologies are necessary for the supply of alternative transportation biofuels [4,5,6,7]. The present article reviews the recent trends and research outputs in the technology of hydrogen production through the catalytic steam reforming (SR) of bio-oil. The review discusses the most important steam reforming processing parameters such as the reactor feed composition, the reactor design and the reaction conditions and presents the recent research findings on the development of effective catalysts. The challenges outlined must be met with increased vigor as the efficient production of renewable hydrogen promises to help move away from the current, fossilbased model of energy production
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
