A recently issued technical investigation commissioned by the members of the Catalytic Advances Program (CAP) details recent advancements in non-noble-metal catalysts for reforming and conversion of hydrocarbons.
See PPT Deck here (as PDF) | See Report TofC here (as PDF)
This TCGR report analyzes the important issues in hydrogen generation from methane, most notably, are thermodynamic limitations and endothermicity of the reaction, requiring operation at high temperature, as well as inherent to that cracking and subsequent catalyst deactivation. From the industrial perspective heat distribution in conventional reformers should be properly considered being influenced by the geometry of burner arrangements; the pitch of the tubes; the type and length of the flame; size, shape, and thickness of the tubes; type of materials and the catalysts.
One of the means to avoid overheating, besides introducing an active catalyst, is also shaping the catalyst in a way that allows rapid gas mixing, efficient heat transfer from the wall of the tube to the catalyst, and uniform temperature gradient throughout the tube.
Figure 1: Possible reaction mechanism for methane reforming over a) Ni/MgO-Al2O3 catalyst prepared by co-impregnation, b) over Ni/Mg-Al-O prepared via cation-anion double hydrolysis method. Notation: * denotes the adsorption state. Source: Guo et al., 2020
It is worth mentioning that there are peculiar features in carbon or coke formation during steam reforming of methane, making it different from coke in many other reactions related to hydrocarbon transformations. Carbon forms needles, growing as filaments with the active catalytic metal (nickel) at the top. This can lead to structural damages of the catalysts and should be avoided, as it leads to catalyst replacement. Among the critical scope items included in this CAP report are:
- Recent advances in hydrogen production via reforming from natural gas and naphtha as well as from some organic compounds are discussed based on papers published by researchers working predominantly in academia. Among the organic compounds the emphasis was primarily on glycerol, a by-product of biodiesel manufacturing.
- A special effort in this report is put on thermodynamics, product quality, catalysts selection, their stability and industrial applicability. Specifically, the catalyst synthesis and properties, and in situ characterization to elucidate the active sites and surface mobility of metals during reforming are addressed.
- In addition, the reaction mechanism can be revealed via isotopic labelling experiments and in situ studies. As coking and possible gasification of carbonaceous is very important for reforming reactions the mechanisms of both processes and types of coke are overviewed.
- Novel ideas about the process technology, such as the use of renewable energy sources for reforming, or novel energy sources including concentrated solar power, electrified reactors, photocatalysis, plasma, solid fuel cells and the combination of reforming with separation, e.g. chemical looping and the use of membrane reactors, are summarized.
TCGR’s report, Advances in Non-Noble-Metal Catalysts for Reforming and Conversion of Hydrocarbons, provides a comprehensive review of the production of syngas by mature and emerging catalytic processes by presenting and discussing the ongoing academic research on catalyst design, with a special focus on catalyst stability with Time on Stream (TOS). This work discusses both reforming of classical hydrocarbons derived from fossil resources, but also renewable feeds such as glycerol, (m)ethanol, bio-oils, and even plastic waste derived streams. Methane reforming is comprehensively covered by an examination of the different conversion processes (steam reforming, dry reforming, auto-thermoforming, and bi- or tri-reforming). Of note, catalytic systems for other potentially valuable hydrocarbon-based feedstocks such as naphtha or glycerol are also presented and discussed.
The PPT Deck, as well as a PDF containing the complete TofC, List of Figures and Tables, are available for download below:
See PPT Deck here (as PDF) | See Report TofC here (as PDF)
More information about this report and other services of CAP can be seen at
https://www.catalystgrp.com/tcg-resources/member-programs/catalytic-advances-program/. Call +1-215-628-4447 or e-mail John Murphy at jmurphy@catalystgrp.com, and we’ll be happy to discuss these and other interesting membership benefits.
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The Catalyst Group Resources (TCGR), a member of The Catalyst Group, is dedicated to monitoring and analyzing technical and commercial developments in catalysis as they apply to the global refining, petrochemical, fine/specialty chemical, pharmaceutical, polymer/elastomer and environmental industries.