Lignocellulosic biomass pyrolysis mechanism: A state-of-the-art review

This review will explore the influences of the active metal, support, promoter, preparation methods, calcination temperature, reducing environment, particle size and reactor choice on catalytic activity and carbon deposition for the dry reforming of methane Bimetallic (Ni−Pt, Ni−Rh, Ni−Ce, Ni−Mo, Ni−Co) and monometallic (Ni) catalysts are preferred for dry reforming compared to noble metals (Rh, Ru and Pt) due to their low-cost Investigation of support materials indicated that ceria−zirconia mixtures, ZrO2 with alkali metals (Mg2+, Ca2+, Y2+) addition, MgO, SBA-15, ZSM-5, CeO2, BaTiO3 and Ca08Sr02TiO3 showed improved catalytic activities and decreased carbon deposition The modifying effects of cerium (Ce), magnesium (Mg) and yttrium (Y) were significant for dry reforming of methane MgO, CeO2 and La2O3 promoters for metal catalysts supported on mesoporous materials had the highest catalyst stability among all the other promoters Preparation methods played an important role in the synthesis of smaller particle size and higher dispersion of active metals Calcination temperature and treatment duration imparted significant changes to the morphology of catalysts as evident by XRD, TPR and XPS Catalyst reduction in different environments (H2, He, H2/He, O2/He, H2−N2 and CH4/O2) indicated that probably the mixture of reducing agents will lead to enhanced catalytic activities Smaller particle size (

Dry reforming of methane: Influence of process parameters—A review

Steam reforming of methane is an extremely important process for the hydrogen and syngas production. Nickel-based catalysts have been extensively employed in the industrial process of steam reforming because of their high activity, low cost, and the plentiful supply of Nickel. Nickel-based catalysts have also shown high activity for CO2 reforming of methane, which has been considered as a good option, with consumption of a significant amount of carbon dioxide. However, a major challenge is that Ni catalysts have a high thermodynamic potential for coke formation during reforming reactions. For steam reforming, coke formation induces deactivation of the catalyst, especially if the carbon forms as carbon filaments. The filamentous carbon material has a high mechanical strength and can cause mechanical deformation of the catalyst. For CO2 reforming, coke formation over Ni catalyst is even more serious and leads to rapid deactivation of the catalyst. It is highly desired to design and synthesize a coke resistant Ni catalyst not only for reforming of methane, but also for reforming of other hydrocarbons (including biomass derived hydrocarbons). Herein we summarize the very recent progresses in the design, synthesis, and characterization of coke resistant Ni catalysts for steam and CO2 reforming of methane. The progresses in the use of promoters, in the effect of supporting materials and in the preparation methods have been discussed. The thermal stability, regeneration, and future development of coke resistant Ni catalysts for these processes are also briefly addressed.

Progresses in the Preparation of Coke Resistant Ni-based Catalyst for Steam and CO2 Reforming of Methane

Valorization of biomass waste to engineered activated biochar by microwave pyrolysis: Progress, challenges, and future directions

The CO2 (dry) reforming of methane (DRM) reaction is an environmentally benign process to convert two major greenhouse gases into synthesis gas for chemical and fuel production. A great challenge for this process involves developing catalysts with high carbon resistance abilities. Herein we synthesize, for the first time, a yolk–satellite–shell structured Ni–yolk@Ni@SiO2 nanocomposite for the DRM reaction by varying the shell thickness of Ni@SiO2 core shell nanoparticles. The formation of Ni–yolk@Ni@SiO2 is proved to be shell thickness dependent. Compared with Ni@SiO2, Ni–yolk@Ni@SiO2 with 11.2 nm silica shell thickness shows stable and near equilibrium conversion for CH4 and CO2 for 90 h at 800 °C with negligible carbon deposition. The dual effects of formation of small satellite Ni particles due to strong Ni–SiO2 interactions and yolk shell structures contribute to its high activity and stability. These findings shed light on the design of other metal yolk silica shell nanocomposites to be utilized in r...

Lijun Jin

Papers

Analysis of coal tar derived from pyrolysis at different atmospheres

Pyrolysis behavior of vitrinite and inertinite from Chinese Pingshuo coal by TG―MS and in a fixed bed reactor

In situ FT-IR spectroscopic studies on thermal decomposition of the weak covalent bonds of brown coal

Preparation of Ni/MgO catalyst for CO2 reforming of methane by dielectric-barrier discharge plasma

Integrated coal pyrolysis with CO2 reforming of methane over Ni/MgO catalyst for improving tar yield