Evaluation of a Catalyst Durability in Absence and Presence of Toluene Impurity: Case of the Material Co2Ni2Mg2Al2 Mixed Oxide Prepared by Hydrotalcite Route in Methane Dry Reforming to Produce Energy

Abstract

Ni, Co, Mg, and Al mixed-oxide solids, synthesized via the hydrotalcite route, were investigated in previous works toward the dry reforming of methane for hydrogen production. The oxide Co2Ni2Mg2Al2 calcined at 800 °C, Co2Ni2Mg2Al2800, showed the highest catalytic activity in the studied series, which was ascribable to an interaction between Ni and Co, which is optimal for this Co/Ni ratio. In the present study, Co2Ni2Mg2Al2800 was compared to a commercial catalyst widely used in the industry, Ni(50%)/Al2O3, and showed better activity despite its lower number of active sites, as well as lower amounts of carbon on its surface, i.e. less deactivation. In addition to this, Co2Ni2Mg2Al2800 showed stability for 20 h under stream during the dry reforming of methane. This good durability is attributed to a periodic cycle of carbon deposition and removal as well as to the strong interaction between Ni and Co, preventing the deactivation of the catalyst. The evaluation of the catalytic performances in the presence of toluene, which is an impurity that exists in biogas, is also a part of this work. In the presence of toluene, the catalytic activity of Co2Ni2Mg2Al2800 decreases, and higher carbon formation on the catalyst surface is detected. Toluene adsorption on catalytic sites, side reactions performed by toluene, and the competition between toluene and methane in the reaction with carbon dioxide are the main reasons for such results.

Cadmium as a Robust and Novel Promoter over Ni@γ-Al2O3 Catalysts in Dry Methane Reforming

“…To test the performance of catalysts, a number of parameters, namely CH 4 and CO 2 conversions, H 2 yield, H 2 /CO ratio, and carbon balance, listed in eqs –, were defined. − normalC normalo normaln normalv normale normalr normals normali normalo normaln : X normali = F normali normali normaln − F normali normalo normalu normalt F normali normali normaln × 100 , normali = normalC normalH 4 .25em normalo normalr .25em normalC normalO 2 normalH 2 .25em normaly normali normale normall normald : Y normalH 2 = F normalH 2 normalo normalu normalt 2 F normalC normalH 4 normali normaln × 100 normalH 2 normalC normalO = F …”

“…To test the performance of catalysts, a number of parameters, namely CH 4 and CO 2 conversions, H 2 yield, H 2 /CO ratio, and carbon balance, listed in eqs –, were defined. − where F i denotes component’s molar flow rates (mol/s), and superscripts in and out indicate the input and output conditions, respectively.…”

Hydrogen Production Performances via Steam Reforming over Hydrotalcite Derived Catalyst: A Sustainable Energy Production Review

“…Ali Awad et al, [48] and Gennequin C. et al, [49] took a successful attempt to increase the lifetime of HT derived catalysts that showed longer deactivation time due to carbon deposition. The development of a bimetallic catalyst was one of the effective solutions to this of type of process [50].…”

Sustainable Biomass Resources for Environmental, Agronomic, Biomaterials and Energy Applications 1

“…The fifth paper is entitled: "Methane catalytic reforming by carbon dioxide on Mg-Al oxides prepared by hydrotalcite route with different surfactants (CTAB, glucose, P123) or with intercalation of SBA-15 and impregnated by nickel" [5]. In this research work, four magnesium-aluminum mixed oxides were synthesized by the hydrotalcite route using four modifying agents (three surfactants: glucose, CTAB, and P123, as well as silica SBA-15), and then calcined at 550°C.…”