Partial oxidation of methane to syngas over Pt/Rh/MgO catalyst supported on FeCralloy woven fibre

Abstract

Integrating a high-pressure syngas step with Fischer-Tropsch synthesis (FT) in a single vessel reduces investment and operating costs for Gas-toLiquids technology (GtL). Methane catalytic partial oxidation (CPOX) to produce syngas for FT is an economic opportunity for micro-refineries. Many metals and metal oxides selectively convert natural gas to CO and H 2 , but they also form coke, which must be removed intermittently, otherwise it deactivates the catalyst and can foul the reactor and process lines. Here, we prepared a 1 % mass fraction (0.01 g/g) Pt/Rh (Pt/Rh = 9) catalyst supported on MgO over FeCralloy woven fibre via solution combustion synthesis. At 900 • C, from 0.1-2 MPa, and with a 2:1 feed composition of CH 4 to O 2 , the reaction consumed all the oxygen and we obtained a H 2 /CO ratio of 2 (ideal for FT). At low pressure and a 0.1 s residence time the catalyst converted 90 % of the methane at 90 % CO selectivity. At 2 MPa, CO yield reached 50 % (< 80 % conversion and 57 % selectivity). Based on thermodynamic calculations, less than 5 % coke forms below 900 • C. At high pressure and short residence time (0.1 s), the coke yield (presumed to be coke crystallites) was 24 %. Increasing the residence time to 0.3 s reduced the amount of coke by 33 % because it is metastable.

Nanosized Composite Pt‐Ru Catalysts for Production of Modern Modified Fuels

“…Fig. 4 indicates that the reduced catalyst sample works stable with a high conversion of CH 4 and selectivity of the desired products, starting from 600 K. However, the unreduced catalyst starts work only at 923 K with 25.0 % conversion of CH 4 This demonstrates that the process runs with high selectivity in accordance with the reaction stoichiometry of SCO of CH 4 to synthesis gas, namely, CH 4 + 1 /2O 2 CO+2H 2 , at the optimum ratio of the initial reaction mixture CH 4 :O 2 = 2.0:1.0, T = 1173 K, GHSV = 9 10 5 h -1 , t = 0.004 s. The SCO of CH 4 to synthesis gas on 1.0 % Pt-, Ru-, and Pt-Ru supported on In this case, the high selectivity by H 2 (78.1-99.0 %) is maintained. The selectivity by CO is increased from 80.0 % to 99.0 % with reducing the contact time from 5.7 10 -3 to 3.4 10 -3 s, reaching 99.0 %, and then slowly declines to 63.39 % when t = 2.3 10 -3 s. When reducing the contact time from 5.7 10 -3 to 2.3 10 -3 s, the H 2 :CO ratio is increased from 2.12 to 2.46.…”

“…Information on the use of metal grids from the Pt, Pt/5 % Rh, Pt/10 % Rh, Pt/10 % Ir and Pd in the reaction of selective catalytic oxidation (SCO) of methane is available in literature. The studies were conducted at atmospheric pressure, 973-1373 K, and 0.21-0.33 10 -3 s contact time (t) 1) with an CH 4 +O 2 +Ar reaction mixture at varying of CH 4 :O 2 ratio. It was shown that 90 % selectivity (S) by CO was observed at 20 % conversion (X) of CH 4 .…”

“…The studies were conducted at atmospheric pressure, 973-1373 K, and 0.21-0.33 10 -3 s contact time (t) 1) with an CH 4 +O 2 +Ar reaction mixture at varying of CH 4 :O 2 ratio. It was shown that 90 % selectivity (S) by CO was observed at 20 % conversion (X) of CH 4 . Selectivity by H 2 was varied in the range of 30-50 %.…”

“…The catalysts containing 0.5 % Ru/SiO 2 , 0.5 % Ru/g-Al 2 O 3 , 0.5 % Ru/YSZ, 0.5 % Ru/TiO 2 , 0.5 % Ru/Y 2 O 3 , 0.5 % Pt/CeO 2 , and 0.5 % Pt/Al 2 O 3 were investigated in SCO of CH 4 to synthe-sis gas [6][7][8]. The experiments were performed at atmospheric pressure and 673-1023 K. The 0.5 % Ru/SiO 2 , 0.5% Ru/g-Al 2 O 3 , 0.5 % Ru/YSZ, and 0.5 % Ru/TiO 2 catalysts provide conversion of CH 4 to 65 % and 82 % selectivity by CO at 1023 K. At 873 K on 0.5 % Pt/CeO 2 and 0.5 % Pt/Al 2 O 3 catalysts the CH 4 conversion was 53 % and 39 % at selectivity by H 2 and CO of 72 % and 42 %, and 64 % and 57 %, respectively.…”

“…Oxidative conversion of CH 4 with lack of oxygen proceeds at short contact times (t = 10 -2 -10 -4 s) and high performance with formation of a mixture of CO and H 2 at the ratio, which is ideal for the production of CH 3 OH and hydrocarbons (Fischer-Tropsch) [9][10][11][12]. The aim of this work was to investigate the activity together with physicochemical properties and quantum chemical calculations of low-percentage Pt-Ru catalysts in the reaction of partial oxidation of methane into synthesis gas at short contact times.…”