Coal fly ash‐derived mesoporous SBA‐15 as support material for production of liquid hydrocarbon through Fischer–Tropsch route

Abstract

The supernatant solution of silicate species extracted from coal fly ash (CFA) by NaOH fusion is used under acidic conditions with surfactant pluronic P‐123 to prepare the mesoporous silica (SBA‐15). Structural properties of prepared SBA‐15 are found close to those prepared by pure chemicals. Furthermore, the synthesized mesoporous silica (SBA‐15) from CFA is used as support in Fischer–Tropsch synthesis (FTS). The obtained mesoporous material has a surface area of 643 m2/g and a pore size of 8.24 nm. Co–Fe bimetallic catalyst containing 15 wt% of cobalt and 5 wt% of iron is prepared by incipient wetness impregnation of cobalt nitrate and iron nitrate salts over CFA‐derived SBA‐15. These mesoporous support and catalyst are characterized by X‐ray diffraction (XRD), N2 adsorption–desorption, H2‐temperature‐programmed reduction (TPR), NH3‐temperature‐programmed desorption (TPD), field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). FTS experiment is showing 65.53% of C5+ selectivity. The results indicate that the nanosubstrate material derived from CFA may be used as support for FTS activity with further improvements.

Comparative Studies of Co/SBA‐15 Catalysts Synthesized with Different Silica Sources Including Coal Fly Ash for Fischer‐Tropsch Synthesis

“…Generally, the preparation of SBA‐15 consists of (a) the formation of micelles in an aqueous solution, (b) the polymerization of an inorganic source, and (c) the removal of surfactants from the pores of the material [49–50] . The SBA‐15 is synthesized by the hydrothermal method in an acidic medium with molar composition: 1.73 TEOS : 0.016 P123 : 18.6 HCl : 133 H 2 O [46,51] . Pluronic triblock copolymer P‐123 [(EO) 20 (PO) 70 (EO) 20 ], a structure‐directing agent, is dissolved in deionized water in an acidic medium with slow addition of TEOS with continuous mechanical stirring.…”

“…[49][50] The SBA-15 is synthesized by the hydrothermal method in an acidic medium with molar composition: 1.73 TEOS : 0.016 P123 : 18.6 HCl : 133 H 2 O. [46,51]…”

A Review on Conversion of Biomass to Liquid Fuels and Methanol through Indirect Liquefaction Route

“…Several types of catalysts are used for the FT process; the most common are Group VIII transition metals i. e., Fe, Co, Ni, and Ru. Ru catalyst favours the hydrogenation of CO and produces long‐chain hydrocarbons [83–84] . Limited reserve and high cost hinder its industrial‐scale application.…”

“…Ru catalyst favours the hydrogenation of CO and produces long-chain hydrocarbons. [83][84] Limited reserve and high cost hinder its industrial-scale application. Nickel also has hydrogenation activity but only favours methane production, also at higher temperatures forms "surface carbonyl" which is volatile and causes the deactivation of the catalyst.…”

Renewable fuels from different carbonaceous feedstocks: a sustainable route through Fischer–Tropsch synthesis

“…Several researchers have reported that bimetallic catalysts have immense ability towards production of higher molecular weight hydrocarbons and paraffins during FT synthesis 99–101 . Duvenhage et al .…”