Exploring Iron‐based Multifunctional Catalysts for Fischer–Tropsch Synthesis: A Review

Abstract

The continuous increase in oil prices together with an increase in carbon dioxide concentration in the atmosphere has prompted an increased interest in the production of liquid fuels from non-petroleum sources to ensure the continuation of our worldwide demands while maximizing CO(2) utilization. In this sense, the Fischer-Tropsch (FT) technology provides a feasible option to render high value-added hydrocarbons. Alternative sources, such as biomass or coal, offer a real possibility to realize these purposes by making use of H(2)-deficient or CO(2)-rich syngas feeds. The management of such feeds ideally relies on the use of iron catalysts, which exhibit the unique ability to adjust the H(2)/CO molar ratio to an optimum value for hydrocarbon synthesis through the water-gas-shift reaction. Taking advantage of the emerging attention to hybrid FT-synthesis catalysts based on cobalt and their associated benefits, an overview of the current state of literature in the field of iron-based multifunctional catalysts is presented. Of particular interest is the use of zeolites in combination with a FT catalyst in a one-stage operation, herein named multifunctional, which offer key opportunities in the modification of desired product distributions and selectivity, to eventually overcome the quality limitations of the fuels prepared under intrinsic FT conditions. This review focuses on promising research activities addressing the conversion of syngas to liquid fuels mediated by iron-based multifunctional materials, highlights their preparation and properties, and discusses their implication and challenges in the area of carbon utilization through H(2)/CO(+CO(2)) mixtures.

Directly converting CO2 into a gasoline fuel

“…The direct CO 2 hydrogenation (CO 2 -FT) is often described as the combination of the reduction of CO 2 to CO via reverse water-gas shift (RWGS) reaction and subsequent hydrogenation of CO to hydrocarbons via Fischer–Tropsch synthesis (FTS)6. The indirect route is often performed by using different reactors with syngas (a mixture of CO and H 2 , derived from coal, natural gas and biomass) and/or methanol intermediate formation17. In contrast, the direct route is more economic and environmentally benign while this approach usually yields CO and light paraffins as major products owing to weak CO hydrogenation activity and over-hydrogenation of olefins18.…”

Pore size effects in high-temperature Fischer–Tropsch synthesis over supported iron catalysts

“…The selectivity of the supported iron catalysts can be further improved by promotion. The supports for iron catalysts are mostly limited to SiO 2 , Al 2 O 3 , TiO 2 , carbon materials, and mixed SiO 2 -Al 2 O 3 oxides including zeolites [4,18]. It is commonly accepted that support chemical composition may have a strong impact on FT catalytic performance [5,2].…”

“…Fischer-Tropsch (FT) synthesis is a key step in direct conversion of syngas (H 2 /CO) into light olefins, liquid fuels, waxes or chemicals [1][2][3][4]. The syngas for FT synthesis can be produced from natural gas, shale gas, coal, or biomass.…”

The performance of chemically and physically modified local kaolinite in methanol dehydration to dimethyl ether

“…Dimethyl ether (DME) is of interest in the production of clean fuel, as a chemical intermediate for the preparation of many important chemicals, such as dimethyl sulfate and high-value oxygenated compounds [1][2][3][4][5]. Its physical properties are similar to those of liquefied petroleum gas (LPG), so it is used as a replace or a blend-stock with LPG for home heating and cooking [6,7] and also considered as an alternative for diesel fuel.…”