Highly selective Fischer‐Tropsch synthesis for C₁₀‐C₂₀ diesel fuel under low pressure

Abstract

This work deals with the improvement of diesel (C10‐C20) production of Fischer‐Tropsch (FT) synthesis at low pressure over Co‐Re/Al2O3 since high catalytic activity and great potential in producing C10‐C20 hydrocarbons were observed under conventional conditions. To improve the catalytic performance, CO conversion and hydrocarbon selectivity were investigated against pressure, syngas H2/CO ratio, gas flow rate, and temperature. 93.7 % of CO conversion was achieved as well as 62.3 % diesel selectivity over Co‐Re/Al2O3 catalyst even after working for 15 days, which was far higher than the maximum value of the Anderson‐Schulz‐Flory (ASF) distribution and the results in literature reports. It is suggested that Re plays an important role in enhancing dissociation of hydrogen as well as the formation of CH, CH2, and CH3 species to convert CO.

Activation and deactivation scenarios in a plasma‐synthesized Co/C catalyst for Fischer‐Tropsch synthesis

“…[49] Other authors assert that selectivity for the diesel-rich C 10 -C 20 product spectrum on a Co catalyst only becomes independent of the H 2 :CO after the inlet syngas ratio reaches 2. [17] This means that at our H 2 :CO of 1.7, the product spectrum was strongly dependent on the gas feed composition, since increasing H 2 content may accelerate H 2 dissociation, which in turn generates the CH 3 species, and further impacts the chain termination process.…”

“…On the contrary, the FTS reaction occurs on the metallic species of Co‐based catalysts, and formation of Co oxides is a definite source of catalyst deactivation . Therefore, promoters such as Re may be added to Co‐based catalysts to enhance both H 2 dissociation and the formation of CH, CH 2 , and CH 3 species to convert CO to mainly the diesel fraction even at low pressure, since Re favours catalyst reducibility through H 2 spillover …”

“…[16] Therefore, promoters such as Re may be added to Co-based catalysts to enhance both H 2 dissociation and the formation of CH, CH 2 , and CH 3 species to convert CO to mainly the diesel fraction even at low pressure, since Re favours catalyst reducibility through H 2 spillover. [17] In this work, the nano-carbon catalyst support was generated in situ through plasma, and it is therefore advanced that such catalysts cannot undergo deactivation due to carbon deposition since the catalysts are themselves encapsulated in carbonaceous material. Nevertheless, it is important to note that four principal factors have been identified to influence the deposition of carbon on FTS catalysts, [6] and they include:…”

Experimental methods in chemical engineering: Temperature programmed reduction—TPR

“…The topic with the most category interconnections is applied science. Generally, engineers employ TPR to identify optimal reduction conditions for a catalyst, e.g., for Fisher-Tropsch, [13][14][15] hydrogenation, dehydrogenation, and hydrodeoxygenation, [16][17][18][19] reverse water gas shift reactions, [20] and reforming [21,22] catalysts. Rives et al [23] characterized anionic clays by reducing the different cations included in the matrix structure.…”

Experimental Methods in Chemical Engineering: Mass Spectrometry—MS

“…Another article combined a homemade H 2 temperature programmed reduction reactor with an MS to study Fischer‐Tropsch synthesis with a Co based catalyst on . () Three articles mention inductively coupled plasma with MS (ICP‐MS), one of which prepared mesoporous metal‐CeO 2 catalysts for the reverse water gas shift reaction,() while another article studied polyethylenimine capped copper nanoparticles to oxidatively degrade organic pollutants for water treatment. () Eight articles mention HPLC electrospray ionization‐mass spectrometry but combining gas chromatography with MS is by far the most common combination with 16 articles of the 30.…”