Catalytic and kinetic evaluation of Fe/HZSM-5 catalyst for Fischer-Tropsch synthesis

Author(s)

da Silva, Lucas Alves ; Heczko, Vilma ; Schmal, Martin ; Camargo, Pedro Henrique Cury ; Alves, Rita Maria Brito ; Giudici, Reinaldo

• Document type: Journal article
• Source: CHEMICAL ENGINEERING JOURNAL; v. 505, p. 14-pg., 2025-01-08.

Abstract

Rising global energy and growing environmental concerns demand cleaner production methods for fuels and platform chemicals. The Fischer-Tropsch synthesis (FTS) is a promising alternative to fossil oil sources for producing valuable hydrocarbons directly from syngas (CO and H-2) such as light olefins and middle distillates. Due to their cost-effectiveness and bifunctional properties, Fe/HZSM-5 catalysts have gained recent interest for FTS. However, research on reaction conditions and CO consumption kinetics for this catalyst remains limited. This work addresses a comprehensive study encompassing catalyst characterization, catalytic activity evaluation, and kinetic modeling of Fe/HZSM-5 catalysts for FTS. Our data showed that Fe presented multiple reduction stages and changed the moderate acidity of the evaluated zeolites upon Fe impregnation. Fe2O3 particles were also found to be transformed into iron carbides species during the catalytic reaction according to the M & ouml;ssbauer spectroscopy. The catalysts were active and stable for FTS (X-CO > 50 %) with a major production of hydrocarbons in C-2-C-4 and C-5-C-8 ranges. Pressure, temperature, feed composition and space velocity significantly influenced the CO conversion. The kinetic model for the Fe/HZSM-5 catalyst was investigated by modeling and in situ DRIFTS, aligning with the carbide mechanism considering dissociative adsorption of CO and H-2, a two-site reaction pathway, and competitive adsorption between CO and CO2 on the metal sites. These findings provide important insights for optimizing catalyst design and reaction conditions to enhance the efficiency of syngas-based fuel production. (AU)

• FAPESP's process: 19/12856-3 - Multi-user equipament approved in grant 2014-50279-4: combustion equipment, Autochem II 2920-Micromeritics
• Grantee: Julio Romano Meneghini
• Support Opportunities: Multi-user Equipment Program
• FAPESP's process: 21/05329-7 - Characterization and evaluation in process of nano-structured and SACs catalysts of Ni and Fe type supported on zeolites for the Fischer-Tropsch synthesis process
• Grantee: Lucas Alves da Silva
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 22/07813-6 - Controlled synthesis of novel nano-catalysts and plasmonic catalysts for Fischer-Tropsch synthesis and hydrogen production via water splitting
• Grantee: Lucas Alves da Silva
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• FAPESP's process: 22/04751-0 - Contribution to the development of reactor technology for the conversion of CO2 into aviation fuel (Project 4AirCRAFT)
• Grantee: Reinaldo Giudici
• Support Opportunities: Regular Research Grants