Síntese de Fischer-Tropsch: um estudo sobre o hidroprocessamento, rotas convencionais e híbridas

Abstract

The transition towards a more sustainable energy matrix and the pursuit of energy security are driving the development of alternative routes for liquid fuel production. In this context, Fischer-Tropsch Synthesis (FTS) stands out as a versatile technology capable of converting synthesis gas (CO + H₂), derived from sources such as natural gas, biomass, or coal, into a wide range of hydrocarbons. However, the primary products of FTS, mainly linear paraffins and high-molecular-weight waxes, do not directly meet the specifications for commercial fuels, primarily due to their inadequate cold flow properties. This work presents a literature review on hydroprocessing as the indispensable technological step for the upgrading of these products. It covers the fundamental reactions of hydrocracking, which adjusts the molecular weight of waxes by converting them into diesel and kerosene fractions, and hydroisomerization, which modifies the molecular structure of linear paraffins into branched isomers, drastically improving their cold flow properties. The key to controlling these reactions is the bifunctional catalyst, whose synergy between a metallic function (usually Pt or Pd) and an acid function (typically shape-selective zeolites) determines the selectivity and yield of the final products. The review demonstrates that the integration of FTS with hydroprocessing results in premium-quality "drop-in" fuels, such as diesel with a very high cetane number and Sustainable Aviation Fuel (SAF), both of which are sulfur-free and burn cleaner than their fossil-based equivalents. Additionally, hydroprocessing is discussed as a flexible technological platform, also fundamental to other advanced biofuel routes, such as HEFA. It is concluded that mastering hydroprocessing is crucial to enabling the production of synthetic and advanced fuels, playing a central role in decarbonization, especially in the aviation sector.