The main catalytic challenges in GTL (gas-to-liquids) processes

In the present review the main catalytic challenges for GTL processes are discussed. It is considered that GTL comprises three main catalytic areas, namely synthesis gas generation, Fischer–Tropsch synthesis and upgrade. Each one is analysed and the main characteristics of traditional and innovative catalysts are presented. For syngas generation, steam methane reforming, non-catalytic partial oxidation, two-step reforming, autothermal reforming and catalytic partial oxidation of methane are discussed. For Fischer–Tropsch, we highlight the role of nanocatalysis, hybrid zeolite-containing catalysts, diffusion limitations and selectivity to high molecular weight hydrocarbons. Also, new reactors technologies such as micro reactors are presented. Finally, special attention is paid to the main upgrade steps (Hydrocracking and Hydroisomerisation/Dewaxing), the new mechanisms of isomerisation being discussed for bifunctional zeolitic catalysts.