Analysis of Fuel Fractions of Fisher-Tropsch Synthesis Based on Biomass Syngas

Ajaykumar Shashikant Patel

Master's thesis

Abstract:

The Fischer-Tropsch (FT) synthesis process is a well-known technique for producing liquid fuels from synthesis gas. Recently, biomass-derived syngas has been considered as a potential feedstock for the FT process to reduce greenhouse gas emissions and promote the use of renewable resources. However, the complexity of biomass-derived syngas can significantly affect the FT synthesis process, leading to changes in the product fractions and properties. In this study, we analyze the fuel fractions produced by the FT synthesis process using biomass-derived syngas. The biomass feedstock used in this study is solid biomass, which is a common and abundant resource. The syngas was produced by gasifying solid biomass with a mixture of air and steam. The resulting syngas composition was analyzed, and the CO/H2 ratio was adjusted to match the optimal conditions for the FT synthesis process. The FT synthesis was carried out in a fixed-bed reactor using a commercial cobalt-based catalyst. The fuel fractions produced by the FT synthesis process were analyzed using gas chromatography-mass spectrometry (GC-MS). The results showed that the main products of the FT synthesis process were linear and branched alkanes, as well as some oxygenated compounds. The yield of liquid hydrocarbons was around 70% of the total products, while the remaining products were mainly gaseous hydrocarbons and carbon dioxide. Further analysis of the liquid fuel fractions showed that the majority of the products were in the range of C5-C18 carbon chain lengths, with a peak at around C10-C12. The boiling point distribution of the liquid fuel fractions showed that the majority of the products had boiling points in the diesel range, with a smaller fraction in the gasoline range. The properties of the liquid fuel fractions, such as density, viscosity, and cetane number, were also analyzed and compared to conventional diesel fuel. This study highlights the potential of using renewable resources for the production of liquid fuels, which can contribute to reducing greenhouse gas emissions and promoting sustainability.

Keywords

Fischer-Tropsch synthesis, Boiling point distribution, Gasifying solid biomass, Syngas composition, Fuel Fraction, Gasoline range

Language used: English

Date on which the thesis was submitted / produced: 18. 4. 2023

Thesis defence

• Supervisor: doc. Ing. Petr Kačer, Ph.D.
• Reader: Tereza Kačerová, Ing., externi

Czech University of Life Sciences Prague

Faculty of Agrobiology, Food and Natural Resources

Master programme:
Sustainable Agriculture and Food Security