Integrated reactor staging and plant optimization of a Biomass-To-Liquid technology

- Kinetics parameters of Fischer-Tropsch are determined with a nonlinear regression.
- The reaction is carried out by using an iron based supported catalyst.
- A satisfactory fitting of the experimental laboratory data is achieved.
- The kinetic model is implemented into an industrial-scale Fischer-Tropsch plant.
- Techno-economic analysis is carried out with different plant configurations.

In this work an industrial Biomass-To-Liquid (BTL) plant simulation and optimization are presented. Biomass is first gasified with oxygen and steam, and the produced syngas is fed to a multi-tubular fixed bed reactor for Fischer-Tropsch (FT) synthesis, obtaining a distribution of hydrocarbons with different molecular weight. A simplified model for the biomass gasification section is implemented in HYSYS® V8.4, while the Fischer-Tropsch reactor is simulated using MATLAB® R2013a. The kinetic parameters of the FT reaction have been determined by using a non-liner regression performed with the experimenta data obtained with a bench-scale FT-rig. The model developed for the Fischer-Tropsch reactor takes into account the catalytic pellet's effectiveness factor and the eventual formation of a liquid phase in each point along reactor's axial coordinate. The whole BTL plant is simulated connecting MATLAB and HYSYS. Moreover, the staging of the Fischer-Tropsch reactor is studied performing a techno-economic analysis of three different plant configurations and evaluating the corresponding pay-back time.