For the production of liquid transportation fuels based on hydrogen and carbon dioxide multiple process routes are known. The Fischer-Tropsch process producing a synthetic crude oil is one promising option to produce a renewable fuel. The work investigates the production of Fischer-Tropsch fuels in a pulp mill with four different process configurations. Based on the educts hydrogen and carbon dioxide the required synthesis gas for the synthesis is generated via either the water gas shift reaction or CO2 electrolysis. After the reactor, the product is split into two liquid streams and one gaseous stream.
The major aspect of the work is the integration into a pulp mill. Surplus heat from the process can be used in the pulp mill and can in return increase the electricity output of the pulp mill. Another option for integration is the utilization of purge streams of the process for the combustion in the lime kiln replacing natural gas.
The process was simulated with a chemical engineering software to generate the mass and energy balance of the processes. The four process configurations are evaluated based on performance indicators like carbon efficiency, Power-to-Fuel efficiency and CO2 emissions. The process with the reverse water gas shift and closed-loop design showed the highest carbon (79.8 %) and Power-to-Fuel efficiency (37.7 %). The open-loop gas loop designs show the highest emission reduction potential.