Accelerating the Green Transition - Investigating the Feasibility of E-Fuel Production Connected to a CHP Plant

Sammanfattning: The overall purpose of this thesis is to investigate the feasibility of producing electrofuels from CO2 and H2 in connection to a CHP plant equipped with carbon capture technology. This is done by investigating the production of e-methane, e-methanol and e-kerosene from captured CO2 and H2 produced from electrolysis. Each of the processes is designed and analyzed in Aspen HYSYS. From this, the energy and product requirements for each process are obtained. With these results, a production model including the electrofuel and hydrogen production, integrated with the CHP plant Filbornaverket, were modelled in the software Energy Optima 3. Both a smaller system using only part of the captured CO2 and a system at full scale using all the captured CO2 are developed. Furthermore, the simulations were done for spot prices in SE4, for both 2021 and 2022. Average energy demands for the e-fuels were 28.8 kWh/kg for e-methane, 9.97 kWh/kg for e-methanol and 37.6 kWh/kg for e-kerosene. This includes the manufacturing process and hydrogen production. Production costs were lowest for the base case 2021, where e-methane, e-methanol and e-kerosene had production costs of 8.9, 2.2 and 16.4 SEK/kgfuel respectively. The highest production costs were for the full case 2022, where the costs were 31.8, 10.8 and 49.9 SEK/kgfuel, following the same order. For both 2021 and 2022, the production costs were higher for the full scale case than the base case. The main reason for this is that the CHP plant could not supply the processes with as much electricity, meaning the electricity costs for production quickly became high. The findings showed that integration of e-fuel production with a CHP plant could result in a lower production cost and energy demand. However, there are still many aspects of this project that needs to be further investigated to be able to say to which extent. The main factor affecting the production cost was electricity prices. And, the main factor affecting the energy demand was hydrogen production. Maximizing the amount of electricity contributed to the e-fuel production from the CHP plant as well as researching other hydrogen production techniques are therefore the largest reduction possibilities. From this, it can still be concluded that there is great potential in integrating e-fuel production with a CHP plant.