The Chair of Renewable Energy Systems (TUM RES) is responsible for the system analysis of the synthesis routes of renewable fuels in the collaborative SynergyFuels project. As part of the system analysis, all individual processes (TCR, EXO, methanol synthesis + purification, isobutanol fermentation, formaldehyde production, ether synthesis, alcohol-to-olefins, and hydrotreatment with refining) were simulated in Aspen Plus. This includes biochemical and thermochemical syntheses and purifications.
If available, experimental data from the work packages were used as the basis for the simulation. Simulated processes based on experimental data are thermocatalytic reforming (TCR), isobutanol fermentation, and ether synthesis and purification for OMBE production. The remaining processes were created based on relevant literature.
| Process | Level of detail | Database |
| TCR | low | experimental |
| EXO | high | literature |
| Methanol synthesis + Distillation | high | literature (kinetic) |
| Isobutanol Fermentation | low | experimental |
| Formaldehyde | low | literature |
| Ether synthesis + Purification (OMBE) | low | experimental |
| Alcohol-to-Olefins | medium | literature (kinetic planed) |
| Hydrotreatment | high | literature |
| Refining | high | literature |
Another result is the development of so-called Fortran subroutines in Aspen. The function of the subroutines is identical to calculator blocks. However, the subroutines are much better suited to extensive calculations, as array and matrix calculations are possible, among other things. The programming structure is also more evident than in calculator blocks. The subroutines are programmed in Fortran77 and used to calculate kinetics, pressure, and heat losses, as well as for user-defined column design and material data calculation. The subroutine is compiled and stored in the simulation. It is then retrieved and calculated like a regular Aspen unit in the solution process to solve the simulation.