## 4 Conclusions  
In this research, the aim was to study the production of transportation fuels from Fischer-Tropsch waves by blending its diesel fraction with fossil diesel (7:93; 15:85; 30:70, and 50:50 wt.%) and by co-processing its heavy fraction with vacuum gas oil (T = 420 \({}^{\circ}\)C, WHSV = 0.5-1.0 h\({}^{-1}\), P = 10.0 MPa). The resulting products were characterised and compared to diesel fuels. In the case of blending experiments, a mixture of 23:77 wt.% of the diesel fraction of the Fischer-Tropsch waves led to a renewable transportation fuel that fulfilled the EN590 standards for commercial petroleum diesel. Higher blending values resulted in a significant deviation in critical parameters, such as density. In the case of hydrocarbons experiments, the most striking results consisted of a significant drop in density, sulphur, and nitrogen content due to a feed rate decrease from 60 g/h (WHSV = 1.0 h\({}^{-1}\)) to 30 g/h (WHSV = 0.5 h\({}^{-1}\)). The co-processing of a heavy fraction of the Fischer-Tropsch waves with vacuum gas oil in a ratio of 50:50 wt.% at WHSV 0.5 h\({}^{-1}\) produced a rich paraffin-based renewable diesel that also meets the essential EN590 standards for diesel fuels, critical in the case of sulphur content, nitrogen content, and CFPP. Thus, according to this work, it is possible to claim the suitability of Fischer-Tropsch waves for renewable transportation fuel production, either by the straight mixture of its diesel fraction with petroleum diesel fuels or hydrocarbons of the heavy fraction with vacuum gas oil in a commercial unit of hydrotreatment.  
Conceptualisation, J.F. and J.M.H.H.; methodology, J.F. and M.B.; validation, J.G., Z.G. and H.d.P.C.; formal analysis, J.F.; investigation, J.M.H.H., M.B. and H.d.P.C.; resources, [PERSON] and J.G.; data curation, J.M.H.H. and H.d.P.C.; writing--original draft preparation, J.G. and J.M.H.H.; writing--review and editing, Z.G. and H.d.P.C.; visualisation, M.B.; supervision, J.M.H.H.; project administration, J.F.; funding acquisition, J.F. and M.B. All authors have read and agreed to the published version of the manuscript.  
This publication is a result of the project CATAMARAN, Reg. No. CZ.02.1.01/0.0/0.0/16_013/0001801, which has been co-financed by European Union from the European Regional Development Fund through the Operational Programme Research, Development and Education. This project has also been financially supported by the Ministry of Industry and Trade of the Czech Republic which has been providing institutional support for long-term conceptual development of research organisation. The result was achieved using the infrastructure of the project Efficient Use of Energy Resources Using Catalytic Processes (LM2018119) which has been financially supported by MEYS within the targeted support of large infrastructures.  
Not applicable.  
The data presented in this study are available on request from the corresponding author. The data are not publicly available due to privacy.  
Authors [PERSON], [PERSON], [PERSON], [PERSON], [PERSON] was employed by the company ORLEN UniCRE a.s. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.