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Figure 7 SimDist analysis of greenoil accumulated downstream
N 2 dilution followed by pressure regulation and controlled evaporation of the main reaction products through a dome pressure regulator. Greenoil could then be separated from lighter products in a liquid trap. Keeping a 50°C temperature at the pressure regulator and the liquid trap during this step was of vital importance, as at higher temperatures, increased greenoil formation and carry-over led to downstream plugging of pipes. At lower temperatures, lighter products were not quantitatively carried over into the gas phase. Samples of greenoil were collected and analysed via sim- ulated distillation (SimDist: see Figure 7 ). Results showed a boiling point range of 200°C up to >700°C, with a sig- nificant peak for C16 species. It should be noted that the greenoil was stored at 50°C for several days before the analysis, potentially allowing for further oligomerisation. It does not necessarily resemble the greenoil composition out of the catalyst bed. The reaction network behind greenoil formation is not yet fully understood and is still a topic of debate in the available literature. 1 Conclusions In this case study, the selective hydrogenation of tail-end acetylene derivatives and propadiene was successfully downscaled in a highly unsaturated hydrocarbon matrix, including 1,3-butadiene, in the laboratory environment. The set-up allows for the testing of commercial catalyst shapes under industrially relevant conditions. The high flex - ibility of the unit allows for screening in a broad parameter range for many types of commercial MAPD catalyst. An optimum operating window was found to maximise MAPD purification at low BD loss. All trend data and performance data were measured in parallel and automatically linked to corresponding online GC data and can be reported on request. This unit is one building block of olefin conversion capabilities in support - ing the needs of refineries in integrating petrochemical complexes. The experimental concept can be transferred to other
selective hydrogenation processes in the gas or liquid phase, like acetylene in a C2 matrix, with stoichiometric or excess levels of hydrogen. The influence of temperature, H 2/acetylenes ratio, liquid state upflow vs downflow, gas phase vs liquid phase operation, and CO poisoning has been tested and discussed. Acknowledgement We thank our colleagues at hte for their support in this study. Special thanks to Tobias Zimmermann for his significant contributions to the study within his occupational activities at hte. Literature 1 Mohundro E L, Overview on C 2 and C 3 Selective Hydrogenation in Ethylene Plants , AIChE 15th Ethylene Producers Conference, 2003. 2 Butadiene, IHS Markit Report, 2021. 3 Propylene, Technoeconomics – Energy and Chemicals, Nexant Market Report , 2018. 4 Iselborn S, B ASF selective and full hydrogenation technology Selop ® , Handbook of Petrochemicals Production Processes , Chap. 2.3, 2nd ed., 2019, edited by R A Meyers, New York, McGraw-Hill Education. 5 Lindlar H, Ein neuer Katalysator für selektive Hydrierungen, Helv Chim Acta 1952, 35, pp.446-450. 6 McCue A J, Anderson J A, Recent advances in selective acetylene hydrogenation using palladium containing catalysts, Front. Chem. Sci. Eng . 2015, 9(2), pp.142-153. Edgar Jordan is Application and Project Manager focused on light ole- fins conversion processes at hte GmbH, Heidelberg, Germany. He has more than five years of experience in high throughput and pilot-scale catalyst testing and holds a PhD in chemistry from the University of Münster, Germany. Charlotte Fritsch is Business Development Manager focused on catalyst testing and process development at hte GmbH, Heidelberg. She holds a PhD in chemistry from Karlsruhe Institute of Technology, Germany. Joachim Haertlé studied chemical and bioengineering at the University of Erlangen and has been working as a project coordinator at hte since 2018.
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