Production of fuel fractions from renewable ethene-propene mixture over Ni/HZSM-5
Balshakou, Siarhei (2024)
Diplomityö
2024
School of Engineering Science, Kemiantekniikka
Kaikki oikeudet pidätetään.
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi-fe2024060443700
https://urn.fi/URN:NBN:fi-fe2024060443700
Tiivistelmä
In the power-to-X concept, clean, renewable energy can be used to produce liquid fuels that are hard to abate, such as diesel and jet fuels. One of the possible ways to synthesise them is the oligomerisation of light olefins that can be obtained from non-petroleum sources. An in-depth study of oligomerisation kinetics, reaction conditions, and catalytic systems is currently gaining more attention as it aligns well with the global trend for decarbonisation.
This master’s thesis aimed to study the co-oligomerisation of ethene and propene to clean synthetic liquid fuels in a fixed bed flow reactor with the aim of maximising jet-fuel fractions. The experimental part used acid mesoporous zeolite (HZSM-5) with a Si/Al ratio of 30 and different Ni content (0 wt.%, 0.42 wt.% and 0.63 wt.%) prepared by wet impregnation method. Before experiments, the catalysts were characterised by X-ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy. Olefin oligomerisation was performed employing a Micromeritics FR100 reactor operating at the following conditions: 180 – 300 °C, 10 – 40 bar, and weight hourly space velocity of 1 – 4 golef/(gcat·h). Both liquid and non-condensable outlet gases were analysed by GCxGC and GC/MS, respectively.
The results indicate that primarily branched hydrocarbons are formed, with C8–C12 being the predominant fraction, corresponding to gasoline. Typical conversions are around 10% for HZSM-5 without Ni and nearly 100% for those containing nickel. Both Ni-containing catalysts exhibit >85% selectivity to aromatics at 300 °C and 30 bar. Temperatures above 250 °C are necessary to ensure an acceptable yield. Space velocity also impacts yield, which increases as WHSV decreases from 4 to 1 golef/(gcat·h). It was also demonstrated that a pressure of 30 bar favours the formation of the C9+ fraction. However, when the pressure reaches 40 bar, the yield drops by 30%.
This master’s thesis aimed to study the co-oligomerisation of ethene and propene to clean synthetic liquid fuels in a fixed bed flow reactor with the aim of maximising jet-fuel fractions. The experimental part used acid mesoporous zeolite (HZSM-5) with a Si/Al ratio of 30 and different Ni content (0 wt.%, 0.42 wt.% and 0.63 wt.%) prepared by wet impregnation method. Before experiments, the catalysts were characterised by X-ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy. Olefin oligomerisation was performed employing a Micromeritics FR100 reactor operating at the following conditions: 180 – 300 °C, 10 – 40 bar, and weight hourly space velocity of 1 – 4 golef/(gcat·h). Both liquid and non-condensable outlet gases were analysed by GCxGC and GC/MS, respectively.
The results indicate that primarily branched hydrocarbons are formed, with C8–C12 being the predominant fraction, corresponding to gasoline. Typical conversions are around 10% for HZSM-5 without Ni and nearly 100% for those containing nickel. Both Ni-containing catalysts exhibit >85% selectivity to aromatics at 300 °C and 30 bar. Temperatures above 250 °C are necessary to ensure an acceptable yield. Space velocity also impacts yield, which increases as WHSV decreases from 4 to 1 golef/(gcat·h). It was also demonstrated that a pressure of 30 bar favours the formation of the C9+ fraction. However, when the pressure reaches 40 bar, the yield drops by 30%.