The total volume of the gases was measured, and a gas sample was collected to analyse its composition by gas chromatography. The solid products were determined by weighing the reactors before and after the runs. The spent catalyst was recovered from the reactor, and its carbon content was determined to assess the coke yield. The distribution of the final products, including pyrolysis oil, gas, coke, and other solid products, was collected. In Figure 1 , the results were normalised to 100, and the variation between the total mass balance was 1.4%. It can be observed in Figure 1 that BASF’s catalysts resulted in pyrolysis oil yields between 75% and 83%, while the thermal pyrolysis process resulted in 89% pyrolysis oil. Although the thermal pyrolysis process achieved a higher yield of pyrolysis oil, its quality significantly differed from these catalytic tests due to a higher yield of heavy oil. The condensed phase from the pyrolysis was investigated using the simulated distillation method. Products with boiling points between C 5 and 216°C were categorised as naphtha, the products with boiling points between 216°C and 343°C were categorised as light cycle oil (LCO), and the rest of the products with boiling points above 343°C were categorised as heavy cycle oil (HCO). As seen in Figure 2 , all three BASF catalysts increased the content of the naphtha range products significantly, as high as 84%, while for the thermal process, the naphtha fraction is only 17% of the produced pyrolysis oil. As one of the objectives of this work was to produce a naphtha-rich liquid product to allow for easy transportation, it can be concluded that using the proprietary catalysts from BASF helped to achieve that objective. Proprietary BASF catalysts allowed further cracking of the heavy molecules to produce more naphtha and less heavy oil fractions than the conventional or thermal pyrolysis process. These catalysts can be fine-tuned to further maximise the naphtha fraction in the pyrolysis oil to achieve a product that can be seamlessly integrated into chemical facilities. This work summarises a comparison of thermal and catalytic pyrolysis processes. While the thermal pyrolysis process is relatively
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First, the recycled LDPE and polypropylene (PP) were mixed in a ratio of 65 and 35 wt%, respectively. In the first bed, the mixed plastic feedstock was introduced. Upon heating, the resultant gases were then directed through the second reactor, filled with either inert material (‘thermal’) or catalyst. The ratio of the introduced feedstock to catalyst was 1 to 1. The feedstock was introduced from ambient temperature into the hot reactor while simulating the following conditions: • Conventional pyrolysis: loaded with inert material (‘thermal’), both reactors heated to 600°C. • Catalytic pyrolysis: loaded with BASF’s proprietary catalysts (Catalyst 1 to Catalyst 3), both reactors heated to 500°C. The test without catalyst was performed at 600°C due to high wax formation at lower temperatures. The feedstock composed of LPDE and PP was ground and sieved to 0.4- 0.8mm and then was mixed for eight hours in a dry mixer. The total content of the condensed phase was measured by the gravimetric method. The composition of the pyrolysis oil was studied by simulated distillation. The non-condensed part was studied in the gas collection system. Figure 1 Mass balance after catalytic vs thermal pyrolysis experiments
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