Co-feeding of vacuum gas oil and pinewood-derived hydrogenated pyrolysis oils in a fluid catalytic cracking pilot plant to generate olefins and gasoline

Abstract

Background: The Waste2Road project exploits new sustainable pathways to generate biogenic fuels from waste materials, deploying existing industrial scale processes. One such pathway is through pyrolysis of wood wastes. Methods: The hereby generated pyrolysis liquids were hydrogenated prior to co-feeding in a fluid catalytic cracking (FCC) pilot plant. So-called stabilized pyrolysis oil (SPO) underwent one mild hydrogenation step (max. 200 °C) whereas the stabilized and deoxygenated pyrolysis oil (SDPO) was produced in two steps, a mild one (maximum 250 °C) prior to a more severe process step (350 °C). These liquids were co-fed with vacuum gas oil (VGO) in an FCC pilot plant under varying riser temperatures (530 and 550 °C). The results of the produced hydrocarbon gases and gasoline were benchmarked to feeding pure VGO. Results: It was proven that co-feeding up to 10 wt% SPO and SDPO is feasible. However, further experiments are recommended for SPO due to operational instabilities originating from pipe clogging. SPO led to an increase in the hydrocarbon gas production from 45.0 to 46.3 wt% at 550 °C and no significant changes at 530 °C. SDPO led to a rise in gasoline yield at both riser temperatures. The highest amount of gasoline was produced when SDPO was co-fed at a 530 °C riser temperature, with values around 44.8 wt%. Co-feeding hydrogenated pyrolysis oils did not lead to a rise in sulfur content in the gasoline fractions. The highest values were around 18 ppm sulfur content. Instead, higher amounts of nitrogen were observed in the gasoline. Conclusions: SPO and SDPO proved to be valuable co-refining options which led to no significant decreases in product quality. Further experiments are encouraged to determine the maximum possible co-feeding rates. As a first step, 20-30 wt% for SPO are recommended, whereas for SDPO 100 wt% could be achievable.

Wood Derived Fast Pyrolysis Bio-liquids as Co-feed in a Fluid Catalytic Cracking Pilot Plant: Effect of Hydrotreatment on Process Performance and Gasoline Quality

“…Table 9 shows the measured parameters of the gasoline samples that are not mentioned in ASTM D4814-16e or DIN EN 228:2017-08. The values marked with an astereisk (*) were first published by Buchele et al 27 The amount of dissolved water in the gasoline sample is the lowest for the VGO gasoline (101 mg/kg) and the highest for the SPO gasoline (184 mg/kg). The nitrogen concentrations of the gasoline samples are 2.3 mg/kg for VGO gasoline, 6.4 mg/kg for PO gasoline, 7.5 mg/kg for SDPO gasoline, and 11.1 mg/kg.…”

“…The checkmark symbol means the parameter has to be measured but there is no value limitation. The values marked with an asterisk (*) were first published by Buchele et al 27 The values from Pb and the total of olefins are below the set maximum values. The content of oxygenated compounds such as alcohols and ethers of all samples lie below 0.1 wt %.…”

“… a Checkmark means the parameter has to be measured but there is no value limitation; the values marked with an asterisk (*) were first published by Büchele et al 27 . …”

“…These parameters however have no indication of maximum or minimum values. The values marked with an asterisk (*) were first published by Büchele et al 27 The detailed breakdown for naphthenes, olefins, and paraffins is available in the Supporting Information .…”

“…Table 9 shows the measured parameters of the gasoline samples that are not mentioned in ASTM D4814-16e or DIN EN 228:2017-08. The values marked with an astereisk (*) were first published by Büchele et al 27 …”