Effect of the hydrogen to feedstock ratio on the hydrotreating of the mixture of petroleum middle distillates and rapeseed oil

Abstract

The hydrotreating of vegetable oils and animal fats is a possible way to produce a high-quality renewable diesel fuel component. It can be produced by processing the bio-raw material in new units or by the co-pro-cessing of the renewable raw material together with the petroleum middle distillates in existing hydrotreating units. This work was focused on investigating the effect of the hydrogen to the feedstock ratio on the hydrotreating of a mixture of petroleum middle distillates and rapeseed oil in a weight ratio of 8:2 in a tubular fixed-bed reactor. The hydrotreating was performed using a sulfided Ni-Mo/Al2O3 catalyst, a temperature of 345 °C, a WHSV of 1.0 h-1, a pressure of 4.0 MPa and a hydrogen to the feedstock ratio in the range of 120-600 m3∙m-3. The hydrogen to feedstock ratio of 120 m3∙m-3 was not sufficient to desulfurise the feedstock to the level of 10 mg∙kg-1. On the contrary, increasing the hydrogen to feedstock ratio to above 240 m3∙m-3 had no significant effect on the yield and quality of the obtained products. Therefore, the ratio of 240 m3∙m-3 was considered as sufficient for the hydrotreating of the mixture of the petroleum middle distillates and rapeseed oil.

Detailed Characterization of Diesel Fractions from Co-Hydroprocessing Vegetable Oil and Petroleum Heavy Vacuum Gas Oil Blends

“…For most hydrocarbon classes, we can even provide far more details, for example, hydrocarbon class distribution by carbon number. As clamined by several studies, the n -paraffin content of the diesel fraction changed the most during the hydroprocessing of raw vegetable oil or its blends with petroleum streams. − To investigate this claim in more detail, Figure shows the distribution of normal paraffins by carbon number (nC15–nC18) for all diesel samples, presented in two panels, due to the very different concentration range. In general, n -heptadecane and n -octadecane, shown in Figure b, are produced at 10 times higher concentration than n -pentadecane and n -hexadecane (Figure a), especially in diesel samples obtained from canola oil/HVGO blends.…”

“…The co-hydroprocessing of different vegetable oils with petroleum feedstocks has been studied by a number of research groups. − Most of the published studies have focused on the hydroprocessing performance (such as conversions of hydrodesulfurization (HDS), hydrodenitrogenation (HDN), hydrodeoxygenation (HDO), catalyst deactivation and stability, etc.) rather than on a detailed analysis and characterization of the derived products from co-processing petroleum and biomass feedstocks.…”

Production of Energy and Hydrogen within Chemical Plants Using Small Nuclear Reactors

“…Řepkový olej obsahuje nejvíce olejové kyseliny (C18), palmový olej obsahuje 44 % palmitové kyseliny (C16) a 39 % olejové kyseliny (C18). Na přeměnu 1 kt palmového oleje na HVO je potřeba 210•10 3 Nm 3 , tedy cca 0,019 kt vodíku 12 . Odhadujeme, že na přeměnu 1 tuny řepkového oleje bude potřeba 0,02•10…”

Influence of Pressure on Product Composition and Hydrogen Consumption in Hydrotreating of Gas Oil and Rapeseed Oil Blends over a NiMo Catalyst

“…The reaction conditions were chosen so that the obtained liquid product met the requirements of EN 590 for the sulfur content in diesel fuels (less than 10 mg•kg −1 ). The hydrogen to feedstock ratio of 240 m 3 •m −3 was considered sufficient for the hydrotreating of the feedstock with a relatively low sulfur content (ca 2800 mg•kg −1 ) and 20 wt% of rapeseed oil [18].…”