Catalytic hydrotreatment of fast pyrolysis liquids in batch and continuous set-ups using a bimetallic Ni–Cu catalyst with a high metal content

Abstract

In this paper, the effects of process conditions on catalyst performance and product properties are reported in both batch and continuous set-ups.

Mono-, bi-, and tri-metallic Ni-based catalysts for the catalytic hydrotreatment of pyrolysis liquids

“…Clearly, the carbonyl compounds, especially ketones and aldehydes (δ = 163 to 215 ppm), are readily converted, while carboxylic acids/esters are still present in the product oil in These results are in good agreement with our previous studies on hydrogenated oils using Ni-Cu at different temperatures [40]. The peak intensity of the resonances in the aromatic region, for a larger part arising from the aromatic units of the pyrolytic lignin fraction, decreased from 15.1 in the PL feed to 7.2% in the product oil.…”

“…The oxygen content in the product oils for the Ni-based catalysts is in a narrow range and between 13.2 and 15.5 wt%. As such, full hydrodeoxygenation at the conditions applied in this study is not taking place, in line with earlier studies using Ni-based catalysts [25,40]. For Ru/C, the oxygen content is the lowest and actually below 10 wt%.…”

“…Solid formation appears very low for all catalysts and is generally below 0.7 wt%. These values are lower than reported in our previous studies on the catalytic hydrotreatment of PLs using Ni-based catalysts (1.2-2.4 wt%) [25,40] at 350°C. These differences may be related to the slightly different experimental procedures used in both studies as well as differences in the properties on the PL feeds used (e.g., water content, coking tendency).…”

“…The intensities and positions of these reflections are somewhat different from the reference data and are associated with the formation of silicate-like structures. The formation of such species has been observed previously for related Ni-based catalysts prepared using a sol-gel technique [29,36,40]. Of interest is the shape of the NiO peaks, which are sharp at the top but considerably broadened at the base (Fig.…”

“…The LG peak is considerably lower in the product oils, indicating that LG is converted during the catalytic hydrotreatment [25,40]. For the product oils, the higher molecular weight tail is significantly reduced to lower values, which indicates that thermal polymerization in the initial stage of the reaction is limited, while hydrocracking at elevated temperatures leads to a reduction of the molecular weight.…”