Hydrodeoxygenation of pyrolysis oil fractions: process understanding and quality assessment through co-processing in refinery units

Abstract

Hydrodeoxygenation (HDO) of pyrolysis oil fractions was studied to better understand the HDO of whole pyrolysis oil and to assess the possibility to use individual upgrading routes for these fractions. By mixing pyrolysis oil and water in a 2 : 1 weight ratio, two fractions were obtained: an oil fraction (OFWA) containing 32 wt% of the organics from the whole oil and an aqueous fraction water addition (AFWA) with the remaining organics. These fractions (and also the whole pyrolysis oil as the reference) were treated under HDO conditions at different temperatures (220, 270 and 310 C), a constant total pressure of 190 bar, and using 5 wt% Ru/C catalyst. An oil product phase was obtained from all the feedstocks; even from AFWA, 29 wt% oil yield was obtained. Quality parameters (such as coking tendency and H/C) for the resulting HDO oils differed considerably, with the quality of the oil from AFWA being the highest. These HDO oils were evaluated by co-processing with an excess of fossil feeds in catalytic cracking and hydrodesulfurisation (HDS) lab-scale units. All co-processing experiments were successfully conducted without operational problems. Despite the quality differences of the (pure) HDO oils, the product yields upon catalytic cracking of their blends with Long Residue were similar. During co-processing of HDO oils and straight run gas oil in a HDS unit, competition between HDS and HDO reactions was observed without permanent catalyst deactivation. The resulting molecular weight distribution of the co-processed HDO/fossil oil was similar to when hydrotreating only fossil oil and independent of the origin of the HDO oil.

Conceptual process design of an integrated bio-based acetic acid, glycolaldehyde, and acetol production in a pyrolysis oil-based biorefinery

“…The higher heating value indicates that the remaining oil has better energy quality, which makes it more suitable for catalytic conversion to conventional fuels. Furthermore, it has been shown that the remaining oil had the same performance as the original forest residue-derived pyrolysis oil in the hydrodeoxygenation and fluid catalytic cracking processes (de Miguel Mercader et al, 2011). Therefore, taking into account its higher LHV and performance, we assumed that the value of the remaining oil was the same as that of the pyrolysis oil feedstock.…”

Evaluation of hydrodeoxygenation reactivity of pyrolysis bio-oil with various Ni-based catalysts for improvement of fuel properties

“…The peak of the more energetic signal at 856-857 eV reveals either Ni 2+ ions or very small NiO particles on the walls of the mesopores. 28 These peaks indicated that NiO was partially present, even aer the reduction. This band indicated that the reduction is not completely accomplished or should be assigned to the phenomenon that the photoelectrons emerged from the core level of nickel are subsequently reabsorbed by other nickel atoms of the metallic particles.…”

A gasoline-grade biofuel formed from renewable polyhydroxybutyrate on solid phosphoric acid

“…For example, catalytic fast pyrolysis at high temperatures (400-650°C) is the first step to liquefy the biomass, and the liquid is further upgraded through multiple reactions including hydrotreatment and catalytic cracking. Different catalysts in multiple reactors under specific reaction conditions including high pressure hydrogen are needed in the reforming process, resulting in high costs of equipment and operation [2,[11][12][13]. Serious coking at high temperatures often results in quick deactivation of the catalysts [14][15][16].…”