Upgrading of lignin-derived bio-oil in non-catalytic plasma reactor: Effects of operating parameters on 4-methylanisole conversion

Improving the Quality of Bio-oil Using the Interaction of Plastics and Biomass through Copyrolysis Coupled with Nonthermal Plasma Processing

Bio-oil produced from the pyrolysis of biomass is chemically complex, viscous, highly acidic, and highly oxygenated. Copyrolysis of biomass and plastics can enhance oil quality by raising the H/C ratio, leading to improved biofuel properties. In this work, copyrolysis of polystyrene and biomass was passed to a second-stage dielectric barrier discharge nonthermal plasma reactor with the aim to further improve the product bio-oil. Pyrolysis of the polystyrene and biomass produces volatiles that pass to the second stage to undergo cracking and autohydrogenation reactions under nonthermal plasma conditions. There was a synergistic interaction between biomass and polystyrene in terms of overall oil and gas yield and composition even in the absence of the nonthermal plasma. However, the introduction of the nonthermal plasma produced a marked increase in monocyclic aromatic hydrocarbons (e.g., ethylbenzene), whereas polycyclic aromatic compounds decreased in concentration. Most notably, the influence of the plasma markedly reduced the quantity of oxygenated compounds in the product oil. It is suggested that the unique reactive environment produced by the plasma involving high-energy electrons, excited radicals, ions, and intermediates increases the interaction of the polystyrene and biomass pyrolysis volatiles. Increasing input plasma power from 50 to 70 W further enhanced the effects of the nonthermal plasma.

Thermochemical Conversion of Lignocellulosic Biomass into Mass-Producible Fuels: Emerging Technology Progress and Environmental Sustainability Evaluation

Lignocellulosic biomass is increasingly recognized as a carbon-neutral resource rather than an organic solid waste nowadays. It can be used for the production of various value-added chemicals and biofuels like bio-oil. However, the undesirable properties of bio-oil such as chemical instability, low heating value, high corrosivity, and high viscosity are greatly restricting the utilization of bio-oil as a drop-in fuel. As a consequence, bio-oil should be upgraded. Recently, several emerging methods, such as electrocatalytic hydrogenation, atmospheric distillation, and plasma-assisted catalysis, have been developed for improving the bio-oil quality under mild conditions. Here, we overview the new knowledge on the molecular structure of lignocellulosic biomass gained over the past years and discuss the future challenges and opportunities for further advances of the bio-oil production and upgrading from lignocellulosic biomass. The development of sustainable biomass resource recycle systems with improved efficiency and minimized environmental impacts is analyzed in details. Also, their environmental impacts and sustainability are evaluated. Lastly, the remaining knowledge gaps are identified, and the future research needs that may lead to massive production of biofuels from lignocellulosic biomass are highlighted.

Catalytic hydrodeoxygenation of anisole over nickel supported on plasma treated alumina–silica mixed oxides

Hydrodeoxygenation (HDO) of anisole, a representative of lignin-derived bio oil, was investigated on plasma treated SiO₂–Al₂O₃ supported Ni nanocatalyst at low hydrogen pressure.

Upgrading of anisole using in situ generated hydrogen in pin to plate pulsed corona discharge

In this paper, corona discharge plasma was used for upgrading of anisole as a model compound of lignin derived bio-oil. The required H₂ was generated in situ via methyl decomposition to H₂.