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The demand for high-performance bio-based materials towards achieving more sustainable manufacturing and circular economy models is growing significantly. Kraft lignin (KL) is an abundant and highly functional aromatic/phenolic biopolymer, being the main side product of the pulp and paper industry, as well as of the more recent 2nd generation biorefineries. In this study, KL was incorporated into a glassy epoxy system based on the diglycidyl ether of bisphenol A (DGEBA) and an amine curing agent (Jeffamine D-230), being utilized as partial replacement of the curing agent and the DGEBA prepolymer or as a reactive additive. A D-230 replacement by pristine (unmodified) KL of up to 14 wt.% was achieved while KL–epoxy composites with up to 30 wt.% KL exhibited similar thermo-mechanical properties and substantially enhanced antioxidant properties compared to the neat epoxy polymer. Additionally, the effect of the KL particle size was investigated. Ball-milled kraft lignin (BMKL, 10 μm) and nano-lignin (NLH, 220 nm) were, respectively, obtained after ball milling and ultrasonication and were studied as additives in the same epoxy system. Significantly improved dispersion and thermo-mechanical properties were obtained, mainly with nano-lignin, which exhibited fully transparent lignin–epoxy composites with higher tensile strength, storage modulus and glass transition temperature, even at 30 wt.% loadings. Lastly, KL lignin was glycidylized (GKL) and utilized as a bio-based epoxy prepolymer, achieving up to 38 wt.% replacement of fossil-based DGEBA. The GKL composites exhibited improved thermo-mechanical properties and transparency. All lignins were extensively characterized using NMR, TGA, GPC, and DLS techniques to correlate and justify the epoxy polymer characterization results. [ABSTRACT FROM AUTHOR]

Textile effluents pose a massive threat to the aquatic environment, so, sustainable approaches for environmentally friendly multifunctional remediation methods degradation are still a challenge. In this study, composites consisting of bismuth oxyhalide nanoparticles, specifically bismuth oxychloride (BiOCl) nanoplatelets, and lignin-based biochar were synthesized following a one-step hydrolysis synthesis. The simultaneous photocatalytic and adsorptive remediation efficiency of the Biochar–BiOCl composites were studied for the removal of a benchmark azo anionic dye, methyl orange dye (MO). The influence of various parameters (such as catalyst dosage, initial dye concentration, and pH) on the photo-assisted removal was carried out and optimized using the Box–Behnken Design of RSM. The physicochemical properties of the nanomaterials were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, thermogravimetric analysis, nitrogen sorption, and UV–Vis diffuse reflectance spectroscopy (DRS). The maximum dye removal was observed at a catalyst dosage of 1.39 g/L, an initial dye concentration of 41.8 mg/L, and a pH of 3.15. The experiment performed under optimized conditions resulted in 100% degradation of the MO after 60 min of light exposure. The incorporation of activated biochar had a positive impact on the photocatalytic performance of the BiOCl photocatalyst for removing the MO due to favorable changes in the surface morphology, optical absorption, and specific surface area and hence the dispersion of the photo-active nanoparticles leading to more photocatalytic active sites. This study is within the frames of the design and development of green-oriented nanomaterials of low cost for advanced (waste)water treatment applications. [ABSTRACT FROM AUTHOR]

This paper presents a techno-economic analysis (TEA) of six (6) scenarios of the kraft lignin catalytic (CFP) and thermal (TFP) fast pyrolysis towards the production of high value-added chemicals (HVACs) and electric energy, based on experimental data from our previous work. ASPEN PLUS was used to simulate the proposed plants/scenarios and retrofitted custom-based economic models that were developed in Microsoft EXCEL. The results showed that scenarios 1 and 2 in which the produced bio-oil is used as fuel for electricity production are the most cost-deficient. On the other hand, scenarios 3 and 6 that utilize the light bio-oil fraction to recover distinct HVACs, along with the use of heavier fractions for electricity production, have showed a significant investment viability, since profitability measures are high. Furthermore, scenarios 4 and 5 that refer to the recovery of mixtures (fractions) of HVACs, are considered an intermediate investment option due to the reduced cost of separation. All the proposed scenarios have a substantial total capital investment (TCI) which ranges from 135 MM€ (scenario 4) to 380 MM€ (scenario 6) with a Lang factor of 6.08, which shows that the CAPEX results are within reason. As far as the comparison of lignin CFP and TFP goes, it is shown that lignin CFP leads to the production of aromatic and phenolic monomers which have a substantial market value, while TFP can lead to important value-added chemicals with a lower OPEX than CFP. A target of return of investment (ROI) of 32% has been set for the selling prices of the HVACs. In summary, this study aims at listing and assessing a set of economic indicators for industrial size plants that use lignin CFP and TFP towards the production of high value-added chemicals and energy production and to provide simulation data for comparative analysis of three bio-oil separation methods, i.e. distillation, liquid-liquid extraction and moving bed chromatography. [Display omitted] • Lignin thermal and catalytic pyrolysis define the basis for the techno-economic screening. • Chromatography, extraction and distillation separation methods are assessed. • Options of co-production of value-added chemicals and electricity are investigated. • Investment on HVACs products leads to significantly reduced pay out times. • Increased CAPEX and OPEX for the moving bed chromatography separation method. [ABSTRACT FROM AUTHOR]

Bifunctional catalysts based on nickel supported on ZSM-5 and BETA zeolites were studied in the hydrodeoxygenation of lignin derived model compounds as well as in surrogate mixtures simulating the light fraction of lignin fast pyrolysis bio-oil. A screening of the hydrodeoxygenation reaction conditions (temperature, time, H 2 pressure, catalyst amount) was carried out using the simplest phenolic compound, phenol. As in real lignin bio-oils more complex phenolic compounds are present, a series of relevant alkyl- and methoxy-substituted phenol and benzene (o- and m-cresol, catechol, anisole, guaiacol, syringol, creosol and 1,2,3-trimethoxybenzene) were also investigated as feedstocks. Furthermore, the effect of the different porous and acidic properties of the zeolitic supports was investigated in the hydrodeoxygenation of guaiacol. The conversion of the model phenolics and the yield of the respective (alkyl)cyclohexanes at relatively mild conditions (220 °C, 50 bar H 2 , 1 h) were in the range of 80–100% and 47–83%, respectively, being dependent mainly on the complexity/side-chain group of the phenolic/benzylic ring and on the balanced content of Brønsted acid sites of increased strength. Regarding the hydrodeoxygenation of the surrogate mixture (C 7 -C 10 phenolics), 100% hydrodeoxygenation efficiency was achieved towards >60% yield of (alkyl)cyclohexanes (C 6 -C 9 hydrocarbons). All hydrodeoxygenation tests were conducted in hexadecane as solvent/substrate in order to simulate model co-processing (i.e. bio-based phenolics with petroleum derived feedstocks) conditions. Reusability tests revealed the stability of the catalysts which showed partial (30%) deactivation after the third catalytic cycle. [Display omitted] • Bifunctional nickel supported zeolites catalysts successfully catalyzed HDO of phenolics to cycloalkanes. • Hydrodeoxygenation is strongly influenced by the structural complexity of the phenolic compound. • Porous properties, number and strength of acid sites oz zeolitic can control the process. • Catalysts were active in the HDO of surrogate mixture simulating light fraction of lignin pyrolysis oil. • Catalyst can be reused up to (at least) three successive catalytic cycles. [ABSTRACT FROM AUTHOR]

[Display omitted] • Lignin valorization process superstructure optimized by mathematical modelling. • Performances of different biorefineries were assessed based on the type of technical lignin. • Phenol-formaldehyde resins revealed the highest costs and yields. • Vanillin production was a profitable option to valorize lignin. • Aromatic monomers can be an opportunity when their market price exceed 2.00€/kg. Lignin, the most abundant aromatic biopolymer on Earth, is often considered a biorefinery by-product, despite its potential to be valorized into high-added-value chemicals and fuels. In this work, an integrated superstructure-based optimization model was set up and optimized using mixed-integer non-linear programming for the conversion of technical lignin to three main biobased products: aromatic monomers, phenol–formaldehyde resins, and aromatic aldehydes/acids. Several alternative conversion pathways were simultaneously compared to assess the profitability of lignins-based processes by predicting the performance of technologies with different TRL. Upon employing key technologies such as hydrothermal liquefaction, dissolution in solvent, or high-temperature electrolysis, the technical lignins could have a market value of 200 €/t when the market price for aromatic monomers, resins, and vanillin is at least 2.0, 0.8, and 15.0 €/kg, respectively. When lower product selling prices were considered, the aromatic monomers and the resins were not profitable as target products. [ABSTRACT FROM AUTHOR]