Search

Catalytic liquefaction of lignin is an attractive process to produce fuels and chemicals, but it forms a wide range of liquid products from monomers to oligomers. Oligomers represent an important fraction of the products and their analysis is complex. Therefore, rapid characterization methods are needed to screen liquefaction conditions based on the distribution in monomers and oligomers. For this purpose, UV spectroscopy is proposed as a fast and simple method to assess the composition of lignin‐derived liquids. UV absorption and fluorescence were studied on various model compounds and liquefaction products. Liquefaction of Soda lignin was conducted in an autoclave, in ethanol and with Pt/C catalyst (H2, 250 °C, 110 bar). Liquids were sampled at isothermal conditions every 30 min for 4 h. UV fluorescence spectroscopy is related to GC–MS, gel‐permeation chromatography (GPC), MALDI‐TOF MS, and NMR characterizations. A depolymerization index is proposed from UV spectroscopy to rapidly assess the relative distribution of monomers and oligomers. [ABSTRACT FROM AUTHOR]

The alcohol‐to‐jet (ATJ) process is a method for the conversion of alcohols to an alternative jet fuel blendstock based on catalytic steps historically utilized by the petroleum refining and petrochemical industry. This pathway provides a means for producing a sustainable alternative jet fuel (SAJF) from a wide variety of resources and offers a near‐term opportunity for alcohol producers to enter the SAJF market and for the aviation sector to meet growing SAJF demand. Herein, the technical background is reviewed and selected variations of ATJ processes evaluated. Simulation and modeling were employed to assess some ATJ conversion schemes, with a particular focus on comparisons between the use of an ethanol or isobutanol intermediate. Although the utilization of isobutanol offers a 34 % lower conversion cost for the catalytic upgrading process, the cost of alcohol production is estimated to contribute more than 80 % of the total cost at the refinery. The cost of feedstock and alcohol production has a dominant effect on the overall process economics. Ready for takeoff: The alcohol‐to‐jet process is a promising pathway for the production of alternative drop‐in jet fuels from sustainably produced alcohols. In this paper, the key engineering barriers are discussed and techno‐economic assessment is used to evaluate potential commercial implementations of this imminent alternative‐fuels process. [ABSTRACT FROM AUTHOR]

The aim of this research was to evaluate the potential for the stabilization of biomass-derived pyrolysis oils by using acid-catalyzed (Amberlyst 70) reactions with alcohol ( T=140-170 °C, P≈20 bar (1 bar=105 Pa)). The alcohol-stabilized oils were further upgraded by catalytic hydrotreatment ( T=400 °C, non-sulfided NiMo/Al2O3 catalyst) to give a biofuel. The concept was evaluated experimentally in terms of overall mass and energy balances and biofuel properties. The pyrolysis oil used in this study was obtained by fractional condensation of pyrolysis vapors and had a very low water content that favored the equilibrium conversion of the stabilization reactions. The energy efficiency was between 44 and 48 %. Preliminary results with acid-leached biomass showed that 43 % of levoglucosan in the pyrolysis oil was converted into methyl levulinate after the pyrolysis oil was purified. The proposed integrated concept of alcoholysis can be applied locally at the pyrolysis oil production site. [ABSTRACT FROM AUTHOR]

Ozonation on the phenols present in pyrolytic aqueous phases attained from biomass thermochemical conversion was evaluated. During ozonation, the dark color of original samples was found to decrease as a function of ozonation time. The oxidation kinetics of phenols was quantified by a method based on the color changes of samples. The oxidation profiles showed different behaviors and in some cases the phenols presented a positive correlation with the relative R color parameter, except eugenol, syringol, and vanillin which were markedly different. Finally, the color changes observed seem to be associated with the changes in the overall content of phenols and with the change in the molecular weight of the heavy fractions that include lignin oligomers. [ABSTRACT FROM AUTHOR]

The Front Cover shows the conversion of alcohols to an alternative jet fuel blendstock based on catalytic steps historically utilized by the petroleum refining and petrochemical industry. This pathway provides a means for producing a sustainable alternative jet fuel (SAJF) from a wide variety of resources, offering a near term opportunity for alcohol producers to enter the SAJF market and for the aviation sector to meet growing SAJF demand. In their Full Paper, S. Geleynse et al. review the technical background and evaluate selected variations of ATJ processes. Simulation and modeling is employed to assess some ATJ conversion schemes, with a particular focus on comparisons between the use of an ethanol or isobutanol intermediate. Key bottlenecks of ATJ production in the near term are discussed and recommendations are provided. More information can be found in the Full Paper by S. Geleynse et al. on page 3728 in Issue 21, 2018 (DOI: 10.1002/cssc.201801690). [ABSTRACT FROM AUTHOR]