Continuous production of glycerol by catalytic high pressure hydrogenolysis of sucrose

Several continuous reactor systems have been discussed for the catalytic high pressure hydrogenolysis of sucrose to glycerol. Theoretically and actually, continuous reactors lead to lower glycerol yields than in a batch process. Two continuous stirred tank reactors in cascade constitute a reasonable compromise. An economic evaluation of the sucrose route to glycerol in comparison with other synthetic glycerol processes based on allyl chloride and acrolein suggests that the sucrose process can be competitive if a sales potential is developed for the by-products propane-l,2-diol, ethylene glycol, and a mixture of higher polyhydric alcohols containing tetritol, pentitol, methyl fructoside, and hexitol

Scope and Mechanistic Analysis for Chemoselective Hydrogenolysis of Carbonyl Compounds Catalyzed by a Cationic Ruthenium Hydride Complex with a Tunable Phenol Ligand

A cationic ruthenium hydride complex, [(C6H6)(PCy3)(CO)RuH]+BF4– (1), with a phenol ligand was found to exhibit high catalytic activity for the hydrogenolysis of carbonyl compounds to yield the corresponding aliphatic products. The catalytic method showed exceptionally high chemoselectivity toward the carbonyl reduction over alkene hydrogenation. Kinetic and spectroscopic studies revealed a strong electronic influence of the phenol ligand on the catalyst activity. The Hammett plot of the hydrogenolysis of 4-methoxyacetophenone displayed two opposite linear slopes for the catalytic system 1/p-X-C6H4OH (ρ = −3.3 for X = OMe, t-Bu, Et, and Me; ρ = +1.5 for X = F, Cl, and CF3). A normal deuterium isotope effect was observed for the hydrogenolysis reaction catalyzed by 1/p-X-C6H4OH with an electron-releasing group (kH/kD = 1.7–2.5; X = OMe, Et), whereas an inverse isotope effect was measured for 1/p-X-C6H4OH with an electron-withdrawing group (kH/kD = 0.6–0.7; X = Cl, CF3). The empirical rate law was determined from the hydrogenolysis of 4-methoxyacetophenone: rate = kobsd[Ru][ketone][H2]−1 for the reaction catalyzed by 1/p-OMe-C6H4OH, and rate = kobsd[Ru][ketone][H2]0 for the reaction catalyzed by 1/p-CF3-C6H4OH. Catalytically relevant dinuclear ruthenium hydride and hydroxo complexes were synthesized, and their structures were established by X-ray crystallography. Two distinct mechanistic pathways are presented for the hydrogenolysis reaction on the basis of these kinetic and spectroscopic data

Effects of solvent on pyrolysis-assisted catalytic hydrogenolysis of softwood lignin for high-yield production of monomers and phenols, as studied using coniferyl alcohol as a major primary pyrolysis product

Pyrolysis-assisted catalytic hydrogenolysis over Pd/C in anisole (phenyl methyl ether) at relatively high temperatures (>300 °C) can convert softwood lignin into aromatic monomers in >60 mol% yield (based on lignin aromatic rings). In this process, lignin is pyrolytically degraded to soluble intermediates prior to catalytic conversion, therefore the pyrolysis stage plays an important role in determining the yield and monomer composition. In this study, pyrolysis-assisted hydrogenolysis of coniferyl alcohol, which is a major pyrolysis product, and milled wood lignin isolated from Japanese cedar was investigated in various solvents, including water, methanol, toluene, hexane, and anisole, to clarify the solvent effects. The effects of the solvent on undesired side reactions were also explored. The results show that anisole is the best solvent for aromatic monomer production, but hexane is the best solvent for phenol production via demethoxylation. These findings provide insights that will facilitate the development of efficient methods for monomer production from lignin

Catalytic Hydrogenolysis of Aryl Ether Substrates

From the Washington University Office of Undergraduate Research Digest (WUURD), Vol. 12, 05-01-2017. Published by the Office of Undergraduate Research. Joy Zalis Kiefer, Director of Undergraduate Research and Associate Dean in the College of Arts & Sciences; Lindsey Paunovich, Editor; Helen Human, Programs Manager and Assistant Dean in the College of Arts and Sciences Mentor: John Bleek

Structure-Activity Relationships in Nucleotide Oligomerization Domain-1 (Nod1)-Agonistic γ-Glutamyl-diaminopimelic Acid Derivatives

N-acyl-γ-glutamyl-diaminopimelic acid is a prototype ligand for Nod1. We report a detailed SAR of C12-γ-D-Glu-DAP. Analogues with glutaric or γ-aminobutyric acid replacing the glutamic acid show greatly attenuated Nod1-agonistic activity. Substitution of the meso-diaminopimelic (DAP) acid component with monoaminopimelic acid, L- or D-lysine, or cadaverine also results in reduced activity. The free amine on DAP is crucial. However, the N-acyl group on the D-glutamyl residue can be substituted with N-alkyl groups with full preservation of activity. The free carboxylates on the DAP and Glu components can also be esterified, resulting in more lipophilic, but active analogues. Transcriptomal profiling showed a dominant upregulation of IL-19, IL-20, IL-22, and IL-24, which may explain the pronounced Th2-polarizing activity of these compounds, and also implicate cell signaling mediated by TREM-1. These results may explain the hitherto unknown mechanism of synergy between Nod1- and TLR-agonists, and are likely to be useful in designing vaccine adjuvants

Techno-economic analysis of production of octane booster components derived from lignin

In this study, a comprehensive process for production of an environmentally friendly octane booster (acetophenone) from lignin is presented, along with a detailed techno-economic analysis. Recognizing that much of the prior research on octane boosters has been confined to experimental lab-level investigations, this study develops comprehensive process design to unravel the intricacies of large-scale acetophenone production. The acetophenone production process involves catalytic hydrogenolysis, which also yields phenol as a valuable side product. Based on the process flow diagram, mass and energy balances were developed, revealing significantly improved yields and purity of acetophenone compared to industry standards, reaching 0.74 kg acetophenone per kg of lignin and 99 wt%. In the techno-economic analysis, calculations involving fixed capital investment (FCI), operating costs, and working capital were conducted based on a feed of 100 kg/h of dry lignin. The results indicate FCI at 2.72 million USD, operating costs at 1.09 million USD per year, and working capital at 0.57 million USD. Assuming a 20-year operational lifespan, the payback period is estimated at 6.09 years, as depicted by the cumulative cash flow diagram. Moreover, techno-economic analysis demonstrates a net present value (NPV) of 3.24 million USD at a 10% discount rate, an internal rate of return (IRR) of 22.73%, and a return on investment (ROI) of 34.39%. These positive outcomes underscore the robust profitability of the proposed acetophenone production plant derived from lignin. Additionally, a sensitivity analysis on the IRR indicates that increasing the production capacity could further enhance profitability, reaffirming the feasibility of the plant’s operation. Crucially, this study highlights the potential for sustainable and economically viable production of acetophenone, offering an environmentally friendly alternative to toxic octane boosters and advancing the development of sustainable fuel additives. Graphical Abstract: [Figure not available: see fulltext.

Selective hydrogenolysis of benzyl ethers in the presence of benzylidene acetals with Raney nickel

3 pages.International audienceA simple method to remove selectively a benzyl group protecting a hydroxyl function in the presence of a benzylidene acetal by catalytic hydrogenolysis with Raney nickel is reported. This method was successfully applied to the synthesis of the C1–C14 fragment of dolabelides

リグニンの溶媒中での熱分解支援接触水素化分解による芳香族モノマー生産

京都大学新制・課程博士博士(エネルギー科学)甲第24712号エネ博第455号新制||エネ||85(附属図書館)京都大学大学院エネルギー科学研究科エネルギー社会・環境科学専攻(主査)教授 河本 晴雄, 教授 亀田 貴之, 教授 髙野 俊幸学位規則第4条第1項該当Doctor of Energy ScienceKyoto UniversityDFA