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We report herein on the conversion of saturated and unsaturated fatty acids to alkanes over Pt/C in high-temperature water. The reactions were done with no added H(2) . The saturated fatty acids (stearic, palmitic, and lauric acid) gave the corresponding decarboxylation products (n-alkanes) with greater than 90 % selectivity, and the formation rates were independent of the fatty acid carbon number. The unsaturated fatty acids (oleic and linoleic acid) exhibited low selectivities to the decarboxylation product. Rather, the main pathway was hydrogenation to from stearic acid, the corresponding saturated fatty acid. This compound then underwent decarboxylation to form heptadecane. On the basis of these results, it appears that this reaction system promotes in situ H(2) formation. This hydrothermal decarboxylation route represents a new path for using renewable resources to make molecules with value as liquid transportation fuels.

Separation of olefin/paraffin is an energy-intensive and difficult separation process in petrochemical industry. Energy-efficient adsorption process is considered as a promising alternative to the traditional cryogenic distillation for separating olefin/paraffin mixtures. In this work, we explored the feasibility of adsorptive separation of olefin/paraffin mixtures using a magnesium-based metal-organic framework, Mg-MOF-74. Adsorption equilibria and kinetics of ethane, ethylene, propane, and propylene on a Mg-MOF-74 adsorbent were determined at 278, 298, and 318 K and pressures up to 100 kPa. A dual-site Sips model was used to correlate the adsorption equilibrium data, and a micropore diffusion model was applied to extract the diffusivities from the adsorption kinetics data. A grand canonical Monte Carlo simulation was conducted to calculate the adsorption isotherms and to elucidate the adsorption mechanisms. The simulation results showed that all four adsorbate molecules are preferentially adsorbed on the open metal sites where each metal site binds one adsorbate molecule. Propylene and propane have a stronger affinity to the Mg-MOF-74 adsorbent than ethane and ethylene because of their significant dipole moments. Adsorption equilibrium selectivity, combined equilibrium and kinetic selectivity, and adsorbent selection parameter for pressure swing adsorption processes were estimated. The relatively high values of adsorption selectivity suggest that it is feasible to separate ethylene/ethane, propylene/propane, and propylene/ethylene pairs in a vacuum swing adsorption process using Mg-MOF-74 as an adsorbent.

We converted palmitic and oleic acids to fuel range hydrocarbons using two activated carbons in near- and supercritical water with no H2 added. The main products from palmitic acid were C8−C15 n-alkanes. The major products from oleic acid were C12−C17 n-alkanes and some C17 olefins. The pseudo-first-order rate constants displayed Arrhenius behavior. The apparent activation energy of 125 kJ/mol for palmitic acid decarboxylation is higher than that observed with a 5% Pt/C catalyst. Nevertheless, these results show that activated carbons possess catalytic activity for the hydrothermal decarboxylation of fatty acids.

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The kinetics of non-catalyzed decompositions of xylose and its decomposition product furfural in high temperature liquid water (HTLW) was studied for temperature from 180 to 220℃ and under pressure of 10MPa. The main products of xylose decomposition were furfural and formic acid, and furfural further degraded to formic acid under HTLW condition. With the assumption of first order kinetics equation, the evaluated activation energy of xylose and furfural decomposition was 123.27kJ•mol -1 and 58.84kJ•mol -1 , respectively.

Transition-metal-catalyzed transfer hydrogenation with an in situ hydrogen donor has received a great deal of attention from both academia and industry as an alternative to the traditional high-pressure-hydrogen process, owing to its better efficiency, atom economy, and sustainability features. Hydrogen stored in the chemical bonds of formic acid (FA), a promising hydrogen storage compound that could be derived from biomass or reduction of CO2, can be extracted selectively and used for diverse catalytic transformations. This Review summarizes and compares recent progress in catalytic transfer hydrogenation (CTH) via heterogeneous hydrogen transfer from FA. Transformations of biomass-derived platform chemicals (e.g., aromatic units, C5 and C6 sugars, furans, glycerol, fatty acids, levulinic acid (LA)), nitrogen-containing compounds (e.g., nitroarenes, quinolines), and organochlorinated compounds via transfer hydrogenation, hydrogenolysis, and hydrodechlorination (HDC) are outlined. Synthesis strategies of the heterogeneous metal catalysts (e.g., metal and support type, metal–support interaction, single-atom, alloy effect, and confinement effect) and optimization of the reaction conditions (e.g., temperature, solvents, additives, and FA dosages) for enhancing the catalytic activity and regulating the product distribution are presented. Structure–activity relationships based on both dehydrogenation and hydrogenation of metal catalysts as well as the mechanistic interpretation of CTH with FA are also highlighted. Finally, current challenges and outlook for the future development of the field are discussed.