Sustainable hydrogen production from bio-oil model compounds (meta-xylene) and mixtures (1-butanol, meta-xylene and furfural).

In the present work m-xylene and an equimolecular mixture of m-xylene, 1-butanol and furfural, all of them bio-oil model compounds, were studied in steam reforming (SR) conditions. Three different nickel catalysts, which showed to be active in 1-butanol SR (Ni/Al2O3, Ni/CeO2-Al2O3 and Ni/La2O3-Al2O3), were tested and compared with thermodynamic equilibrium values. Tests were carried out at temperatures from 800 to 600°C at atmospheric pressure with a steam to carbon ratio (S/C) of 5.0. Despite the different bio-oils fed, the amount of moles going through the catalytic bed was kept constant in order to obtain comparable results. After their use, catalysts were characterized by different techniques and those values were correlated with the activity results. All catalysts were deactivated during the SR of the mixture, mainly by coking. The highest hydrogen yields were obtained with Ni/Al2O3 and Ni/CeO2-Al2O3 catalysts in the SR of m-xylene and SR of the mixture, respectively.

Production of furfural from pentosan-rich biomass: analysis of process parameters during simultaneous furfural stripping.

Among the furan-based compounds, furfural (FUR) shows interesting properties as building-block or industrial solvent. It is produced from pentosan-rich biomass via xylose cyclodehydration. The current FUR production makes use of homogeneous catalysts and excessive amounts of steam. The development of greener furfural production and separation techniques implies the use of heterogeneous catalysts and innovative separation processes. This work deals with the conversion of corncobs as xylose source to be dehydrated to furfural. The results reveal differences between the use of direct corncob hydrolysis and dehydration to furfural and the prehydrolysis and dehydration procedures. Moreover, this work focuses on an economical analysis of the main process parameters during N2-stripping and its economical comparison to the current steam-stripping process. The results show a considerable reduction of the annual utility costs due to use of recyclable nitrogen and the reduction of the furfural purification stages.

Catalytic reactive distillation process development for 1,1 diethoxy butane production from renewable sources.

Some acetals can be produced from renewable resources (bioalcohols) and seem to be good candidates for different applications such as oxygenated diesel additives. In the present case the production of 1,1 diethoxy butane from bioethanol and butanal is presented. Butanal can be obtained from biobutanol following a partial oxidation or a dehydrogenation process. In this paper innovative process development about the synthesis of the mentioned acetal including catalytic reactive distillation experimental and simulation results will be presented and discussed. Katapak SP modules containing Amberlyst 47 resin were used as structured catalytic packings. This reactive system allowed reaching higher conversions than the equilibrium ones at the same temperatures. All the experimental data gathered allowed to tune a simulation model for the reactive distillation operation which showed a fairly good behavior in order to perform initial 1,1 diethoxy butane production process design studies.

Furfural production from xylose using sulfonic ion-exchange resins (Amberlyst) and simultaneous stripping with nitrogen.

The aim of this work deals with the development of new approaches to the production of furfural from xylose. It combines relatively cheap heterogeneous catalysts (Amberlyst 70) with simultaneous furfural stripping using nitrogen under semi-batch conditions. Nitrogen, compared to steam, does not dilute the vapor phase stream when condensed. This system allowed stripping 65% of the furfural converted from xylose and almost 100% of selectivity in the condensate. Moreover, high initial xylose loadings led to the formation of two water-furfural phases, which could reduce further purification costs. Constant liquid-vapor equilibrium along stripping could be maintained for different xylose loadings. The modeling of the experimental data was carried out in order to obtain a liquid-vapor mass-transfer coefficient. This value could be used for future studies under steady-state continuous conditions in similar reaction-systems.