Hydrogen produced from renewable energy sources is of great interest as an alternative to fossil fuels and as a means for power generation via fuel cells. The aqueous fraction of bio-oil can be effectively reformed to hydrogen-rich streams in the presence of active catalytic materials. In this paper, we present the experimental work carried out in a fixed bed reactor for the reforming of bio-oil. The performance of the reactor was studied at various conditions and compared to the values theoretically predicted by thermodynamic equilibrium. The effect of reaction temperature, steam-to-carbon ratio in the feed, and space velocity was investigated in the presence of a commercial nickel catalyst. Runs were conducted with acetic acid, acetone, and ethylene glycol, representative model compounds of bio-oil, and the aqueous phase of a real bio-oil derived from beech wood. The results of the selected model compounds show that all can be effectively reformed with hydrogen yields up to 90% at reaction temperatures higher than 600 °C and steam-to-carbon ratios higher than 3. The reforming of the aqueous fraction of bio-oil proved to be more difficult, with the hydrogen yield fluctuating at about 60%. The most serious problem encountered in these experiments is coking. The formation of carbonaceous deposits in the upper part of the catalyst zone limits the reforming time and necessitates frequent regeneration of the catalyst.

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This work presents a Computer-Aided Molecular Design (CAMD) method for the synthesis and selection of binary working fluid mixtures used in Organic Rankine Cycles (ORC). The method consists of two stages, initially seeking optimum mixture performance targets by designing molecules acting as the first component of the binaries. The identified targets are subsequently approached by designing the required matching molecules and selecting the optimum mixture concentration. A multiobjective formulation of the CAMD-optimization problem enables the identification of numerous mixture candidates, evaluated using an ORC process model in the course of molecular mixture design. A nonlinear sensitivity analysis method is employed to address model-related uncertainties in the mixture selection procedure. The proposed approach remains generic and independent of the considered mixture design application. Mixtures of high performance are identified simultaneously with their sensitivity characteristics regardless of the employed property prediction method.

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Hydrogen produced from renewable energy sources can present significant environmental benefits as a means for clean power generation via fuel cells. The aqueous fraction of bio-oil can be used as a source for hydrogen production, if reformed in the presence of active catalytic materials. Recently, we introduced the concept of the spouted bed reactor for this particular process. The aim of the current work is to further investigate the suitability of the novel reactor. The effect of temperature, H2O/C ratio, space velocity, and heat treatment of support was investigated in the presence of Ni/Olivine catalysts. Runs were conducted with ethylene glycol and acetic acid as representative model compounds of the aqueous phase of bio-oil. The organics converted fully toward gases with high selectivity in hydrogen, while the known problem of coking was notably avoided. Ethylene glycol reforming seems to proceed primarily via decomposition followed by reforming of secondary products. Hydrogen yield during acetic acid reforming is higher under equivalent conditions. Tests using the aqueous phase of bio-oil proved more complicated due to the serious thermal instability of the feed. A new injection-cooling system was developed in order to achieve efficient feeding of bio-oil.

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Hydrocracking of vegetable oils is a prominent technology for the production of biofuels. This work compares the product yields and quality of hydrocracking fresh and used cooking oil under nominal operating conditions. Cracking, heteroatom removal and saturation reaction mechanisms are evaluated for both feedstock types and for three typical hydrocracking temperatures. The assessment of both feedstocks indicates that they are both suitable for high diesel yields with smaller kerosene/jet and gasoline/naphtha yields. As temperature increases, diesel selectivity increases for both feedstock types. However, the used oil feedstock exhibits higher kerosene/jet and naphtha selectivity at low temperatures (350 °C) and lower at the highest hydrocracking temperature (390 °C).