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Investigating the effect of minor components on chemical composition, thermal behavior, and morphology of biodiesel precipitate was the main objective of this study. Blends of distilled palm oil biodiesel (DPOB) spiked with the minor components were prepared and held at 20 °C for 16 h to promote the formation of precipitate. The precipitate was then isolated and analyzed using FTIR, DSC, and SEM/EDS. In contrast to monopalmitin, free steryl glucosides (FSG) were found to induce the formation of multicomponent precipitate. DSC measurements demonstrated the formation of a hydrated phase, called α-gel, when monopalmitin crystallized at high levels of moisture. The α-gel was found to have a lower crystallization temperature than the α form and to be more soluble. Precipitate possessing a flake-like morphology was observed as a result of monopalmitin crystallization whereas a layered structure resulting from extensive sticking of fibrillar aggregates was observed for the precipitate isolated from biodiesel spiked with FSG. Flakes resulting from monopalmitin crystallization were smaller as moisture content increased whereas follicle-like structures were observed for a mass ratio of moisture to FSG exceeding a critical value (>18), in addition to the fibrillar aggregates. Thus, interaction among biodiesel minor components was confirmed to result in precipitate of different sizes shapes, and properties.

[EN] An original way to perform the exsolution of Ni nanoparticles on a ceramic support was explored for the development of methane steam reforming catalyst in SOFC anode conditions. The n=2 Ruddlesden-Popper (RP) phase La1.5Sr1.5Mn1.5Ni0.5O7 +/-delta has been synthesized by the Pechini method and subsequently reduced with an H-2-N-2 mixture at different temperatures and reducing times to induce the formation of two phases: LaSrMnO4 (n=1 RP) decorated with metallic Ni nanoparticles. Preliminary measurements of catalytic behavior for the steam reforming have been carried out in a reduction-reaction process with a mixture of 82 mol %CH4, 18 mol %N-2 and low steam to carbon ratio (S/C=0.15). The catalyst exhibits a selectivity for CO production (0.97), 14.60 mol % CH4 conversion and around 24.19 mol % H-2 production. Such catalytic behavior was maintained for more than 4 h, with a constant rate of hydrogen production and CH4 conversion rate., The authors acknowledge the financial support of the Colombian Administrative Department of Science, Technology and Innovation COLCIENCIAS (Project #110265842833 "Symmetrical high temperature Fuel Cell operating with Colombian natural gas" (contract #038-2015) and S. Vecino-Mantilla's Ph.D. scholarship (call #647)) and of the Spanish National Research Council CSIC (Project #COOPA20112). The authors are also grateful to UIS' X-Ray Laboratory (Parque Tecnologico Guatiguara) for XRD measurements, UPV's Electronic Microscopy Laboratory for the FESEM analysis, and finally to Margarita Vecino-Mantilla, Carolina Cardenas-Velandia, Santiago Paez-Duque, Ivan Suarez-Acelas (UIS), Maria Fabuel (UPV) and Olivier Gardoll (UCCS) for their contribution to materials synthesis and characterization. As well as Santiago Palencia, Monica Sandoval (UIS) and Caroline Pirovano (UCCS) are warmly acknowledged for useful discussions.

The transformation of dl limonene (mixture of d- and l-form ~ 1:1) that came from the pyrolysis of scrap tires rubber was studied using four heteropolyacid catalysts (H3PW12O40, H3PMo12O40, H4SiW12O40 and H4PMo11VO40) supported on Q-10, SBA-15, MCM-41, and KIT-6. The catalyst activity was measured using a py/GC/FID under a nitrogen atmosphere. The active phase and support were characterized using various technical methods (XRD, Raman, TEM, N2 adsorption–desorption, NH3-TPD, and py-FTIR). The highest weak acidity and largest number of Lewis acid sites promoted the conversion of dl limonene. The isomerization reactions seemed to be more favored than disproportionation reactions. The p-cymene yield was favored, with a high weak acidity and high Lewis/Bronsted acid sites ratio. Moreover, the results show that the use of amorphous support with a higher pore size seems to promote the conversion of dl limonene and the production of p-cymene. HPA-based catalysts with Si are more favorable for converting dl limonene to p-cymene than those with P. For the HPA-based catalysts with P, the highest acidity favors the highest conversion, especially the Lewis acid sites. In this study, the isomerization reactions seem to be more favored than disproportionation reactions.

Bio-oil is produced by biomass pyrolysis. It contains hundreds of chemical compounds including alkanes, aromatic hydrocarbons, esters, ethers, ketones, aldehydes, acids, alcohols, and phenols. Phenols are compounds of increasing interest; they can be used as feedstock in many industrial applications such as the production of fuel additives, chemical synthesis, or as food antioxidants. Therefore, the valorization of phenols stemming from bio-oil can be an appropriated alternative to reduce the dependence on petro-based phenols in the chemical industry. The most important phenols in bio-oil from agricultural wastes are phenol, guaiacol, cresols, syringol, and xylenol. These compounds were separated by silica gel column chromatography technique, using 3 different solvents: a dichloro-methane—acetone mixture, ethyl acetate, and methanol. Column elution was followed by thin-layer chromatography (TLC). Phenolic fraction was obtained and not individual phenols. This fraction was analyzed using gas chromatography—fame ionization detector (GC—FID) and gas chromatography—gas chromatography—mass spectrometry (GC—MS) with a DB-1701 column, and it was quantified using the relative response factor. Dichloromethane—acetone mixture was the best eluent to obtain this phenolic fraction, specifically during the first three elution steps.

Reactivation and reuse of Spent Bleaching Earth (SBE) to improve Palm Oil Biodiesel (POB) filterability were examined in this study. The SBE was reactivated by washing with hexane, heating treatment at 500 °C and a combination of heating and acid treatment with 0.1 M HCl solution. The resulting adsorbents, denominated as extracted bleaching earth, calcinated bleaching earth (CBE) and regenerated bleaching earth (RBE), respectively, were characterized by several techniques. Virgin Bleaching Earth (VBE) was also characterized. As a result, solvent extraction of residual oil alone was found not to be an effective method for reactivation of SBE. In contrast, the other two methods tested resulted in an adsorbent capable of achieving the needed filterability. Reactivation was found to have a negligible effect on the crystal structure of the parent clay. It was also found not to alter the layered structure of the clay. SBET of CBE (98.94 m2/g) was smaller than that of VBE (160.11 m2/g), but the amount of N2 adsorbed was not significantly different to each other, evidencing that SBE recovered its initial adsorptive properties after being reactivated. Acid treatment led to a rise in SBET of RBE compared to CBE (121.70 m2/g), but it did not significantly increase its adsorption capacity. This was consistent with EDS analyses, where the content of Al+3, Mg+2, and Fe+3, the octahedral cations susceptible of being dissolved during acid treatment, was not statistically different between RBE and CBE.

Precipitate formation has become an issue of concern for biodiesel producers in the last few years. Precipitate induces a number of undesired consequences. Characterization of precipitate has revealed the preponderant presence of free steryl glucosides (FSG) and monoglycerides (MG). These minor components may interact with moisture, exacerbating precipitate formation. Therefore, the effect of FSG, MG, and moisture content on precipitate formation and filterability of palm oil biodiesel (POB) was investigated. Blends of distilled palm oil biodiesel spiked with the minor components were prepared following a three-factor, five-level center composite design and tested for the cold soak filtration time (CSFT) and the precipitate content. CSFT was found to be influenced only by FSG whereas the precipitate content was found to be influenced by FSG, MG, and moisture. Increasing FSG increased precipitation at low levels of moisture; in contrast, when MG increased, the precipitate content decreased. Interaction with moisture exacerbated precipitation. A model capable of explaining 80% of the CSFT variability and a model capable of explaining more than 96% of the precipitate content variability were obtained using multiple regression analysis.

Corrigendum to ‘‘Influence of minor components on precipitate formation and filterability of palm oil biodiesel’’ [Fuel 144 (2015) 130–136] Vladimir Plata , Carlos Ortiz , Paola Gauthier-Maradei , Viatcheslav Kafarov a Centro de Investigacion para el Desarrollo Sostenible en Industria y Energia, Universidad Industrial de Santander, Carrera 27 calle 9, Bucaramanga, Colombia b INTERFASE, Universidad Industrial de Santander, Carrera 27 calle 9, Bucaramanga, Colombia