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A new acid catalyst based in a carbonaceous solid was functionalized using sulfuric acid as source of ASO 3 H acid groups. This carbon-based material prepared by the pyrolysis of waste tire rubber was used either as catalyst or as catalytic support. The pyrolysis process was performed with a flow of N 2 at relatively low temperature to obtain a mesoporous carbon and achieve an effective sulfonation. The sulfonation method of carbon obtained from tire rubber was through direct immersion into concentrated H 2 SO 4 under reflux. The mesoporous solids were characterized by several analytic techniques including an elemental analysis derived from scanning electronic microscopy (SEM). These ones indicated the presence of polycyclic disordered carbon plates in the carbonaceous structure with a low surface area and wide pores that provided many surface acid sites. The high catalytic activity and stability of this catalyst is related to the acid site density of Bronsted acid sites and to its homogeneous distribution. The hydrophobicity presented by this material favorably prevented hydration of hydrophilic AOH and ASO 3 H functional groups. The transesterification and esterification of waste oil under sub-critical methanol mainly in the presence of sulfonated char were achieved. Hence, it was required shorter times, low temperature and significantly, a low amount of methanol compared to other studies.

Renewable biodiesel with a high content of n-C17 alkanes was prepared through the catalytic hydrodeoxygenation of oleic acid under optimum conditions of temperature, reaction time and weight percentage of Ni deposited in γ-Al2O3. The hydrotreated vegetable oil (HVO) was blended with petrodiesel (20 % and 40 % of HVO) to evaluate its behaviour in a diesel engine. Comparative studies of power and emission of atmospheric pollutants such as NOx, CO, HC and smoke were evaluated under prepared blends and petrodiesel. The presence of HVO biodiesel at full load generated a slight decrease in power compared to petrodiesel; however, the decrease in emission of pollutants when using the blends containing HVO was significant. In the case of 40 % HVO were able to reduce more of 20 % of CO and HC emissions, and more than 40 % reduction in smoke when compared with petrodiesel. The NOx emissions of the blends with HVO had a significant slightly decrease. Further, the properties of Ni/γ-Al2O3 catalysts are justified by the results of EDS characterization, surface area (SBET), XRD, XPS, HR-TEM and it’s capacity to produce biodiesel.

Abstract:To contribute to the search for an oxygen-free biodiesel from vegetable oil, a process based in the oleic acid hydrodeoxygenation over Ni/γ-Al 2 O 3 catalysts was performed. In this work different wt % of Ni nanoparticles were prepared by wetness impregnation and tested as catalytic phases. Oleic acid was used as a model molecule for biodiesel production due to its high proportion in vegetable oils used in food and agro-industrial processes. A theoretical model to optimize yield of n-C 17 was developed using size, distribution, and wt % of Ni nanoparticles (NPs) as additional factors besides operational conditions such as temperature and reaction time. These mathematical models related to response surfaces plots predict a higher yield of n-C 17 when physical parameters of Ni NPs are suitable. It can be of particular interest that the model components have a high interaction with operation conditions for the n-C 17 yields, with the size, distribution, and wt % of Ni NPs being the most significant. A combination of these factors statistically pointed out those conditions that create a maximum yield of alkanes; these proved to be affordable for producing biodiesel from this catalytic environmental process.

Acetobacter aceti and Gluconobacter roseus, which are known to be responsible for the spoilage of wine, are used for current generation in batch-type microbial biofuel cells and it has been shown for the first time that these two microorganisms do not require mediators for the transfer of electrons to the anode. Three biofuel cells were constructed with two cells containing the pure cultures of each of the microorganisms as the biocatalyst (A-MFC, G-MFC) and the third cell was constructed with the mixed culture of these two microorganisms as the biocatalyst (AG-MFC). The performance of the biofuel cells was evaluated in terms of open circuit voltage (OCV), fuel consumption rate, internal resistance, power output, and coulombic efficiency. The mixed culture cell (AG-MFC) exhibits a better overall performance compared to the other cells.