The aim of the present work is to study the effect of different activation methods for the production of a biomass-based activated carbon on the CO ${}_2$ and CH ${}_4$ adsorption. The influence of the activation method on the adsorption uptake was studied using three activated carbons obtained by different activation methods (H ${}_3$ PO ${}_4$ chemical activation and H ${}_2$ O and CO ${}_2$ physical activation) of olive stones. Methane and carbon dioxide pure gas adsorption experiments were carried out at two working temperatures (303.15 and 323.15 K). The influence of the activation method on the adsorption uptake was studied in terms of both textural properties and surface chemistry. For the three adsorbents, the CO ${}_2$ adsorption was more important than that of CH ${}_4$ . The chemically-activated carbon presented a higher specific surface area and micropore volume, which led to a higher adsorption capacity of both CO ${}_2$ and CH ${}_4$ . For methane adsorption, the presence of mesopores facilitated the diffusion of the gas molecules into the micropores. In the case of carbon dioxide adsorption, the presence of more oxygen groups on the water vapor-activated carbon enhanced its adsorption capacity.

Density and compressibility are primordial parameters for the optimization of diesel engine operation. With this objective, these properties were reported for waste cooking oil biodiesel and its blends (5% and 10% by volume) mixed with diesel. The density measurements were performed over expanded ranges of pressure (0.1 to 140 MPa) and temperature (293.15 to 353.15 K) compatible with engine applications. The isothermal compressibility was estimated within the same experimental range by density differentiation. The Fatty Acid Methyl Esters (FAMEs) profile of the biodiesel was determined using a Gas Chromatography–Mass Spectrometry (GC-MS) technique. The storage stability of the biodiesel was assessed in terms of the reproducibility of the measured properties. The transferability of this biodiesel fuel was discussed on the basis of the standards specifications that support their use in fuel engines. Additionally, this original set of data represents meaningful information to develop new approaches or to evaluate the predictive capability of models previously developed.