Obtención de parámetros óptimos de un carbón activado cubano de cáscara de coco para almacenamiento de metano

The material studied is a Cuban AC (activated carbon) from coconut shell as starting material. The objective of present work is to investigate if the Cuban AC could produce any beneficial effects on methane storage. A factorial designs 3 plans was development, considering the variability of two parameters were related: temperature °C (X1) and time min. (X2) and its influence on output variables such as: yield, mechanical resistance, index of iodine, molasses and ashes. By means of the optimization of multiple response there were obtained for the system of equations the following optimized results: T= 800 °C and t = 85 min. and the output variables: yield = 59.4 %, iodine number = 1 057 mg/g, molasses = 22.4 %, mechanical stress = 96% and ashes = 5.6 % which represent very good experimental reproducibility. The ACoptimum obtained under these conditions was evaluated with N2 (77 K) reaching values of Vmicro (0.63 cm/g) and Wm (1.3 nm) calculated by DR. The methane adsorption of ACoptimun was carried out to ambient temperature (298 K) and 35 MPa. Experimental data showed characteristic of type1 isotherms. Toth model was employed to evaluate and describe the quantity of methane adsorbed in the ACoptimum. A good fit for Toth model was obtained, which are supported by (F-test) there is not a statistically significant difference (SD) at 95 % confidence level and lineal good fit R (99.4) between Ncalculated (mmol/g) vs Nexperimental (mmol/g). Toth model indicates besides the heterogeneity of the methanegranular activated carbon system. The AC optimum can be considered a good candidate to storage of methane INTRODUCCIÓN Natural gas (methane 85 to 90 %) is a promising one due to its abundance and little pollution, especially as vehicle fuel allowing such less exhaustion than reformulated gasoline or diesel. However, it is hard to commercialize, since the low volumetric density at room. Commonly there are three methods to settle this problem, namely liquefied natural gas (LNG), compressed natural gas (CNG) and adsorbed natural gas (ANG). Among them, ANG is the most feasible approach, for its relatively low pressure (3.5 MPa) but high energy density. Previous studies have proven that porous carbon possessing large surface area and special porosity features might be the commercially potential adsorbent. The thickness of the methane compressed to 3.4 MPa can increase in a factor of 4 (for effect of packing) Carlos Alberto Rey-Mafull, Orlando Ferreira Cruz-Junior*, Rubén Aja-Muñiz** Instituto de Ciencia y Tecnología de Materiales,mafull@imre.oc.uh.cu.*Instituto Nacional de Pesquisas da Amazônia, Manaus; Brasil.** Centro de Investigaciones para la Industria Minero Metalúrgica