María del Carmen Martínez

Determination of relationships among autochthonous grapevine varieties (Vitis vinifera L.) in the Northwest of the Iberian Peninsula by using microsatellite markers

Fifty six grapevine varieties traditionally grown in the Northwest region of the Iberian Peninsula were analysed for six microsatellite loci, in order to determine the relationships among them as well as the plant material that should be collected and preserved in germplasm banks. Previous morphological and molecular results were taken into account for assessment of the existing synonymies among accessions from different European countries. Percent distribution of the main alleles was calculated. Multivariate analysis was carried out and similarities among the studied material were described and commented.

Coal liquefaction, deactivation of coal hydrogenation catalysts

Abstract A Spanish subbituminous coal was catalytically hydrogenated and catalyst deactivation was investigated. The catalyst hydrogenation activities were evaluated for conversion gas and liquid yields and for oil formation. Determination of pore size distribution, surface acidity, specific surface area and elemental analysis of fresh and aged catalyst were carried out. The results indicated that the HT-400E catalyst shows higher activity for hydrogenation and it undergoes higher deactivation than HT-500E. The surface acidity is reduced by 74.9% and the surface area by 97%. The activity for desulfuration and oil formation is higher for HT-500E.

Characterization of coal hydrogenation catalysts. Determination of acid strength distribution

Abstract A method for the evaluation of the acidic nature of the surfaces of solid catalysts used for coal hydrogenation and liquid coal hydrocracking has been developed, which involves dynamic chemisorption measurement using temperature-programmed gas chromatography. Three basic adsorbates, ammonia, pyridine and n -butylamine and two detectors, thermal conductivity (HWD) and flame ionization (f.i.d.) have been tested. Only f.i.d. with pyridine and n -butylamine can be used for quantitative measurements. This method provides a simple and rapid tool for determining the surface properties of solid catalysts at temperatures at which the catalytic processes occur and it has been developed to study the deactivation of acid catalyst sites during coal hydrogenation and liquid coal hydrocracking. The Benesi method has also been used for comparative purposes.