A Spanish subbituminous A coal was liquefied in a 250-ml autoclave for 1 h, at 17 MPa hydrogen pressure and 400 rpm stirring speed. The liquid products were fractionated into oils, asphaltenes, and preasphaltenes using pentane, toluene and THF as extractive solvents. The effect of hydrogen availability on liquefaction yields was explored using different tetralin:coal ratios under different temperatures. The results are compared with those obtained in earlier studies [1,2], under different hydrogen pressures and tetralin:coal ratios, and with other solvents and with catalysts. Total conversion, asphaltenes, preasphaltenes and oils increase while gases decrease when the tetralin:coal ratio is raised, not observing further conversion over 2:1, 3:1, 4:1 and 6:1 ratios, at 400, 425, 450 and 475 degrees C, respectively. Retrogressive reactions are produced at 475 degrees C for tetralin:coal ratios under 4:1 but not for higher ones. In order to obtain the highest conversion (approximate to 84%), which coincides with vitrinite + exinite content, 475 degrees C and 6:1 or higher tetralin:coal ratios have to be used. Such or higher conversions, can be obtained with more appropriate operating conditions (425 degrees C, 3:1 solvent:coal ratio) if better solvents or active catalysts are used.