In this work, a solar parabolic trough collector (PTC) has been dimensioned and its technical feasibility has been evaluated in order to be used as ammonia direct vapor generator in an advanced absorption air-cooled Solar-GAX cycle of 10.6 kW cooling capacity. A detailed numerical simulation model that takes into account the geometry and the optical, thermal and fluid dynamic behavior of the PTC has been developed. The model has been solved in order to reach minimal thermal losses through the PTC, and maximum coefficient of performance (COP) of the Solar-GAX cycle. Under design conditions, the solar PTC efficiency, the COP of the Solar-GAX cycle and the global efficiency of the system were 0.62,0.87 Y and 0.54 respectively. The calculated efficiency is 25.5 % higher than that provided by a single effect water-lithium bromide cycle coupled in an indirect form with a solar PTC system.