Separation of ethanol-water and methanol-water mixtures has been accomplished experimentally using a horizontal zero-gravity distillation column. A countercurrent flow between liquid and vapor phases was established utilizing the principle of the heat pipe. The concentration profile along the column has been investigated with various product rates. A high degree of separation was achieved in a relatively short column lined with capillary wicks. The flexible column orientation can also be a tremendous advantage as compared to the necessarily vertical operation of the conventional distillation columns.