Bubble columns, in which a gas is passed up through a head of liquid, have been limited to very low superficial gas velocities. Higher rates, such as those used in conventional distillation columns, have not previously been explored. In fact, higher gas rates have been thought to lead to dangerous operating conditions. In this paper, new data for high gas rates, under distillation conditions and at a semiworks scale, are presented for liquid-continuous operations. Both sieve trays and structured packing have been used as internals. Mass transfer and hydraulic data are included.