Introductory Remarks

The chemical process industry benefits greatly from any improvements on mass transfer equipment performance due to its impact on energy consumption in distillation intensive processes containing conventional equipment -trays and/or packings-. In existing grass-roots plants, processes intensification - higher throughputs, higher purities, or yields- is typically achieved by upgrading from conventional to high-performance equipment and operating conditions. In high pressure distillation systems designed with trays, these are upgraded to either high-capacity trays or high-performance random packings. The latter typically achieved using fourth-generation random packings. These types of packings exhibit better hydraulics that leads to higher efficiencies as a consequence of an improved geometry.

The non-conventional approach presented in this work consists in blending two-different sizes of random packings. This approach has been available for 15 years. The random packing blend capacity is like the larger random packing size with an improved efficiency. This efficiency is close to the smaller packing size, or 10-15% higher efficiency of the larger packing.

In this work, blending two different size of third-generation random packings will exhibit hydraulic and mass transfer characteristics like those of fourth-generation packings.

Experimental work conducted in a state-of -the-art test system with air-water and a standard distillation system confirm this non-traditional approach. The hydraulic modeling of these random packing blends confirms a well-known design methodology for these commercial random packings.

Case studies will be presented.