Question

Question: to conduct air separation based on cryogenic distillation, consider the variety of column internals which may be available from the main column vendors for an ASU. Which internals would you recommend (giving the name of the vendor and the exact recommended internals)? Justify your choice briefly.
Do not copy a reference from websites or offer wrong answer, otherwise I will downvote, thanks.

Answer 1

Air separation units are worked on the principle of low-temperature distillation or cryodistillation principle. So for effective mass transfer inside cryogenic distillation column various types of internals used like packing, sieve plate, valve cup plates and staggered packing. Mainly three types of column internals used in ASU

1. Plate column (sieve plate, bubble cup, valve cup plate)

2. Packed column (

A. unstructured packing- reaching ring, poul rings, ceramic packing, berl saddle, intolax and superintolax saddles .

B. Staggered packing

3. Molecular Sieve separation

But most of the latest technologies used staggered packing in place of other options in new air separation units. Because it has a lower pressure drop as compare to tray column. The staggered packing also facilitates higher turndown capacity(40% of design capacity) than plate column. It also enables pure argon gas production, reduces the dependency of pure hydrogen source.

Companies like air separation limited, AST Canada, Air liquide, Universal industrial gas Ltd and Lindey and Sulzer used staggered packing with some other internal modification for effective separation of gases from air.