Distillation

Until the 1980s almost all air distillation was performed in columns containing sieve trays. Due to the close relative volatility between argon and oxygen and the purity of the products, columns with over 100 separation stages are not uncommon. Therefore, tray spacing is generally 150 mm or less. Pressure drop across a large number of trays in the low pressure column increases the pressure of the boiling fluid in the low pressure column sump. This increases the pressure of the condensing nitrogen at the top of the high pressure column. In turn, the pressure of the air at the discharge of the main air compressor is increased. This leads to an increase in power consumption. As a result, there is an incentive to use a liquid-vapour contact device with lower pressure drop.

Today, most modern cryogenic air separation plants use low pressure drop structured packing in one or more of the distillation columns. The pressure drop through structured packing is only one-fifth to one-tenth that of a trayed column. The use of struc tured packing has led to more than 3% power savings for a typical oxygen plant. It has also allowed the use of over 175 stages of separation in the side argon column of Figure 6 for the production of argon with less than 5 p.p.m. oxygen through distillation. This eliminates the need for a second deoxidation (Deoxo) process using hydrogen and a catalyst, thereby making pure argon production much simpler.

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

Get My Free Ebook


Post a comment