Atmospheric gas separation method

A method of cryogenically separating a mixture of atmospheric gases within a distillation column system having at least one distillation column, said method comprising:

• forming descending liquid and ascending gaseous phases of said mixture of said atmospheric gases within said at least one distillation column;
• contacting said descending liquid and ascending gaseous phases of said mixture within structured packing contained within at least one section of said at least one distillation column so that said descending liquid phase becomes ever more concentrated in lower volatility components of said mixture as it descends through said structured packing while said gaseous phase becomes ever more concentrated in higher volatility components of said mixture as it ascends through said structured packing;
• said structured packing being constructed of corrugated sheet metal with a specific area within a range of between about 450 m.sup.2 /m.sup.3 and about 1000 m.sup.2 /m.sup.3 and flow channels oriented at an angle of between about 30 degrees and about 45 degrees;
• and
• operating the column so that the at least one section has a pressure of greater than about two bars, a flow parameter .PSI., equal to C.sub.L /C.sub.v where C.sub.v is a vapor rate of the ascending gaseous phase and C.sub.L is a liquid rate of the descending liquid phase, of either within a flow parameter range of between about 0.01 and about 0.1 or greater than 0.1, and the vapor rate of less than a critical vapor rate at which said at least one section of said distillation column floods and greater than a minimum vapor rate equal to about exp[-0.0485(ln.PSI.).sup.2 -0.595 ln .PSI.-3.748-0.000421A], where A is the specific area of said structured packing, when .PSI. is within said range and to about 0.0305e.sup.-0.000421A .PSI..sup.-0.372 when .PSI. is greater than 0.1.

A method of cryogenically separating a mixture of atmospheric gases within a distillation column system having at least one distillation column, said method comprising:

• forming descending liquid and ascending gaseous phases of said mixture of said atmospheric gases within said at least one distillation column;
• contacting said descending liquid and ascending gaseous phases of said mixture within structured packing contained within at least one section of said at least one distillation column so that said descending liquid phase becomes ever more concentrated in lower volatility components of said mixture as it descends through said structured packing while said gaseous phase becomes ever more concentrated in higher volatility components of said mixture as it ascends through said structured packing;
• said structured packing being constructed of corrugated sheet metal with a specific area within a range of between about 170 m.sup.2 /m.sup.3 and about 250 m.sup.2 /m.sup.3 and flow channels oriented at an angle of about 30 degrees or less;
• and
• operating the column so that the at least one section has a pressure of greater than about two bars, a flow parameter .PSI., equal to C.sub.L /C.sub.v where C.sub.v is a vapor rate of the ascending gaseous phase and C.sub.L is a liquid rate of the descending liquid phase, of either within a flow parameter range of between about 0.01 and about 0.1 or greater than 0.1, and the vapor rate of less than a critical vapor rate at which said at least one section of said distillation column floods and greater than a minimum vapor rate equal to about exp[0.0485(ln.PSI.).sup.2 -0.595 ln .PSI.-2.788-0.00236A], where A is the specific area of said structured packing, when .PSI. is within said range and to about 0.0796e.sup.-0.00236A .PSI..sup.-0.372 when .PSI. is greater than 0.1.

A method of cryogenically separating a mixture of atmospheric gases within a distillation column system having at least one distillation column, said method comprising:

• forming descending liquid and ascending gaseous phases of said mixture of said atmospheric gases within said at least one distillation column;
• contacting said descending liquid and ascending gaseous phases of said mixture within structured packing contained within at least one section of said at least one distillation column so that said descending liquid phase becomes ever more concentrated in lower volatility components of said mixture as it descends through said structured packing while said gaseous phase becomes ever more concentrated in higher volatility components of said mixture as it ascends through said structured packing;
• said structured packing being constructed of corrugated sheet metal with a specific area within a range of between about 250 m.sup.2 /m.sup.3 and about 1000 m.sup.2 /m.sup.3 and flow channels oriented at an angle of about 30 degrees or less;
• and
• operating the column so that the at least one section has a pressure of greater than about two bars, a flow parameter .PSI., equal to C.sub.L /C.sub.v where C.sub.v is a vapor rate of the ascending gaseous phase and C.sub.L is a liquid rate of the descending liquid phase, of either within a flow parameter range of between about 0.01 and about 0.1 or greater than 0.1, and the vapor rate of less than a critical vapor rate at which said at least one section of said distillation column floods and greater than a minimum vapor rate equal to about exp[-0.0485(ln.PSI.).sup.2 -0.595 ln .PSI.-3.156-0.000893A], where A is the specific area of said structured packing, when .PSI. is within said range and to about 0.05515e.sup.-0.000893A .PSI..sup.-0.372 when .PSI. is greater than 0.1.

A method of cryogenically separating a mixture of atmospheric gases within a distillation column system having at least one distillation column, said method comprising:

• operating said distillation column at a pressure within a range of between about 3.5 bars and about 7.5 bars;
• forming descending liquid and ascending gaseous phases of said mixture of said atmospheric gases within said at least one distillation column;
• and
• contacting said descending liquid and ascending gaseous phases of said mixture within structured packing contained within at least one section of said at least one distillation column and having a packing density of about 750 m.sup.2 /m.sup.3 and having flow channels oriented at an angle of about 45 degrees so that said descending liquid phase becomes ever more concentrated in lower volatility components of said mixture as it descends through said structured packing while said gaseous phase becomes ever more concentrated in higher volatility components of said mixture as it ascends through said structured packing;
• said liquid and gaseous phases of said mixture of atmospheric gases being contacted through a height of said structured packing such that said liquid and gaseous phases respectively contain lower and higher volatility components of said mixture in predetermined concentrations and said height of the structured packing in meters is approximately equal to a product of a number of theoretical stages required to produce said predetermined concentrations of said lower and higher volatility components and a quantity equal to a sum of 0.181 added to said pressure multiplied by -0.00864.

A method of cryogenically separating a mixture of atmospheric gases within a distillation column system having at least one distillation column, said method comprising:

• operating said distillation column at a pressure within a range of between about 7.5 bars and about 20 bars;
• forming descending liquid and ascending gaseous phases of said mixture of said atmospheric gases within said at least one distillation column;
• and
• contacting said descending liquid and ascending gaseous phases of said mixture within structured packing contained within at least one section of said at least one distillation column and having a packing density of about 750 m.sup.2 /m.sup.3 and having flow channels oriened at an angle of about 45 degrees so that said descending liquid phase becomes ever more concentrated in lower volatility components of said mixture as it descends through said structured packing while said gaseous phase becomes ever more concentrated in higher volatility components of said mixture as it ascends through said structured packing, thereby to effect said cryogenic separation;
• said liquid and gaseous phases of said mixture of atmospheric gases being contacted through a height of said structured packing such that said liquid and gaseous phases respectively contain lower and higher volatility components of said mixture in predetermined concentrations and said height of the structured packing in meters is approximately equal to a product of a number of theoretical stages required to produce said predetermined concentrations of said lower and higher volatility components and 0.116.