Integrated high temperature method for oxygen production

A process for recovering oxygen from an oxygen-containing gas mixture comprising the steps of:

• (a) compressing said oxygen-containing gas mixture;
• (b) dividing the resulting compressed gas mixture of step (a) into a first and a second compressed gas stream;
• (c) heating said first and second compressed gas streams and combining the resulting heated streams into a combined feed stream;
• (d) passing said combined feed stream into a membrane separation zone comprising one or more oxygen-selective ion transport membranes;
• (e) withdrawing from said membrane separation zone a high-purity oxygen permeate stream and an oxygen-containing nonpermeate stream;
• (f) further heating said non-permeate stream;
• and
• (g) passing the further heated non-permeate stream through an expansion turbine to generate shaft power and withdrawing therefrom a turbine exhaust stream;
• wherein the operating temperatures of said membrane separation zone and said expansion turbine are independently maintained by controlling the rate of heat addition to each of said first and second compressed gas streams in step (c), whereby said membrane separation zone and said expansion turbine are thermally delinked for optimum efficiency in recovering said oxygen.

A method of operating a process for recovering oxygen from an oxygen-containing gas mixture which comprises the steps of:

• (a) compressing said oxygen-containing gas mixture;
• (b) heating the resulting compressed gas mixture of step (a) by combusting said mixture with a fuel in a first direct-fired burner;
• (c) passing the resulting compressed and heated stream of step (b) into a membrane separation zone comprising one or more oxygen-selective ion transport membranes, and withdrawing therefrom a hot high-purity oxygen permeate stream and a hot oxygen-containing non-permeate stream;
• (d) measuring the temperature of said hot oxygen-containing non-permeate stream, comparing the measured temperature with a first set point temperature, and utilizing the difference between the measured temperature and the first set point temperature to correct the firing rate of said first direct-fired burner, thereby maintaining said first set point temperature;
• (e) further heating said non-permeate stream by combusting said stream with a fuel in a second direct-fired burner;
• (f) passing the further heated non-permeate stream of step (e) through an expansion turbine to generate shaft power and withdrawing therefrom a turbine exhaust stream;
• and
• (g) measuring the temperature of said further heated non-permeate stream prior to said expansion turbine, comparing the measured temperature with a second set point temperature, and utilizing the difference between the measured temperature and the second set point temperature to correct the firing rate of said second direct-fired burner, thereby maintaining said second set point temperature;
• whereby the operating temperatures of said membrane separation zone and said expansion turbine are independently maintained, and whereby said membrane separation zone and said expansion turbine are thermally delinked for optimum efficiency in recovering said oxygen.

A method of operating a process for recovering oxygen from an oxygen-containing gas mixture which comprises the steps of:

• (a) compressing said oxygen-containing gas mixture;
• (b) heating the resulting compressed gas mixture of step (a) by indirect heat exchange with a hot combustion gas stream, yielding a cooled combustion gas stream;
• (c) passing the resulting compressed and heated stream step (b) into a membrane separation zone comprising one or more oxygen-selective ion transport membranes, and withdrawing therefrom a hot high-purity oxygen permeate stream and a hot oxygen-containing non-permeate stream;
• (d) combusting said hot oxygen-containing non-permeate stream with a fuel in a first direct-fired burner to yield said hot combustion gas stream;
• (e) measuring the temperature of said hot oxygen-containing non-permeate stream, comparing the measured temperature with a first set point temperature, and utilizing the difference between the measured temperature and the first set point temperature to correct the firing rate of said first direct-fired burner, thereby maintaining said first set point temperature;
• (f) heating said cooled combustion gas stream by combusting said stream with a fuel in a second direct-fired burner to yield a high temperature combustion product;
• (g) passing said high temperature combustion product through an expansion turbine to generate shaft power and withdrawing therefrom a turbine exhaust stream;
• and
• (h) measuring the temperature of said high temperature combustion product prior to said expansion turbine, comparing the measured temperature with a second set point temperature, and utilizing the difference between the measured temperature and the second set point temperature to correct the firing rate of said second direct-fired burner, thereby maintaining said second set point temperature;
• whereby the operating temperatures of said membrane separation zone and said expansion turbine are independently maintained, and whereby said membrane separation zone and said expansion turbine are thermally delinked for optimum efficiency in recovering said oxygen.