Method and System for Injecting Low Pressure Oxygen from an Ion Transport Membrane into an Ambient or Super Ambient Pressure Oxygen-Consuming Process

Abstract

A stream of sub ambient oxygen from an ion transport membrane is injected into an ambient pressure or super ambient pressure oxygen-consuming process through an annular space in between concentrically disposed inner and outer tubes where a high velocity gas is injected into the process from the inner tube.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]None.BACKGROUND[0002]1. Field of the Invention[0003]The present invention relates to injection of oxygen from ion transport membranes.[0004]2. Related ArtOxy-Combustion in Glass Manufacturing Process[0005]Air-fired glass melting furnaces has been converted to oxygen-fired technology (i.e., oxy-combustion with oxygen concentrations in the oxidant of up to 100%) primarily due to environmental regulations. Oxy-combustion is one of the most thermally efficient and cost-effective ways to enable glass manufacturers to meet NOx emissions restrictions. Compared with air-fired combustion, oxy-combustion has the potential to reduce NOx emissions by up to 85%.[0006]Besides the reduction of NOx emissions, the oxy-combustion has several other significant advantages over traditional air-fired combustion processes:[0007]the mass and volume of the flue gas are reduced by ˜75%;[0008]there is less heat loss in the flue gas due to the reduction of the flue ...

AI Technical Summary

Benefits of technology

[0021]There is disclosed a method for injecting low pressure oxygen from an ion transport membrane into an ambient or super ambient pressure oxygen-consuming process, comprising the following steps. A super ambient pressure, oxygen-containing feed gas is fed to a first ion transport membrane to produce a sub-ambient pressure first permeate stream essentially consisting of oxygen and a first non-permeate stream essentially consisting of oxygen-deficient feed gas, the ion transport membrane comprising a material that is a hybrid electron / O2− anion hybrid conductor. A high velocity gas is injected into the oxygen-consuming process from an interior of an inner tube, the high velocity gas having a velocity of at least 80 m / s. The sub-ambient pressure first permeate stream is injected into the oxygen consuming process form an annular space in between the inner tube and an outer tube concentrically disposed around the inner tube, the first permeate stream being sucked from the annular space by the relative vacuum created by expansion of the high velocity gas from the inner tube, the sub ambient pressure first permeate stream having a pressure of at least 8000 Pascal.

Problems solved by technology

However, economically speaking, oxygen (for use in oxy-fuel combustion) is costly for glass melting furnaces.

The main cost increase is the separation of oxygen from air using a cryogenic air separation unit (ASU).

This separation process requires a great deal of energy.

However, handling pure O2 at a temperature higher than 650° C. is very difficult and there are very few materials that have been shown to reliably withstand such high temperatures in the O2 rich environment.

The O2 product may be available at a desirably high pressure of about 2.2 bar, but at the expense of relatively low recoveries.

There are difficulties experienced when attempting to inject such low pressure O2 into the furnace.

Compressing O2 at 900° C. is considered undesirable due to the significant material constraints noted above.

Cooling the O2 down then compressing it is another option, but such an approach will decrease the energy efficiency.

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