Combustion with oxygen allows considerably larger amounts of energy to be incorporated into existing furnaces for aluminum, copper, and steel production, thus increasing production capacity. In addition, heat recovery from the waste gas becomes superfluous due to the greatly reduced waste gas volumes. This considerably simplifies the plant design: plant costs, fuel requirements and CO2 emissions are reduced. Due to the on-site production of oxygen, the associated operating costs are only incurred when the plant is operating at full capacity. They are considerably lower than the oxygen price at delivery. The process also produces concentrated CO2, the separation of which normally requires a considerable amount of energy. Subsequent processes for sector coupling, i.e. the conversion of electricity into synthetic raw materials or fuels, could benefit immensely from this in the future.
Glass and ceramics industry
The melting of glass and the sintering of ceramics require very high temperatures, which are usually produced by burning fossil fuels. To reduce thermal losses and fuel requirements, the combustion air is usually preheated with exhaust gas. This increases the combustion efficiency. However, high preheating temperatures are usually avoided due to rising NOx emissions. Alternatively, the level of efficiency can be increased by combustion with oxygen-enriched air or with pure oxygen (oxyfuel technology). Through the integration of oxygen membranes, the required oxygen can be provided directly at the gas-fired industrial furnace as required and a large amount of thermal energy can be conserved, especially at high process temperatures. The additional power required for heating the membranes is only 0.2 kWh/m3 O2 and thus, only a fraction of the savings. Combustion with pure oxygen can significantly reduce NOx emissions. Since pure CO2 is also produced, highly efficient sector coupling is also possible.
Cement and lime industry
Due to their process temperatures and continuous operation, lime and cement production is particularly well-suited for thermal integration of the membrane separation process. The oxygen produced can not only be used to increase the efficiency of combustion, but it also promotes the burnout behavior of difficult substitute fuels. In addition to reducing the fuel requirement and fuel-related CO2 emissions, oxygen enrichment of the combustion air increases the CO2 concentration in the exhaust gas and lowers the waste gas volumes. This reduces the effort required for conventional separation of CO2.
(De)centralized medical care
The oxygen separation process takes place at about 850 °C, so that the oxygen produced is always sterile. Combustible or biologically active substances are completely destroyed and the reaction products potentially produced on the air side do not enter the oxygen. The very high purity of the oxygen produced enables simple dosage or uncomplicated production of defined gas mixtures. The supply for individual patients is just as possible as that of hospitals or military infirmaries. The oxygen price resulting from the investment and operating costs is noticeably lower than the delivery of oxygen.
Sewage treatment plants account for around 20 % of municipal energy consumption, with about half of this energy being used for the ventilation of the activation basin. Industrial gas producers have already shown that by using oxygen instead of air, the amount of gas to be injected can be reduced to about 4 %, i.e. to 40 liters of oxygen instead of 1000 liters of air. In addition, oxygen can also be used to treat highly polluted industrial waste water or to assist in adapting sewage treatment plants to cope with strongly varying loads. For decentralized oxygen generation, the sewage gas produced in digestion tanks can be used advantageously for heating the oxygen generators. The remaining electrical energy consumption of 0.2 kWh/m3 O2 is very low. As the required amount of oxygen is significantly less than the required amount of air, the total electricity consumption can be reduced by more than 60 %.
In professional fish farming, fumigation with oxygen can improve disease resistance, accelerate feed intake and growth, and increase stocking density. At water temperatures above 15 °C and decreasing solubility of the gases, oxygen is therefore often introduced. The usual small amounts of oxygen required by small- and medium-sized pond systems or by aquafarming companies come at a high cost due to the complex logistics involved. With oxygen generators based on mixed ionic-electronic conducting membranes, fish farmers can cost-efficiently produce the required oxygen themselves.