Three prototypes of innovative non-cryogenic on site oxygen generators, based on the application of pressure swing adsorption (PSA) technique were developed. Two end user applications, aquaculture industry and glass making industry, were explored.
According to the experimental results, in the first case the application of oxygen on-site generators, increases the amount of dissolved oxygen (DO) into the water where fishes live, improving the water quality and subsequently the fish density in the rearing units. Moreover the choice of the non-cryogenic way showed a positive effect on the cost connected to the investment and to the plant operation: in fact the non-cryogenic solution is more economic and easier to practise mainly in decentralised areas.
The second application consists of a conversion to oxygen-fuel combustion of a scaled furnace for glass smelting. This inhibits NOx emissions by replacing the air with oxygen, thus eliminating the nitrogen from the combustion atmosphere. This procedure gets a significant advantage provided that oxygen could be produced with a cheaper and simpler way than cryogenic process.
The design of the adsorption beds and of the generators was carried out with by means of a computer code developed and implemented for the project. For application in the glass industry, an integrated strategy was developed to predict the combustion of a fuel in oxygen. Particular attention was paid to monitor oxygen and NOx during the experiments.
An innovative polarographic sensor for oxygen monitoring was designed and manufactured: three electrodes were adopted to prevent phenomena of polarisation. Moreover, since the intensity of the polarographic current increases with the temperature, a proper termistor was inserted to compensate the effect.
The NOx monitoring system manufactured consists of an air exhauster which is linked with the diffusion collar to two electro-chemical capillary diffusion barrier gas sensors. The polluting exhausts are sucked up passing through a filter in order to prevent contamination or damage to the sensors. The NOx sensors are connected with a digital controller.
A research is proposed to develop innovative on-site Oxygen and Nitrogen generators based on Air Pressure Swinging through Phillipsite and Chabazite adsorpting media. The proposed process is cheaper than the cryogenic one (by the elimination of the costs of liquefaction and transportation). An on-site production of both Oxygen (90-93% purity) can be obtained with no additional need of purification. To most users, these purities are suitable to many processes formerly served by cryogenic products -including aqua culture, food preservation, pulp-and-paper, glass making, metal processing, petroleum refining. The non cryogenic process is valuable to foster the O2 and N2 use in decentralised areas and promoting gas use in developing Countries.
The research goal is the integration of several expertise's addressed to :
1) Improvement of the Aqua culture Industry productivity,
2) Reduction of NOx released by the furnaces of Glass Fibreglass Industry.
The major Research tasks are :
- characterisation of the adsorpting minerals,
- design and fabrication of three prototypes
- testing of the generators prototype performances
1) In two fish rearing units of Aqua culture Installations
2) In one glass furnace of Glass Industry.
(1) The adoption of pure oxygen in the fish rearing industry will reflect a saving up to 25% (fresh water) and 20% (salt water) and strong environmental advantages because the water can be recirculated inside the Aqua culture plant.
(2) By blending oxygen with any number of fuels, the oxy-fuel burners will produce a hotter flame which will lower the overall costs and reduce the NOx emissions, per ton of produced glass, from the present 4.5Kg to 0.9 Kg.
Funding SchemeCSC - Cost-sharing contracts
17000 La Rochelle
16100 Calata Gadda Genova
17014 Cairo Montenotte Savona
15710 Aigaleo Athens