Onsite / self-generating plants.

With onsite solutions from Westfalen, it is possible to generate nitrogen, oxygen, hydrogen and compressed air on your own premises. Compared to other forms of supply, on-site generation of gases offers many advantages:

Cost reduction of up to 50 percent.
Immediately available gases.
High level of independence with regard to high planning and supply security.

Produce nitrogen onsite.

On-site production of nitrogen from ambient air is carried out with a membrane, PSA or LIN assist system from Westfalen, depending on the quantity required and the desired purity of the gas:

Membrane technology.

Produce nitrogen with hollow fibre modules.

Membrane systems enable the on-site production of nitrogen from ambient air. The air is compressed in the compressor, cleaned in the dryer and then fed to the membrane system. Here, gas separation takes place in hollow fibre modules under pressure. Unwanted gases are discharged to the outside through the walls of the hollow fibres. Finally, nitrogen flows out of the module and is buffered so that a uniform product flow is guaranteed.

Key data membrane system.

Requirement quantities	2 – 2000 Nm3/h
Delivery pressure (without redensification)	3 – 12 bar
Purity	95 – 99,5 Vol.-%
Space required	10 – 100 m2

PSA technology.

Produce nitrogen with pressure swing adsorption.

PSA systems (Pressure Swing Adsorption) enable the onsite generation of nitrogen from ambient air. First, the air is compressed to up to eight bar with an air compressor, then cleaned in the dryer and then fed to the adsorption tanks. In these, the oxygen is retained with molecular sieves, the nitrogen escapes via the container head and is evenly released with the help of a nitrogen buffer.

Key data for the PSA system.

Requirement quantities	2 – 2000 Nm3/h
Delivery pressure (without redensification)	6,5 bar
Purity	95 – 99,999 Vol.-%
Space required	10 – 100 m2

LIN Assist technology.

Produce nitrogen with cryogenic air separation.

LIN assist plants (LIN = Liquefied Nitrogen) enable the onsite production of nitrogen from ambient air. First, the air is compressed, then purified by means of pressure swing adsorption and then fed to the rectification column. This is where the cryogenic air separation takes place, with nitrogen collecting at the top and residual gas containing oxygen at the bottom. Two per cent of the nitrogen production is used to cool the rectification column. Controls regulate the stable process sequence, gas purity and flow rate.

Key data LIN-Assist system.

Requirement quantities	200 – 10.000 Nm3/h
Delivery pressure (without redensification)	3 – 7 bar
Purity	99,998 – 99,9999 Vol.-%
Space required	100 – 250 m2

Produce oxygen onsite.

For on-site generation of oxygen from ambient air, Westfalen offers systems with VSA or Cryo technology, depending on the quantity required and the desired purity: VSA technology Generate oxygen with vacuum alternating adsorption.

VSA installations.

Vacuum swing adsorption enables the on-site generation of oxygen from ambient air.

First, the air is compressed to approx. 0.7 bar and fed to the adsorption vessel. There, a molecular sieve filters the air flow and retains the nitrogen. This is then sucked out with the help of a vacuum pump. The remaining oxygen flows out of the top of the tank and is brought to a uniform product flow by means of an oxygen buffer.

Key data for the VSA system.

Requirement quantities	100 – 6.000 Nm3/h
Delivery pressure (without redensification)	0,3 bar
Purity	90 – 95 Vol.-%
Required space	50 – 200 m2

Cryogenic technology.

Produce oxygen with cryogenic equipment.

Cryogenic plants enable the onsite production of oxygen from ambient air in purities above 95 per cent by volume. For this purpose, the air is first compressed, then purified and fed into a high-pressure rectification column. This is where the cryogenic air separation takes place, enriching the oxygen at the bottom of the plant to up to 40 per cent. In a subsequent low-pressure column, the oxygen is again separated from the nitrogen. The process is therefore also suitable for the production of high-purity gaseous nitrogen.

Key data for the cryogenic system.

Requirement quantities	1.000 – 10.000 Nm3/h
Delivery pressure (without redensification)	1 bar
Purity	bis zu 99,5 Vol.-%
Space required	100 – 300 m2

Produce hydrogen onsite.

Steam Reforming.

Produce hydrogen with steam reforming.

Steam reformers enable the onsite generation of hydrogen from natural gas. First, the natural gas is compressed and separated from sulphur and hydrogen sulphide with catalysts. Then the filtered gas is mixed with steam, heated and fed into the reformer. This produces the synthesis gases hydrogen, carbon monoxide, carbon dioxide, water vapour and methane. The carbon monoxide is now converted into carbon dioxide and hydrogen with a catalyst. Finally, unwanted gas components are removed by adsorption.

Key data Steam-Reformer

Required quantities	50 – 10.000 Nm3/h
Delivery pressure (without redensification)	8 – 15 bar
Purity	mindestens 99,9 Vol.-%
Space required	30 – 400 m2

Produce compressed air.

Compressor technology.

Generate compressed air with screw compressors.

Screw compressors enable the generation of compressed air from ambient air. First, the air is filtered, compressed and cooled. Compressed air is then produced in the high-pressure stage. After cooling down again, the compressed air is post-treated in adsorption dryers to achieve dew points between -20 and -60 degrees Celsius. For higher capacities, several compressors can be connected in parallel.

Key data compressor unit.

Required quantities	1.000 – 3.000 Nm3/h
Delivery pressure (without redensification)	8 – 10 bar
Dew points	-20 – -60°C
Space requirement per compressor	10 m2