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| Stock Number: |
600108 |
| Capacity: |
530,000 tons/year or 1,500 tons/day |
| Raw Material: |
Natural Gas, Air, and Water |
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| Brief Overview: |
| Natural gas is reformed with steam to produce hydrogen plus carbondioxide. Air supplies most of the nitrogen. N2 and H2 react under high pressure and temperature in the ammonia converter into ammonia. |
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| Process Description: |
| Compression
As will be seen from the following, one mole of methane produces four moles of hydorgen, and since the ammonia synthesis reaction requires high pressure, it is obviously far more economical to compress the methane than to compress the hydrogen at a later step in the process.
However, the information of hydrogen out of methane is favoured by lower pressure, but at low pressure the volume of the gases is much longer, which results in a much bigger size of all equipment. A very high pressure increases the investment because the equipment must be stronger. The choice of operating pressure is made on an economic basis.
Desulfurization
Sulfer is a poison to almost all catalyst used in the process and should be removed from the gas. The feed is desulfurized with zinc oxide at high temperature before it enters the reforming section.
Reforming
The reforming process is carried out in two steps. Feedgas from the desulfurizer is mixed with steam. The combined steam is preheated and sent to the primary reformer furnace. The reforming reaction takes place in catalyst filled tubes in the radiant section of the furnace. Roughly 40% of the methane is converted to carbon oxides and hydrogen.
The effluent of the primary reformer is sent to the top of the secondary reformer where the formation of hydrogen and carbon oxides out of methane is completed. Process air which is compressed and preheated in the convertion section of the primary reformer, is also fed to the secondary reformer.
In the upper section of the reactor, oxygen in the air reacts with primary reformer effluent to form carbon oxides and water. The mixture then passes over a bed of catalyst where the heat of the above oxidation reaction converts methane to hydrogen and carbon oxides. |
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| Major Equipment: |
| Primary Reformer - Here natural gas is partly reformed into hydrogen. Fired with natural gas. 176 burners installed
Compressors - Centrifugal compressors are used mainly. They are small and can handle tremendous amounts of gas at speeds, 12,000 rpm. Our synthetic gas compressor for example requires 32,000 HP, approximately the same amount of HP as the steamer "Rotterdam" (35,000 HP)
Noise Abatement - A silencer has been installed in the blow-off circuit to prevent nuisance resulting from high noise levels. |
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