Nitrogen is an inert gas, which is often used in high temperature treatment of various materials or parts of the protective atmosphere. Therefore, impurities (oxygen and water vapor) in nitrogen should be removed to a low level.

一般来说，由制氮机制取的氮气中含氧量小于0.5%时，宜采用脱氧剂直接除氧，含氧量为0.5-3%时，宜采用催化剂加氢除氧，含氧量大于3%时可采用分级催化除氧。

Generally speaking, when the oxygen content in nitrogen produced by nitrogen generator is less than 0.5%, Deoxidizer should be used for direct deoxidation; when the oxygen content is 0.5-3%, catalyst hydrogenation should be used for deoxidation; when the oxygen content is more than 3%, staged catalytic deoxidation can be used.

因为氮气中含氧量过高，按化学计量所需的氢气量大，一次全部加入时，可能有爆炸的危险；且反应中放出的热量较大，易烧坏催化剂。因此，必须严格控制加氢量进行分级除氧。原料氮气中含氧量过高时，亦可用部分纯氮稀释原料气，使混合气体中含氧量小于3%再进行加氢催化除氧。

Because the oxygen content in nitrogen is too high, the amount of hydrogen required by stoichiometry is large, and there may be a risk of explosion when all the nitrogen is added at one time; And the heat released in the reaction is large, which is easy to burn the catalyst. Therefore, it is necessary to strictly control the amount of hydrogenation for staged deaeration. When the oxygen content in the feed nitrogen is too high, the feed gas can also be diluted with some pure nitrogen to make the oxygen content in the mixed gas less than 3%, and then the hydrogen catalytic deoxidation can be carried out.

采用脱氧剂杂质氧的典型工艺流程：氮气经催化除氧器（除去氧）、水冷却器和吸附干燥器（除去水汽）、气体过滤器（除去尘埃颗粒）后，即得纯氮产品。

The typical process flow of removing impurity oxygen by deoxidizer is: nitrogen passes through catalytic deaerator, water cooler, adsorption dryer and gas filter to get pure nitrogen product.

采用加氢催化除氧的典型工艺流程：在氮气中加适量氢气（添加量为氮气中含氧量的二倍以上），然后通过催化除氧器（除去氧）、水冷却器和吸附于燥器（除去水汽）、气体过滤器（除去尘埃粒）后，即得纯氮产品。

The typical process flow of hydrocatalytic deoxidization is adopted: firstly, appropriate amount of hydrogen is added into nitrogen (the addition amount is more than twice of the oxygen content in nitrogen), and then pure nitrogen product is obtained through catalytic deoxidizer (deoxidization), water cooler and adsorption in dryer (moisture removal) and gas filter (dust removal).

当氮气中含氧量较大（大于3%），可采用分级加氢催化除氧工艺，氮气在进入催化除氧器前，需要严格控制加氢量，通过催化除氧器1（一次除氧），再加入少量氢气进入催化除氧器2进行二次除氧。

When the oxygen content in nitrogen is large (more than 3%), the staged hydrogenation catalytic deoxidation process can be used. Before the nitrogen enters the catalytic deoxidizer, the amount of hydrogenation should be strictly controlled. The catalytic deoxidizer 1 (primary deoxidization) and a small amount of hydrogen should be added to the catalytic deoxidizer 2 for secondary deoxidization.

如果原料氮气中含氧较高，对纯氮又要求不许有过量氢气存在。此时，氮气纯化装置采用先加氢催化除氧，再用活性氧化铜等除氢的方法纯化氮气，其典型的工艺流程为：在原料氮气中根据氧的含量，添加稍为过量的氢（按化学计量）后通过催化除氧器除氧，再通过电加热器和氧化反应除去氮气中的过量氢。常用的脱氢剂除活性氧化铜外，也可用银分子筛等。

If the oxygen content in the nitrogen is high, the pure nitrogen should not have excessive hydrogen. At this time, the nitrogen purification unit adopts the method of hydrogenation catalytic deoxidation first, and then active copper oxide to purify nitrogen. The typical process flow is as follows: according to the oxygen content in the raw nitrogen, add a little excess hydrogen (according to stoichiometry), deoxidize it through the catalytic deaerator, and then remove the excess hydrogen in the nitrogen through electric heater and oxidation reaction. In addition to active copper oxide, silver molecular sieve can also be used as dehydrogenation agent.