The hydrogen ammonia content in the circulating hydrogen is relatively high

This post was last edited by lxf392172584 on 2015-7-24 at 18:16. Our hydrodesulfurization system is primarily used to remove nitrogen from petroleum products, converting it into nitrogen compounds which are then dissolved in water for removal in subsequent stages. The nitrogen content in the recycled hydrogen affects: 1. the nitrogen content in the oil products; 2. a high nitrogen content directly impacts the purity of the recycled hydrogen and thus the reaction activity of the catalysts; 3. the level of nitrogen (ammonia) in the recycled hydrogen can also indicate the amount of water injected at the heat exchangers and air coolers. Generally, we require that the nitrogen content in the recycled hydrogen not exceed 50PPM; of course, the lower, the better. A high nitrogen content is first attributed to whether the amount of water used for injection is sufficient, as well as to the formation of ammonium salts and some ammonia as a result of the dissolution of certain components; secondly, it may be due to insufficient catalyst activity, since the removal of nitrogen requires relatively high catalyst activity and higher reaction temperatures. Finally, there is the issue of raw materials; if the nitrogen content in these materials increases after they are cut, and this increase is not addressed in a timely manner, then the nitrogen content will continue to rise.

1. It is related to the nitrogen content in the raw materials. 2. It is related to the sulfur content in the raw materials. 3. It is related to the water injection volume. After hydrogenation, nitrogen turns into NH3 while sulfur turns into H2S; these two can react to form ammonium hydrosulfide. This compound is soluble in water, and when there is more ammonia than sulfur, the NH3 content in the recycle hydrogen increases. In such cases, it is necessary to increase the amount of water added, or to incorporate high-sulfur materials into the feedstock.

Which tar hydrogenation unit is it?

Henan Liyuan’s 300,000-ton high-temperature coal tar hydrogenation plant.

I heard there are some issues with Liyuan’s cracking process. Do you use high-temperature coal tar for hydrogenation?

No problem, it’s running quite stably at the moment!

What is the ammonia concentration during actual operation? I would like to ask for advice

The feedstock for coal tar hydrogenation differs from traditional petroleum-based feedstocks, as it usually has a low sulfur content and a high nitrogen content. It is recommended to analyze the sulfur and nitrogen contents and then determine the sulfur-nitrogen balance; the amount of sulfur added must be sufficient, as well as the water injection volume.