What output level constitutes a medium-sized nitrogen fertilizer plant?

Determining whether a plant falls into the category of medium-scale nitrogen fertilizer or small-scale nitrogen fertilizer is not based on the capacity of a single unit, but rather on an entire production unit; with an annual output of 150,000 tons, it should be classified as a medium-scale nitrogen fertilizer plant. Therefore, environmental protection standards should be implemented in accordance with the requirements for medium-nitrogen fertilizers.

During the planned economy era, nitrogen fertilizer plants were built on the basis of 1000-millimeter synthetic and copper washing towers, with a single unit having an annual production capacity of 60,000 tons of synthetic ammonia; such plants were known as Zhongni. (What is now referred to as the 8.13 Project originally involved 60,000 tons of synthetic ammonia along with 110,000 tons of urea.) However, this was not always the case – some plants used dual 800-millimeter towers, and there were variations in their configurations. Most of these Zhongni plants were under the direct control of the provincial chemical industry department, but later they came under the direct management of local municipalities； This term is still used in the old standards, but in fact it’s **not used this way anymore**. There are also specific environmental protection regulations and local laws; generally, local requirements are stricter than those set at the national level, so it is necessary to follow the local rules.

Today, the terms \"small nitrogen fertilizers\" and \"small synthetic ammonia\" are no longer in use, and the former Small Nitrogen Fertilizers Association no longer exists either. Because currently, the capacity of most ammonia synthesis plants has exceeded that of medium-sized plants and even large-scale plants.

In my opinion, if we really need to use production volume to determine the scale of a fertilizer company at present, 18.30 should be used as the base figure. The current 18.30 enterprises have also reached this scale through technological upgrades, and their energy consumption remains quite high.

It can be defined based on the synthesis system: those with a synthesis tower diameter of less than 800 mm are classified as low-nitrogen fertilizers; those with a diameter of 1000 mm to 2000 mm and an annual production capacity per system of less than 300,000 tons of ammonia are classified as medium-nitrogen fertilizers; those with an annual production capacity per system exceeding 300,000 tons of ammonia are classified as high-nitrogen fertilizers.

Synthetic ammonia with an annual production of less than 100,000 tons is considered a low-volume fertilizer； Synthetic ammonia with an annual production of more than 100,000 tons but less than 300,000 tons is classified as medium-sized fertilizer ； Synthetic ammonia with an annual production of over 300,000 tons is considered a major fertilizer.

It is undisputed that enterprises with a single unit capable of producing 300,000 tons per year are large nitrogen fertilizer manufacturers； At present, the distinction in production capacity within the country holds little significance. The key point is that during the planned economy era, the level of capacity determined investment decisions, **policies, and the scale of enterprises; nowadays, enterprises, regardless of their scale, are all just workers ； The focus of investment is no longer **waiting**, but the companies themselves; therefore, there is no real need to distinguish between large and small-scale production processes.

It seems that classifying products as high, medium, or low based on production volume is no longer very clear these days; more emphasis is placed on energy consumption and environmental protection

It seems that 30W is some kind of threshold; anything below 30W falls under one set of rules, while anything above 30W falls under another set of rules!