By Li Feng, Beijing Sujia Huifeng Chemical Technology Consulting Co., Ltd.

Capacity expands rapidly but utilization remains low

The large-scale production of pyridine in China began in the early 21st century. In 2001, the 16 kt/a synthetic pyridine line, which was jointly developed by Nantong Acetate Chemical Plant and Reilly Company of the United States, was successfully put into operation, and the products are mainly sent to Syngenta. In 2004, Nanjing Red Sun Group invested and built the first set of 12 kt/a pyridine production unit with independent intellectual property in Nanjing Chemical Industry Park. In 2007, Red Sun Group's proprietary pyridine and its series of products were successfully put into production, including pyridine and 3-methylpyridine, with a capacity of 25 kt/a. Most of the Red Sun Group's pyridine products are for captive use and rarely entered the market. Domestic users still rely on imported pyridines.
   Since 2007, pyridine production facilities have been established in Hubei, Anhui, Shandong, Henan and Hebei. Capacity and production increased rapidly, and domestic products began to replace imported cargos. The development of China's pyridine industry in recent years is shown in Table 1.

Table 1   Development situation of China’s pyridine industry

   From 2001 to 2017, the average annual growth rate of domestic pyridine production capacity was 15.72%. The main reason of this rapid development is that pyridine is a relatively new element in the new generation of environmentally friendly, efficient, low-toxic insecticides and herbicides.
   At present, the pyridine products in China are mainly made via synthesis method, which takes up 99% of the total production, and coal tar separation method only accounts for 1%. At present, the operating rate of domestic pyridine plants is low as the synthesis process of pyridine is very complicated.
   The main producers of pyridine and its series products are Nanjing Red Sun Group, with an annual production capacity of 75 kt/a. In addition, Jiangsu Nantong Vertellus, Shandong Lvba, Guangzhou Longsha, Shandong Weifang Green Olive, Hebei Tangshan Chenhong, Sanonda Group and Henan Xinxiang Hengji Company also have scaled production. See Table 2 for details.

Table 2  China’s pyridine producers (synthesis route)  (t)

   China's pyridine production enterprises are mainly concentrated in Shandong and Jiangsu provinces. Among them, Jiangsu pyridine production capacity accounted for 42.35% of the total and Shandong 16.47%. It is estimated that China's pyridine production capacity will reach 200 kt/a by 2020. 

Market demand is robust

   In recent years, the development of the national economy has driven the market demand for pyridine and its series products, which are applied to sectors like pesticides, pharmaceuticals, tires, and daily chemicals. The accelerated pace of weeding and the booming of the automotive industry and the feed industry all support the development of the downstream products such as paraquat herbicides, SBV (styrene-butadiene-2-vinylpyridine (2-VP)) and pyridine latex.
   In 2017, the   apparent consumption of pyridine in China was 95 921.043 tons. During the period 2010-2017, the average annual growth rate of apparent consumption was 7.85%. During the period from 2010 to 2012, the average annual growth rate of China's pyridine self-sufficiency rate was 6.32%. In recent years, the apparent consumption and self-sufficiency rate of Chinese pyridine are shown in Table 3.

Table 3   Apparent consumption and self-sufficiency of China’s pyridine industry (t)

Application of pyridine products

   Pyridine products are mainly used to produce pesticides, medicines and veterinary drugs and their intermediates.

Table 4   China’s pyridine consumption structure (%)

   1. Pesticides: demand growth over 20%
   Pesticides containing pyridyl groups have developed rapidly in China, including highly effective insecticides and herbicides, as well as highly effective fungicides. As of June 2010, there are 45 registered active ingredients containing the pyridine ring in China, including paraquat, chlorpyrifos, imidacloprid, nicosulfuron and other mainstream pesticides with mature market, large capacity and high yield. Pyridine downstream pesticides with good market prospects have been developed, including fluazinam, fluroxypyr, flurazepam, and flupirtine.
   China has nearly 400 active compound manufacturers in more than 2 600 pesticide production enterprises (including sanitary pesticide manufacturers). At present, compounds containing a pyridine ring structure have become an innovative direction for new pesticide companies.
   Pyridine and its derivatives can also be used as raw materials to synthesize chlorantraniliprole, cyanamide, acetamiprid, nitenpyram, pymetrozine, etc. in insecticides; sulfonamide, sulfomesulfuron, pyrfluoxetine, acetylene oxalate, etc.; oxypoxystrobin, boscalid, fluopyram, fluopyram, etc. in the fungicide.
   It is expected that the consumption of pyridine pesticides in the world will increase by more than 15% in the next few years, and the demand for pyridine series products will increase by over 20%.
   2. Medicine: huge potential
   In the field of medicine, pyridine and its series products can be used to manufacture more than 50 kinds of drugs, such as penicillin, norfloxacin, dexamethasone acetate, omeprazole, lansoprazole, acetylspiramycin, sulfa drugs, praziquantel, hydrocortisone and some anti-tumor drugs and vasodilators, as well as compound raw materials of some common drugs such as cefotaxime, prednisone, sulfazone pipechic acid, iodine, progesterone, vitamin A, vitamin D2, vitamin D3, and cephalosporin 4.
   The pyridine base mainly includes 2-methylpyridine, 3-methylpyridine, 4-methylpyridine, 2-methyl-5-ethylpyridine and the like. 2,6-Lutidine can be used to produce broad-spectrum anthelmintics, cortisone, acetate, niacin, and the like. 2,4,6-Trimethylpyridine can be used to prepare auxin and vitamin A. 3,3,5-Trimethylpyridine is a key intermediate in the synthesis of the antiulcer drug omeprazole.
   At present, more and more pesticides and pharmaceutical brands on the market are derivatives of pyridine compounds, which is a trend in the creation and development of new pesticides and new medicines in the future.
   3. Niacin and nicotinamide: taking 35% of the pyridine consumption
   Niacin and nicotinamide synthesized from 3-methylpyridine have the largest demand for pyridine series products, and about 35% of the pyridine series products in the world are used for the production of niacin and nicotinamide.
   The annual output of niacin and nicotinamide in China has reached more than 20 kt, and the annual export volume has reached 10 kt. The annual demand for 3-methylpyridine alone has reached more than 8 kt. Niacin and nicotinamide are also important vitamin B products and are used in large quantities in pharmaceutical and feed additives.

Two factors lead to import reducing

   In 2017, China imported 2 737.4 tons of pyridine and pyridinium. From 2010 to 2017, the average annual growth rate of China's pyridine and pyridinium imports was -25.46%. And the imports are mainly coming from India, the United States, Taiwan, and Japan.
   China's import of pyridine and pyridinium has been greatly reduced for two reasons: the rapid increase of domestic production and anti-dumping policy. On February 5, 2016, the Ministry of Commerce issued the No. 1 Announcement of the Year, reviewing the anti-dumping period of the imported pyridine originating from the Indian Jubilant. It is decided that since February 5, 2016, the anti-dumping tax rate applicable to Indian companies will be adjusted to 17.6%. It is expected that the consumption market of pyridine and pyridinium in China will further expand, and the import amounts will continue to decline.
   In 2017, China's export of pyridine and pyridinium was 3 396.334 tons. During the period of 2010-2017, the average annual growth rate of pyridine and pyridinium exports was 8.22%.