Changes in the Raw Material Routes Worth Focusing     

In the construction wave of integrated pesticide and intermediate projects, China's pesticide players should grasp and understand the overall progress in the synthesis technology of pesticides and intermediates and the changes in the supply and demand of their raw materials to ensure that the integrated pesticide and intermediate projects are low-cost, cleaner, technologically advanced and competitive.
   With the implementation of the circular economy and low-carbon economy in China and the accelerating adjustment of pesticide production and mix, many pesticide companies have been exploring the integrated upstream and downstream development model by building large-scale raw material and intermediate units for the production of pesticide active ingredients. Needless to say, this idea is correct. But several key factors, such as the advance of the synthesis technology of pesticides and their intermediates, the changes of balance between the supply and demand of raw materials, stricter state industrial entry threshold policies and more stringent work safety and environmental protection policies, may have huge impacts on the competitiveness of the integrated pesticide and intermediate projects. Therefore, much attention should be paid to these factors.
   Take 3,5,6-trichloropyridin-2-ol sodium (TCPS), the intermediate of chlorpyrifos, as an example. Now, almost all Chinese TCPS producers use trichloroacetyl chloride and acrylonitrile as raw materials to produce TCPS. This synthesis route has a low yield rate, leading to large amounts of wastes that become the bottleneck of the development of TCPS. With the development of the pyridine synthesis technology, large-scale pyridine plants are under construction in China. Pyridine can be chlorinated into tetrachloro pyridine, which is then turned into TCPS by hydrolysis and acidification. This can greatly enhance the yield rate. With the increasing supply of pyridine in China, the pyridine route will have a brighter prospect than the trichloroacetyl chloride route.
   Take glyphosate as another example. Its major production routes are the glycine route and the IDA route, among which the glycine route accounts for 55% of the total capacity of glyphosate in China. The IDA route is cleaner and has better prospects. The major factor restricting its development in China is the serious short supply of its raw material - diethanolamine. But now, China is building or planning to build more ethanolamine units (CCR2010 No7 page27). With the increasing supply of diethanolamine, the glycine route will have better prospects.
   The third example is phenoxy acid herbicides, whose major raw material is o-cresol. China has long relied on imported o-cresol. This has restricted the development of phenoxy acid herbicides in China. Internationally, the advanced o-cresol production technology mainly uses the phenol alkylation method. The main bottleneck that restricts the development of the phenol alkylation method in China is that the co-produced 2,6-xylenol has not market. With breakthroughs in the production technology of polyphenylene oxide (PPO), China plans to build more PPO projects. If pesticide makers can seize the opportunity to construct phenol alkylation units to attach PPO plants, they can solve the raw material supply problem of phenoxy acid herbicides and sell 2,6-dimethylphenol to the PPO plants.
   The fourth example is the carbamate insecticides, whose major members are carbofuran and propoxur. Their major raw material is catechol. In recent years, China has achieved a breakthrough in the synthesis technology of catechol and the co-generation of hydroquinone with the phenol hydroxylation method. In Lianyungang, Jiangsu province, Sanjili Chemical Industrial Co Ltd and Rhodia have both operated catechol production facilities. It is worth attention that in China, there are still several hydroquinone production plants that use the aniline oxidation method that can produce serious environmental pollution. As China enforces stricter environmental protection policies, these units will be closed in the near future. But in recent years, the demand for the downstream products of hydroquinone is very vigorous, leading to the soar of hydroquinone prices. By taking account of carbamate pesticides, projects that use the cleaner phenol hydroxylation technology to synthesize catechol and hydroquinone will have high competitiveness.
   The major varieties of benzoyl urea series insecticides include diflubenzuron, hexaflumuron, teflubenzuron, flufenoxuron, triflumuron, fluazuron and novaluron. They are all use 2,6-difluorophenyl formamide as the raw material. China has long imported 2,6-dichloro-benzonitrile for the synthesis of 2,6-difluorophenyl formamide. This has greatly enhanced the production costs of these pesticides and seriously hurt the international competitiveness of concerned makers. In recent years, China's chlorotoluene capacity has expanded rapidly, leading to a growing amount of 2,6-dichlorotoluene as a byproduct. This has provided pesticide producers the possibility to use 2,6-dichlorotoluene to synthesize benzoyl urea insecticides.
   There are many such examples else. For instance, dichloroaniline, which is the raw material of herbicides such as diuron, linuron and propanil, has long been produced from costlier o-dichlorobenzene. If it is produced from p-nitrochlorobenzene which is oversupplied in China and high-quality and cheap, its production cost will fall significantly.