Red Sun: Diquat dichloride aims to create new burndown herbicide market trend

Editor：Mickey Shan

Feature : Showcase of China’s ″Specialized and Novel″ crop protection products/technologies/applications

▋ Special sponsor: Lansheng Biotechy 

▋ A total of 11 enterprises are introduced in this series; The Feature was first published in the latest "2023 China Pesticide Industry Watch" 

The overall industrial upgrading of Chinese manufacture industry happens to coincides with the unprecedented changes in the last 100 years. 

In this new era full of opportunities and policy support, the Chinese pesticide enterprises have worked hard to achieve constant technical breakthroughs via innovation and upgrading, as based on the experiences gained in the past decades. Some enterprises have so far made preliminary achievements, having formed an advanced and sophisticated technology and product cluster. 

In this Feature, we have selected 11 Chinese pesticide manufacturers that are characterized with professionalism, intensification, specialization and novelty, which is a presentation of Chinese pesticide enterprise’s research and development of new products, breakthroughs in technical innovation, upgrading of type of formulations and continued exploration of applications. The publication will exhibit the achievements in each individual sector, which is internationally advanced, revealing the new competitiveness of Chinese pesticide industry.

▉Series of special topics are released in succession → specially planned by AgroPages

• Lansheng Biotech：Green chemical innovation drives fine chemical production to reach a new level

• Eastlake High-Tech: Application of microreaction, continuous flow technologies to improve quality of plant growth regulators

• Qilu, industry leader of high quality spinosad

• KingAgroot – Innovative flagship integrating compound creation and biotechnical breeding

• CAC Nantong: Cyproflanilide, a created novel insecticide with unique action mechanism

• Yonon: Production of L-glufosinate on multienzyme

• Lier Chemical: 20,000-ton L-glufosinate production capacity to start running soon

• Red Sun: Diquat dichloride aims to create new burndown herbicide market trend

• Fosetyl-aluminium: Focusing on European wine grape market, Limin’s product concept upgraded

• Pilarbio: Working imaginatively on CS – an innovative cutting-edge formulation

• Chengdu New Sun: Making breakthroughs in industrialized application of plant growth regulation coronatine, first time in the world

 Red Sun: Diquat dichloride aims to create new burndown herbicide market trend 

A new series of opportunities for burndown herbicide development

The rapid and thorough weeding effect of paraquat is well known, making it a widely used product in agricultural production. However, due to its extreme toxicity to human and lack of dedicated antidote, the sale and use of paraquat aqueous solution was banned in China on July 1, 2016. Since then, the ban has been extended worldwide. In Vietnam, paraquat was banned in March 2017, while in Thailand and Brazil, it was banned from December 2019 and 2020, respectively.

As a substitute for paraquat, diquat has made a return in the market. Diquat is a burndown herbicide with contact toxicity that was developed and launched to market in 1958, which can be used in non-arable land weeding, as well as cultivated land protection against weeds. It can also be used as a crop seed drying agent. It offers fast weeding and is passivated rapidly in soil, being widely applied to directional weeding in croplands and orchards. It is effective for controlling annual weeds, such as eleusine indica, horseweed herb, crab grass, purslane, Conyza bonariensis, aglaonema and Equisetum ramosissimum, and is also effective against perennial weeds.

Diquat used to be a highly regarded burndown herbicide, until paraquat was introduced in 1962, which occupied a much higher market share than diquat, as the cost of diquat is higher than paraquat. With the ban of paraquat in China and other countries in 2016, a big gap is left over in the burndown herbicide market. Hence, a new round of opportunities of development of diquat has ushered in. At this time, the development and market launch of Red Sun’s diquat dichloride is expected to break into the existing market of burndown herbicides and bring benefit to farmers around the world.

A more cost-effective high-efficient burndown herbicide - diquat dichloride

Diquat can be divided into diquat dichloride and diquat dibromide. Diquat dibromide was commercialized earlier, and is the common variety commercially available on the market.

Diquat dichloride is made using dibromide monohydrate solution as a raw material, while chlorine gas is used as and oxidant for oxidization of bromine ion to generate bromine, resulting in diquat dichloride. Diquat dichloride has a better cost advantage than diquat dibromide under the same conditions, with an efficacy level 1.4 times the level of diquat dibromide. Diquat dichloride has a wide herbicidal spectrum, which can effectively control most annual broadleaf weeds and part of grassy weeds, with an excellent effect in terms of controlling the worst weeds in crop fields and against weeds resistant to glyphosate. It is also a fast-acting product, being superior to other herbicide varieties, and has low residue, being passivated and detoxicated in soil while being friendly to the environment and having good fertilizer and water retention.

Diquat dichloride is widely used in crop drying, which is beneficial to stubble cleaning and drying, helping improve land utilization, increasing yield, facilitating agricultural mechanization and saving farming costs, being an excellent product variety to replace paraquat and glyphosate. It also helps solve the high-cost issue of applications in favor of farmers.

Breaking through paraquat industry chain dominated by foreign companies

After 10 years of considerable efforts, in 2016, Nanjing Red Sun independently developed a new green diquat dichloride production process using its industrial chain advantages. The difference between diquat dichloride and diquat dibromide lies in their different cations in the functional group of the product from the process of synthesis. In the past, diquat dibromide used 2-Chloropyridine as the starting material, being synthesized in two steps, catalytic coupling and salt-forming reaction, reacted with 1,2-dibromoethane and compounded into diquat dibromide. The total yield of the reaction is as high as 86%, generating 2.0 tons of wastewater per ton of product and 0.6 tons of zinc chloride waste.

Red Sun’s newly developed diquat dichloride production process is a breakthrough against the 60-year domination of the dehydrogenation coupling technology by European and American companies. Red Sun’s production process reduces the cost of diquat by 20% to 30%, generating considerable profits for manufacturers and retailers.

Currently, Red Sun has filed for a patent for its diquat dichloride technology, being an exclusive manufacturer of diquat dichloride in China and a legally qualified producer of diquat dichloride mother liquor and soluble concentrate. Chongqing Huage Biochemical, a subsidiary of Red Sun, has a production capacity of 20,000 tons of diquat dichloride converted to 100% content. In 2022, market sales exceeded 2,000 tons valued at RMB200 million. In China, the company’s diquat dichloride has overtaken the diquat dibromide market and parts of the paraquat market.

Red Sun’s diquat dichloride has the following 7 major advantages:

1. Certificate advantage

Diquat dichloride is a pyridine herbicide independently developed by Red Sun. In terms of mother liquor, Red Sun is the only diquat dichloride 42% mother liquor registrant (registered in May 2018 under No. PD20181694). In terms of formulations, Red Sun’s diquat dichloride 20% SL was granted registration in March 2020, under No. PD20200072.

2. Raw material advantage

The intermediate of diquat dichloride is 2,2’-Dipyridyl. Red Sun has a large production capacity of this intermediate, with an obvious raw material advantage.

3. Cost advantage

To achieve the same weeding effect, the cost of diquat dichloride is much lower than diquat dibromide. At same cost of application, the weeding effect of diquat dichloride is considerably better than diquat dibromide.

4. Capacity advantage

Red Sun is the largest diquat technical manufacturer in China and owns the entire industrial chain, covering the raw material, intermediate, technical, formulation and terminal markets, offering the advantages of cyclic production and ecological protection.

Red Sun has established a new diquat industrial chain with independent intellectual property rights. When the production of diquat dichloride and diquat dibromide are both running, the production capacity of diquat is 20,000 tons (converted to 100% content), which will account for more than half of the global diquat production capacity.

5. Herbicidal activity advantage

Diquat dichloride is made from diquat dibromide by replacing bromide ions with chloride ions. As the oxidation of chloride ion is stronger than bromine ion, the replacement of bromide ions in diquat dibromide by chloride ions makes the newly produced saline in diquat dichloride more active.

6. Production process advantage

Red Sun has successfully created a new diquat industrial chain with independent intellectual property rights, which is a leading production process, being environmentally-friendly and safe with less waste discharge.

7. Application technology advantage

In recent years, Red Sun has conducted thousands of field demonstrations on diquat dibromide, and mastered the method for using diquat across the south and north of the country. Red Sun has largely solved the problem of the resumed growth of the grass family, using different diquat formula combinations during different time periods, representing a technical backup for the company’s development of diquat dichloride.

In terms of the overseas marketing of diquat dichloride, diquat dichloride is currently undergoing trials in Vietnam, its registration in Paraguay has been completed, its registration process, in cooperation with a multinational company in Brazil, is in progress, and its registration applications in other countries are underway. Premium customers are welcome to cooperate in the registration process.

In the coming years after its corporate restructuring, Red Sun will continue to focus on diquat dichloride, which is the major and exclusive product variety for the company, and will promote the product in the international market. Red Sun is working hard to regain the eighth place in terms of global pesticide production, by virtue of its five new technologies and products:, which are nano pesticide, diquat dichloride, 2,2’-Dipyridyl, L-glufosinate and Chlorantraniliprole. If its plan progresses smoothly, Red Sun’s Phase I Chlorantraniliprole will enter production in May this year, followed by the operation of Phase I L-glufosinate in June.

This article was initially published in AgroPages' 2023 China Pesticide Industry Watch magazine.