Introduction to a new composite catalytic process for biphenyldichlorobenzene

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Biphenyldichlorobenzene (4,4’-bis(chloromethyl)biphenyl), as a key intermediate in the fine chemical industry, plays a vital role in fluorescent brighteners, electronic materials, and the pharmaceutical sector. However, for a long time, traditional production processes have been plagued by three major problems: low yields, high costs, and severe pollution, which hinder the upgrading and development of the related industrial chains. Recently, a new composite catalytic synthesis process for biphenyldichlorobenzene has been developed. This technology has achieved significant advancements in terms of reaction efficiency, product yield, environmental sustainability, and production costs, providing the industry with a new generation of more competitive technical solutions. I. Technical breakthrough: The key lies in composite catalysts. The synthesis of biphenyldichlorobenzene is not a new topic, but traditional processes use zinc chloride as a catalyst, which leads to poor reaction selectivity and numerous side reactions. To suppress side reactions, dispersants and polymerization inhibitors had to be added during the production process. This not only prolonged the reaction time (to about 20 hours) but also resulted in a product yield that remained around 55% for a long time; furthermore, subsequent separation proved difficult, generating large amounts of waste liquid that was hard to handle. The core of the new process lies in the development of a novel composite catalyst system. Through the synergistic action of different catalytic components, this system achieves two key advancements: it facilitates the main reaction efficiently – the catalyst’s activity is sufficient to activate the reactants effectively, reducing the reaction time from 20 hours to about 10 hours, thereby increasing efficiency by 100%. Effective suppression of side reactions: Its unique catalytic properties prevent the occurrence of key side reactions at the source, eliminating the need for additives such as dispersants and polymerization inhibitors. This simplifies the formulation and production process, and reduces the formation of impurities from the outset. Comparison of key parameters between old and new processes: Parameters, Advantages of the new process over the existing one. Reaction time: approximately 20 hours vs. approximately 10 hours; Efficiency increases by 100%, with production capacity doubling. Molar yield: approximately 55% vs. ≥65%; Yield increases by over 10 percentage points, and raw material costs are significantly reduced. Product purity: 98–98.5% vs. ≥98.5%, meeting the requirements for high-end applications; metal ion content is low. Additives required: dispersants and polymerization inhibitors are needed in the old process, while none are required in the new process. The process is simplified, costs are reduced, and it is more environmentally friendly. Waste treatment: Large volume of waste liquid, high treatment costs; Reduced volume of waste liquid leads to a significant decrease in environmental pressures. II. Economic analysis: Significant cost advantages. In addition to the improvements in technical parameters, the new process also offers economic advantages. By increasing yield, reducing raw material consumption, and lowering the costs associated with waste treatment, the new process offers a significant competitive advantage in terms of production costs. Reduced raw material costs: When producing one ton of biphenyldichlorobenzene, the cost of the main raw materials in the new process is approximately 3,000 yuan lower compared to the traditional process. Catalyst is recyclable: The new composite catalyst can be easily recycled and reused up to 10 times, further reducing costs. Comprehensive cost advantage: It is estimated that at a production scale of thousands of tons, the total cost of the new process (including treatment of waste water, waste gas, and solid waste) is 35,000–45,000 yuan per ton lower than the industry average for traditional processes. With the current market price of the product ranging from 55,000 to 65,000 yuan per ton, the new process provides enterprises with a considerable profit margin. III. Market Analysis: A combination of existing and new supply, with premiumization as the trend – The market landscape for dibenzodichlorobenzene is undergoing changes. Its downstream applications are mainly divided into two categories: 1. Existing market: Fluorescent brighteners (CBS). CBS is currently the main source of demand for biphenyl dichlorobenzene, accounting for 70%-80% of the total demand. CBS is known as a “super optical brightener”. It is widely used in high-end detergents and offers advantages such as high efficiency, stability, and environmental friendliness. It has obtained safety certifications from markets including the EU and Japan. Currently, the global annual production of CBS is around 21,000–32,000 tons, which corresponds to a consumption of 10,000–16,000 tons per year of biphenyldichlorobenzene. There is high and stable demand for this product in the market, but competition is fierce; it is sensitive to the prices of upstream raw materials, and the profit margin is relatively limited. 2. Incremental markets: With technological advancements, electronic materials and pharmaceutical intermediates are seeing an expanding use of biphenyldichlorobenzene in high-end applications, making it an important area for future growth. Electronic materials: Used as monomers for synthesizing high-performance polyimides (PI), and applied in flexible circuit boards, 5G communication devices, etc. Pharmaceutical intermediates: used in the synthesis of various drugs. This market segment has high requirements for product purity (≥99.5%), is relatively less sensitive to price, and holds great growth potential. Due to quality limitations, traditional crafts face certain difficulties in entering this high-value-added market. IV. Conclusion The new process has brought improvements to multiple key stages in the traditional production of biphenyldichlorobenzene. With high yields, stable quality, and low costs, it not only provides a more competitive raw material option for the traditional fluorescent brightener market, but also offers a technical foundation for companies to enter the rapidly growing markets of electronic materials and pharmaceutical intermediates, thanks to its advantage in purity. Against the backdrop of the fine chemical industry’s transformation toward greener, more efficient, and higher-value-added processes, this technology possesses good industrialization potential and market competitiveness. For enterprises interested in optimizing their existing production processes or extending their industrial chains, this is a technology option worth considering.