Understand the comprehensive utilization of C9

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In China, ethylene production plants primarily use naphtha and hydrocracking tail oil as feedstocks for cracking; the C5 fraction accounts for 10%-15% of the ethylene produced, while the C9 fraction accounts for 10%-20% of it. In recent years, to meet market demands, the downstream products of C9 have been gradually upgraded and developed, achieving breakthroughs in integrated process technologies; as a result, both the degree of raw material utilization and its efficiency have improved. Pyrolyzed C9 contains a large amount of dicyclopentadiene, and is a raw material for producing high-grade petroleum resins and pharmaceutical intermediates. By tapping into the utilization value of these by-products, companies can enhance their economic efficiency and competitiveness. 1C9 comprehensive utilization process and current status: The C9 fraction is complex, comprising around 150 different compounds, with a high proportion of unsaturated components, including numerous unsaturated alkenes and polycyclic aromatic hydrocarbons. Achieving a clear separation is almost impossible. Research institutions at home and abroad can only perform a rough classification of C9, dividing it into active components and inactive components. After separation, C9 feedstocks have the following main industrial applications: 1) Production of petroleum resins through thermal polymerization. 2) Producing aromatic solvent oil through cracking and hydrogenation. 3) Produce DCPD (dicyclopentadiene) through polymerization and purification. Market analysis of 2C9 in comprehensive use; Analysis of the market status and trends of 1C9 aromatic solvent oils. C9 aromatic solvent oils are environmentally friendly cleaning products that can be used as a substitute for more toxic xylene in industries such as paints and coatings. Currently, **a directive has been issued requiring the use of aromatic solvent oils instead of xylene in the production of paints. Aromatic solvent oils are important solvents in the paint and coating industry. In the past, the market for such solvent oils relied entirely on xylene; today, it consists of a mixture of xylene and C9 aromatic solvent oils. Both can be used as substitutes for each other, yet they also have their own distinct characteristics. Due to its higher boiling point compared to common aromatics such as benzene, toluene, and xylene, as well as its slow volatility and strong solvating power, C9 aromatic compounds have excellent solving capabilities for synthetic resins. They can be used as diluents in paints and inks, emulsifiers for pesticides, cleaners for precision machinery, and solvents in certain chemical reactions. Abroad, there is significant emphasis on developing high-boiling aromatic solvents. Companies such as Mobil Oil, Union Carbon, Exxon, and Shell in the United States were among the first to use heavy aromatics to produce such solvents. Japanese companies like Maruzen Oil and Mitsubishi Oil also rushed to keep up, with their annual production reaching over 40,000 tons. The aromatic content of the aromatic solvent oil produced by the American company Exxon is over 99%, which gives it excellent solvency. It contains a small amount of components with lower boiling points; therefore, it retains its solubility even at the high boiling point and during the later stages of film evaporation, which enables the coating to remain smooth and shiny without any orange peel effect. Since there are no residual residues in the boiling range, they do not remain in the paint film for an extended period and thus do not affect its properties ； It has a low bromine value, so it does not affect the performance of the resins and reactive pigments in the coating ； It has a very high flash point, low toxicity, and is safe to use. This aromatic solvent features an appropriate boiling range, a high boiling point, a suitable evaporation rate, and strong dissolving power; it is widely used in the coating industry, especially in bake-type coatings, where it helps to improve their application properties and the quality of the coating film. In the SO-100 solvent oil produced by the American company Exxon, nonane aromatic hydrocarbons account for 85% to 90% ； In Suwazol100 from Nihon Maruzen Oil Company, C9 aromatic hydrocarbons account for 97%–99% ； In the Solvesso 100 solvent oil produced by Nippon East Asia Fuel using U.S. ESSO technology, C9 aromatics account for 85% to 90%. 2 Market Conditions and Trend Analysis of Dicyclopentadiene. Dicyclopentadiene can be used in the production of ethylene-propylene rubber, unsaturated polyesters, synthetic petroleum resins, synthetic coating resins, adhesive resins, paper filling resins, as well as in pharmaceuticals and fuels. It is also used in the manufacture of synthetic materials and synthetic fragrances, as well as serving as an intermediate in organic chemistry. Dicyclopentadiene can be depolymerized into cyclopentadiene, which is an intermediate for synthetic resins, pesticides, pharmaceuticals, and fragrances. How to make rational use of China’s abundant resources to produce DCPD in order to meet the growing industrial demands, and how to develop and apply DCPD to guide its consumption, are important issues. In Japan, a considerable portion of dicyclopentadiene resin is used in the production of printing inks. In 2017, the overall operating rate of the domestic dicyclopentadiene market saw a recovery. Since the second half of 2015, the overall performance of the domestic bisphenol A market has been weak; manufacturers have found it difficult to maintain profits, and producers’ enthusiasm for manufacturing has declined. However, as the utilization rate of hydrogenation resins increased, bisphenol A manufacturers became more motivated to produce, with an estimated output of 220,000 tons in 2017. 3 Market Conditions and Trend Analysis of Petroleum Resins Petroleum resins are resinous substances produced by polymerizing olefins or cycloolefins, which are by-products of petroleum cracking. It features a low acid value, good miscibility, a low melting point, as well as resistance to water, ethanol, and chemicals. Soluble in aliphatic hydrocarbons and chlorinated hydrocarbons, insoluble in lower alcohols and similar compounds. It is mainly used in the coating industry; for example, petroleum resin emulsions are used to enhance synthetic latex coatings, while light-colored petroleum resins are used to produce oil-based varnishes to improve gloss and adhesion. It is also used in the rubber industry, where resins with a low softening point are used as plasticizers, while resins with a higher softening point are used to increase the hardness of synthetic rubber. It is also used in the production of hot melt adhesives, traffic sign paints, printing inks, and paper hydrophobics. The application of petroleum resins in our country is experiencing rapid development; in the fields of hot-melt adhesives and pressure-sensitive adhesives, petroleum resins are gradually replacing terpene resins and rosin resins. In rubber processing, petroleum resins serve both to soften and thicken materials as well as to act as fillers and reinforcing agents; they can completely replace coal tar-based guayule resins and partially replace rosin resins, and their usage is increasing rapidly. In addition, there is also a certain amount of use in areas such as oilfield chemicals and asphalt modifiers. In summary, the annual demand for petroleum resins in China is currently growing at an annual rate of around 12%. In recent years, with the rapid development of the national economy, China’s ethylene industry has grown swiftly, becoming the world’s second-largest producer of ethylene after the United States. In the coming years, several new or expanded ethylene production facilities will still be put into operation in our country. Based on a survey of the current progress of various ethylene projects in the country, China’s ethylene production capacity is expected to reach approximately 32.3 million tons by 2020. The structure of raw materials used for ethylene cracking in our country is skewed, with naphtha accounting for a much higher proportion than the world average (47%), while the proportion of light hydrocarbons is significantly lower than the world average (49%). As the production capacity of ethylene in the Middle East and North America, which uses cheap ethane as a raw material, expands rapidly, the current reliance of domestic ethylene cracking units on liquid feedstocks results in uncompetitive costs for them. To address the issue of naphtha being used as a raw material for ethylene production and its impact on the competitiveness of the products, it is essential to extract the by-products generated during ethylene cracking and to use technological innovations to increase the added value of downstream products.