Aromatic hydrocarbons are of great significance to the coal chemical industry

In the context of breakthroughs in key technologies such as coal-to-oil, coal-to-olefin, coal-to-coal ether, and coal-to-natural gas, coal-based aromatics can be considered as the last major bastion of coal chemical technology in China. After years of unremitting efforts, this fortress was eventually conquered.

In mid-April, China Huadian Corporation announced in the Great Hall of the People that the coal-based aromatics technology developed by Huadian Group and Tsinghua University and possessing China's independent intellectual property rights and reaching the international advanced level has been launched at Huadian Coal Yulin Coal Chemical Industry Base. .

Experts in the industry stated that the successful research and development of coal-to-aromatic technology has created a new approach to coal-based energy and chemical engineering, making China the first country in the world to use coal as raw material to produce petrochemical products for the entire industrial chain.

Major breakthroughs in coal-rich China have been actively promoting oil substitution strategies to ensure energy security.

The Huafang Group's coal-based aromatics test project in Yulin, Shaanxi Province is the world's first coal-to-aromatic project and is also an important component of Huadian's innovation-driven strategy. Yuncheng Citizen, general manager of Huadian Group, expressed that: “In the process of building green energy, Huadian Group attaches great importance to the clean and efficient use of coal resources. The successful development of coal-based aromatics technology replaces China’s petrochemical raw materials and seizes the world’s energy and chemical industry. The new opportunities for development are of great significance."

According to reports, the world's first 10,000-ton methanol-to-aromatic industrial test facility was built at Huadian Coal's Shaanxi Yulin Coal Chemicals Base in 2012. On January 13, 2013, it successfully achieved a successful commissioning test. The methanol conversion rate of the first feed material was higher than 99.99%, and the content of methylbenzene (mainly toluene, xylene, and trimethylbenzene) in the oil phase product reached more than 90%. On March 18, the pilot test technology passed the national appraisal of scientific and technological achievements. Hu Qianlin, deputy secretary-general of the China Petroleum and Chemical Industry Federation, gave an opinion on behalf of the expert group of the appraisal committee: The technology is innovative, and it is generally at the international leading level of similar technologies. Its successful development is the development of complete sets of coal-based aromatics technology. Foundation.

According to industry experts, coal-based aromatics undergoes three major steps. After coal is clean coal gasified, it will produce syngas, and the synthesis gas will be converted into methanol. The methanol will be further transformed into aromatics. The first two steps have mature industrial technology abroad, but the industrialization of methanol to aromatics is still a blank.

Jin Yong, professor of the Department of Chemical Engineering at the Tsinghua University and an academician of the Chinese Academy of Engineering, told the “State-owned Enterprise” reporter that one way to rapidly industrialize coal-based aromatics technology is to produce aromatics directly from methanol. Objectively speaking, methanol-to-aromatics has become a key strategic technology related to the implementation of China's oil substitution strategy, the realization of deep transformation of coal resources, and the efficient and clean use of coal resources. The development of Huadian's coal-based aromatics technology has become a representative of the comprehensive strength of the national basic chemical industry.

Kang Kejun, vice president of Tsinghua University, also said that this breakthrough will make it possible to use China's abundant coal resources to produce high-end petrochemical products.

Aromatic aromatic hydrocarbons are key raw materials for chemical fiber, engineering plastics and high-performance plastics, and are widely used in apparel fabrics, aerospace, transportation, decoration, electrical products, mobile communications and other fields. As a bulk basic organic chemical raw material, aromatics are closely related to our lives. At present, China's annual consumption exceeds 20 million tons. Especially in the past 10 years, China's engineering plastics, rubber antioxidants, dyes and other industries have developed rapidly and demand for aromatics is huge. Due to insufficient production capacity, aromatics imports have approached 50% of total demand over the years. However, due to the fact that more than 97% of conventional aromatics are manufactured from petroleum feedstocks, the price is high all year round. In addition, with the limited supply of petroleum resources and the impact of low-cost petrochemical products in the Middle East, under the background of the gradual increase of China's oil dependence on foreign markets, the original aromatic hydrocarbon production road becomes increasingly unsustainable. New routes must be sought instead of traditional petroleum routes to produce aromatics.

According to statistics from the Nitrogen Fertilizer Industry Association, China's methanol production in 2012 was 31.64 million tons, an increase of 19.08% over the previous year, and the start-up load of the plant reached 61.3%.

One side is the shortage of aromatic hydrocarbons, while the other is the excess of methanol. The two items that appear to be unrelated are in fact closely linked.

Jin Yong told the “State-owned Enterprise” reporter that methanol is a platform compound. Based on methanol as an aromatic hydrocarbon, it can not only reduce the dependence of aromatics production on petroleum raw materials, but also find a practical and feasible technical route for domestic excess methanol production capacity.

Tsinghua University professor Wei Fei told the "State-owned Enterprise" reporter that at present, the aromatics gap in China is 6 million to 7 million tons. If one ton of aromatics consumes 3 tons of methanol, then only methanol used for aromatics will reach more than 20 million tons. . This will effectively alleviate the excess of methanol in China.

Huadian's use of methanol to convert aromatics can be described as more effective. Ding Huande, chairman of Huadian Coal, told the reporter: “As far as the company itself is concerned, actively developing and applying coal-to-aromatic technology can extend the industrial chain, promote industrial optimization and upgrading and structural adjustment, and form a company’s core competitiveness through technological innovation to achieve sustainable development. development of."

Green Chemistry For a long time, there have been two major problems in the coal chemical industry: technology and environmental protection. So, is coal-to-aromatic technology environmentally friendly when it comes to converting methanol to aromatics?

"The advanced nature of this technology is mainly reflected in the fact that the core fluidized bed unit operates very smoothly and with high elasticity, and the degree of continuous and automation is also very high; methanol can be completely converted, and 3.07 tons of methanol can produce 1 ton of aromatic hydrocarbons, and the by-products A lot of hydrogen; process wastewater does not contain ammonia nitrogen, exhaust gas does not contain * nitrogen." Jin Yong introduced.

The research and development of coal-to-aromatic technology has implemented the concept of “green chemistry” from beginning to end. According to the reporter's knowledge, the coal-based methanol production process has undergone off-removal and denitrification treatment, and the aromatic product produced has been cleaner. At the same time, the high selectivity of the catalyst has also resulted in far fewer components of the aromatic hydrocarbon product than the petroleum-based product group. As a result, the aromatics separation process avoids the complex process of extracting petroleum-based aromatics and the energy consumption of products is greatly reduced. In addition, a large amount of hydrogen, which is by-produced from the methanol to aromatics process, and some of the lower alkanes can also be used as raw materials for the production of methanol, thereby greatly reducing the raw material consumption of methanol to aromatics. For Huadian, through the comprehensive utilization of energy and materials in coal mines, power plants and chemical plants, coal-to-aromatic technology has achieved the goal of maximizing the comprehensive utilization of resources and substantially reducing pollutant emissions.

Future Development It is reported that Huadian will accelerate the construction of a million-ton methanol industrial aromatics demonstration plant, build an industrial chain of coal-based aromatics and downstream derivatives from coal-methanol-aromatic-polyester, and build integrated coal-fired power resources. The use of industrial clusters.

Cloud citizens said that due to the fact that the two key issues of fluidized bed reactor amplification and catalyst stability have now been effectively solved, there has been technical support for the amplification of the device to millions of tons.

Huadian plans to complete the process package design, feasibility study report, and preliminary design of the one-million-ton demonstration project during the year, and initiate the preparation work for the “four connections and one leveling” project site. Based on the success of the 10,000-ton methanol-based aromatics industrial test facility, Huadian Shaanxi Yulin Coal Chemical Base will be fully launched during the year, and the world’s first million-ton coal-based aromatics demonstration unit will gradually become industrialized in the coming years.

In the future, Huadian will further increase the transformation of scientific and technological achievements, promote the transition from low-level energy development to high-end resource economy, and strengthen and expand the coal chemical industry.