Recently, a research and interview team organized by the News Center of the State owned Assets Supervision and Administration Commission of the State Council visited China Salt Industry Group Co., Ltd. Several media reporters visited Jintan, Jiangsu, to visit the largest and most technologically advanced well and mine salt production enterprise in China's salt industry under China Salt Group. They gained a comprehensive understanding of the salt production, packaging, and shipping process; We conducted an in-depth investigation of China's first internationally leading salt cavern compressed air energy storage test demonstration project, to understand the operating principle of this large-scale energy storage "power bank" and its positive significance for the development of new energy storage.

As the only central enterprise in the salt industry, China Salt Group, established in 1950, shoulders the significant responsibility of ensuring the quality and safety of national salt and supply security. It has always led the development of salt production concepts and technologies in China, promoted the greater role of salt in maintaining people's health and building a healthy China, and has grown into the world's second largest salt industry enterprise. At the same time, China Salt Group focuses on innovating industry value, forward-looking layout and exploring strategic emerging industries for comprehensive utilization of salt cavern resources, constructing a new development pattern that organically integrates economic, political and social attributes, and actively serving the national "dual carbon" strategy and energy security.

Accelerate the digital, intelligent, and green transformation and upgrading of traditional industries

It is reported that China National Salt Corporation has long been committed to promoting the healthy development of the salt industry, actively carrying out technological innovation, and leading the upgrading of salt production technology and processes in China. Among them, the affiliated Zhongyan Jintan Salt Chemical Co., Ltd. (hereinafter referred to as Zhongyan Jintan) is one of the first national high-tech enterprises in the salt industry and the first batch of State owned Assets Supervision and Administration Commission of the State Council's "Science and Technology Reform Demonstration Enterprises". It has one national postdoctoral workstation and three provincial technology research and development centers.

During a visit to Zhongyan Jintan Jinsai Salt Factory, the reporter learned from the staff that in 2004, Zhongyan Jintan completed and put into operation a multi effect evaporation salt and nitrate co production device with an annual output of 600000 tons. In 2010, it also completed and put into operation a heat pump technology salt production project with an annual output of 1 million tons. The success of the two major projects has driven a major leap forward in domestic salt production technology, reducing energy consumption to about 45 kilograms of standard coal per ton, which is at an advanced level in the industry and ushering in an era of high production capacity and low energy consumption in salt production.

In 2018, Zhongyan Jintan underwent three phases of steam turbine transformation, pioneering the use of a turbine driven compressor instead of an electric motor in the salt industry, becoming the first salt production enterprise in China to adopt a mechanical thermal compression (MVR) salt production device driven by a turbine.

Zhongyan Jintan vigorously promotes intelligent and digital production. This factory with an area of nearly 120000 square meters has less than 20 employees on duty in the workshop from production, quality inspection to product delivery, but has a strong "output" capability of producing 6000 tons of salt per day. Only three staff members are needed on site in the salt and nitrate workshop to control valves and equipment through computers, transforming brine into edible solid salt through multiple processing steps. At present, the per capita salt production value of Zhongyan Jintan ranks among the top in the country.

Zhongyan Group regards Zhongyan Jintan as an important specialized technology research and transformation center, conducting basic research in nine key research areas and directions, including mining technology, brine purification and salt production technology, thermoelectric technology, special salt technology, salt mud utilization technology, electromechanical instrument integration technology, information technology, analysis and inspection technology, and salt production engineering technology. It has obtained a total of 264 authorized national patents and participated in and led the formulation and revision of a series of technical standards.

The reporter learned from Zhongyan Jintan Special Salt Factory that Zhongyan Jintan's salt products include six categories: industrial salt, edible salt, household salt, water treatment salt, animal husbandry salt, and road salt. They cover various aspects of people's food, clothing, housing, and transportation, and are exported to more than 30 countries and regions overseas. The quality and types of exported salt, as well as the total export volume of edible salt, rank first in the national salt industry. At the same time, China Salt Group has explored the comprehensive utilization of salt cavern resources in the pilot project of China Salt Jintan, accumulating valuable experience.

Open up new fields and tracks of development through technological innovation

In 2021, in order to implement the national strategy and unify the planning of salt cavern gas storage, compressed air energy storage and other salt cavern comprehensive utilization businesses, Zhongyan Group established Zhongyan Salt Cavern Comprehensive Utilization Co., Ltd. (hereinafter referred to as Zhongyan Salt Cavern) based on the pilot project of Zhongyan Jintan. The company planned research and development investment, optimized resource allocation, and opened up new salt cavern resource comprehensive utilization main business sectors on the basis of existing salt, salt chemical and agricultural fertilizer main business sectors, forming the current "1+3" industrial system.

The reporter learned at the site of the Zhongyan Salt Cave Gas Storage that as early as the beginning of the 21st century, the national "West East Gas Pipeline" project was selected in the Yangtze River Delta region to build a natural gas reserve reservoir that plays a role in peak shaving and valley filling. The Jintan area attracted the attention of experts with its unique geographical advantages and superior salt cave resources. The needs of the country are the responsibility of state-owned enterprises. Zhongyan Group actively serves the national strategy, based on the salt caves in Jintan area, and takes the lead in researching, developing and utilizing salt caves in China.

To utilize salt caverns for gas and energy storage, it is not only necessary to use large equipment to produce salt to absorb brine, but also to "shape" the salt cavern cavity to ensure that the "shape" of the salt cavern meets the "energy storage" requirements. While increasing the update of salt production technology, China National Salt Corporation has formed a complete set of salt cavern gas storage construction technologies through continuous construction practice and learning from mature foreign experience, including exploration, drilling, design, cavity making, operation, and monitoring. A series of technologies such as "plugging the old cavity of the original brine well and drilling new wells" are all pioneering in China. The technologies of old cavity renovation, salt cavity repair, and fiber optic monitoring have reached the international advanced level, and a series of new technologies and equipment with independent intellectual property rights have been developed, laying a solid foundation for expanding the comprehensive utilization of salt caverns.

Since 2005, China Salt Group has been cooperating with PetroChina to promote the national key project of "West East Gas Transmission and Storage", and later cooperated with Sinopec to build the "Sichuan East Gas Transmission and Storage" to serve major national strategies and ensure national energy security. On March 29, 2006, the first salt cavern gas storage facility in Asia, the Jintan gas storage facility, began construction comprehensively. From then on, "salt cavern energy storage" opened its doors on the land of China.

The emergency peak shaving guarantee scope of Jintan gas storage for the "West East Gas Pipeline" covers 14 cities and 74 counties in four provinces (municipalities directly under the central government) of Jiangsu, Zhejiang, Shanghai, and Anhui. Calculated based on a daily gas consumption of 1.5 cubic meters per household, it can meet the gas demand of 16 million households in the Yangtze River Delta region during peak shaving period, equivalent to replacing 6.4 million tons of standard coal, reducing emissions of 450000 tons of sulfur dioxide, 3.5 million tons of dust, and 4.55 million tons of carbon dioxide acid gas. The Jintan Salt Cave Gas Storage has played an important role as an underground granary in emergency situations such as extreme cold weather in the Yangtze River Delta in 2008 and floods in Henan in 2021.

In November 2014, the construction of the Ganghua Jintan salt cavern gas storage facility officially began, and the commercial application of the salt cavern gas storage facility became a reality. In January 2022, the Ganghua Salt Cave Gas Storage Project was awarded the "19th China Civil Engineering Zhan Tianyou Award". In September 2022, "Research and Application of Key Technologies for Jintan Salt Rock Chamber Energy Storage" was selected as an advanced and applicable technology catalog for mineral resource conservation and comprehensive utilization by the Ministry of Natural Resources of China.

In 2015, in order to solve the problem of abandoned wind and solar energy in the utilization of new energy, China Salt Group took the lead in cooperating with Tsinghua University to start the scientific and technological research of the "salt cavern based compressed air energy storage system project". In 2017, it was approved by the National Energy Administration and became the first and only national demonstration project of compressed air energy storage in China, undertaking the important task of developing a Chinese solution for salt cavern compressed air energy storage technology and creating a fully independent intellectual property technology system in China.

In 2018, China Salt Group, together with China Huaneng and Tsinghua University, officially began the construction of the Jintan Salt Cave Compressed Air Energy Storage Power Station project. It was completed and put into operation in September 2021, and officially connected to the grid for commercial operation in May 2022. It was selected for the "Striving for a New Era" theme achievement exhibition, attracting attention from multiple parties and triggering a new investment boom in the energy storage field, driving the accelerated development of new salt cave energy storage.

This power station has created records such as "the world's largest non staged compressed air energy storage system air turbine", "the world's highest parameter multi-stage centrifugal air compressor", "the world's largest single capacity and highest temperature parameter oil gas heat exchanger", etc. The core equipment has achieved 100% localization, which is a key technology for China to build a new type of power system and achieve the goals of "carbon peak and carbon neutrality". The project's electricity to electricity conversion efficiency has reached over 60%, which is 7 percentage points higher than the internationally advanced McIntosh power station in the United States. It can achieve peak shaving electricity of 130 million kWh per year and reduce carbon dioxide emissions by 30000 tons. Based on the project, 2 IEC international standards have been published, 1 IEC international standard has been approved, 12 national and industry standards have been published or are currently being developed, and 56 core patents have been obtained.

At present, China Salt Group has taken multiple measures to accelerate the development of comprehensive utilization of salt caverns. Cooperate with the China Geological Survey to conduct a nationwide survey of salt cavern resources and coordinate the development and utilization of salt cavern resources. Strengthening the promotion and application of existing technologies, new salt cavern compressed air energy storage projects have been launched in Yulin, Shaanxi and other places. Deepen cutting-edge research, cooperate with Tsinghua University, Chinese Academy of Sciences, South University of Science and Technology and other universities and scientific research institutes, focus on tackling core technologies such as hydrogen storage in salt caverns, liquid flow batteries in salt caverns, break technical barriers in related fields abroad, and actively create a source of original technologies for comprehensive utilization of salt caverns.

Accelerate the construction of a new development pattern for modern salt industry

In the 14th Five Year Plan, China National Salt Corporation clearly proposed to focus on both upgrading traditional industries and cultivating strategic emerging industries. Based on existing work, it will vigorously promote low sodium salt to better meet the needs of people's healthy living and national economic development; Intensify the development of new technologies for green energy conservation, circular economy, quality improvement and efficiency enhancement in the salt chemical industry, optimize the supply structure, and maintain the stability of the basic chemical supply chain; Developing strategic new industries such as microbial fertilizers and soil remediation technologies to ensure national food security; Promote the large-scale development of comprehensive utilization of salt cavern resources, build a new pattern of "multi energy storage", and help achieve the "dual carbon" goal.

In the future, China National Salt Group will continue to thoroughly study and implement the spirit of Xi Jinping Thought on Socialism with Chinese Characteristics for a New Era and the Party's 20th Congress, keep in mind that "the country is the biggest", give better play to the supporting role of scientific and technological innovation, industrial control and security, lead China's salt industry and drive the upstream and downstream to form a strategic emerging industrial ecosystem, promote the formation of new technologies, new products, new formats and new models, create new quality productivity of modern salt industry, make new contributions to the construction of a modern and powerful country with Chinese characteristics, and demonstrate the mission of state-owned central enterprises.