**1. Introduction**

Steel production is an energy-, resource-, and pollution-intensive process [1,2]. China is currently the world's largest steel producer; indeed, the country's steel production accounted for 49.2% of the world's total steel production in 2017 [3]. The energy consumption of China's steel industry accounted for over 20% of the national industry energy consumption in 2017, and the CO<sup>2</sup> emissions from steel enterprises also accounted for over 10% of the country's total CO<sup>2</sup> emissions [4–6]. As such, improving the energy efficiency of steel production should be a primary concern for China, especially in times of high energy price volatility.

The rapid development of China's steel industry began in the 1990s. From 1990 to 2017, the world's total steel production increased by 850 Mt, of which 87% came from China [7]. Rapid expansion of production capacity has had generally positive effects on the energy efficiency of the industry, and the energy intensity (EI) of China's steel industry decreased by 11.5% from 2006 to 2017 [8]. However, there is still a gap between the EI of China0 s steel industry and the world0 s advanced level.

In 2018, the production of China's steel industry increased to 928 Mt. After years of rapid expansion, China's steel industry is currently at the end of the stage of production growth. In fact, the industry

is facing numerous pressures, such as overcapacity and resources, energy, and environmental issues. These issues must be solved under the condition of ensuring an adequate steel supply, and this is a challenge for the Chinese government. environmental issues. These issues must be solved under the condition of ensuring an adequate steel supply, and this is a challenge for the Chinese government. There are various energy-efficiency opportunities that exist in China, and many existing research works on the steel industry from a technical point of view are available in the literature, and the

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the industry is facing numerous pressures, such as overcapacity and resources, energy, and

There are various energy-efficiency opportunities that exist in China, and many existing research works on the steel industry from a technical point of view are available in the literature, and the energy saving potential of China has been assessed in scientific papers [9–15]. However, currently, a comprehensive review of China's steel industry is still necessary to give readers a clear understanding of the present situation and development plan to realize the production structure adjustment and technical level upgrade. energy saving potential of China has been assessed in scientific papers [9–15]. However, currently, a comprehensive review of China's steel industry is still necessary to give readers a clear understanding of the present situation and development plan to realize the production structure adjustment and technical level upgrade. The work presented in this paper is a unique study for the steel industry, as an extensive review of China's steel industry was conducted in this study. This paper specifically discusses (1) the

The work presented in this paper is a unique study for the steel industry, as an extensive review of China's steel industry was conducted in this study. This paper specifically discusses (1) the development and present situation of steel production and consumption in China; (2) the implementation rate of major energy-saving technologies, gas recovery and utilization, and secondary energy generation in key enterprises in the country; (3) the development of the overall energy intensity (EI), specific process EIs, and the EI gap in key steel enterprises between China and the world; and (4) the carbon emissions of China's steel production and its main sources. development and present situation of steel production and consumption in China; (2) the implementation rate of major energy-saving technologies, gas recovery and utilization, and secondary energy generation in key enterprises in the country; (3) the development of the overall energy intensity (EI), specific process EIs, and the EI gap in key steel enterprises between China and the world; and (4) the carbon emissions of China's steel production and its main sources. This paper also presents an analysis of the reasons behind the EI gap between China's and the world's steel industries. The factors considered include scrap ratio (SR), production structure, energy

This paper also presents an analysis of the reasons behind the EI gap between China's and the world's steel industries. The factors considered include scrap ratio (SR), production structure, energy structure, and industrial concentration. In addition, development plans for major energy conservation in China's steel industry are also introduced and analyzed. These plans include eliminating backward production capacity, developing and implementing energy-saving technologies, and adjusting production structures by increasing scrap consumption in steel production. structure, and industrial concentration. In addition, development plans for major energy conservation in China's steel industry are also introduced and analyzed. These plans include eliminating backward production capacity, developing and implementing energy-saving technologies, and adjusting production structures by increasing scrap consumption in steel production. We hope this study could be a useful reference for global policy makers, researchers, and

We hope this study could be a useful reference for global policy makers, researchers, and industrial energy users, and be helpful for energy conservation and emission reduction work of China's steel industry. industrial energy users, and be helpful for energy conservation and emission reduction work of China's steel industry.

#### **2. Development and Present Situation of China's Steel Industry 2. Development and Present Situation of China's Steel Industry**

#### *2.1. Steel Production and Consumption 2.1. Steel Production and Consumption*

The rapid development of China's steel industry began in the 1990s, and the rise of this industry has had an important impact on the development of the global steel production (Figure 1). China became the world's largest steel producer in 1996 and has retained this status thus far. From 1990 to 2017, the world's total steel production increased by 850 Mt, of which 87% came from China [7]. The rapid development of China's steel industry began in the 1990s, and the rise of this industry has had an important impact on the development of the global steel production (Figure 1). China became the world's largest steel producer in 1996 and has retained this status thus far. From 1990 to 2017, the world's total steel production increased by 850 Mt, of which 87% came from China [7].

**Figure 1. Figure 1.** Development of global steel production. Development of global steel production.

*2.2. Production Route.*

*2.2. Production Route.* 

In 2017, the world's total steel production was 1689.4 Mt (Figure 2), and the top 10 steel producers included China (831.7 Mt), Japan (104.7 Mt), India (101.4 Mt), the United States, (81.6 Mt), Russia (71.3 Mt), South Korea (71.0 Mt), Germany (43.4 Mt), Turkey (37.5 Mt), Brazil (34.4 Mt), and Italy (24.1 Mt) [16]. In 2017, the world's total steel production was 1689.4 Mt (Figure 2), and the top 10 steel producers included China (831.7 Mt), Japan (104.7 Mt), India (101.4 Mt), the United States, (81.6 Mt), Russia (71.3 Mt), South Korea (71.0 Mt), Germany (43.4 Mt), Turkey (37.5 Mt), Brazil (34.4 Mt), and Italy (24.1 Mt) [16]. In 2017, the world's total steel production was 1689.4 Mt (Figure 2), and the top 10 steel producers included China (831.7 Mt), Japan (104.7 Mt), India (101.4 Mt), the United States, (81.6 Mt), Russia (71.3 Mt), South Korea (71.0 Mt), Germany (43.4 Mt), Turkey (37.5 Mt), Brazil (34.4 Mt), and Italy (24.1 Mt) [16].

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**Figure 2.** Top 15 global steel producers. **Figure 2.** Top 15 global steel producers. **Figure 2.** Top 15 global steel producers.

As the world's largest steel producer, China is also the world's largest steel consumer. In 2017, China's steel consumption accounted for 46.4% of the world's total steel consumption; by comparison, European Union (EU) countries and North American Free Trade Agreement (NAFTA) countries accounted for 10.2% and 8.9% of the world's total steel consumption, respectively [16]. In addition, Japan accounted for 4.1% of the world's total steel consumption, and other Asian countries consumed 15.9% of the world's total steel (Figure 3). As the world's largest steel producer, China is also the world's largest steel consumer. In 2017, China's steel consumption accounted for 46.4% of the world's total steel consumption; by comparison, European Union (EU) countries and North American Free Trade Agreement (NAFTA) countries accounted for 10.2% and 8.9% of the world's total steel consumption, respectively [16]. In addition, Japan accounted for 4.1% of the world's total steel consumption, and other Asian countries consumed 15.9% of the world's total steel (Figure 3). As the world's largest steel producer, China is also the world's largest steel consumer. In 2017, China's steel consumption accounted for 46.4% of the world's total steel consumption; by comparison, European Union (EU) countries and North American Free Trade Agreement (NAFTA) countries accounted for 10.2% and 8.9% of the world's total steel consumption, respectively [16]. In addition, Japan accounted for 4.1% of the world's total steel consumption, and other Asian countries consumed 15.9% of the world's total steel (Figure 3).

**Figure 3.** Global steel consumption in 2017 [16], with permission from World Steel Association 2019. **Figure 3.** Global steel consumption in 2017 [16], with permission from World Steel Association 2019. **Figure 3.** Global steel consumption in 2017 [16], with permission from World Steel Association 2019.
