Preface

Coal has been utilized heavily during the last century and will likely continue to be used for at least the next several decades, particularly in Asian countries. Coal is relatively cheaper than other fossil fuels, making it an attractive option when other fuel prices increase. In addition, many countries possess large coal resources. Even with competition from petroleum and natural gas as energy sources, coal has acted as a moderate helper to meet the world energy demand Recent global warming and health hazards caused by micro-sized ultrafine particles prompted bans to the further utilization of coal.

Coal is a valuable asset that is abundantly stored within the Earth. Some suggestions propose the utilization of coal in its solid, liquid, and gaseous forms separately. Advocates of this approach argue that by doing so, coal resources can be optimally harnessed, ensuring maximum internal asset retention. However, economic considerations often lead to simpler methods of coal utilization, such as straightforward combustion for heat and electricity generation.

What will be the role of coal in the 21st century? Will its use be phased out or will it continue to play a basic role for certain countries and industries? And if so, for how long? With worsening climate change worldwide, CO2 emissions related to coal usage will determine the fate of coal energy in the 21st century.

Although the International Energy Agency's (IEA) Net Zero by 2050 roadmap envisions the end of coal generation by 2040, there is a high probability that this timeline will not be met. Actual costs and commercial availability of alternative clean energy technology will surely have a detrimental effect on this scenario.

The primary areas of coal utilization in the present day include electricity generation, iron/steel blast furnaces, kilns for cement production, and certain high-temperature industries. Unlike historical uses for small-scale applications like house heating, modern coal utilization is concentrated in large-scale industrial processes. This circumstance might justify more in-depth technological efforts for improving efficiencies and disseminating best practices in the coal energy field.

While finding ways to eliminate or substantially reduce CO2 emissions is crucial for the long-term sustainability of coal energy, the reality is that many developing countries, especially in Asia, heavily rely on coal for energy security. This dependence is likely to persist at least during the early part of the 21st century. As such, sharing information about ways to minimize CO2 emissions and maximize process efficiencies while minimizing costs and environmental impacts should be encouraged.

Lessons from highly optimized experiences in developed countries, along with innovative statistical tools, are ready to be employed in the coal energy field. Leveraging these resources can enhance efficiency, reduce waste, and promote sustainable practices in coal utilization. This book discusses some of these issues.

The book contains six chapters in three sections on the past/future of coal energy, statistical tools application, and application technologies. The first section deals with the past and future of coal energy, ranging from fundamental questions on coal usage to the development history in coal mining. The second section includes two chapters that discuss the issue of improving productivity and effectiveness in the coal energy industry and the application of existing statistical tools. The third section presents examples of practical applications in coal utilization, such as gasification and high-value utilization of fly ash.

Chapter 1 critically deals with the pros and cons of coal energy with some philosophical discussion, while more focused on the detrimental impacts that have accumulated by coal mining as well as the future direction for environmentally benign coal use. Chapter 2 explains the history of and the equipment developed for enhancing productivity in coal mining as well as current clean coal technologies, including USC(Ultra-Supercritical)/IGCC(Integrated Gasification Combined Cycle) and recent CCUS(Carbon Capture Utilization and Storage) projects in Japan.

Chapter 3 presents an example of applying factor analysis in coal mining by extracting statistically significant variables from management/technology at seven Indian mines for resolving low productivity problems. Chapter 4 describes the Lean Six Sigma method for detecting which factors cause product failures and for seeking improvement suggestions in a rotary kiln case. Coal is still a major heating medium in rotary kilns used by the cement and smelting industries.

Chapter 5 explains the bubbling fluidized bed coal gasifier, providing information on basic fluidization fundamentals and examining practical pilot-scale details beneficial in university research labs. Chapter 6 demonstrates the utilization of waste coal fly ash, which can otherwise cause environmental problems for value-added materials like zeolites. It also summarizes existing literature data regarding synthesis methods and properties of zeolite products.

Some chapters in the book might not be considered novel scientific papers like those that typically appear in scientific journals. Instead, they are technical reports that share more in-depth, on-site information on the specific field of coal energy. This practical approach becomes significant when considering the widespread use of coal energy in existing facilities. These facilities often seek ways to maximize efficiency using tools that are readily available, along with external insights and on-site information that represent the best practices in the field.

I would like to thank all of the authors who shared their valuable experience and data on coal energy for this book. Thanks also to the staff at IntechOpen, particularly Publishing Process Managers Ms. Martina Scerbe and Ms. Ana Cink for all their help throughout the publication process.

> **Yongseung Yun** Institute for Advanced Engineering, Yongin, Republic of Korea

Section 1

Past and Future of Coal

Energy

Section 1
