Preface

The exponential growth of the global population and concurrent fast industrialization has led to massive generation of municipal wastes, with raised challenges of safe disposal. The proper management of municipal wastes through recycling is an essential approach for global sustainable development. So far, many countries have established regulatory guidelines for different waste management routes and pollution control measures. However, most of the applied routes are waste dumping, composting, or direct discharge in water bodies without adequate pretreatment, which seriously threatens the environment and humans. Thus, proper waste segregation and separation provide an efficient option for converting waste into energy. On the other hand, energy demand correlates with population growth, as population directly increases eventual energy demand. Thus, global energy demand and environmental pollution are two inevitable issues that demand the discovery and development of alternative energy sources. Waste-to-energy is a widely used statement for efficient waste management, which is getting much attention. For almost two decades, biofuel production from biowastes receives paramount of importance and eventual growth and development. In general, it is widely accepted that biowaste-derived fuels can reduce the current dependence on fossil-based products. Among different biofuel production routes, anaerobic digestion (AD) is by far the single most important technology for providing clean renewable biogas to millions of people in rural areas of developing countries. AD technology has several inherent benefits ranging from generating renewable energy and remediating biowaste curtailing CO2/CH4 emissions to improving health/hygiene and overall socio-economic status of rural communities in developing nations.

This book provides basic knowledge and recent research on biogas production, focusing on the enhancement of biomethane and integrated production routes. It comprises nine chapters divided into two sections. The first section focuses on the production and upgrading of biogas, and the second section presents some integrated approaches of biogas production with other applications such as microalgae cultivation and biofertilizer production.

We would like to express our gratitude to the faculty members of the participating institutes. We are also grateful to IntechOpen's Commissioning Editors and Author Service Managers for being generously helpful throughout the process of creating and publishing this book.

> **Abd El-Fatah Abomohra** Professor, Department of Environmental Engineering, School of Architecture and Civil Engineering, Chengdu University, China
