Waste Biorefineries: Advanced Design Concepts for Integrated Waste to Energy Processes

By Jinyue Yan and Chaudhary Awais Salman

Waste Biorefineries: Advanced Design Concepts for Integrated Waste to Energy Processes presents a detailed guide to the design of energy-efficient and cost-effective waste-integrated biorefineries. Integrating thermochemical processing of waste with existing waste-to-energy technologies, the book includes the latest developments and technologies. It introduces current waste valorization techniques and examines reasons to modify existing waste-to-energy systems through the integration of new processes. In addition, the book explains the design of novel biorefineries and methods to assess these processes alongside detailed results, including the integration of waste-based CHP plants with waste gasification and the integration of pyrolysis technologies and biogas plants with waste thermochemical processing.Other sections discuss the issues and challenges of commercializing waste-to-energy technologies, including uncertainty in waste thermochemical process designs, the environmental impact of waste-integrated biorefineries, and the role of integrated waste-to-energy management in smart cities and urban energy systems. This book will be an invaluable reference for students, researchers and those in industry who are interested in the design and implementation of waste-to-energy systems, waste biomass-based combined heat and power plants, biogas plants and forest-based industries.

• Presents advanced and novel waste conversion processes and provides the tools, data and models for waste-to-energy processes and waste biorefineries availability
• Provides comprehensive uncertainty analysis of waste-to-energy designs and modelling processes
• Examines the replicability potential of methods for the design of waste biorefineries for different regions and markets with different sets of products

• Language: English
• Publisher: Elsevier Science
• Release date: Apr 25, 2023
• ISBN: 9780323983457

Jinyue Yan

Dr. Prof. Jinyue Yan, Fellow of European Academy of Sciences, KTH-Royal Institute of Technology and Mälardalen University, Sweden. Prof. Yan is the EiC of Elsevier’s journal Advances in Applied Energy and has served as the editorial board members for many prestigious journals such as Energy, Energy Conversion and Management, Journal of Energy Storage, International Journal of Energy Research and etc. Prof. Yan has published more than 400 journal in the field of solar thermal energy utilization, large-scale renewable energy systems.

Book preview

Part I

Introduction

Chapter 1: Overview of municipal waste management and challenges associated with its treatment

Abstract

This chapter starts with defining waste and how it is used currently. This chapter introduces the current and potential future role of waste toward sustainable development. There is considerable excitement about the circular economy, where waste is treated as a useful economic resource. How is waste currently managed? The chapter also described the waste hierarchy and fundamentals of waste management system. The book focuses on resource recovery from waste so the question how can we convert nonrecyclable waste to value-added bioproducts other than heat and power is also raised. The chapter ends with the aims, objectives, and research questions covered in this book.

Keywords

Municipal solid waste; Waste management; Sustainable waste handling; Waste hierarchy; Integrated waste management

The future is not an ordeal of fate, but the result of decisions we make today.

—Franz Aly

1.1: Introduction

Waste can be defined as unusable or unwanted materials. Waste can also be described as the byproduct generated as a result of activities of humans. It can also refer to the discarded by-products generate from a production process or activity European Union (Art. 3 (1),2008/98/EC) defines waste as any substance or object which the holder discards or intends or is required to discard. According to UN Environmental Program (UNEP), wastes are objects which the owner does not want, need or use any longer, which require treatment of disposal. Organisation for Economic Co-operation and Development (OECD) define waste as unavoidable materials for which there is currently no or near future economic demand and for which treatment and/or disposal may be required.

The idea that waste does not have any value or economic benefits implies that it cannot be used anymore as it fulfills its purpose already. This approach is not efficient in longer run because there are materials in waste which can be reused and recycled. Moreover, in recent years, there has been a shift toward a more circular economy approach, where waste is seen as a resource that can be recovered, reused, and recycled. This circular economy approach recognizes that waste can have economic benefits if it is managed and treated properly, rather than just being discarded. Amount and properties of waste varies with regions and countries. Developed countries generate more waste than developing countries. Waste generation is typically seen as a strong indicator of consumption trends of society and country's economy and material efficiency. The amount of waste generated in a country is directly linked to its consumption patterns. A country with a high GDP per capita and high consumption levels will typically generate more waste and vice versa. In addition, through analyzing the amount of waste generated per unit of GDP, the country's material efficiency can also be measured. The less the amount of generated waste per GDP, the more material efficient the country is. Waste generation is also linked to country's industrialization and urbanization level. With more industries, waste generation will be high. Moreover, through analyzing of waste quantity and its composition, one can measure a country's economic development and can also identify or pinpoint areas where waste reduction and management measures can be implemented. Though with sustainable production and consumption, a lot of waste can be avoided, reused or recycled. However, a large amount of waste is still classified as nonrecyclable due to various factors such as through poor waste management or complex and composite structure of material. Nonrecyclable waste still has numerous resources that can be recovered in the form of products and materials. In addition, organic fraction nonrecyclable fraction of waste can be used to generate energy, which is the main focus of this book.

Waste can be categorized into various fractions such as construction waste, industrial waste and municipal solid waste (MSW). Medical waste and sludge from wastewater treatment plants (WWTPs) are also types of waste. This book is about MSW and sludge from WWTPs. Other types of waste are not considered in this book. MSW is primarily produced in households, but the term also includes waste from industrial and commercial sectors. The most common way of managing the nonrecyclable organic fraction of MSW is through landfilling, incineration, or dumping. However, European Union legislation for waste management (Directives 2006/12/EC and 1999/31/EC of the European Parliament and the Council) has stipulated that instead of landfilling or dumping, nonrecyclable organic fraction MSW should be used primarily for waste to energy (WtE).

Globally, 37% of waste is disposed of in landfill and 33% is dumped openly, whereas WtE covers only 6% of global waste management [1]. At the same time, waste generation is increasing globally. In 2019, 2.1 billion tons of waste was generated globally [2]. The worldwide generation of waste is expected to increase to 3.4 billion tons per annum by 2050 [1]. The World Bank further estimated that the worldwide growth in MSW will continue despite the concerns and efforts of many countries to limit it. Hence countries will need to invest advanced waste management systems by enforcing stringent policies to handle waste.

MSW comprises two main fractions: recyclable and nonrecyclable waste. Recyclable waste can be categorized into plastics, glass, and packaging materials. Some of the waste can be hazardous, inert, electronic and bulky waste. Another waste classification approach is to classify them into organic and inorganic fractions.

The organic fraction of nonrecyclable waste can be further classified into fractions such as biodegradable, lignocellulosic, and refuse-derived fuel (RDF). Table 1 shows the various types of MSW and their brief description. Biodegradable waste can be broken down into methane and carbon dioxide through AD and landfilling. The lignocellulosic fraction of MSW is mainly derived from woody biomass residues and garden waste sometimes also called yard waste. Some of the lignocellulosic waste is biodegraded, while the rest is treated via composting, landfilling or incineration. RDF is composed of the organic fraction of mixed MSW, which is dry compared with biodegradable waste. RDF is produced through mechanical and biological treatment which includes shredding, grinding of MSW, and then removing contaminants such as glass, metal, and noncombustible materials. Another form of biowaste is sewage sludge which is collected from municipalities and is a by-product of WWTPs. Sludge created in WWTPs is separated and its carbon content can be recovered as biomethane via AD. AD also produces digestate as a by-product, which contains residual organic compounds and nutrients in the form of nitrogen, phosphorous and potassium.

Table 1

1.2: Waste management for sustainable development

Waste generation is directly related to consumption patterns of humans and their lifestyles; Regions with different cultural, economic, and social factors generate waste with different properties [3]. For example, in developed countries, waste generation tends to be higher due to higher levels of consumption and a higher standard of living. The waste generated in developed countries is typically more diverse and contains a higher proportion of packaging materials, electronics, and other consumer goods. In contrast, in developing countries, waste generation is typically lower and more organic in nature which typically contains a higher proportion of food waste and biomass. Furthermore, waste management practices and infrastructure also vary between regions and countries, which can affect the sustainable development of country. In developed countries, emphasis is on sustainable and efficient waste management, which is more advanced and there is a greater emphasis on recycling and reducing waste. Whereas in developing countries, waste management infrastructure is inefficient and less developed, and waste is often disposed of in open dumps or landfills. Shifting of unsustainable waste management practices toward sustainable development require targeted strategies toward regions without affecting the environment and public health of community. A sustainable and good waste management system helps to achieve the sustainable development goals (SDGs) by United Nations. An efficient waste management reduces the spread of hazardous substances and greenhouse gas emissions from waste landfills. Affordable energy can be recovered from waste while reusing and recycling of waste decreases the net amount of waste generation.

Currently—to develop efficient waste management—waste hierarchy is the one of the best waste management methods or model to adopt. It is a qualitative model that helps to visualize the waste management practices of states or regions. It provides guidelines to prioritize waste management methods over one another. Description of waste hierarchy is provided below.

1.2.1: Hierarchy of waste

Waste hierarchy is the model used to assess the waste management systems. The model is qualitative as it aids to visualize the waste management practices of states or regions. Waste hierarchy contains following five methods: (1) waste prevention, (2) reuse of original product or material, (3) recycling of waste, (4) energy recovery from waste, and (5) landfilling or disposal. How successful a country's waste management practices is dependent on which steps they are taking to treat their waste. Waste prevention, reusing of products, and waste recycling is considered as the most attractive waste management practices in waste hierarchy followed by energy recovery and landfilling. In an efficient waste management systems, only nonrecyclable waste should be converted to