Preface

Chapter 8 **Analysis on High Temperature Gasification for Conversion of**

Chapter 9 **Efficiency of Plasma Gasification Technologies for Hazardous**

Chapter 10 **Small-Scale Energy Use of Agricultural Biogas Plant Wastes by**

Chapter 11 **Pyrolysis and Gasification Characteristics of High Ash Indian**

Jayaraman Kandasamy and Iskender Gökalp

Said Samih, Sherif Farag and Jamal Chaouki

Chapter 13 **Integrated Gasification System for Power and Hydrogen**

Lukman Adi Prananto and Muhammad Aziz

Chapter 12 **Innovative Microreactors for Low-grade Feedstock**

**Section 4 Process Integration and Utilization 255**

Dariusz Wiśniewski, Mariusz Siudak and Janusz Piechocki

Annarita Salladini, Emanuela Agostini, Alessia Borgogna, Luca Spadacini, Maria Cristina Annesini and Gaetano Iaquaniello

**RDF into Bio-Methanol 143**

**Waste Treatment 165**

**Gasification 191**

**VI** Contents

**Section 3 Low-grade Coal Gasification 207**

**and Turkish Coals 209**

**Gasification 237**

**Production 257**

Victor Zhovtyansky and Vitas Valinčius

Society has evolved to use energy in gas and electricity in a more user-friendly form. The most coveted energy forms nowadays are gas in nature and electricity due to their environmental cleanness and convenience. Even with plentiful shale gas available in some countries, many areas around the globe still lack a gas source and a sustainable supply of electricity.

Gas energy that contains a heating value even one-tenth of natural gas is a more attractive option instead of using solid feedstock directly in combustion or pyrolysis mode. Combus‐ tion produces a gas of mainly CO2, which does not possess any heating value. In contrast, gasification converts solid feedstock into gas, which possesses energy content and can be cleaned in easier way than in liquid or in solid shape.

Recently, gasification market trend has started to switch to low-grade feedstock such as bio‐ mass and wastes, which are inherently low grade in terms of heating value and homogeneity. In this sense, the most promising area of development in gasification field lies in low-grade feedstock that should be converted into more user-friendly gas or electricity form in utilization.

Gasification technology has been around more than a century, and it has reached a commer‐ cial scale of 3,000 ton/day in coal gasification cases. With cheaper natural gas available by shale gas revolution, adopting coal in gasification in large scale has dropped to a minimal level in most countries. Low-grade feedstock such as biomass and wastes becomes more inter‐ esting for gasification at much smaller capacity of few dozens to few hundreds of tons per day.

Most key nations that require gasification technology for low-grade feedstock must be those in active development and in short of clean and easy-to-use energy, especially electricity. Developing countries can bypass the centralized energy distribution system through a prop‐ er localized distributed energy system that can save a heavy infrastructure expenditure.

Typical examples of low-grade feedstock are biomass, wastes, low-grade coals, and petrole‐ um residues (petroleum coke and asphalt). They contain higher pollution-incurring compo‐ nents like sulfur and nitrogen and in a heterogeneous state with many contaminants as in wastes, in addition to the inherent nature of low heating value.

Biomass is regarded as carbon neutral, which should be a good feedstock in climate-con‐ scious society. Since biomass feedstock can be obtained in local areas especially in tropical and subtropical countries, most pragmatic route in securing electricity and clean gas for household or industries can come from gasification of biomass. Biomass that suits in gasifi‐ cation encompasses from wood chips, straw, rice husk, miscanthus, and leftover from oil extraction of palm trees.

Municipal and industrial wastes are attractive feedstock for gasification. Wastes in principle should be treated for disposal through an environmentally clean process, which means tip‐ ping fee can supplement the economics of waste gasification. The most common way to treat wastes is through incineration, which is more viable with large-scale facility. Most countries prohibit using small-scale incinerators because of involved higher risk of producing dioxin than larger facilities. When wastes need to be disposed in small scale (about 30–150 ton/ day), gasification can be a profitable choice than incineration.

I would like to thank all the authors for contributing each chapter and who went through together a lengthy revising process, sometimes four times. I also like to express my sincere thanks to Ms. Kristina Kardum who provided support during the long 9-month process. With cooperation from all participants, I am glad to see the final product as the book *Gasifi‐*

**Dr. Yongseung Yun**

Preface IX

Yongin, Republic of Korea

Institute for Advanced Engineering

*cation for Low-Grade Feedstock*.

Low-grade coals are available in large quantity in India, Turkey, South Asian countries, and Eastern Europe countries. Low-grade coals that typically contain high ash, high volatile mat‐ ter, and moisture make exporting and long transportation difficult due to their low energy quality and their propensity for self-heating that might lead to fire during transportation. The low-grade coal is best to be utilized at local mine area, which makes gasification a good technology choice for extracting energy value in gas form. Due to the ever more stringent environmental regulations, these coals should be utilized through clean technology, and gasification can also be a tool that suits to this purpose.

Examples of distinctive target market that applies gasification for low-grade feedstock are localized distributed electricity and clean gas that can replace expensive natural gas/naph‐ tha/heavy oil. Further, high-purity carbon monoxide gas separated from syngas that is pro‐ duced from industrial/municipal wastes can be a cheaper raw material for acetic acid/acetic anhydride compared to the case manufactured from heavy oil or naphtha.

The book has complied the contributed 13 chapters by individual authors from 13 countries who have different level of background and expertise. In one sense, it might appear to be too general and diverse in topics. But, the book tried to shed light on the works on gasifica‐ tion from many parts of the world and thus can feel the technology status and the areas of interest regarding gasification for low-grade feedstock.

The book comprises four sections that allocate each section on low-grade feedstock. The first section containing five chapters examines biomass gasification that has attracted practical interests as a way to provide energy in the form of gas, solid fuel, and electricity. Definitely biomass gasification is the technology that exhibits most attention from many research groups and companies during the last several years for immediate commercialization. The second section looks into waste gasification with five chapters to examine the recent trend and diverse applicable cases, including one chapter on plasma gasification. The third section of two chapters deals with gasification for low-grade coals, one for the Indian and Turkish coals, and one for the development of fluidized-bed TGA to identify the fundamental kinetic data. The last section deals with the process integration and utilization with one chapter, concentrating on the possible routes of syngas utilization.

It took 9 months in finishing the editing process, which was actually much harder than my experience in earlier two books with IntechOpen. In fact, initial diverse topics and a wide range of author expertise only convinced me the necessity for filling up the information gap between the in-depth gasification information on coal and natural gas and the recently oc‐ curring practical need on gasification for low-grade feedstock that should be in a more com‐ pact plant scale. I hope this book can act as catalyst in fulfilling virtuous circle of information on gasification for low-grade feedstock and eventual practical applications for localized distributed energy in a less-privileged region.

I would like to thank all the authors for contributing each chapter and who went through together a lengthy revising process, sometimes four times. I also like to express my sincere thanks to Ms. Kristina Kardum who provided support during the long 9-month process. With cooperation from all participants, I am glad to see the final product as the book *Gasifi‐ cation for Low-Grade Feedstock*.

Municipal and industrial wastes are attractive feedstock for gasification. Wastes in principle should be treated for disposal through an environmentally clean process, which means tip‐ ping fee can supplement the economics of waste gasification. The most common way to treat wastes is through incineration, which is more viable with large-scale facility. Most countries prohibit using small-scale incinerators because of involved higher risk of producing dioxin than larger facilities. When wastes need to be disposed in small scale (about 30–150 ton/

Low-grade coals are available in large quantity in India, Turkey, South Asian countries, and Eastern Europe countries. Low-grade coals that typically contain high ash, high volatile mat‐ ter, and moisture make exporting and long transportation difficult due to their low energy quality and their propensity for self-heating that might lead to fire during transportation. The low-grade coal is best to be utilized at local mine area, which makes gasification a good technology choice for extracting energy value in gas form. Due to the ever more stringent environmental regulations, these coals should be utilized through clean technology, and

Examples of distinctive target market that applies gasification for low-grade feedstock are localized distributed electricity and clean gas that can replace expensive natural gas/naph‐ tha/heavy oil. Further, high-purity carbon monoxide gas separated from syngas that is pro‐ duced from industrial/municipal wastes can be a cheaper raw material for acetic acid/acetic

The book has complied the contributed 13 chapters by individual authors from 13 countries who have different level of background and expertise. In one sense, it might appear to be too general and diverse in topics. But, the book tried to shed light on the works on gasifica‐ tion from many parts of the world and thus can feel the technology status and the areas of

The book comprises four sections that allocate each section on low-grade feedstock. The first section containing five chapters examines biomass gasification that has attracted practical interests as a way to provide energy in the form of gas, solid fuel, and electricity. Definitely biomass gasification is the technology that exhibits most attention from many research groups and companies during the last several years for immediate commercialization. The second section looks into waste gasification with five chapters to examine the recent trend and diverse applicable cases, including one chapter on plasma gasification. The third section of two chapters deals with gasification for low-grade coals, one for the Indian and Turkish coals, and one for the development of fluidized-bed TGA to identify the fundamental kinetic data. The last section deals with the process integration and utilization with one chapter,

It took 9 months in finishing the editing process, which was actually much harder than my experience in earlier two books with IntechOpen. In fact, initial diverse topics and a wide range of author expertise only convinced me the necessity for filling up the information gap between the in-depth gasification information on coal and natural gas and the recently oc‐ curring practical need on gasification for low-grade feedstock that should be in a more com‐ pact plant scale. I hope this book can act as catalyst in fulfilling virtuous circle of information on gasification for low-grade feedstock and eventual practical applications for

anhydride compared to the case manufactured from heavy oil or naphtha.

day), gasification can be a profitable choice than incineration.

VIII Preface

gasification can also be a tool that suits to this purpose.

interest regarding gasification for low-grade feedstock.

concentrating on the possible routes of syngas utilization.

localized distributed energy in a less-privileged region.

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

**Section 1**

**Biomass Gasification**

**Section 1**

**Biomass Gasification**

**Chapter 1**

**Provisional chapter**

**Biomass Gasification: An Overview of Technological**

**Biomass Gasification: An Overview of Technological** 

Biomass gasification has been regarded as a promising technology to utilize bioenergy sustainably. However, further exploitation of biomass gasification still needs to overcome a significant number of technological and logistic challenges. In this chapter, the current development status of biomass gasification, especially for the activities in China, has been presented. The biomass characters and the challenges associated with biomass collection and transportation are covered and it is believed that biomass gasification coupled with distributed power generation will be more competitive in some small communities with large amount of local biomass materials. The technical part of biomass gasification is detailed by introducing different types of gasifiers as well as investigating the minimization methods of tar, which have become more and more important. In fact, applying biomass gasification also needs to deal with other socio-environmental barriers, such as health concerns, environmental issues and public fears. However, an objective financial return can actually accelerate the commercialization of biomass gasification for power and heat generation, and in the meantime, it will also contribute to other technical

**Keywords:** biomass gasification, gasifiers, tar removal, socio-environmental impact

Fossil fuel is on the verge of depletion in this century. Scientists and governments around world are looking for new energy resources which could be used safely and efficiently with enough amount for deployment and security. Bioenergy is a renewable energy, which

> © 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,

distribution, and reproduction in any medium, provided the original work is properly cited.

DOI: 10.5772/intechopen.74191

**Barriers and Socio-Environmental Impact**

**Barriers and Socio-Environmental Impact**

Xiang Luo, Tao Wu, Kaiqi Shi, Mingxuan Song and

Xiang Luo, Tao Wu, Kaiqi Shi, Mingxuan Song and

Additional information is available at the end of the chapter

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.74191

Yusen Rao

**Abstract**

breakthroughs.

**1. Introduction**

Yusen Rao

#### **Biomass Gasification: An Overview of Technological Barriers and Socio-Environmental Impact Biomass Gasification: An Overview of Technological Barriers and Socio-Environmental Impact**

DOI: 10.5772/intechopen.74191

Xiang Luo, Tao Wu, Kaiqi Shi, Mingxuan Song and Yusen Rao Xiang Luo, Tao Wu, Kaiqi Shi, Mingxuan Song and Yusen Rao

Additional information is available at the end of the chapter Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.74191

#### **Abstract**

Biomass gasification has been regarded as a promising technology to utilize bioenergy sustainably. However, further exploitation of biomass gasification still needs to overcome a significant number of technological and logistic challenges. In this chapter, the current development status of biomass gasification, especially for the activities in China, has been presented. The biomass characters and the challenges associated with biomass collection and transportation are covered and it is believed that biomass gasification coupled with distributed power generation will be more competitive in some small communities with large amount of local biomass materials. The technical part of biomass gasification is detailed by introducing different types of gasifiers as well as investigating the minimization methods of tar, which have become more and more important. In fact, applying biomass gasification also needs to deal with other socio-environmental barriers, such as health concerns, environmental issues and public fears. However, an objective financial return can actually accelerate the commercialization of biomass gasification for power and heat generation, and in the meantime, it will also contribute to other technical breakthroughs.

**Keywords:** biomass gasification, gasifiers, tar removal, socio-environmental impact

#### **1. Introduction**

Fossil fuel is on the verge of depletion in this century. Scientists and governments around world are looking for new energy resources which could be used safely and efficiently with enough amount for deployment and security. Bioenergy is a renewable energy, which

Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons

is stored in the organic form in the chemical state and supports human beings' daily life since our ancestor apes knew how to use fire to cook. In these millions of years, bioenergy was mostly used in small scale like household cooking. Now, people have realized that efficient exploitation of biomass resource can actually reduce their dependency over fossil fuel. Biomass gasification has been regarded as an effective pathway to utilization of bioresource. It takes biomass as raw materials and employs pyrolysis or thermal cracking under anoxic conditions. This is an energy conversion process including a group of complex chemical reactions that large organic molecules degrade into carbon monoxide, methane and hydrogen and other flammable gases in accordance with chemical bonding theory. Biomass feedstock with the gasification agent is heated inside an integrated gasifier. With temperature increase, biomass goes through dehydration, volatilization and decomposition. Eventually, the produced gases are used for central gas supply and power generation. This technology has already been developed over several decades and progressively achieved commercialization all over the world, especially in Sweden, Germany, Canada, the United States, India and China. In the early stage, downdraft gasifier had been implemented at a large scale in China and India due to its relatively low tar production. Recently, the development of circulating fluidized bed (CFB) gasifier makes it adaptable for both biomass quality and the raw particle size. Besides, CFB is also easy for scale-up and ash cleaning.

**2. Biomass characteristics and general conversion**

**2.1. Composition of biomass and its common characteristics**

if employed as resources for thermo-chemical processing.

biomass is zero. The final products of conversion of biomass (CO2

mass also has less harmful releases such as NOx

domestic waste would be the way out in future.

Biomass includes all the living or recently living organisms, like land plants, grasses, waterbased vegetation and manures [2], and these organisms consist of a number of major elements such as C, H, O, N, P and S. The classification of biomass into different categories is based on their properties. One feasible way is based on the appearances and the growth environment of biomass: woody plants, herbaceous plants/grasses, aquatic plants, manures and wastes [2]. Biomass could also be divided into two types: low moisture content and high moisture content. The low moisture content biomass can be used in thermo-chemical processes (i.e., gasification, combustion and pyrolysis), while the high moisture content plants are more suitable to be used in some wet processing technologies (i.e., fermentation and anaerobic digestion) [3]. Such high moisture contents would consume a large amount of energy for the drying process

Biomass Gasification: An Overview of Technological Barriers and Socio-Environmental Impact

http://dx.doi.org/10.5772/intechopen.74191

5

Biomass is derived from solar energy via photosynthesis. Under a good illumination condition, carbon dioxide in the atmosphere can be converted into organic materials or, in another way, the solar energy is stored as chemical energy, which existed as chemical bonds in the organisms [4]. The said chemical energy is released when these bonds are broken either via thermo-chemical or wet processing. This is an ongoing energy transfer from the sun and hence the sustainability of biomass resource could be ensured. As we have known, the total energy captured annually in biomass is more than that of the annual energy consumption globally [5]. On the other hand, biomass is clean as it is carbon neutral. On the view of carbon network, the net emission of carbon dioxide into the environment during the harvesting of energy from

absorbed into the plants from the atmosphere during photosynthesis. The conversion of bio-

However, the characters of biomass also create many barriers during its actual application. On the aspect of species diversity, biomass usually does not behave as steady as fossil fuels, which causes a lot of difficulty during project planning stage including gasifier type, plant size and the way of energy output. On the other hand, the varieties of biomass resource also lead to different heating values and moisture contents. Compared with other energy carriers, biomass has much lower heating values. Taking wood and wheat straw as examples, their lower heating values are only 18.6 and 17.3 MJ/kg, respectively, while the lower heating value of coal is as high as 23–28 MJ/kg [2, 7]. The reason for this disparity is that the oxygen content of biomass carbohydrates is very high while the combustible elements such as C and H are low. In addition, the intrinsic moisture content in biomass is also very high, which requires more energy for drying before further processes take place [3]. Hence, use of biomass requires the complexity in material handling, pre-treatment and the design of processing facilities [3]. For the purpose of transportation and collection, biomass is unlike any other renewable resources (solar, wind, hydropower) where it is able to be stored directly and transported somewhere else. However, biomass is highly dispersed in regional distribution and the low volumetric of biomass makes it a bit more difficult for the collection and transportation. Therefore, smallscale gasification unit operated in small communities with abundant biomass resource or

and SOx

and H2

compared with fossil fuels [6].

O) are originally

China, as a large agricultural country, produces a large number of crop straw, poultry manure, agricultural by-products and other plant biomass every year. Thus, research and development on key technologies and integrated peripherals of biomass gasification become very necessary. China has already developed various gasifiers, the size of which range from 400 KW to 10 MW. However, compared with fossil fuel, biomass has lower bulk density and energy density, which make it uneconomic for collection and transportation. Therefore, biomass gasification coupled with distributed power generation in small communities with abundant biomass resource would be the way out in future [1].

In recent years in China, the yield of domestic waste has increased every year and exceeds 400 million tonnes per year. Chinese government's 13th five-year plan proposed that the proportion of waste harmless treatment should be no less than 70% by 2020. But waste landfill is still the primary method used to deal with waste in rural areas. Compared with landfill, gasification has advantages of lower environmental impacts and does not consume land resource. When contrasting gasification with incineration, the gasification technology has better quality of gaseous emissions with much lower capital input, which makes gasification more suitable for distributed deployment in rural area. Therefore, there will be a great demand for deployment of waste gasification treatment plants in Chinese rural areas, and more and more people are now focusing on the development of more efficient small-scale gasifiers with capacity under 300 tonne/day. The relevant equipment has also been deployed in Iran, Thailand, Burma and Laos. However, several technical barriers are still there such as effective removal of tar with low cost, environmental influence, accuracy control of gasifier inner temperature, solidification of fly ash and so on.

Therefore, this chapter introduces both technological and logistics challenges of biomass gasification via introducing biomass characters and gasifier technologies. The details of tar minimization and socio-environmental impacts of biomass gasification are also presented as main contents to help understand the primary barriers for the deployment of biomass gasification.
