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About this book

This book covers alternative fuels and their utilization strategies in internal combustion engines. The main objective of this book is to provide a comprehensive overview of the recent advances in the production and utilization aspects of different types of liquid and gaseous alternative fuels. In the last few years, methanol and DME have gained significant attention of the energy sector, because of their capability to be utilized in different types of engines. This book will be a valuable resource for researchers and practicing engineers alike.

Table of Contents




Chapter 1. Introduction to Alternative Fuels and Their Utilization Strategies in Internal Combustion Engines

Increasing global demand of fossil fuel and harmful pollutant emitted by petroleum-fuelled internal combustion (IC) engines are two major concern for Indian transport sector, which require an immediate action to explore the alternative fuels such as biofuels, biodiesel, alcohols, etc. This book is based on such alternative fuels and covers different aspects of alternative fuels such as production and utilization. This book is divided into four sections. First section is based on introduction of alternative fuels and their utilization strategies in different type of IC engines. Second section deals with biofuel production from different sources such as agricultural waste, organic waste, microalgae, etc. Third section of this book is based on utilization of alternative fuels in engines. This section shows the potential of different alcohols and ethers to be utilized in engines. Last section of this book is based on advance topics related to alternative fuels. Overall, this book presents an overall picture of alternative fuels and shows the potential of alternative fuels for sustainable transport sector.
Akhilendra Pratap Singh, Nirendra N. Mustafi, Yogesh C. Sharma, Avinash Kumar Agarwal

Biofuel Production


Chapter 2. Agricultural Waste Derived 2nd Generation Ethanol Blended Diesel Fuel in India: A Perspective

The Ministry of New and Renewable Energy announced the National Biofuels Policy in 2009 to promote biofuels in India, and the Union Cabinet approved the National Biofuels Policy–2018 to succeed the existing policy from 2009. Biofuels have attracted worldwide attention over the past decade and it is imperative that biofuels be noticed to accelerate developments. It is noticed that the conversion of agricultural waste into 2nd generation ethanol has opened the door to unused resources and has promoted environmental sustainability. The 2nd generation ethanol, made from agricultural residues, offers significant prospective due to the extensive accessibility, abundance and comparatively inexpensive biomass. The use of agricultural waste to produce 2nd generation ethanol is proving to be a substitute source of energy for a narrow range of nonrenewable energy and food crops. Although this process has many challenges and limitations which are discussed in the chapter e.g. biomass transportation and handling, effective pretreatment methods, high costs based on current technologies that enable high efficiency and high process costs. The use of ethanol blended with diesel fuel has recently attracted the attention of many researchers. The usage of 2nd generation ethanol blended in diesel fuels will develop the agricultural commodity markets and create additional returns from 2nd generation ethanol derived from crop residues. The announcement by the Government of India on stringent emission regulations and the increased use of biofuels may lead to the use of 2nd generation ethanol blended with diesel fuel as a marketable fuel. This chapter highlights agricultural waste, its sources and various practices that include the processes undergone to produce 2nd generation ethanol economically, it also provides insight and suggests a renewable alternative fuel for diesel engines which will help in meeting the stringent emission standards.
Rabinder Singh Bharj, Gurkamal Nain Singh, Rajan Kumar

Chapter 3. Biofuels from Renewable Biomass Resources: An Overview of Technologies for Production, Environmental and Economic Impacts

In recent years, there is a great deal of social obligation involve with scientists to common people that a sustainable chemical processes having industrial importance which is associated with greener concept and environmentally benign methodology is the need of the hour. This trends of technology driven greener process will continues to roll on for next few decades. With this aspects in mind, biomass, a sustainable alternative feedstock, can be processed into liquid and solid fuels via thermal, light-induced, catalytic and bio-based techniques. Conversion of biomass materials into value added products and energy can address environmental sustainability and recycling of waste materials. Utilization of bio-based energy has not been explored fully. We continue to rely on fossil fuels, nuclear energy and hydroelectricity to meet our energy demands. Alcohols and its derivatives are the important source of bioenergy that are hidden in biomass. In this context, the production of alcohols or esters is an extremely important industrial process as they are useful as precursors, reagents, solvents or additives in perfumes, essential oils, food flavorings, cosmetics, etc. Even though there have been numerous methods available for the production of alcohols and esters, designing non-hazardous methods to generate chemical products that limit the usage of hazardous substances is highly required. The present chapter aims at the analysis of various green methods reported for the production of alcohols and esters from renewable energy sources. Also provide a broad overview of the environmental and economic impacts of biofuels. The major environmental impacts are conceived under two headings, viz. direct emissions those that are expelled during the biofuels production and consumption and indirect emissions those that are associated with their land use.
J. Thangaraja, Akella Sivaramakrishna, Rajagopal Desikan

Chapter 4. Second Generation Bioethanol Production from Organic Waste

Increasing global urge to decrease fossil fuel dependency, and better control of pollution needs the development of alternative energy resources like biodiesel, alcohols etc. Use of organic waste as feedstock for biofuel production is an innovative approach to solve the waste management problems, fossil fuel dependence, greenhouse gas (GHG) emissions and most importantly prevent the nation’s economy from global oil price fluctuations. Rice paddy straw is an attractive lignocellulose material for bioethanol production since it has several features, such as elevated content of cellulose and hemicellulose, which can readily be hydrolysed into fermentable sugars. Further fermentation can be done to produce ethanol from the hydrolysed intermediate product. The ethanol production process using rice paddy straw involve mainly the preparation of raw material which is known as pre-treatment (physical or chemical pre-treatment) and fermentation. One of the key challenges in implementing bioethanol production from rice paddy straw is the choice of a suitable pre-treatment method. Moreover, India is an agricultural based country where rice is one of the major product. Utilization of rice paddy straw as a biofuel may result in saving of significant foreign exchange for the country and also reduce environmental concerns.
Tomesh Kumar Sahu, Satyajit Gupta, Pravesh Chandra Shukla

Chapter 5. Biofuel Production from Agricultural Waste—An Economical Approach

Biofuel is an important solution to the fuel crisis which may affect the future generation. Also production of biofuel will greatly reduce the need and dependency of fossil fuels. It also can greatly reduce the environmental pollution. Different types of biofuels include bioethanol, biodiesel, biogas and biobutanol. Biodiesel is a very good replacement fuel for petroleum and also produce less toxins and a biodegradable one. Thus bioethanol is a clean gas produced through fermentation technology. High energy biofuel, biobutanol can also be produced by the fermentation of agricultural residues. All these energy rich high value fuels can be produced from agricultural wastes, which are getting wasted as such in the nature. The current chapter mainly deals with different ways in which biofuels can be produced using agricultural waste thereby making entire process cost effective and economical. This can make every country independent for biofuel production making the nature stable for future generation.
Elsa Cherian, Harikrishnan Hariharan

Chapter 6. Sustainable Production of Green Fuels and Chemicals Using Microalgae as Feedstock

The most crucial challenges faced by our society today are energy security, uncertainty in fuel prices and the environmental impact due to the harmful emissions. The last decade has seen intensive research efforts in exploitation of microalgae as a potential source of fuel and other value added products. This chapter provides an overview of microalgae based biorefinery concept aimed at economical and efficient product formation. The integrated approach of carbon dioxide sequestration and wastewater treatment along with biomass accumulation of microalgae provides dual advantage of reducing pollution load and simultaneously generating biomass for valorisation. The commercialization potential of microalgal fuels and chemicals has also been highlighted in this chapter.
Jayati Trivedi, Neeraj Atray

Biofuels for Engine Applications


Chapter 7. Future Automotive Powertrains for India: Methanol Versus Electric Vehicles

Oil and gas demands in India are growing at an alarming rate and gap between demand and supply has emerged as a great concern for the country’s economy. Globally, petroleum reserves are depleting rapidly, and may not sustain beyond 2050. Therefore, finding alternative, renewable and eco-friendly fuels is an absolute need for the age, not only due to petroleum resource scarcity but also due to adverse impact of combustion generated emissions on human health and environment. Electric vehicles (EVs) are emerging into the transport sector globally as well as in India because apparently they are marketed to be producing zero tailpipe emissions. EVs are also expected to reduce dependence on imported petroleum fuels, if electricity is produced from indigenous energy resources or from renewable resources. However, there are several critical issues associated with EVs such as storage batteries, driving range, total weight of the vehicle, lack of recharging facilities, and their high costs. On the other hand, fuels derived from stray carbon in waste biomass, municipal solid waste (MSW) or low grade high ash coal are considered to be superior alternative fuels for transport sector. Among different alternative fuels, methanol has been given greater attention in recent times. Methanol fuelled vehicles (MFV) are quite practical, economical and eco-friendly and can contribute significantly to the transport sector. Methanol fuelled vehicles have higher power density, comparable cost-benefit ratio, and relatively cleaner emission spectra compared to conventional petroleum fuelled vehicles. In this chapter, possible strategies to adopt methanol in existing IC engines are discussed and current national and global status of methanol fuelled vehicles is presented. Next section discusses different types of EVs and their current national and global status, including their historical evolution and risks involved in their mass penetration. The reasons why MFV are a reliable future option for Indian transport sector on a large scale, while EVs seem impractical for large scale implementations are also discussed at length.
Hardikk Valera, Avinash Kumar Agarwal

Chapter 8. Engine Parameters Assessment for Alcohols Fuels Application in Compression Ignition Engines

An increasing interest of governments on alternative fuels for internal combustion engines (ICE) as a possible route to reduce pollutant and CO2 emissions has been shown. Advanced combustion concepts combined with alternative fuels have the potential to improve efficiency and emissions levels. In this framework, the compression ignition (CI) engines have a higher brake thermal efficiency compared to the spark ignition (SI) engines and therefore lower efficiency related CO2 emissions. High research octane number (RON) fuels can be used in CI engines to realize premixed combustion thus reducing the soot emissions, and to a certain extent also NOx. Thus, alternative alcohol fuels such as methanol and ethanol represent a valuable option for further reducing the CO2 footprint of CI engines. In this chapter, the main advantages and drawbacks of using alcohols as primary fuel or additive in diesel are evaluated in terms of performance, combustion characteristics and emissions, with particular reference to energetic analysis.
Sam Shamun, Giacomo Belgiorno, Gabriele Di Blasio

Chapter 9. A Comprehensive Review on Oxygenated Fuel Additive Options for Unregulated Emission Reduction from Diesel Engines

Compared to petrol and diesel engines, higher fuel economy along with higher power output is obtainable from diesel engines. Further, it has better thermal efficiencies and torque characteristics. On the negative side, the diesel engines are a major source of both regulated and unregulated emissions causing deterioration in air quality causing greater health hazard. Therefore, there is an urgent need to mitigate the society from this peril. From the authors’ point of view compared to regulated emissions unregulated emissions should be tackled with greater zeal. There are three possibilities
to get rid of IC engines and to use electric vehicles,
to discard present day petro diesel and go for hydrogen as a fuel,
to use alternate source of energy like biodiesel and oxygenated additives to diesel.
The third one is relatively easy, quick and viable since no major change to be incorporated to the millions of existing engines. In this chapter, a review on the option of using oxygenated fuel additives such as biodiesel, acetone–butanol–ethanol (ABE) solution and water-emulsion as additives to reduce unregulated emissions is carried out. From this review, it becomes clear that more systematic research is absolutely essential to come to a definite conclusion on unregulated emissions such as polycyclic aromatic hydrocarbons (PAHs), persistent organic compounds (POPs) and carbonyls. When biodiesel and/or ABE solution in the diesel blends is used emissions such as particulate matter (PM), CO, PAHs and POPs do reduce. However, in most cases, the NOx emission increases. Further, through this review, a combination of factors such as higher oxygen content, more complete combustion and cooling effect could be brought out. Unregulated pollutant emissions can be reduced considerably if diesel blend, which contains proper amount of biodiesel, ABE solution and a small amount of water (0.5%), is employed appropriately. This means that such green fuels exhibit excellent performance in both brake thermal efficiency (BTE) and NOx–PM trade-off and in significant emission reductions for PAHs and POPs. This chapter proposes a green diesel fuel blend not only for scientific study but also for future practical application.
Vijayashree, V. Ganesan

Chapter 10. Influence of DEE on Entropy Generation and Emission Characteristics of DI Diesel Engine Fuelled with WCO Biodiesel

This study present the influence of oxygenate additive DEE on entropy generation, exergy performance coefficient, emission, and performance characteristics of direct-injection (DI) diesel engine fuelled with WCO (waste cooking oil) biodiesel. Experiments are conducted at constant speed of 1600 rpm for full load condition. DEE is mixed with WCO biodiesel blend in the proportion of 5, 10, and 15%. Performance and exergy parameters for WCO biodiesel blend are compared with that of diesel fuel. It is found that addition of DEE enhance the engine performance effectively from the energy and exergy point of view. Reduction in NOx emission is also observed with the addition of DEE. The exergetic efficiency is increased by 8.5% for 15%DEE addition and NOx emission is reduced from 1900 ppm to 420 ppm with the addition of DEE. Lower entropy generation and improve exergy performance coefficient is also observed.
Veena Chaudhary, R. P. Gakkhar

Chapter 11. Bioethanol Operation in a DI Diesel Engine with DEE Fumigation

Engine experiments were conducted with bioethanol in a direct injection (DI) diesel engine with the help of an ignition improver by fumigation technique. The diethyl ether (DEE) was fumigated along with the air in the suction at four different flow rates of 60, 120, 180 and 240 g/h. The results were compared and found to be good agreement with diesel data. The overall heat release rate and useful work for the bioethanol and DEE operation was observed to be higher compared to that of diesel at full load. There was a simultaneous reduction of brake specific nitric oxide (BSNO) and smoke emission with these fuels at every load. But, the brake specific carbon monoxide (BSCO) and brake specific hydrocarbon (BSHC) emission were found to be increased with the higher flow rates of DEE compared to diesel at full load.
Dulari Hansdah, Prabha Chand, S. Murugan

Advancements in Alternative Fuels


Chapter 12. Combustion and Emission Characteristics, and Emission Control of CNG Fueled Vehicles

Natural gas (NG) is considered as one of the most attractive alternative fuels for vehicles due to its clean-burning characteristics. Rapid growth of urbanization and industrialization has multiplied transport fuel demand worldwide. Vehicle population particularly in metropolitan cities has grown exponentially. Adverse effects of vehicular emissions on the environment and human health have forced regulatory bodies to impose increasingly stringent emission legislations. This has necessitated use of cleaner alternative fuels such as NG in the transport sector. NG fuelled vehicles (NGV) have several advantages such as low photochemical reactivity of the exhaust, zero evaporative emissions, minimized cold-start and low-temperature emissions, and suitability for lean-burn operations. Compressed NG (CNG) vehicles have been used since 1960s and have proven safety record. The most important advantage of NGV is that NG is readily available at low cost worldwide, including many developing countries and technologies exist for its transportation, storage, and distribution systems are well matured. This chapter reviews the state-of-the-art in the NG fueled vehicles, focusing on engine combustion and emissions characteristics of NGVs. Worldwide prospects and challenges of NG as a transport fuel are also included. Technical aspects such as CNG properties, and their effect on engine performance, and emissions are discussed. Hydrogen enriched CNG (HCNG) significantly improves mixture flammability limit thus contributing to lean-burn operation of NG fueled spark ignition (SI) engines. Hence, HCNG has shown to be advantageous over traditional SI engines in terms of fuel economy and pollutant emissions. This chapter provides an overview of recent progress on HCNG fueled engines as well. An overview of the emission control strategies for NGVs is presented towards the end. Finally, main challenges and future R&D required for NGVs are identified.
Nirendra N. Mustafi, Avinash Kumar Agarwal

Chapter 13. Biogas for Transport Sector: Current Status, Barriers, and Path Forward for Large-Scale Adaptation

Global demand for conventional petroleum fuels for powering transport vehicles is enormous and is increasing sharply with time. However, depleting petroleum reserves, and negative impacts of vehicular emissions on human health remain the most important concerns, which motivate researchers to look for alternative and eco-friendly fuels for the transport sector. On the other hand, emerging stringent regulations are forcing engine researchers and manufacturers to develop appropriate and newer engine technologies to comply with these emissions regulations in addition to improving the fuel economy. Among different alternative fuel options, biogas certainly can be regarded as one of the most attractive options since it is mainly produced from waste materials such as agricultural wastes, municipal solid wastes, food wastes and vegetable market waste, in addition to human and animal excreta, which are unlimited resources. Though biogas technology is considered as a matured technology, its full potential is yet to be explored globally. Raw biogas contains some impurities hence it cannot be used directly in engines/vehicles, therefore it must be upgraded for these applications. This chapter explores the state-of-the-art technologies associated with the biogas generation, biogas upgradation, storage, and utilization. Biogas-to-useable fuel conversion techniques are also discussed. An estimate of biogas generation potential worldwide is explored, and techno-economic feasibility is addressed. Recent case studies on assessing performance of biogas operated vehicles are reviewed. Finally, the main barriers in biogas adaptation for vehicular applications are identified, and necessary recommendations are made.
Nirendra N. Mustafi, Avinash Kumar Agarwal

Chapter 14. CO2 Sequestration in Shale with Enhanced Gas Recovery

Shale is an important geological media for carbon capture utilization and storage. On one hand it can be regarded as impermeable caprock to prevent CO2 migration from reservoir, and on the other hand it can also treated as both natural gas and CO2 storage reservoir. CO2-shale reactions within caprock can interfere with the integrity of the rock integrity and compromise the long-term carbon storage safety and stability; however this interaction can also improve the conductivity of the rock to enhance the shale gas recovery from the organic-rich shale. This chapter presents a review of the current state of knowledge regarding CO2 and shale interactions and their potential impacts on shale properties and groundwater quality in the context of CO2 enhanced shale gas recovery. The characterization of shale and CO2 which is critical to the understanding of various interactions between CO2 and shale is first summarized. The major interaction mechanisms between CO2 and shale including CO2-shale-water geochemical reactions, CO2 adsorption induced clay swelling and organic matter extraction with supercritical CO2 and their impact on rock porosity and permeability, and mechanical properties, gas adsorption capacity and groundwater quality are surveyed. Finally, the open questions in this field are emphasized and new research needs are highlighted.
Danqing Liu, Sen Yang, Yilian Li, Ramesh Agarwal

Chapter 15. BioGTL: A Potential Technique for Converting Methane to Methanol (Waste to Energy)

Methane, the potential fuel, is a major contributor to the global warming chaos due to its heat capturing ability and its increasing release from anthropogenic routes, such as oil and coal mining, as a waste. Owing to technical and economic constraints the methane is flared at the sites, thus preventing the marketing and causing wastage of a potential energy resource. In 2017, for 220 million barrels of oil produced per day, 140 billion m3 of natural gas was flared per year according to the Global Gas Flaring Reduction (GGFR) report by the World Bank. This enormous amount gas that is wasted can be captured and converted to energy (liquid fuels) through existing chemical and emerging biological routes. Due to the prominent disadvantages associated with chemical route such as energy intensiveness, inefficiency in yield, high-cost, etc., biological route for methane-to-methanol conversion is favourable, which can be operated at ambient temperature and pressure conditions. The methanotrophs, among various groups of methane utilizers, play the key role in biological methane (gas) to methanol (liquid) conversion (BioGTL). Besides, Bio-GTL (biological gas to liquid) would prove to be an economically viable technology for capturing the methane released at underrated diffused sites operated by small companies in remote areas. An efficiency (moles of methanol produced per mole methane consumed) of 80% for BioGTL has been reported in 2014. However, the scale-up of this interesting and highly potential technology has been a challenge and hence, demands attention and appropriate R&D measures.
Aradhana Priyadarsini, Lepakshi Barbora, Vijayanand S. Moholkar

Chapter 16. Microbial Desulphurization of Refractory Organic Sulphur Compounds from Transportation Fuels

The sulphur content in crude oil ranges from 1000 to 3000 ppm but the environmental regulations require less than 10 ppm sulphur to meet the stringent protocols on reduced SO2 emission by transportation fuels. Hydrodesulphurization (HDS), which is the most employed technology to reduce sulphur (S) suffers from severe and hazardous operation conditions, inefficiency, high capital and operating costs, generation of the hazardous H2S end product etc. During the last decades, several advances have been made in developing chemical, physical and biological technologies complementary to HDS to achieve ultra-low sulphur fuel. Biodesulphurization (BDS) is one of these emerging nonconventional technologies that can be merged with other desulphurization technologies, such as the oxidative desulphurization process, to produce S-free fuels. The BDS process involves the use of free or immobilized microorganisms, their enzymes or cellular extracts, as catalysts to remove the S present in fuels. The most extensively studied and utilized microorganisms for BDS processes are Gram-positive bacteria. Gram-negative bacteria with high tolerance to organic solvents and metals, broad metabolic versatility and easy genetic manipulation also make them ideal candidates for the purpose. This chapter reviews research findings of utilization of mesophilic, thermophilic and Gram-negative bacteria for desulphurization of gasoline, jet and diesel fuel to be used as transportation fuel.
Pushpita Das, Lepakshi Barbora, Vijayanand S. Moholkar
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