Volume 6. Evaluation and Utilization of Bioethanol Fuels II.

Konur, O., Ed. 2023. Evaluation and Utilization of Bioethanol Fuels II: Biohydrogen Fuels, Fuel Cells, Biochemicals, and Country Experiences, Handbook of Bioethanol Fuels: Production and Utilization Volume 6, Ed. O. Konur. Boca Raton, FL: CRC Press. DOI: https://doi.org/10.1201/9781003226574 400 pp., eBook ISBN: 9781003226574.

The sixth volume of this handbook provides an overview of the research on the country-based experience of bioethanol fuels at large, Chinese, US, and European experience of bioethanol fuels, production of bioethanol fuel-based biohydrogen fuels for fuel cells, bioethanol fuel cells, and bioethanol fuel-based biochemicals with a collection of 17 chapters. Thus, it complements the fifth volume of this handbook.

Hence, the sixth volume indicates that the research on the evaluation and utilization of bioethanol fuels has intensified in recent years to become a major part of the bioenergy and biofuels research together primarily with biodiesel, biohydrogen, and biogas research as a sustainable alternative to crude oil-based gasoline and petrodiesel fuels as well as natural gas and syngas.

This book is intended for students, researchers, engineers, policy makers, economist, business managers, and social scientists, working on the production, utilization and evaluation of bioethanol fuels.

Part 29. Country-based Experience of Bioethanol Fuels 212 pp.

• Konur, O. 2023ce. Country-based experience of bioethanol fuels: Scientometric study. In Evaluation and Utilization of Bioethanol Fuels II: Biohydrogen Fuels, Fuel Cells, Biochemicals, and Country Experiences, Handbook of Bioethanol Fuels: Production and Utilization Volume 6, O. Konur, pp. 3-41. Boca Raton, FL: CRC Press. 23 pp.

Crude oil-based gasoline fuels have been widely used in the transportation sector since the 1920s. However, there have been great public concerns over the adverse environmental and human impact of these fuels. Hence, biomass-based bioethanol fuels have increasingly been used in blending gasoline fuels. The research in the field of experiences of countries has also intensified in recent years. The primary focus of research in this area has been the optimization of bioethanol and biomass production and the development of policies to promote the production and use of bioethanol fuels worldwide. In this context, the experiences of Brazil, the USA, China, and to a lesser extent Thailand, Europe, India, Malaysia, Sweden, Colombia, Canada, and the UK have been extensively studied. In this context, there has been a significant focus on evaluative studies in bioethanol fuels such as technoeconomic and life cycle studies. However, it is essential to develop efficient incentive structures for the primary stakeholders to enhance research in this field. As there have been no scientometric studies in this field, this book chapter presents a scientometric study of research in this field. It examines the scientometric characteristics of both the sample and population data presenting the scientometric characteristics of these both datasets in the order of documents, authors, publication years, institutions, funding bodies, source titles, countries, Scopus subject categories, keywords, and research fronts.

• Konur, O. 2023cf. Country-based experience of bioethanol fuels: Review. In Evaluation and Utilization of Bioethanol Fuels II: Biohydrogen Fuels, Fuel Cells, Biochemicals, and Country Experiences, Handbook of Bioethanol Fuels: Production and Utilization Volume 6, O. Konur, pp. 26-41. Boca Raton, FL: CRC Press. 16 pp.

Crude oil-based gasoline fuels have been widely used in transportation sector since the 1920s. However, there have been great public concerns over adverse environmental and human impact of these fuels. Hence, biomass-based bioethanol fuels have increasingly been used in blending gasoline fuels and in fuel cells. Research in the field of experiences of countries has also intensified in recent years. The primary focus of research in this area has been optimization of bioethanol and biomass production and development of policies to promote production and use of bioethanol fuels worldwide. In this context, experiences of Brazil, the USA, China, and, to a lesser extent, Europe, India, Malaysia, and Colombia have been extensively studied. Further, there has been a significant focus on evaluative studies in bioethanol fuels such as techno-economic and life cycle studies. However, it is essential to develop efficient incentive structures for the primary stakeholders to enhance research in this field. Although there has been a limited number of review papers on the country experiences of bioethanol fuels, there has been no review of the 25 most-cited articles in this field. Hence, this book chapter presents a review of the 25 most-cited articles in the field of country-based experiences of bioethanol fuels. Then, it discusses the key findings of these highly influential papers and comments on future research priorities in this field.95.1 Introduction

96 Senatore, A., Dalena, F., Basile, A. (2023) Ethanol: brief review of the major production methods in the world. In Evaluation and Utilization of Bioethanol Fuels II: Biohydrogen Fuels, Fuel Cells, Biochemicals, and Country Experiences, Handbook of Bioethanol Fuels: Production and Utilization Volume 6, Ed. O. Konur, pp. 42-60. Boca Raton, FL: CRC Press. 19pp. Alessandro Senatore, Francesco Dalena, Angelo Basile

The two major producers of bioethanol fuels are the USA from corn and Brazil from sugarcane. The USA has used the dry grind (DG) and, to a lesser extent, the wet milling (WM) processes, while Brazil has used the Melle-Boinot (MB) and the modified Melle-Boinot (MMB) processes to convert sugarcane into bioethanol. The key steps used in these processes are the physical, chemical, and enzymatic pretreatments of the biomass, fermentation of the hydrolysates by yeasts, and distillation of bioethanol fuels from the fermentation broth. This book chapter reviews the research on these production methods in terms of productivity and production costs for these three production processes to produce bioethanol fuels from corn and sugarcane in the USA and Brazil, respectively.

97 Konur, O. 2023cg. Chinese experience of bioethanol fuels: Scientometric study. In Evaluation and Utilization of Bioethanol Fuels II: Biohydrogen Fuels, Fuel Cells, Biochemicals, and Country Experiences, Handbook of Bioethanol Fuels: Production and Utilization Volume 6, Ed. O. Konur, pp. 61-88. Boca Raton, FL: CRC Press. 28 pp.

The crude oil-based gasoline fuels have been widely used in the transportation sector since the 1920s. However, there have been great public concerns over the adverse environmental and human impact of these fuels. Hence, biomass-based bioethanol fuels have increasingly been used in blending gasoline fuels, in the fuel cells, and in the biochemical and biohydrogen fuel production in a biorefinery context. Bioethanol fuels also play a critical role in maintaining the energy security in the supply shocks related to oil price shocks, COVID-19 pandemics, or wars in the aftermath of the Russian invasion of Ukraine. However, it is necessary to pretreat the biomass to enhance the yield of the bioethanol prior to the bioethanol production through the hydrolysis of the biomass and fermentation of the resulting hydrolysates. China has been one of the most-prolific countries engaged in the bioethanol fuel research. The Chinese research in the field of the bioethanol fuels has intensified in this context in the key research fronts of the production of bioethanol fuels, utilization of bioethanol fuels, and to a lesser extent the evaluation of bioethanol fuels. For the first research front, pretreatment and hydrolysis of the feedstocks and to a lesser extent fermentation of the feedstock-based hydrolysates, production of bioethanol fuels, and distillation of bioethanol fuels are the key research areas, while for the second research front, utilization of bioethanol fuels in fuel cells and transport engines, bioethanol-based biohydrogen fuels, bioethanol sensors, and to a lesser extent bioethanol-based biochemicals are the key research areas. The research in this field has also intensified for the feedstocks of bioethanol fuels for their utilization, starch feedstock residues, cellulose, wood biomass, lignocellulosic biomass at large, and to a lesser extent industrial waste, lignin, grass, hydrolysates, biomass at large, sugar feedstocks, sugar feedstock residues, algal biomass, lignocellulosic wastes, starch feedstocks, urban wastes, forestry wastes, food wastes, and plants. However, it is essential to develop efficient incentive structures for the primary stakeholders to enhance the research in this field. The scientometric analysis has been used in this context to inform the primary stakeholders about the current state of the research in a selected research field. As there have been no published scientometric studies in this field, this book chapter presents a scientometric study of the Chinese research in the bioethanol fuels. It examines the scientometric characteristics of both the sample and population data presenting scientometric characteristics of these both datasets in the order of documents, authors, publication years, institutions, funding bodies, source titles, countries, Scopus subject categories, Scopus keywords, and research fronts.

98 Konur, O. 2023ch. Chinese experience of bioethanol fuels: Review. In Evaluation and Utilization of Bioethanol Fuels II: Biohydrogen Fuels, Fuel Cells, Biochemicals, and Country Experiences, Handbook of Bioethanol Fuels: Production and Utilization Volume 6, Ed. O. Konur, pp. 89-109. Boca Raton, FL: CRC Press. 21 pp.

Crude oil-based gasoline fuels have been widely used in the transportation sector since the 1920s. However, there have been great public concerns over the adverse environmental and human impact of these fuels. Hence, biomass-based bioethanol fuels have increasingly been used in blending gasoline fuels, in fuel cells, and in biochemical and biohydrogen fuel production in a biorefinery context. However, it is necessary to pretreat biomass to enhance the yield of the bioethanol prior to the bioethanol fuel production from the feedstocks through the hydrolysis of biomass and fermentation of the resulting hydrolysates. China has been one of the most prolific countries engaged in bioethanol fuel research. The Chinese research in the field of bioethanol fuels has intensified in this context in the key research fronts of the utilization of bioethanol fuels and to a lesser extent the production of bioethanol fuels. For the first research front, the direct utilization of bioethanol fuels in fuel cells and to a lesser extent utilization of bioethanol fuels in the transport engines, bioethanol biosensors, and the utilization of bioethanol fuels for the production of biohydrogen fuels for fuel cells have been prolific research fronts. Further, for the second research front, hydrolysis and pretreatments of biomass have been the prolific research fronts. The research in this field has also intensified for the feedstocks of bioethanol fuels for their utilization and to a lesser extent cellulose, starch feedstock residues, wood biomass, lignocellulosic biomass at large, industrial waste, and sugar feedstock residues. However, it is essential to develop efficient incentive structures for the primary stakeholders to enhance the research in this field. Although there has been a number of review papers on bioethanol fuels, there has been no review of the most-cited 25 Chinese articles in this field. Thus, this book chapter presents a review of these most-cited 25 articles. Then, it discusses the key findings of these highly influential papers and comments on future research priorities in this field.

99 Konur, O. 2023ci. The US experience of bioethanol fuels: Scientometric study. In Evaluation and Utilization of Bioethanol Fuels II: Biohydrogen Fuels, Fuel Cells, Biochemicals, and Country Experiences, Handbook of Bioethanol Fuels: Production and Utilization Volume 6, Ed. O. Konur, pp. 110-138. Boca Raton, FL: CRC Press. 29 pp.

The crude oil-based gasoline fuels have been widely used in the transportation sector since the 1920s. However, there have been great public concerns over the adverse environmental and human impact of these fuels. Hence, biomass-based bioethanol fuels have increasingly been used in blending gasoline fuels, in the fuel cells, and in the biochemical production in a biorefinery context. Bioethanol fuels also play a critical role in maintaining the energy security in the supply shocks related to oil price shocks, COVID-19 pandemics, or wars in the aftermath of the Russian invasion of Ukraine. However, it is necessary to pretreat the biomass to enhance the yield of the bioethanol prior to the bioethanol production through the hydrolysis of the biomass and fermentation of the resulting hydrolysates. The USA has been one of the most prolific countries engaged in the bioethanol fuel research. The US research in the field of the bioethanol fuels has intensified in this context in the key research fronts of the production of bioethanol fuels, and to a lesser extent utilization and evaluation of bioethanol fuels. For the first research front, pretreatment and hydrolysis of the feedstocks and to a lesser extent fermentation of the feedstock-based hydrolysates, production of bioethanol fuels, and distillation of bioethanol fuels are the key research areas while for the second research front, utilization of the bioethanol fuels in the fuel cells and transport engines, and the production of biohydrogen fuels for the fuel cells are the key research areas. The research in this field has also intensified for the feedstocks of lignocellulosic biomass at large, cellulose, starch feedstock residues, wood biomass, bioethanol fuels, lignin, and to a lesser extent grass biomass, industrial waste, sugars, biomass at large, starch feedstocks, hydrolysates, lignocellulosic wastes, sugar feedstock residues, sugar feedstocks, and algal biomass. However, it is essential to develop efficient incentive structures for the primary stakeholders to enhance the research in this field. The scientometric analysis has been used in this context to inform the primary stakeholders about the current state of the research in a selected research field. As there have been no published scientometric studies in this field, this book chapter presents a scientometric study of the research in the bioethanol fuels. It examines the scientometric characteristics of both the sample and population data presenting scientometric characteristics of these both datasets in the order of documents, authors, publication years, institutions, funding bodies, source titles, countries, Scopus subject categories, Scopus keywords, and research fronts.

100 Konur, O. 2023cj. The US experience of bioethanol fuels: Review. In Evaluation and Utilization of Bioethanol Fuels II: Biohydrogen Fuels, Fuel Cells, Biochemicals, and Country Experiences, Handbook of Bioethanol Fuels: Production and Utilization Volume 6, Ed. O. Konur, pp. 139-158. Boca Raton, FL: CRC Press. 20 pp.

Crude oil-based gasoline fuels have been widely used in the transportation sector since the 1920s. However, there have been great public concerns over the adverse environmental and human impact of these fuels. Hence, biomass-based bioethanol fuels have increasingly been used in blending gasoline fuels, in fuel cells, and in biochemical production in a biorefinery context. However, it is necessary to pretreat the biomass to enhance the yield of the bioethanol prior to bioethanol fuel production from feedstocks through the hydrolysis of the biomass and fermentation of the resulting hydrolysates. The USA has been one of the most prolific countries engaged in bioethanol fuel research. US research in the field of bioethanol fuels has intensified in this context in the key research fronts of the production of bioethanol fuels, and to a lesser extent in the utilization and evaluation of bioethanol fuels. For the first research front, pretreatment and hydrolysis of the feedstocks and to a lesser extent fermentation of the feedstock-based hydrolysates and production of bioethanol fuels are the key research areas while for the second research front, direct utilization of bioethanol fuels in fuel cells and bioethanol-based biohydrogen fuels are the key research areas. Research in this field has also intensified for feedstocks of wood biomass, starch feedstock residues, grass, bioethanol fuels, cellulose, lignin, and to a lesser extent starch feedstocks, lignocellulosic biomass at large, and sugar feedstock residues. However, it is essential to develop efficient incentive structures for the primary stakeholders to enhance the research in this field. Although there have been a large number of review papers on bioethanol fuels, there has been no review of the 25 most-cited articles in this field. Thus, this chapter presents a review of these 25 most-cited articles. Then, it discusses the key findings of these highly influential papers and comments on future research priorities in this field.

101 Konur, O. 2023cm. European experience of bioethanol fuels: Scientometric study. In Evaluation and Utilization of Bioethanol Fuels II: Biohydrogen Fuels, Fuel Cells, Biochemicals, and Country Experiences, Handbook of Bioethanol Fuels: Production and Utilization Volume 6, Ed. O. Konur, pp. 159-188. Boca Raton, FL: CRC Press. 30 pp.

Crude oil-based gasoline fuels have been widely used in the transportation sector since the 1920s. However, there have been great public concerns over the adverse environmental and human impact of these fuels. Hence, biomass-based bioethanol fuels have increasingly been used in blending gasoline fuels, in fuel cells, and in biochemical and biohydrogen fuel production for fuel cells in a biorefinery context. Bioethanol fuels also play a critical role in maintaining energy security in supply shocks related to oil price shocks, COVID-19 pandemic, or wars in the aftermath of the Russian invasion of Ukraine. However, it is necessary to pretreat the biomass to enhance the yield of bioethanol prior to bioethanol production through hydrolysis of the biomass and fermentation of the resultant hydrolysates. Europe has been one of the most prolific producers of research in bioethanol fuel research, producing 28% of the global research output in this field. The European research in the field of bioethanol fuels has intensified in this context in the key research fronts of the production of bioethanol fuels and utilization of bioethanol fuels and to a lesser extent the evaluation of bioethanol fuels. For the first research front, pretreatment and hydrolysis of feedstocks, fermentation of feedstock-based hydrolysates, and production of bioethanol fuels and to a lesser extent distillation of bioethanol fuels are the key research areas while for the second research front, utilization of bioethanol fuels in fuel cells and transport engines and bioethanol-based biohydrogen fuels and to a lesser extent bioethanol sensors and bioethanol-based biochemicals are the key research areas. Research in this field has also intensified for the feedstocks of lignocellulosic biomass at large, bioethanol fuels, cellulose, wood biomass, starch feedstock residues, lignin, and sugars and to a lesser extent industrial wastes, hydrolysates, biomass at large, sugar feedstock residues, urban wastes, and food wastes. However, it is essential to develop efficient incentive structures for the primary stakeholders to enhance research in this field. Scientometric analysis has been used in this context to inform the primary stakeholders about the current state of research in a selected research field. As there have been no published scientometric studies in this field, this chapter presents a scientometric study of research in the European experience of bioethanol fuels. It examines the scientometric characteristics of both the sample and population data presenting the scientometric characteristics of these both datasets in the order of documents, authors, publication years, institutions, funding bodies, source titles, countries, Scopus subject categories, Scopus keywords, and research fronts.

102 Konur, O. 2023cn. European experience of bioethanol fuels: Review. In Evaluation and Utilization of Bioethanol Fuels II: Biohydrogen Fuels, Fuel Cells, Biochemicals, and Country Experiences, Handbook of Bioethanol Fuels: Production and Utilization Volume 6, Ed. O. Konur, pp. 189-211. Boca Raton, FL: CRC Press. 24 pp.

Crude oil-based gasoline fuels have been widely used in transportation sector since the 1920s. However, there have been great public concerns over adverse environmental and human impact of these fuels. Hence, biomass-based bioethanol fuels have increasingly been used in blending gasoline fuels, in fuel cells, and in biochemical and biohydrogen fuel production in a biorefinery context. However, it is necessary to pretreat biomass to enhance yield of bioethanol prior to bioethanol fuel production from feedstocks through hydrolysis of biomass and fermentation of resulting hydrolysates. Europe has been one of the most prolific producers engaged in bioethanol fuel research, producing 28% of the global research output in this field. European research in the field of bioethanol fuels has intensified in this context in the key research fronts of production of bioethanol fuels, utilization of bioethanol fuels, and, to a lesser extent, evaluation of bioethanol fuels. For the first research front, pretreatment of feedstocks and, to a lesser extent, hydrolysis of feedstocks, fermentation of hydrolysates, production of bioethanol fuels are the key research areas, while for the second research front, utilization of bioethanol fuels in fuel cells and bioethanol-based biohydrogen fuels are the key research areas. Research in this field has also intensified for feedstocks of wood biomass, bioethanol fuels, cellulose, lignocellulosic biomass at large, starch feedstock residues, lignin, sugars, and biomass at large. However, it is essential to develop efficient incentive structures for the primary stakeholders to enhance research in this field. Although there has been a number of review papers on bioethanol fuels, there has been no review of the 25 most-cited articles in this field. Thus, this book chapter presents a review of these 25 most-cited articles. Then, it discusses key findings of these highly influential papers and comments on future research priorities in this field.

Part 30. Bioethanol Fuel-based Biohydrogen Fuel Production 62 pp.

103 Konur, O. 2023co. Bioethanol fuel-based biohydrogen fuels: Scientometric study. In Evaluation and Utilization of Bioethanol Fuels II: Biohydrogen Fuels, Fuel Cells, Biochemicals, and Country Experiences, Handbook of Bioethanol Fuels: Production and Utilization Volume 6, Ed. O. Konur, pp. 215-236. Boca Raton, FL: CRC Press. 22 pp.

Crude oil-based gasoline fuels have been widely used in the transportation sector since the 1920s. However, there have been great public concerns over the adverse environmental and human impact of these fuels. Hence, biomass-based bioethanol fuels have increasingly been used in blending gasoline fuels and in fuel cells. In the meantime, the research in nanomaterials and fuel cells has intensified in recent years. Furthermore, the research in hydrogen fuels has also intensified in the primary research fronts of water-based photocatalytic hydrogen production, water-based electrocatalytic hydrogen production, reforming of bioethanol fuels for the production of biohydrogen fuels, biohydrogen fuel production, and hydrogen storage with more focus on nanomaterial development for hydrogen production and storage in recent years. Thus, the research in the field of the production of biohydrogen fuels from bioethanol fuels has progressed in the research fronts of biohydrogen production by steam reforming of bioethanol and to a lesser extent by photocatalytic biohydrogen production from bioethanol fuels, the oxidative steam reforming of bioethanol fuels, the partial oxidation of bioethanol fuels, autothermal reforming of bioethanol fuels, and biohydrogen production from bioethanol fuels in general. However, it is essential to develop efficient incentive structures for the primary stakeholders to enhance the research in this field. This chapter presents a scientometric study of the research in bioethanol-based biohydrogen fuels. It examines the scientometric characteristics of both the sample and population data presenting scientometric characteristics of both these datasets in the order of documents, authors, publication years, institutions, funding bodies, source titles, countries, Scopus subject categories, keywords, and research fronts.

104 Konur, O. 2023cp. Bioethanol fuel-based biohydrogen fuels: Review. In Evaluation and Utilization of Bioethanol Fuels II: Biohydrogen Fuels, Fuel Cells, Biochemicals, and Country Experiences, Handbook of Bioethanol Fuels: Production and Utilization Volume 6, Ed. O. Konur, pp. 237-251. Boca Raton, FL: CRC Press. 15 pp.

Crude oil-based gasoline fuels have been widely used in the transportation sector since the 1920s. However, there have been great public concerns over the adverse environmental and human impacts of these fuels. Hence, biomass-based bioethanol fuels have increasingly been used in blending gasoline fuels and in fuel cells. In the meantime, research in nanomaterials and fuel cells has intensified in recent years. Furthermore, research in hydrogen fuels has also intensified in the primary research fronts of water-based photocatalytic hydrogen production, water-based electrocatalytic hydrogen production, reforming of bioethanol fuels and other fuels for the production of biohydrogen fuels, biohydrogen production, and hydrogen storage, with more focus on nanomaterial development for hydrogen production and storage in recent years. Thus, the research in the field of the production of biohydrogen fuels from bioethanol fuels has progressed in the research fronts of biohydrogen production by the steam reforming of bioethanol and, to a lesser extent, photocatalytic biohydrogen production, biohydrogen production by the oxidative steam reforming of bioethanol, biohydrogen production by the partial oxidation of bioethanol, autothermal reforming of bioethanol, and biohydrogen production from bioethanol in general. However, it is essential to develop efficient incentive structures for the primary stakeholders to enhance research in this field. Although there have been a number of review papers on the bioethanol-based production of biohydrogen fuels, there has been no review of the 25 most-cited articles in this field. This chapter presents a review of the 25 most-cited articles in the field of bioethanol-based biohydrogen fuels. Then, it discusses the key findings of these highly influential papers and comments on future research priorities in this field.

105 Phung T. K., Vu, K.B. (2023) Recent advances in the steam reforming of bioethanol for the production of biohydrogen fuels. In Evaluation and Utilization of Bioethanol Fuels II: Biohydrogen Fuels, Fuel Cells, Biochemicals, and Country Experiences, Handbook of Bioethanol Fuels: Production and Utilization Volume 6, Ed. O. Konur, pp. 252-273. Boca Raton, FL: CRC Press. 23 pp. Thanh Khoa Phung, Khanh B. Vu

Hydrogen is considered to be one of the new generation fuels for the future replacing fossil fuels. Currently, hydrogen is mainly produced by steam reforming of methane and oil-derived hydrocarbons (95% of total hydrogen production). These processes emit CO2 to the environment, therefore, zero-emission green hydrogen produced from green resources is essential and necessary. Steam reforming of ethanol is one of the promising processes to produce green hydrogen. This chapter summarizes the recent catalysts, their supports and promoters, the reaction conditions, and the mechanisms. It covers noble metal catalysts, nickel (Ni) and cobalt (Co) catalysts for the steam reforming of bioethanol fuels and discusses the effects of the operating and reaction conditions, membrane-assisted ethanol steam reforming (ESR), and reaction mechanisms ofESR. These studies hint that the operating conditions of ESR can be optimized using a wide set of catalysts and catalyst supports as well as catalyst promoters to obtain a high biohydrogen yield.

Part 31. Bioethanol Fuel Cells 40 pp.

106 Konur, O. 2023cq. Bioethanol fuel cells: Scientometric study. In Evaluation and Utilization of Bioethanol Fuels II: Biohydrogen Fuels, Fuel Cells, Biochemicals, and Country Experiences, Handbook of Bioethanol Fuels: Production and Utilization Volume 6, Ed. O. Konur, pp. 277-297. Boca Raton, FL: CRC Press. 21 pp.

Crude oil-based gasoline fuels have been widely used in the transportation sector since the 1920s. However, there have been great public concerns over the adverse environmental impact of these fuels. Hence, biomass-based bioethanol fuels have increasingly been used in blending gasoline fuels and in fuel cells. In the meantime, the research in nanotechnology has intensified in recent years. The research in fuel cells has also intensified in recent years in three primary research streams solid oxide fuel cells (SOFCs), polymer electrode membrane fuel cells (PEMFCs), and microbial fuel cells (MFCs). The research in the direct ethanol fuel cells (DEFCs) has been a stream of the research on the PEMFCs. On the other hand, the research on the direct utilization of bioethanol fuels in these DEFCs has intensified in recent years, primarily in the research fronts of the ethanol electrooxidation on the platinum (Pt) electrocatalysts and the palladium (Pd) electrocatalysts for the DEFCs. The other research fronts are the ethanol electrooxidation on both Pt and Pd electrocatalysts and the other electrocatalysts, the other issues in the ethanol electrooxidation, and the DEFCs themselves. Further, the focus of the research has been on the development of nanomaterials and conventional materials for the most efficient processes for ethanol electrooxidation and the DEFCs. However, it is essential to develop efficient incentive structures for the primary stakeholders to enhance the research in this field. As there has not been any scientometric study on bioethanol fuel cells, this book chapter presents a scientometric study of the research in bioethanol fuel cells. It examines the scientometric characteristics of both the sample and population data presenting the scientometric characteristics of these both datasets in the order of documents, authors, publication years, institutions, funding bodies, source titles, countries, Scopus subject categories, keywords, and research fronts.

107 Konur, O. 2023cr. Bioethanol fuel cells: Review. In Evaluation and Utilization of Bioethanol Fuels II: Biohydrogen Fuels, Fuel Cells, Biochemicals, and Country Experiences, Handbook of Bioethanol Fuels: Production and Utilization Volume 6, Ed. O. Konur, pp. 298-313. Boca Raton, FL: CRC Press. 17 pp.

Crude oil-based gasoline fuels have been widely used in the transportation sector since the 1920s. However, there have been great public concerns over the adverse environmental impact of these fuels. Hence, biomass-based bioethanol fuels have increasingly been used in blending gasoline fuels and in fuel cells. In the meantime, research in nanotechnology has intensified in recent years. Research in fuel cells has also intensified in recent years in three primary research streams: solid oxide fuel cells (SOFCs), polymer electrode membrane fuel cells (PEMFCs), and microbial fuel cells (MFCs). Research in direct ethanol fuel cells (DEFCs) has been a stream of the research on PEMFCs. On the other hand, the research on the direct utilization of bioethanol fuels in these DEFCs has intensified in recent years, primarily in the research fronts of ethanol electrooxidation on platinum (Pt) electrocatalysts and on palladium (Pd) electrocatalysts for DEFCs. Other research fronts are ethanol electrooxidation on both Pt and Pd electrocatalysts and on other electrocatalysts, other issues in ethanol electrooxidation, and the DEFCs themselves. Further, the recent research focus has been on the development of nanomaterial-based electrocatalyst systems to improve the efficiency of DEFCs. However, it is essential to develop efficient incentive structures for the primary stakeholders to enhance the research in this field. Although there have been a number of review papers on bioethanol fuel cells, there has been no review of the 25 most-cited articles in this field. This chapter presents a review of the 25 most-cited articles in the field of bioethanol fuel cells. Then, it discusses the key findings of these highly influential papers and comments on future research priorities in this field.

Part 32. Bioethanol Fuel-based Biochemicals 58 pp.

108 Konur, O. 2023cs. Bioethanol fuel-based biochemical production: Scientometric study. In Evaluation and Utilization of Bioethanol Fuels II: Biohydrogen Fuels, Fuel Cells, Biochemicals, and Country Experiences, Handbook of Bioethanol Fuels: Production and Utilization Volume 6, Ed. O. Konur, pp. 317-337. Boca Raton, FL: CRC Press. 21 pp.

Crude oil-based gasoline fuels have been widely used in the transportation sector since the 1920s. However, there have been great public concerns over the adverse environmental and human impacts of these fuels. Hence, biomass-based bioethanol fuels have increasingly been used in blending gasoline fuels, in fuel cells, and in producing valuable biochemicals in a biorefinery context. In the meantime, research in nanomaterials and nanotechnology has intensified in recent years. The research on the production of biochemicals from bioethanol fuels has primarily intensified on the research fronts of bioethylenes, biobutadienes, biobutanols, and bioacetaldehydes and, to a lesser extent, bioethyl acetates, biopropylenes, bioacetic acids, biodiethyl ethers, and bioisobutenes. Further, the focus of the research has been on the development of the catalysts and catalyst supports, and the applications of nanotechnology have been relatively scarce. However, it is essential to develop efficient incentive structures for the primary stakeholders to enhance research in this field. Scientometric analysis has been used in this context to inform the primary stakeholders about the current state of research in this research field. As there have been no scientometric studies on biochemical production in general and on biochemical production from bioethanol fuels, this chapter presents a scientometric study of the research on bioethanol fuel-based biochemical production. It examines the scientometric characteristics of both the sample and population data and presents them in the order of documents, authors, publication years, institutions, funding bodies, source titles, countries, Scopus subject categories, keywords, and research fronts.

109 Konur, O. 2023st. Bioethanol fuel-based biochemical production: Review. In Evaluation and Utilization of Bioethanol Fuels II: Biohydrogen Fuels, Fuel Cells, Biochemicals, and Country Experiences, Handbook of Bioethanol Fuels: Production and Utilization Volume 6, Ed. O. Konur, pp. 338-353. Boca Raton, FL: CRC Press. 16 pp.

Crude oil-based gasoline fuels have been widely used in the transportation sector since the 1920s. However, there have been great public concerns over the adverse environmental and human impacts of these fuels. Hence, biomass-based bioethanol fuels have increasingly been used in blending gasoline fuels and in fuel cells. In the meantime, research in nanomaterials and nanotechnology has intensified in recent years. Research in the field of chemicals has also intensified in recent years. However, due to societal concerns about the sustainability of the environmental and human impacts of the chemicals, the production of biochemicals from bioethanol fuels has become an alternative research field. Thus, research on the production biochemicals from bioethanol fuels has primarily intensified in the research fronts of biobutanols, bioethylenes, bioacetaldehydes, bioacetic acids, biobutadienes, bioethyl acetates and, to a lesser extent, biodiethyl ethers, bioisobutenes, and biopropylenes. The focus of research has been more on the development of catalysts and catalyst supports rather than the operating conditions. On the other hand, it is essential to develop efficient incentive structures for the primary stakeholders to enhance research in this field. Although there have been a number of review papers on the production of biochemicals from bioethanol fuels, there has been no review of the 25 most-cited articles in this field. This chapter presents a review of the 25 most-cited articles in the field of bioethanol-based production of biochemical production. Then, it discusses the key findings of these highly influential papers and comments on future research priorities in this field.

110 Caballero, V.; Savoy, A.W.; Wang, Y. (2023) An overview of bioethanol conversion to hydrocarbons. In Evaluation and Utilization of Bioethanol Fuels II: Biohydrogen Fuels, Fuel Cells, Biochemicals, and Country Experiences, Handbook of Bioethanol Fuels: Production and Utilization Volume 6, Ed. O. Konur, pp. 354-371. Boca Raton, FL: CRC Press. 19 pp. Vannessa Caballero, Anthony William Savoy, Junming Sun, Yong Wang

The emerging demand for sustainable, environmentally conscious feedstocks coupled with the increasingly large supply of bio-derived ethanol makes it an appealing alternative to petroleum-based feedstocks. A simple dehydration reaction of ethanol can readily occur on aluminum oxide or silica/aluminum Brønsted acidic zeolite catalysts to produce ethylene at industrial scales. Activation of the C=C bond of ethylene on acidic catalysts can form a carbenium intermediate, which opens a whole array of potential reaction network via oligomerization/cracking reaction. From this standpoint, ethanol can be selectively converted into several chain hydrocarbons ranging from C₃ to C₄ light olefins, such as propylene, n-butenes, and 1,3-butadiene, or even to C₅–C₁₂ oligomers, aromatics, and paraffins that fall into gasoline and middle distillate fuel classifications. As will be discussed thoroughly in this chapter, enhancing catalytic selectivity, activity, and stability is a focus of past and current research and mainly pertains to modifying catalytic composition by tuning the Si/Al ratio in zeolites, adding secondary dopants, or optimizing reaction conditions. As a result, many researchers have developed highly effective catalytic systems that illustrate the efficacy of ethanol as a platform molecule for value-added chemicals, as well as the possible reaction pathways involved in these systems. However, much work is still needed to elucidate the fundamental site requirements and reaction mechanisms associated with the complex reaction network of ethanol to hydrocarbons.