Densification Impact On Raw Chemically And Thermally Pretreated Biomass Physical Properties And Biofuels Production

First-generation ethanol plants did not have many operational challenges as the feedstocks (e.g., corn) used for fuel production are dense, stable, storable, and shippable commodity-type products with fewer conversion challenges. These feedstock properties led the first-generation large-scale biorefineries to grow exponentially. In the second-generation biofuels, the feedstocks used are agricultural and forest residues, dedicated energy crops, industrial wastes, and municipal solid waste. When the industry tested these feedstocks for biofuel production, they faced flowability, storage, transportation, and conversion issues. One way to overcome some of the feeding, handling, transportation, and variable moisture challenges is to densify the biomass. Pellet mills and briquette presses are commonly used to produce densified products. The densified products have uniform size, shape, higher bulk density, and better downstream conversion performance. Also, the densified products are aerobically stable and can be stored for longer durations without any loss in quality.This book's focus is on understanding how the densification process variables, biomass types and their blends, mechanical preprocessing, and thermal and chemical pretreatment methods impact the quality of the densified products produced for biofuel production. Finally, the book also explores the conversion performance of densified biomass for biofuel production.

"First-generation ethanol plants were designed based on corn (maize grain), a dense, stable, storable and shippable commodity-type product with multiple applications. With these properties, corn was used as a feedstock for large-scale biorefineries without any challenges for a considerable length of time to allow its usage to grow exponentially. In the second-generation biofuels, the feedstocks used are low-cost carbon resources such as crop and forest residues and municipal solid waste. These materials are not dense; they have irregular size and shape, variable moisture, and are not readily storable and shippable. When the industry tested these feedstocks for biofuel production, they faced flowability, storage, transportation, and conversion issues. One way to overcome feeding, handling, transportation, and variable moisture challenges is to densify the biomass. The densification systems such as pellet mill and briquette press are commonly used to produce densified products. The densified products have uniform size, shape, and higher density. Also, the densified products are aerobically stable as they have the moisture of less than 10 % (w.b.). This book's focus is to understand how the densification process variables, biomass types and their blends, mechanical preprocessing, and thermal and chemical pretreatment methods impact the quality of the densified products produced for biofuel production"--

This monograph discusses the various biomass feedstocks currently available for biofuels production, and mechanical preprocessing technologies to reduce the feedstock variability for biofuels applications. Variability in the properties of biomass—in terms of moisture, particle size distribution, and low-density—results in storage, transportation, handling, and feeding issues. Currently, biorefineries face serious particle bridging issues, uneven discharge, jamming of equipment, and transportation problems. These issues must be solved in order for smooth operations to be possible. Mechanical preprocessing technologies, such as size reduction, densification, and moisture management using drying and dewatering, can help to overcome these issues. Many densification systems exist that will assist in converting low-density biomass to a high-density commodity type feedstock. In 6 chapters, the impact of densification process variables, such as temperature, pressure, moisture, etc., on biomass particle agglomeration, the quality of the densified products, and the overall energy consumption of the process are discussed, as are the various compression models for powders that can be used for biomass particles agglomeration behavior and optimization of the densification process using statistical and evolutionary methods. The suitability of these densified products for biochemical and thermochemical conversion pathways is also discussed, as well as the various international standards (CEN and ISO) they must adhere to. The author has worked on biomass preprocessing at Idaho National Laboratory for the last ten years. He is the principal investigator for the U.S. Department of Energy Bioenergy Technologies Office-funded “Biomass Size Reduction and Densification” project. He has developed preprocessing technologies to reduce cost and improve quality. The author has published many papers and books focused on biomass preprocessing and pretreatments. Biomass process engineers and biorefinery managers can benefit from this book. Students in chemical, mechanical, biological, and environmental engineering can also use the book to understand preprocessing technologies, which greatly assist in improving the biomass critical material attributes. The book can help policymakers and energy systems planners to understand the biomass properties limitations and technologies to overcome the same.

Engineering the physical, chemical, and energy properties of lignocellulosic biomass is important to produce high-quality consistent feedstocks with reduced variability for biofuels production. The emphasis of this book will be the beneficial impacts that mechanical, chemical, and thermal preprocessing methods can have on lignocellulosic biomass quality attributes or specifications for solid and liquid biofuels and biopower production technologies. "Preprocessing" refers to treatments that can occur at a distance from conversion and result in an intermediate with added value, with improved conversion performance and efficiency. This book explores the effects of mechanical, chemical, and thermal preprocessing methods on lignocellulosic biomass physical properties and chemical composition and their suitability for biofuels production. For example, biomass mechanical preprocessing methods like size reduction (which impacts the particle size and distribution) and densification (density and size and shape) are important for feedstocks to meet the quality requirements for both biochemical and thermochemical conversion methods like enzymatic conversion, gasification, and pyrolysis process. Thermal preprocessing methods like drying, deep drying, torrefaction, steam explosion, hydrothermal carbonization, and hydrothermal liquefaction effect feedstock's proximate, ultimate and energy property, making biomass suitable for both solid and liquid fuel production. Chemical preprocessing which includes washing, leaching, acid, alkali, and ammonia fiber explosion that can enable biochemical composition, such as modification of lignin and hemicellulose, and impacts the enzymatic conversion application for liquid fuels production. This book also explores the integration of these preprocessing technologies to achieve desired lignocellulosic biomass quality attributes for biofuels production.

Engineering the physical, chemical, and energy properties of lignocellulosic biomass is important to produce high-quality consistent feedstocks with reduced variability for biofuels production. The emphasis of this book will be the beneficial impacts that mechanical, chemical, and thermal preprocessing methods can have on lignocellulosic biomass quality attributes or specifications for solid and liquid biofuels and biopower production technologies. "Preprocessing" refers to treatments that can occur at a distance from conversion and result in an intermediate with added value, with improved conversion performance and efficiency. This book explores the effects of mechanical, chemical, and thermal preprocessing methods on lignocellulosic biomass physical properties and chemical composition and their suitability for biofuels production. For example, biomass mechanical preprocessing methods like size reduction (which impacts the particle size and distribution) and densification (density and size and shape) are important for feedstocks to meet the quality requirements for both biochemical and thermochemical conversion methods like enzymatic conversion, gasification, and pyrolysis process. Thermal preprocessing methods like drying, deep drying, torrefaction, steam explosion, hydrothermal carbonization, and hydrothermal liquefaction effect feedstock's proximate, ultimate and energy property, making biomass suitable for both solid and liquid fuel production. Chemical preprocessing which includes washing, leaching, acid, alkali, and ammonia fiber explosion that can enable biochemical composition, such as modification of lignin and hemicellulose, and impacts the enzymatic conversion application for liquid fuels production. This book also explores the integration of these preprocessing technologies to achieve desired lignocellulosic biomass quality attributes for biofuels production.

This book is the outcome of contributions by many experts in the field from different disciplines, various backgrounds, and diverse expertise. This book provides information on biomass volume calculation methods and biomass valorization for energy production. The chapters presented in this book include original research and review articles. I hope the research presented in this book will help to advance the use of biomass for bioenergy production and valorization. The key features of the book are: Providing information on biomass volume estimation using direct, nondestructive and remote sensing methods Biomass valorization for energy using thermochemical (gasification and pyrolysis) and biochemical (fermentation) conversion processes.

Woody biomass is most widely used for energy production. In the United States, roughly 2% of the energy consumed annually is generated from wood and wood-derived fuels. Woody biomass needs to be preprocessed and pretreated before it is used for energy production. Preprocessing and pretreatments improve the physical, chemical, and rheological properties, making them more suitable for feeding, handling, storage transportation, and conversion. Mechanical preprocessing technologies such as size reduction and densification, help improve particle size distribution and density. Thermal pretreatment can reduce grinding energy and torrefied ground biomass has improved sphericity, particle surface area, and particle size distribution. This book focuses on several specific topics, such as understanding how forest biomass for biofuels impacts greenhouse gas emissions; mechanical preprocessing, such as densification of forest residue biomass, to improve physical properties such as size, shape, and density; the impact of thermal pretreatment temperatures on woody biomass chemical composition, physical properties, and microstructure for thermochemical conversions such as pyrolysis and gasification; the grindability of torrefied pellets; use of wood for gasification and as a filter for tar removal; and understanding the pyrolysis kinetics of biomass using thermogravimetric analyzers.

This book aspires to be a comprehensive summary of current biofuels issues and thereby contribute to the understanding of this important topic. Readers will find themes including biofuels development efforts, their implications for the food industry, current and future biofuels crops, the successful Brazilian ethanol program, insights of the first, second, third and fourth biofuel generations, advanced biofuel production techniques, related waste treatment, emissions and environmental impacts, water consumption, produced allergens and toxins. Additionally, the biofuel policy discussion is expected to be continuing in the foreseeable future and the reading of the biofuels features dealt with in this book, are recommended for anyone interested in understanding this diverse and developing theme.