Jaya Shankar Tumuluru

United States Department of Agriculture | USDA · Agricultural Research Service (ARS)

Torrefaction of biomass can be described as a mild form of pyrolysis at temperatures typically ranging between 200 and 300°C in an inert and reduced environment. Common biomass reactions during torrefaction include devolatilization, depolymerization, and carbonization of hemicellulose, lignin and cellulose. Torrefaction process produces a brown to...

There is a growing interest internationally to use more biomass for power generation, given the potential for significant environmental benefits and long-term fuel sustainability. However, the use of biomass alone for power generation is subject to serious challenges, such as feedstock supply reliability, quality, and stability, as well as comparat...

Developing uniformly formatted, densified feedstock from lignocellulosic biomass is of interest to achieve consistent physical properties such as size and shape, bulk and unit density, and durability, which significantly influence storage, transportation and handling characteristics, and, by extension, feedstock cost and quality. A variety of densi...

The chapter provides an insight into biological preprocessing and subsequent biochemical routes , mainly enzymatic hydrolysis and subsequent fermentation or anaerobic digestion of Pelletized Biomass into value-added products , till date.

In this study, we evaluated the pelleting characteristics of southern yellow pine (SYP), switchgrass (SG), and their blends for thermochemical conversion processes, such as pyrolysis and gasification. Using a pilot-scale ring-die pellet mill, we specifically assessed the impact of blend moisture, length-to-diameter (L/D) ratio in the pellet die, an...

This review uses a more holistic approach to provide comprehensive information and up-to-date knowledge on solar energy development in India and scientific and technological advancement. This review describes the types of solar photovoltaic (PV) systems, existing solar technologies, and the structure of PV systems. Substantial emphasis has been giv...

Torrefaction, a thermal pretreatment process, is gaining attention as it improves the physical properties and chemical composition of biomass for recycling. During torrefaction, biomass is heated slowly in an inert or oxygen-deficit environment to a maximum temperature of 300°C. The torrefaction process creates a solid uniform product with lower mo...

In this Research Topic, the editorial team welcomed Original Research dealing with the latest advances in biomass upgrading through torrefaction, from both fundamental and practical points of view. The ultimate objective was to gain deeper insight into the biomass torrefaction to promote its technological development and commercialization. Specific...

Low bulk density, variable moisture content, and particle size of municipal solid waste (MSW) create feeding, handling, storage, and transportation challenges. In this study, MSW bales were size-reduced in stage-1 and stage-2 hammer mill grinders fitted with 50.8-mm and 6.35-, 12.7-, and 19.05-mm screens. Ground MSW was densified further in a pilot...

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 proper...

The back cover image is based on the Case Report Briquetting characteristics of woody and herbaceous biomass blends: Impact on physical properties, chemical composition, and calorific value by Jaya Shankar Tumuluru et al., https://doi.org/10.1002/bbb.2121. The back cover image is based on the Case Report Briquetting characteristics of woody and her...

Intercropping (or polyculture) is gaining a lot of interest as it increases yields, allows better utilization of resources (water and nutrients), and provides better land management. The objective of this study is to understand the briquetting characteristics of woody and herbaceous biomass blends, which might result from intercropping. Tests were...

The objective of the study is to understand the impact of process variables on particle binding during corn stover pelleting. Initial particle attrition or percent fines <425 microns in 1/4-in. (6.35mm) and 7/16-in. (11.11-mm) hammermill screen size was 34.36% and 20.24%, respectively. Single pellet press was used to do the pelleting tests by varyi...

Various woody, herbaceous, and municipal solid waste (MSW) biomass feedstocks such as such as lodgepole pine, hybrid poplar, corn stover, other agricultural straws, switchgrass, miscanthus, and other forms of MSW are available for bioenergy applications. All of these have different feedstock physical and chemical compositions. The focus of this cha...

Compression tests and models are commonly used to understand the densification characteristics of metal, pharmaceuticals, agriculture, and food. Compression models help reveal the behavior of biomass grinds or particles during pelleting and can help to optimize the pressures required to manufacture a quality pellet. Pellets are formed by using eith...

The primary solid fuel standard used in the United States is the Pellet Fuel Institute (PFI) standard. In contrast, combined standards throughout various European countries—such as Austria, Sweden, the United Kingdom, France, and Denmark—are governed by what is known as the European Committee for Standardization (CEN). CEN/TC 335 developed technica...

This monograph discusses the various biomass feedstocks currently available for biofuels production, as well as the mechanical preprocessing technologies that can be effectively used to reduce feedstock variability for biofuels applications. Variability in the properties of biomass—in terms of moisture, particle size distribution, and low-density—r...

Even though densified products have many advantages in terms of storage, handling, transportation, and conversion performance, existing methods to produce dense biomass pellets are currently not considered due to the prohibitive costs to densify them. At present, new preprocessing technologies are developed to address the cost and quality issues as...

Raw biomass is difficult to use as a feedstock for biofuels production at the commercial scale. In its raw form, biomass is bulky, wet, and scattered. Densification technologies help to convert the raw biomass into a solid product that has improved storage, transport, and handling characteristics. The commonly used densification technologies that a...

The primary question many biofuels producers have is the suitability of densified products for biochemical and thermochemical conversion processes to produce liquid fuels. In general, the belief is the densification of biomass will increase biomass recalcitrance for both biochemical and thermochemical conversions. This chapter will discuss the suit...

Complete utilization of lignocellulosic biomass through the creation of value-added coproducts is one of the key strategies of the Bioenergy Technologies Office (BETO) for the cost-effective production of biofuels and biochemicals. A green approach to producing lightweight and high specific surface area (SSA) activated carbons (ACs) from sustainabl...

Biomass-derived coal or “biocoal” produced using a torrefaction process presents a carbon-neutral option of coal for power generation. While torrefaction delivers a carbon content and hydrophobicity comparable to coal, it lowers its density and creates material handling, storage, and transportation challenges. Densification into briquettes would he...

The benefits of using pelleted corn stover compared to loose corn stover with low severity soaking in aqueous ammonia pretreatment and reduced enzyme loadings were studied. Loose and pelleted corn stover were treated with the same set of pretreatment and hydrolysis conditions. A range of low to high severity pretreatment conditions and enzyme loadi...

The existing wood pellet markets face increasing competition – both the large-scale use for co-firing with coal or standalone bio-powerplants (price pressure from other low-carbon electricity technologies) and the residential use (competition from e.g., district heating, heat pumps, biogas and biomethane, as well as renewable power-to-gas). On the...

The blending of woody and herbaceous biomass can influence pellet quality and the energy consumption of the process. This work aims to understand the pelleting characteristics of 2-inch top-pine residue blended with switchgrass at high moisture content. The process variables tested are blend moisture content, length-to-diameter (L/D) ratio in the p...

Biomass could be a key source of renewable energy. Agricultural waste products, such as corn stover, provide a convenient means to replace fossil fuels, such as coal, and a large amount of feedstock is currently available for energy consumption in the U.S. This study has two main objectives: (1) to understand the impact of corn stover moisture cont...

Briquetting tests were conducted on lodgepole pine, switchgrass, and corn stover biomass. Three moisture levels (12, 15, and 18 % [w.b.]) and three-hammer mill screen sizes (4.8, 12.7, and 19.05 mm) were used to understand the impact of these variables on briquette-quality attributes such as unit and bulk density, durability rating, and briquetting...

An abundant, low-cost, and high-quality supply of lignocellulosic feedstock is necessary to realize the large-scale implementation of biomass conversion technologies capable of producing renewable fuels, chemicals, and products. Barriers to this goal include the variability in the chemical and physical properties of available biomass, and the seaso...

Densified products produced from pellet mill are commercially used as a commodity type product for energy applications that are transported nationally and internationally. The quality of the pelletized biomass produced depends on the process variables such as die diameter, length to diameter (L/D) ratio, die speed, preheating, and steam conditionin...

Currenlty biorefineries are not able to operate at the desired capacity due high moisture, particle size variability, poor flow properties due to cohesive and elastic properties, and high preprocessing costs. According to conventional methods it takes about $62/dry ton to preprocess herbaceous biomass at 30% moisture content and densify into pellet...

Currently biorefineries are not able to operate at the desired capacity due to biomass variability and specification limitations. Raw biomass resources do not meet conversion specifications due to the diversity, variability, and uncertainty associated with large-scale biomass resources. As such, there is a need to fully recognize the magnitude of b...

In the present study briquetting characteristics of blends of corn stover, switchgrass and lodgepole pine were evaluated. Briquetting tests were conducted using hydraulic briquette press. The feedstock that was tested was blends of corn stover, switchgrass and lodgepole pine. The raw material what was procured in bales and chips was size reduced in...

Pelleting tests on alfalfa at different moisture content were conducted. The quality attributes like density and durability of the pellets were evaluated. Alfalfa was procured from a local company in Idaho Falls, Idaho. Tests on alfalfa were conducted using three different mills (lab scale flat die, pilot scale ring die, and commercial scale ring d...

Currently, biorefineries are not able to operate at the desired capacity due to variability in feedstock properties such as moisture content, particle size and elastic and cohesive properties which create feeding and handling challenges. The moisture variability largely depends on the time of harvest, and storage methods followed. It is very diffic...

In the present research grinding and densification characteristics of municipal solid waste were studied. Grinding tests on MSW bales were conducted using a commercial scale grinder including densification tests using a briquette press. The MSW was initially procured in bales (4x4x4 ft) and ground in the stage- 1 grinder (Vermeer horizontal grinder...

As the world continues to deplete its nonrenewable resources, there has begun a shift toward using renewable materials for the production of fuels and chemicals. Terrestrial biomass, as well as municipal solid wastes, provides renewable feedstocks for fuel and chemical production. However, one of the major challenges to using biomass as a feedstock...

Optimization is a crucial step in the analysis of experimental results. Deterministic methods only converge on local optimums and require exponentially more time as dimensionality increases. Stochastic algorithms are capable of efficiently searching the domain space; however convergence is not guaranteed. This article demonstrates the novelty of th...

The economical and sustainable production of bioenergy depends on efficient feedstock supply systems. The development of feedstock supply systems requires balancing cost of delivered feedstock, feedstock quality, and the quantity of biomass available for feedstock production to meet the demand. Relevant quality characteristics of feedstocks depend...

In the present study a Box–Behnken experimental design was used to understand the effect of the moisture content of lodgepole pine grind (33–39%, w.b.), die speed (40–60 Hz) and preheating temperature (30–90 °C) on the pellet quality and specific energy consumption. The partially dried pellets produced had high-moisture content in the range of 19–2...

Deep drying and torrefaction compose a thermal pretreatment method where biomass is heated in the temperature range of 150–300 °C in an inert or reduced environment. The process parameters, like torrefaction temperature and residence time, have a significant impact on the proximate, ultimate, and energy properties. In this study, torrefaction exper...

A major challenge in the production of pellets is the high cost associated with drying biomass from 30 to 10% (w.b.) moisture content. At Idaho National Laboratory, a high-moisture pelleting process was developed to reduce the drying cost. In this process the biomass pellets are produced at higher feedstock moisture contents than conventional metho...

Torrefaction is a mild form of pyrolysis at temperatures typically ranging between 200 and 300°C in an inert and reduced environment. During torrefaction biomass undergoes devolatilization, depolymerization, and carbonization of hemicellulose, lignin, and cellulose and produces a brown to black uniform solid material. Torrefaction results in remova...

[Free article link valid until July 16, 2016: http://authors.elsevier.com/a/1T6HY3QkGxgqog ] Harvested hay or biomass are traditionally baled for better handling and they are transported to the outlet for final utilization. For better management of bale logistics, producers often aggregate bales into stacks so that bale-hauling equipment can haul...

Background: Traditionally harvested hay or biomass are baled for better handling and they are transported to the outlet for final utilization (e.g., animal consumption, potential biorefinery). To better manage the bale collection, producers often aggregate bales into stacks before transporting to an outlet. The motivation for forming subfield stack...

This chapter provides an overview of lignocellulosic crop supply chains such as Miscanthus, switch grass, reed canary grass, rye, and giant reed by outlining typical logistic operations in support of a liquid biofuel market. We present two strategies for managing feedstocks within the biomass supply system: (1) the conventional bale feedstock suppl...

Terrestrial lignocellulosic biomass has the potential to be a carbon neutral and domestic source of fuels and chemicals. However, the innate variability of biomass resources, such as herbaceous and woody materials, and the inconsistency within a single resource due to disparate growth and harvesting conditions, presents challenges for downstream pr...

To meet the Billion-Ton vision (Biomass Supply for Bioenergy and Bioproducts Industry: The Technical Feasibility of a Billion-Ton Annual Supply) and create a national-scale biofuel and biochemical industry, it will be necessary to consider a diverse portfolio of biomass feedstock resources. Quality and variability of feedstock characteristics becom...

Pretreatment and densification of biomass can increase the viability of bioenergy production by providing a feedstock that is readily hydrolyzed and able to be transported greater distances. Ammonia Fiber Expansion (AFEXTM) is one such method targeted for use at distributed depots to create a value-added and densified feedstock for bioenergy use. H...

In the present study, 6-mm ground corn stover and switchgrass were torrefied in temperatures ranging from 180 to 270°C for 15- to 120-min residence time. Thermogravimetric analyzer was used to do the torrefaction studies. At a torrefaction temperature of 270°C and a 30-min residence time, the weight loss increased to >45%. At 180°C and 120 min, the...

The goal of feedstock preconversions by mechanical or chemical separation is to improve the quality attributes and reduce the cost targets. The work outlined by this abstract describes the effects of alkaline preconversion on various quality attributes of multi-pass corn stover. Multi-pass corn stover was placed in a well-mixed reactor for 24 hours...

One of the major limitations of biomass is its low bulk density. Low bulk density results in higher transportation costs, larger storage foot print and handling and feeding issues. Densification of biomass increases the bulk density and helps to overcome these limitations. Commonly used densification systems are pellet mill and briquette press. The...

Food by definition consists of protein, carbohydrate, and fat used by the body to sustain growth, maintain, and support vital processes. Snack foods are considered healthy if they have less fats and less salt. Snacks, as they become part of regular meal, have a major role in everyday diet. Snacks that have no nutritional value are considered as jun...

Combining ammonia fiber expansion (AFEX) pretreatment with a depot processing facility is a promising option for delivering high value densified biomass to the emerging bioenergy industry. However, because the pretreatment process results in a high moisture material unsuitable for pelleting or storage (40% wet basis), the biomass must be immediatel...

In this work a new hybrid genetic algorithm was developed which combines a rudimentary adaptive steepest ascent hill climbing algorithm with a sophisticated evolutionary algorithm in order to optimize complex multivariate design problems. By combining a highly stochastic algorithm (evolutionary) with a simple deterministic optimization algorithm (a...

In the present analysis various fuel from biomass and fossil sources, their mass and energy densities, and their break-even transportation distances to transport them effectively were analyzed. This study gives an insight on how many times more energy spent on transporting the fuels to different distances than the energy that is originally present....

Preprocessing costs, in particular grinding costs, associated with size reduction of baled herbaceous feedstocks such as corn stover make up a significant portion of the costs associated with conversion of biomass to a liquid or solid biofuel. Generally the size reduction occurs in two stages, first the breaking apart of the baled feedstock combine...

One of the major limitations of biomass is its low bulk density. This makes it difficult to transport biomass efficiently for longer distances. Pelleting and briquetting systems are commonly used to make densified products from biomass. In the present study a laboratory scale continuous hydraulic briquetting press was used to understand the impact...

Decentralized biomass processing facilities, known as biomass depots, may be necessary to achieve feedstock cost, quantity, and quality required to grow the future U.S. bioeconomy. In this paper, we assess three distinct depot configurations for technical difference and economic performance. The depot designs were chosen to compare and contrast a s...

In the present study a Box-behnken experimental design was used to understand the effect of the moisture content of lodgepole pine grind (33–39%, w.b.), die speed (40–60 Hz) and preheating temperature (30–90 °C) on the pellet quality, and specific energy consumption. The partially dried pellets produced had high-moisture content in the range of 19...

According to researchers at Idaho National Laboratory’s Bioenergy Program, torrefaction of woody biomass could reduce variability in biomass feedstock and create a commodity-type product for green energy generation and usage. Faculty members Jaya Shankar Tumuluru and Richard Hess explain. http://www.iom3.org/materials-world-magazine/feature/2015/j...

The quality and specific energy consumption (SEC) of the biomass pellets produced depend upon pelleting process conditions. The present study includes understanding the effect of feedstock moisture in the range of 28–38% (wet basis [w.b.]) and preheating in the range of 30–110°C at two die speeds of 40 and 60 Hz on the physical properties and SEC....

Wood chips, torrefied wood chips, ground switchgrass, and wood pellets were tested for off‑gas emissions during storage. Storage canisters with gas‑collection ports were used to conduct experiments at room temperature of 20 °C and in a laboratory oven set at 40 °C. Commercially-produced wood pellets yielded the highest carbon monoxide (CO) emission...