Engineering Commons^™

Maximizing Charge Dynamics In Znin2s4/Cn Van Der Waals Heterojunction For Optimal Hydrogen Production From Photoreforming Of Glucose, Jinqiang Zhang, Xinyuan Xu, Lei Shi, Huayang Zhang, Shaobin Wang, Hongqi Sun

Research outputs 2022 to 2026

Biomass photoreforming stands out as a promising avenue for green hydrogen, leveraging solar energy for the generation and transformation of clean and renewable energy resources. The pursuit of efficient photocatalysts is motivated by the unsatisfied hydrogen evolution performance arising from the complex and stubborn structure of biomass. Herein, we loaded 2-dimensional (2D) ZnIn2S4 onto 2D carbon nitride nanosheets, resulting in the formation of Van der Waals (VDW) heterojunctions (ZIS/CN). Band structure and morphology of CN were rationally tailored through precursor engineering to effectively magnify interfacial internal electric field and minimize diffusion pathway within the VDW heterostructure, realizing optimal charge dynamics …

Partially Oxidative Torrefaction Of Woody Biomass Pellets: Burning Behaviour And Emission Analysis, Sajid Riaz, Yasir M. Al-Abdeli, Ibukun Oluwoye

Research outputs 2022 to 2026

Non-conventional torrefaction under partially oxidative conditions is an emerging cost-effective thermochemical pre-treatment method to improve the quality of biomass for energy applications. The literature lacks data on the combustion of biomass torrefied under oxygen-deficient atmosphere with actual reactor conditions (inevitable non-uniformities in the thermal environment). In this work, a dual mode fixed-bed biomass (torrefaction) reactor and combustor was operated on Australian biomass pellets, to torrefy the fuels at 275 °C for 30 min using partially oxidative atmosphere (O₂: 5 vol %, balance N₂) and then to combust them. Combustion behaviour with a particular focus on gaseous …

Exploration Of The Sludge Biodiesel Pathway, Zachary Christman

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Wastewater sludge is an overlooked source of fat, oil, and grease (FOG) that could be converted into biodiesel. The United States produces about 8 million tons of sludge per year. The disposal cost for this amount of sludge is about 2 billion dollars. The widespread availability and low cost of sludge compared to other biodiesel raw materials make it an economical choice for a renewable fuel. Using sludge as a raw material can produce 25 to 30 mg per gram of fatty acid methyl ester (FAME); the main component of biodiesel. Sludge biodiesel has the potential of transforming a portion …

Nsf Career Award Supports Schwartz's Research On The Chemical Process For Making Rubber Component, Marcus Wolf

General University of Maine Publications

advance his ongoing dissection of the Lebedev process. The well-known, multi-step chemical reaction is used to make butadiene from biomass-derived ethanol. However, little research has been conducted on the Lebedev process at the molecular level. Understanding the intricacies of this process will help researchers create new catalysts necessary for the chemical reactions to make goods from both petroleum and biomass, that would increase butadiene yield.

Challenges To Levulinic Acid And Humins Valuation In The Sugarcane Bagasse Biorefinery Concept, Emília Savioli Lopes, Jean Felipe Leal Silva, Elmer Ccopa Rivera, Alana Petrina Gomes, Melina Savioli Lopes, Rubens Maciel Filho, Laura Plazas Tovar

Faculty Publications

© 2020, Springer Science+Business Media, LLC, part of Springer Nature. Levulinic acid (LA) is currently one of the most promising chemicals derived from biomass. However, its large-scale production is hampered by the challenges in biomass hydrolysis and the poor selectivity due to the formation of humins (HUs). This study addresses these challenges using the biorefinery concept of biomass fractionation. A three-step process (pretreatment, delignification, and acid-catalyzed conversion) was optimized to produce LA from SCB considering the yield (YLA), efficiency (ELA), and concentration of LA (CLA) as functions of temperature, reaction time, acid concentration, and solids loading. By means of a …

A Review Of Coal Heating Value Correlations With Application To Coal Char, Tar, And Other Fuels, Andrew P. Richards, Denver Haycock, Jacob F. Frandsen, Thomas H. Fletcher

Faculty Publications

Accurately measuring a fuel’s heating value is one of the first steps in the classification of a new fuel. Heating values are widely used in coal combustion research and are becoming more useful in other fuel types as well. Many different empirical correlations to predict heating values based on primary organic (CHONS) elemental composition are found in the literature, many of which were originally created to predict heating values of parent coal, and some of which have been extended for biomass. However, no correlations exist for heating values of coal chars and tars. Thirteen literature heating value correlations (10 model …

Heating Rate And Temperature Effects On Pyrolysis Products From Live Wildland Fuels, Mohammad-Saeed Safdari, Elham Amini, David R. Weise, Thomas H. Fletcher

Faculty Publications

Wildland fire, which includes both planned (prescribed fire) and unplanned (wildfire) fires, is an important component of many ecosystems. During wildland fires, low heating rate pyrolysis (slow pyrolysis) occurs during preheating and/or smoldering of plant material. High heating rate pyrolysis (fast pyrolysis) exists in the flame region. Pyrolysis temperature and heating rate play important roles on the yields and the compositions of pyrolysis products. In this work, the effects of pyrolysis temperature and heating rate on the yields and the compositions of pyrolysis products from 14 plant species native to the forests of the southern United States are shown. The …

Pyrolysis Kinetics Of Live And Dead Wildland Vegetation From The Southern United States, Elham Amini, Mohammad-Saeed Safdari, David R. Weise, Thomas H. Fletcher

Faculty Publications

The fundamental combustion behavior of live wildland vegetation is not fully understood. Since the combustion process during wildland fire starts with pyrolysis, there is a need for better understanding of pyrolysis to develop improved wildland fire models. The kinetics of pyrolysis of live and dead wildland vegetation has not been explored in detail. In this study, the pyrolysis kinetics were determined for 14 different plant species (live and dead) which are all native to the forests in the southern United States. Pyrolysis experiments were carried out in a Thermogravimetric analyzer (TGA) under inert conditions at 5 different heating rates ranged …

Characterization Of Pyrolysis Products From Fast Pyrolysis Of Live And Dead Vegetation Native To The Southern United States, Mohammad-Saeed Safdari, Mahmood Rahmati, Elham Amini, Joel E. Howarth, Jansen P. Berryhill, Mark Dietenberger, David R. Weise, Thomas H. Fletcher

Faculty Publications

Prescribed burning (controlled burning) is used to decrease accumulation of combustible materials and reduce impact of uncontrolled wildland fires. Prescribed fires are often used to burn undergrowth in Southern forests of the United States. In order to improve prescribed fire application, accomplish desired fire effects, and limit potential runaway fires, an improved understanding of the fundamental processes related to combustion of heterogeneous fuel beds of live and dead fuels is needed. The initial processes of combustion involve pyrolysis and ignition. During this research, fast pyrolysis of 14 live and dead (biomass) plant species which are native to the Southern United …

Co-Gasification Of Coal And Biomass Wastes In An Entrained Flow Gasifier: Modelling, Simulation And Integration Opportunities, Dalia A. Ali Eng, Mamdouh A. Gadalla Prof., Omar Y. Abdelaziz, Christian P. Hulteberg, Fatma H. Ashour Prof.

Chemical Engineering

Gasification processes convert carbon-containing material into syngas through chemical reactions in the presence of gasifying agents such as air, oxygen, and steam. Syngas mixtures produced from such processes consist mainly of carbon monoxide (CO), hydrogen (H2), carbon dioxide (CO2), and methane (CH4); this gas can be directly utilised as a fuel to produce electricity or steam. Besides, it is regarded as a basic feedstock within the petrochemical and conventional refining industries, producing various useful products like methanol, hydrogen, ammonia, and acetic acid. In this work, a rigorous process model is developed to simulate the co-gasification of coal-biomass blends through an …

Development Of A Mobile 100 Kg/H Plant For Pyrolysis Using A Mechanically Fluidized Reactor, Dhiraj Kankariya, Stefano Tacchino, Dominic Pjontek, Franco Berruti, Cedric Briens

5th International Congress on Green Process Engineering (GPE 2016)

Current pyrolysis processes perform the thermal decomposition of biomass into a liquid bio-oil, bio-char and non-condensable gases, at around 500 °C, without the addition of oxygen gas. The bio-oil is a complex mixture of many components that is used either as a substitute for fuel oil or for applications such as liquid smoke and bio-phenol resins that do not require pure chemicals.

The large-scale mechanical fluidized reactor (MFR) is a new technology for the pyrolysis of biomass developed by ICFAR, which does not require a sand bed and, thus, provides an undiluted solid char residue, which is essential to realize …

Integrating Batch Pyrolysis And Fractional Condensation (2d Mfr) To Get High-Value Products From Biomass, Mohammad Hossain, Chiara Barbiero, Ian Scott, Franco Berruti, Cedric Briens

5th International Congress on Green Process Engineering (GPE 2016)

Agricultural crop residues are a source of inexpensive biomass to convert into bioproducts. The recovery of valuable chemicals from plant waste would partly solve the disposal issue and offer a more environmentally friendly alternative to synthetic chemical production. One approach to separate and concentrate valuable chemicals from biomass is pyrolysis using a batch reactor process. A mechanically fluidized reactor (MFR) was developed to pyrolyze biomass from ambient to temperatures near 600 °C, forming gases that are then condensed in an ice-chilled condenser to form a bio-oil. The bio-oil produced by the MFR can be separated within temperature ranges, termed one-dimensional …

Catalytic Property Of Olivine For Bio-Oil Gasification, Mohammad Latifi, Franco Berruti, Cedric Briens

5th International Congress on Green Process Engineering (GPE 2016)

Introduction

Biomass is an attractive renewable source of fuel and energy. Thermochemical processes can convert biomass to a liquid bio-oil or to a syngas. The advantage of using bio-oil as an intermediate is that, in contrast with both raw biomass and gas, it can easily be produced in small distributed units, stored and transported. Not only can platform chemicals and clean fuels be produced from syngas, but hydrogen is itself an alternative fuel. A high hydrogen production is usually desired: for example, methanol production requires a syngas with a molar H₂/CO ratio of 2. Therefore, maximum hydrogen production …

Using The Jiggled Bed Reactor To Develop Activated Carbons From Biomass Residues, Anastasia Colomba, Franco Berruti, Cedric Briens

5th International Congress on Green Process Engineering (GPE 2016)

Activated carbons are the most used adsorbent material. Their applications range from wastewater treatment, air purification, removal of contaminants and many others. According to “Global Activated Carbon Market Forecast & Opportunities 2017”, the demand for activated carbon is expected to increase more than 10% per year for the next 5 years to make it a $3 billion market by 2017. Current processes for the production of activated carbons from renewable resources do not provide valuable co-products. This presentation focuses on the conversion to activated carbon of the bio-char co-product of the pyrolysis process. Pyrolysis also provides valuable bio-oil, which is …

Adhesives From Biomass Pyrolysis, Dongbing Li, Franco Berruti, Cedric Briens

5th International Congress on Green Process Engineering (GPE 2016)

Fast pyrolysis of waste biomass with high lignin content, such as birch wood, birch bark, hydrolysis lignin, kraft lignin or low-cost digestate from biogas production, provides oils that can be substituted for phenol in phenol-formaldehyde resins. Biomass fast pyrolysis was performed in a dedicated fluidized bed pyrolyzer that incorporated two crucial innovations: a fractional condensation train provided dry bio-oils with ~1% of moisture and much reduced acidity; autothermal pyrolysis with partial oxidation reduces operating and capital costs, as well as increasing the quality of the dry bio-oil. Dry bio-oil obtained from autothermal fast pyrolysis of kraft lignin can be used …

Fundamental Study And Applications To Biomass Pyrolysis Of The Mechanically Fluidized Reactor, Valentina Lago, Franco Berruti, Cedric Briens

5th International Congress on Green Process Engineering (GPE 2016)

Lignin has great potential for the production of aromatics currently derived from petroleum, since it is the most abundant source of aromatics in nature. At present, Kraft lignin is used as fuel within the pulping process but, alternatively, it could be converted to high-value chemicals using thermochemical processes such as pyrolysis. Kraft lignin, however, is a very cohesive and thermally sensitive powder with foaming and agglomerating tendency under reaction conditions. Consequently, a novel reactor design, designated as Mechanically Fluidized Reactor (MFR) has been developed to successfully process Kraft lignin.

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Hydrodynamic Study Of A Circulating Fluidized Bed Used For Biomass Gasification Between 20 °C And 900 °C, Sébastien Pecate, Mehrdji Hemati, Mathieu Morin, Yilmaz Kara, Sylvie Valin

Fluidization XV

This work, carried out in the GAYA project frame and subsidized by ADEME, concerns the hydrodynamic study of a 60 kWth circulating fluidized bed pilot plant constructed at the Laboratoire de Génie Chimique in Toulouse for biomass gasification. In that process, biomass gasification and heating of fluidisation material (sand, olivine, catalyst…) which also acts as heat transfer medium, are performed in two separate reactors: a dense fluidized bed and a transported bed. Thermal energy, required in order to heat the fluidisation material, is supplied by the partial combustion of the char produced in the gasification reactor. The hydrodynamic study carried …

Co2 Char Gasification Rates Of Sawdust, Switchgrass, And Corn Stover In A Pressurized Entrained-Flow Reactor, Thomas H. Fletcher, Aaron D. Lewis, Emmett G. Fletcher

Faculty Publications

An entrained-flow flat-flame burner reactor was used to measure apparent CO2 gasification rates of near-spherical biomass chars of poplar sawdust, switchgrass, and corn stover using particle residence times1258−1891 K and 6.1− 13.5 atm, respectively. A new method was developed to produce near-spherical particles from nonspherical biomass chars. The apparent CO2 gasification rates for the three biomass chars with mean diameters near 100 μm were fit to a global first-order model, and the optimal kinetic parameters are reported. The measured gasification rate of poplar sawdust was about 3.9 times faster than that of switchgrass char, but only about 20% faster than …

Optimization Of Mixing In A Simulated Biomass Bed Reactor With A Center Feeding Tube, Michael T. Blatnik

Masters Theses 1911 - February 2014

Producing gasoline-type fuels from lignocellulosic biomass has two advantages over producing alcohol-type fuels from plant sugars: gasoline has superior fuel characteristics and plant lignin/cellulose does not compete with human food supplies. A promising technology for converting lignocellulose to fuel is catalytic fast pyrolysis (CFP). The process involves injecting finely ground biomass into a fluidized bed reactor (FBR) at high temperatures, which reduce the biomass to gases that react inside the catalyst particles. This entails complex hydrodynamics to efficiently mix a stream of biomass into a catalyst bed that is fluidized by a separate stream of inert gas. Understanding the hydrodynamics …

Goali: Multicomponent Molecular Transport In Nanoporous Materials, Douglas M. Ruthven, David Sholl, Ronald Chance

University of Maine Office of Research Administration: Grant Reports

In recent years novel diffusion controlled catalytic processes and non-conventional separation processes such as adsorption and membrane processes have gained an increasingly important place in the petroleum and petrochemicals industries. Several factors have driven this trend, including the need to improve the energy efficiency and throughput of refineries, stricter limits on the allowable composition of gasoline and diesel fuel requiring the removal of aromatics and sulfur containing compounds to extremely low levels, the need to process increasingly complex deposits of both natural gas and liquid hydrocarbons, and the possibility of producing liquid fuels from non-traditional sources such as biomass. Although …

Prediction Of Tar And Light Gas During Pyrolysis Of Black Liquor And Biomass, Thomas H. Fletcher, Harland R. Pond, Jarom Webster, Judson Wooters, Larry L. Baxter

Faculty Publications

A generalized model for describing the pyrolysis behavior of low-grade fuels is being developed for incorporation into larger combustion simulation models. Light gas and tar yields from black liquor or biomass pyrolysis can be predicted using the chemical percolation devolatilization (CPD) model originally developed for coal. The initial approach is to measure the average chemical structures in a black liquor sample using 13C NMR spectroscopy. These chemical structures are then used in pyrolysis model predictions. With few changes from the coal-derived kinetic parameters, the model describes the organic pyrolysis behavior of black liquor samples obtained in a nitrogen-purged furnace. It …

Numerical Computation Of Hydrodynamic Behavior Of Biomass Particles In Circulating Fluidized Beds, Afsin Gungor Dr.

The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering

A model using a particle based approach is developed to accurately predict the hydrodynamic behavior of biomass particles in CFBs. Generally, the change in the pressure gradient with height in CFB riser is small. Numerical results are in good agreement with experiments, both in form and magnitude.

Historical And Recent Developments In The Enzymatic Hydrolysis Of Brazilian Feedstocks For Ethanol Production, Elba P.S. Bon

Bioenergy - II: Fuels and Chemicals from Renewable Resources

N/A

Simulation Of Corn Stover And Distillers Grains Gasification With Aspen Plus, Ajay Kumar, Hossein Noureddini, Yaşar Demirel, David Jones, Milford Hanna

Yaşar Demirel Publications

A model was developed to simulate the performance of a lab‐scale gasifier and predict the flowrate and composition of product from given biomass composition and gasifier operating conditions using Aspen Plus software. Mass balance, energy balance, and minimization of Gibbs free energy during the gasification were applied to determine the product gas composition. Carbon conversion efficiency and tar content were provided to the model as inputs as these could not be predicted by the model based on minimization of Gibbs free energy. Experiments for validation of the model were performed on a lab‐scale fluidized bed gasifier using corn stover and …

H2-Rich Syngas From Renewable Sources By Dual Fluidized Bed Steam Gasification Of Solid Biomass, Christoph Pfeifer, Tobias Pröll, Bernhard Puchner, Hermann Hofbauer

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

Steam gasification of solid biomass yields high quality producer gases that can be used for efficient combined heat and power production (CHP) and as a renewable resource for chemical syntheses. The dual fluidized bed steam gasification technology provides the necessary heat for steam gasification by circulating hot bed material that is heated in a second fluidized bed reactor by combustion of residual biomass char. The hydrogen content in producer gas of such gasifiers is about 40 vol% (dry basis). Addition of carbonates to the bed material and adequate adjustment of operation temperatures in the reactors allow selective transport of CO2 …

Fast Pyrolysis Of Biomass In A Circulating Fluidised Bed, Manon Van De Velden, Xianfeng Fan, Andy Ingram, Jan Baeyens

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

CFB biomass pyrolysis produces mostly bio-oil. Reaction rates are fast (k > 0.5 s-1). Yields exceed 60 wt% of bio-oil at 500 °C and at a residence time for oil and char t < 2.5 s. as achieved in plug flow CFB-mode, shown by PEPT to occur at U > (Utr + 1) m/s and G > 200 kg/m² s.

Thermal Conversion Of Biomass And Waste, Liban Yassin, Paola Lettieri, Stefaan Simons, Antonino Germanà

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

This paper investigates the process designs of 2 fluidized bed gasification plants utilizing clean biomass. Energy and mass balances for each process were carried out and ChemCAD was used to evaluate the energy recovery process by simulating the operation of a steam turbine and a combined cycle gas turbine (CCGT).

Analysis Of Grain Screenings By X-Ray Photoelectron Spectroscopy, Guilin Jiang, Ghaleb A. Husseini, Larry Lin Baxter, Matthew R. Linford

Faculty Publications

Determining the chemical structure and composition of biomass fuels using x-ray photoelectron spectroscopy XPS can provide fundamental knowledge of their structures that is useful in understanding and predicting their combustion behavior. Grain screenings are an example of an agricultural residue byproduct of food and feed production of potential interest for biomass combustion. The XPS spectra of grain screenings provide both its elemental composition and indications of its bonding. Traditional fuel analyses of this fuel are also provided. These include: ultimate analysis — the elemental composition of the overall fuel C, H, N, S, and O; chlorine analysis — reported here …

Analysis Of Sawdust By X-Ray Photoelectron Spectroscopy, Guilin Jiang, Ghaleb A. Husseini, Larry Lin Baxter, Matthew R. Linford

Faculty Publications

Determining the chemical structure and composition of biomass fuels using x-ray photoelectron spectroscopy XPS can provide fundamental knowledge of their structures that is useful in understanding and predicting their combustion behavior. Sawdust is an example of a forest product residue byproduct of paper and lumber production of potential interest for biomass combustion. The XPS spectra of sawdust provide both its elemental composition and indications of its bonding. Traditional fuel analyses of this fuel are also provided. These include: ultimate analysis — the elemental composition of the overall fuel C, H, N, S, and O; chlorine analysis — reported here as …

Analysis Of Sugar Beet Pulp By X-Ray Photoelectron Spectroscopy, Guilin Jiang, Ghaleb A. Husseini, Larry Lin Baxter, Matthew R. Linford

Faculty Publications

Determining the chemical structure and composition of biomass fuels using x-ray photoelectron spectroscopy XPS can provide fundamental knowledge of their structures that is useful in understanding and predicting their combustion behavior. Sugar beet pulp is an example of an agricultural residue byproduct of food and feed production of potential interest for biomass combustion. The XPS spectra of sugar beet pulp provide both its elemental composition and indications of its bonding. Traditional fuel analyses of this fuel are also provided. These include: ultimate analysis — the elemental composition of the overall fuel C, H, N, S, and O; chlorine analysis — …