Chemical Engineering Commons^™

Increased Energy Yield Through Fast Pyrolysis: Empowering Malawian Villages, Diehl Mutamba

Undergraduate Honors Theses

Biomass contributes to several renewable energy technologies. This project will explore the use of fast pyrolysis to produce fuels by designing an apparatus for fast pyrolysis. Malawian people harvest firewood from the forests, which is a major contributor to deforestation. Furthermore, they convert some of it to charcoal with about 10-15% efficiency to sell to city dwellers. The project will enable herbaceous fuels to replace wood, increase charcoal yields and create new products. Firewood and charcoal produce smoke and carbon monoxide (CO) that compromises the villagers’ health.

This project will address deforestation problems, improve sustainability, decrease health hazards and improve …

Experimental Evaluation Of Lignocellulosic Biomass Pyrolysis By Dielectric Heating And Thermocatalytic Upgrading Of Pyrolysis Vapors Via Iron-Doped Montmorillonite Clay Catalyst, Candice Raffaela Ellison

LSU Doctoral Dissertations

This work is an investigation of microwave-assisted biomass pyrolysis and thermocatalytic upgrading of pyrolysis vapors. In the first two chapters, the microwave susceptibility of mixtures of biomass with potential microwave absorbers are characterized by dielectric measurements at microwave frequencies. Dielectric constant and dielectric loss factor of biomass mixtures with char and biomass mixtures with bentonite are found to increase quadratically with increasing weight percent of char or bentonite.

Chapter 3 presents a finite element model, developed in COMSOL Multiphysics, comparing two waveguide applicator configurations for microwave processing using biomass as a model material. A standing wave configuration results in intense …

Effects Of Water Content And Particle Size On Yield And Reactivity Of Lignite Chars Derived From Pyrolysis And Gasification, Yong Huang, Yonggang Wang, Hao Zhou, Yaxuan Gao, Deliang Xu, Lei Bai, Shu Zhang

Faculty & Staff Scholarship

Water inside coal particles could potentially enhance the interior char–steam reactions during pyrolysis and gasification. This study aims to examine the effects of water contents on the char conversion during the pyrolysis and gasification of Shengli lignite. The ex-situ reactivities of chars were further analyzed by a thermo gravimetric analyzer (TGA). Under the pyrolysis condition, the increase in water contents has monotonically decreased the char yields only when the coal particles were small (μm). In contrast, the water in only large coal particles (0.9–2.0 mm) has clearly favored the increase in char conversion during the gasification condition where 50% steam …

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 …

Model For The Evolution Of Pore Structure In A Lignite Particle During Pyrolysis. 2. Influence Of Cross-Linking Reactions, Molten Metaplast, And Molten Ash On Particle Surface Area, He Yang, Thomas H. Fletcher, Sufen Li, Haoquan Hu, Lijun Li

Faculty Publications

A model for the evolution of the pore structure in a lignite particle during pyrolysis was established previously based on the chemical percolation devolatilization (CPD) model, using coal polymer network parameters to calculate the surface area and porosity of the particle. In this paper, to get the accurate surface area of coal particle at high pyrolysis temperature, the previous model was improved by considering the effects of cross-linking reactions, molten Metaplast, and ash. The good agreement of the predicted surface area with experiments at temperature below 1200 K in the previous model is maintained, and model accuracy is improved at …

The Formation Of Polycyclic Aromatic Hydrocarbons From The Pyrolysis Of Model 1-Alkene Fuels, Eva Christine Caspary

LSU Doctoral Dissertations

To understand the role of 1-alkenes and allylic radicals in the reaction pathways leading to the formation and growth of polycyclic aromatic hydrocarbons (PAH), pyrolysis experiments have been performed with three 1-alkene fuels—propylene (CH₂=CH–CH₃), 1-butene (CH₂=CH–CH₂–CH₃), and 1-pentene (CH₂=CH–CH₂–CH₂–CH₃)—at temperatures of 600 – 1000 °C and a fixed residence time of 0.31 s. The experiments are carried out in an isothermal laminar-flow quartz-tube reactor. Analyses of the pyrolysis products by gas-chromatographic and high-pressure liquid-chromatographic techniques reveal that the three fuels differ in: 1) their conversion behavior, 2) the relative amounts of the major C₂ – C₄ species produced, and 3) …

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 …

Influence Of Pre-Treatment On Grass Pyrolysis For High Value Products, Chiara Barbiero, Charles Greenhalf, Franco Berruti, Cedric Briens

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

Pyrolysis of biomass is a process which yields high quality, clean, and green products like bio-oil and bio-char. Bio-oil has a wide range of applications and also includes liquid fuels and raw chemical products. Therefore, it will be attractive to tailor the bio-oil properties to improve the yields of specific compounds that are economically interesting. In particular, pyrolytic sugar can be used for fermentation while phenolic compounds have an array of industrial applications such as adhesives; moreover, they can substitute petroleum-based phenols. However, it is difficult to achieve high yields of specific chemicals in the bio-oil without adequate biomass pre-treatments. …

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 …

Low-Temperature Artificial Maturation Studies Of Type Ii And Type Iii Kerogens: Implications For Biogenic Gas Production, Albert Willy Nguena Kamga

Chemistry & Biochemistry Theses & Dissertations

Ancient organic matter (OM) in shales and coals, known mainly as Type II and Type III OM are known to produce both biogenic, thermogenic gas and oil. In this dissertation, mild artificial maturation, via closed system pyrolysis, is employed to determine the thermal reactivity of Type II and Type III OM beyond diagenesis. We select three Type II kerogens: i) Type II kerogen isolated from recent cores (3.3 Ma, Ro = 0.28) recovered from an upwelling basin in Namibia, Africa referred to as ODP Sediment, ii) Type II-S isolated from sediments (150 Ma, Ro = 0.38) recovered from an outcrop …

A Comparison Of Simple Global Kinetic Models For Coal Devolatilization With The Cpd Model, Andrew Richards, Thomas H. Fletcher

Faculty Publications

Simulations of coal combustors and gasifiers generally cannot incorporate the complexities of advanced pyrolysis models, and hence there is interest in evaluating simpler models over ranges of temperature and heating rate that are applicable to the furnace of interest. In this paper, six different simple model forms are compared to predictions made by the Chemical Percolation Devolatilization (CPD) model. The model forms included three modified one-step models, a simple two-step model, and two new modified two-step models. These simple model forms were compared over a wide range of heating rates (5000 to 10⁶ K/s) at final temperatures up to …

Growth Of Polycyclic Aromatic Hydrocarbons During The Supercritical Pyrolysis Of N-Decane, Subramanian Venkateswaran Kalpathy

LSU Doctoral Dissertations

In order to serve a dual role as a propellant and as a coolant, fuels in the pre-combustion environment of future high-speed aircraft will be exposed to temperatures and pressures of up to 700 °C and 130 atm—conditions that are supercritical for jet fuels. Under such conditions, fuel can undergo pyrolytic reactions leading to the formation of polycyclic aromatic hydrocarbons (PAH), which are precursors to fuel-line solid deposits that can hinder safe operation of the aircraft. Therefore, to prevent solid deposit formation, it is extremely important to understand the PAH formation pathways in the supercritical fuel pyrolysis environment. To better …

Aspen Simulation Of Oil Shale And Biomass Process, Anand Alembath

Masters Theses

"This thesis focuses on design and analysis of two major chemical processes using computer simulation which performs a steady state computation. The objective is to design processes using Aspen simulation to establish optimum operating conditions by performing various simulation runs which are challenging to execute at lab scale.

Increasing energy needs and decline of global oil prices has shifted our focus on commercially developing unconventional and renewable resources. Commercialization of any process relies on developing a process model that identifies different process parameters by performing a steady state mass and heat balance. Aspen simulation is considered an effective process modeling …

Experimental And Theoretical Investigation Of Sustainable Fast Pyrolysis Biofuels From Woody Biomass, Bethany Jean Klemetsrud

Dissertations, Master's Theses and Master's Reports

Biofuels are an important advancement in alternative energy that can provide substantial environmental benefits compared to their conventional fossil fuel counterparts Said benefits are usually measured using life cycle assessments. However, it is not well understood yet how different methodological choices such as system boundaries, biomass feedstocks, conversion pathways, geographical data, etc. affect the conclusions drawn from biofuels LCA. This research shows large variability in life cycle assessment results and limits comparison across different biofuel pathways due to methodological choices set forth by policy and certification schemes. Advanced biofuels have not reached large scale production due to a limited understanding …

Synthesis Of Porous Carbon Nanosheets And Its Application In Sodium-Ion Battery, Jing-Fei Zhang, Jing Lu, Xiao-Yu Yang, Yun-Di Huang, Lin Xu, Dong-Mei Sun, Ya-Wen Tang

Journal of Electrochemistry

Owning to sodium’s high abundance, relatively low cost, similar chemical properties to Li and very suitable redox potential of E₀(Na⁺/Na) = -2.71 V versus SHE which is only 0.3 V above that of lithium, rechargeable sodium ion battery hold much promise as potential alternatives to current lithium ion batteries for energy storage applications. Carbon material is regarded as the most promising anode candidate for sodium ion battery. Particularly, carbon nanosheet with porous structure and high conductivity is expected to have improved sodium ion storage properties. In this paper, we present a two-step pyrolysis-based method for facile …

Targeted Products From Fast-Hydropyrolysis And Hydrodeoxygenation Of Biomass, Ian Tad Smith

Open Access Theses

Previously, the H2Bioil process was proposed as a possible way to convert sustainably available intact biomass into liquid fuels. The optimization of this process and possible synergies with other biomass conversion processes are presented in this thesis.

The selectivity of the PtMo hydrodeoxygenation catalyst was tuned using two different hydrogen partial pressures: 25 bar, and 2.5 bar. This effect was studied on cellulose and intact biomass samples to determine the effect that hydrogen has upon the retention of aromatic compounds found in intact biomass. These experiments show that it is possible for the hydrogenation activity of the PtMo catalyst to …

Modeling Light Gas And Tar Yields From Pyrolysis Of Green River Oil Shale Demineralized Kerogen Using The Chemical Percolation Devolatilization Model, Daniel Barfuss, Ronald J. Pugmire, Thomas H. Fletcher

Faculty Publications

Recent detailed chemical structure analyses of three demineralized kerogens from Green River oil shale samples were used to generate input parameters for the chemical percolation devolatilization (CPD) model. This model uses a lattice network to describe pyrolysis of solid hydrocarbons, such as coal and biomass. It was necessary to modify the formulation of the CPD model to account for the long aliphatic carbon chains found in oil shale, because gases formed from these long chains condense at room temperature and are counted as tar. It was initially assumed that 20% of the aliphatic material was released as light gas during …

Model For The Evolution Of Pore Structure In A Lignite Particle During Pyrolysis, Sufen Li, He Yang, Thomas H. Fletcher, Ming Dong

Faculty Publications

In this paper, on the basis of the chemical percolation devolatilization (CPD) model and using the coal polymer network parameters to calculate the surface area and porosity of the particle, a model for the evolution of pore structure in a lignite particle during pyrolysis is established. The model connects the polymer network structure and the pore structure, and it may extend the application range of network statistical devolatilization models. Model predictions agree with experimentally observed trends reported in the literature for porosity and internal surface area with increasing mass release. Particle porosity increases during pyrolysis because of mass release and …

Simulation Of The Swelling Of High-Volatile Bituminous Coal During Pyrolysis. Part 2: Influence Of The Maximum Particle Temperature, He Yang, Thomas H. Fletcher, Ming Dong

Faculty Publications

A model was established previously to predict the swelling ratio of high-volatile bituminous coal during pyrolysis based on the assumption that the structure of bubble distribution in the particle at the beginning of the plastic stage is a central bubble surrounded by many surrounding bubbles. The initial number and size of the bubbles when the particles become plastic are calculated by the pressure in the particle, and the chemical percolation devolatilization (CPD) model is used to describe pyrolysis. In this paper, to obtain accurate results at low pyrolysis temperatures, the previous model is improved and the following parts in the …

Modeling Of Biomass Torrefaction And Pyrolysis And Its Applications, Jordan L. Klinger

Dissertations, Master's Theses and Master's Reports - Open

Utilizing biomass provides a possible near-term alternative solution for fossil energy dependence in both electricity generation and transportation. Though thermochemical conversion can produce solid/liquid fuels that are compatible in existing infrastructure, detailed scientific chemical and mechanistic understanding are still being developed. In contribution to these efforts, this work is focused on development of a semiempirical, lumped parameter, chemical kinetic model to describe the degradation of woody biomass.

The initial kinetic model was developed in the torrefaction region to describe the gas-phase evolution of products (water, organic acids, permanent gases, and furfural) through a three consecutive reaction model. In this model, …

Gasification Of Biomass, Coal, And Petroleum Coke At High Heating Rates And Elevated Pressure, Aaron D. Lewis

Theses and Dissertations

Gasification is a process used to convert any carbonaceous species through heterogeneous reaction to obtain the desired gaseous products of H2 and CO which are used to make chemicals, liquid transportation fuels, and power. Both pyrolysis and heterogeneous gasification occur in commercial entrained-flow gasifiers at pressures from 4 to 65 atm with local gas temperatures as high as 2000 °C. Many gasification studies have been performed at moderate temperatures, heating rates, and pressures. In this work, both pyrolysis and char gasification experiments were performed on coal, petroleum coke, and biomass at conditions pertinent to commercial entrained-flow gasifiers. Rapid biomass pyrolysis …

Simulation Of The Swelling Of High-Volatile Bituminous Coal During Pyrolysis, He Yang, Sufen Li, Thomas H. Fletcher, Ming Dong

Faculty Publications

In this paper, a model is established to predict the swelling ratio of high-volatile bituminous coal during pyrolysis, based on the assumption that the structure of bubble distribution in the particle at the beginning of the plastic stage is a central bubble surrounded by many surrounding bubbles. The initial number and size of the bubbles when the particles become plastic are calculated by the pressure in the particle. The chemical percolation devolatilization (CPD) model is used to describe pyrolysis. The pyrolysis of eight types of high-volatile bituminous coals is simulated, and the results are compared with experimental results to verify …

Simulation Of The Evolution Of Pressure In A Lignite Particle During Pyrolysis, He Yang, Sufen Li, Thomas H. Fletcher, Ming Dong, Weishi Zhou

Faculty Publications

The evolution of pressure in a lignite particle during pyrolysis was simulated on the basis of the gas motion equation in porous media and considering the Klinkenberg effect. The chemical percolation devolatilization (CPD) model was used to describe pyrolysis. The pore diameter in the particle is close to the average free path of volatile gas molecules; therefore, the solid phase restrains the movement of gas. Because flow out of the particle is restricted, the internal pressure rises. The internal pressure first increases and then decreases during pyrolysis, and the evolution is influenced by heating conditions. The pressure rise is larger …

Characterization Of Macromolecular Structure Elements From A Green River Oil Shale, I. Extracts, Mark S. Solum, Charles L. Mayne, Anita M. Orendt, Ronald J. Pugmire, Jacob Adams, Thomas H. Fletcher

Faculty Publications

This paper is the first of two associated papers describing the structural details of three sections of an oil shale core taken at the Skyline 16 mine in the Utah Uinta Basin. Bitumen was extracted from the shale using methanol/dichloromethane. Kerogen was isolated from the shale, using a nine-step extraction procedure using HCl and HF. Bitumen samples from the three cores were analyzed using high-resolution ¹³C NMR liquid-state spectroscopy, showing carbon aromaticities of 7%−11%. Aliphatic carbons were dominated by methylene structures, with average aliphatic chain lengths of 24 carbons. The three parent shales and the demineralized kerogens were each …

Characterization Of Macromolecular Structure Elements From A Green River Oil Shale, Ii. Characterization Of Pyrolysis Products By 13c Nmr, Gc/Ms, And Ftir, Thomas H. Fletcher, Ryan Gillis, Jacob Adams, Trent Hall

Faculty Publications

This paper is Part II of a study of the chemical structural components of the organic matter of oil shale in the Green River formation. Three sections of a well-characterized oil shale core from the Utah Green River formation were demineralized, and the resulting kerogen was pyrolyzed at 10 °C/min in nitrogen at atmospheric pressure at temperatures up to 525 °C. The pyrolysis products (light gas, tar, and char) were analyzed using ¹³C NMR, GC/MS, and (FTIR). Pyrolysis yields of 80% (daf basis) were achieved at these conditions, with 60% daf tar yield at the highest temperature. The solid-state …

An Experimental Investigation Of The Effects Of N-Decane On The Supercritical Pyrolysis Of Toluene, Catherine A. Grubb

LSU Master's Theses

Future and current high-speed jet aircraft will require their fuels to act as the primary coolants as well as propellants. Fuels will be exposed to severe temperatures and pressures in hypersonic aircraft, up to 700°C and 130 atm, respectively, conditions that are supercritical for most pure hydrocarbons. Under supercritical conditions, hydrocarbon fuels undergo pyrolytic reactions, which may lead to the formation of polycyclic aromatic hydrocarbons (PAH), known precursors to carbonaceous solid deposits. Such deposits may clog fuel lines and injection nozzles, hindering safe engine performance. Hence, it is important to understand the reactions that lead to the formation of PAH. …

Black Liquor Pyrolysis, Jarom D. Webster, Dr. Thomas H. Fletcher

Journal of Undergraduate Research

The black liquor recovery boiler is the largest and most expensive piece of equipment in a modern pulp mill. Inside this boiler, black liquor is burned to produce electricity for the mill and also to recover spent chemicals. Black liquor combustion occurs in three stages: drying, pyrolysis, and char combustion. Understanding black liquor pyrolysis is an important step to controlling and improving the efficiency of the recovery boiler.

High-Pressure Vapor-Phase Catalytic Hydrodeoxygenation Of Lignin-Derived Compounds To Hydrocarbons On Bimetallic Catalysts In The Range Of 0.2-2.4 Mpa., Sara Lynn Yohe

Open Access Dissertations

Biomass, as the only renewable source of carbon, presents a sustainable alternative to liquid fossil fuels for the production of renewable transportation fuels and chemicals. The lignin portion of biomass poses a significant challenge in the upgrading and conversion of lignocellulosic biomass to fuels and chemicals, and in many current biorefineries is not utilized. However, the lignin fraction is a valuable feedstock due to its aromatic structure, lower O:C ratio than cellulose and hemicellulose, and high energy content (up to 40%) and weight fraction (average 25 wt%) of biomass. Several processes (including fast-pyrolysis, fast-hydropyrolysis, and liquid phase processing) are able …

On Electric Conduction Of Amorphous Silicon Carbonitride Derived From A Polymeric Precursor, Yaohan Chen, Fuqian Yang, Linan An

Chemical and Materials Engineering Faculty Publications

A long-existing problem that the conductivity of amorphous silicon carbonitrides derived from polymeric precursor increases significantly with pyrolysis temperature is investigated. We show that the conductivity exhibited an Arrhenius dependence on pyrolysis temperature, with the activation energy of ∼3.41 eV. Structural analysis using Raman spectroscopy reveals that the free carbon within the material undergoes a sp³-to-sp² transition as pyrolysis temperature increases, with the activation energy of ∼3.6 eV. We conclude that the pyrolysis-temperature induced increase in the conductivity is mainly due to the increase in the conductivity of the free carbon. A simple model is proposed to …

Comparison Of Biomass To Bio-Oils Reactor Systems: Direct Conversion Vs. Companion Coal Gasification, Alexandra Eicher

Honors Theses and Capstones

It is well known that the United States’ dependence on crude-oil negatively affects its economy, safety, and environment. To alleviate these negative consequences, a more economical and environmentally-friendly source of fuel, such as biomass, should be explored. The conversion of biomass to bio-oils involves the pyrolysis of biomass at about 500°C, thus requiring a great deal of heat. This heat source could be the excess waste heat from a coal gasifier.

As such, this report specifies the design of an industrial plant that produces bio-oils from biomass by using the waste heat from a coal gasifier. It is designed to …