• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 40
  • 27
  • 8
  • 7
  • 3
  • 2
  • 1
  • Tagged with
  • 123
  • 123
  • 78
  • 52
  • 33
  • 29
  • 29
  • 22
  • 16
  • 15
  • 15
  • 13
  • 11
  • 11
  • 10
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Biocarbon for fossil coal replacement / Biokol for ersättning av fossil kol

Phounglamcheik, Aekjuthon January 2018 (has links)
This research aims to provide a full view of knowledge in charcoal production for fossil coal replacement. Charcoal from biomass is a promising material to replace fossil coal, which is using as heating source or reactant in the industrial sector. Nowadays, charcoal with quality comparable to fossil coal is produced by high-temperature pyrolysis, but efficiency of the production is relatively low due to the trade-off between charcoal property and yield by pyrolysis temperature. Increasing charcoal yield by means of secondary char formation in pyrolysis of large wood particles is the primary method considering in this work. This research has explored increasing efficiency of charcoal production by bio-oil recycling and CO2 purging. These proposed techniques significantly increase concentration and extend residence time of volatiles inside particle of woodchip resulting extra charcoal. Characterization of charcoals implies negligible effect of these methods on charcoal properties such as elemental composition, heating value, morphological structure, and chemical structure. Besides, reactivity of charcoal slightly increased when these methods were applied. A numerical model of pyrolysis in a rotary kiln reactor has been developed to study the effect of design parameters and conditions in reactor scale. The simulation results showed fair prediction of temperature profiles and products distribution along the reactor length. Nonetheless, to deliver full knowledge in charcoal production, further works are planned to be done at the end of this doctoral research.
82

Experimental Evaluation of Solids and Ash Removal Pathways of Fast Pyrolysis Bio-oils

Mazerolle, Dillon 27 November 2019 (has links)
Biomass liquefaction by fast pyrolysis is considered to be a key technology in future biorefineries for the production of low-carbon renewable liquids. These liquids may be used as a fuel for heat and power, as an intermediate for catalytic upgrading to distillate transportation fuels (such as renewable diesel or biojet) and as a raw material for advanced bioproducts. With the estimated supply of bioenergy required to meet international GHG reduction targets, the use of high ash (mineral-containing) biomass sources, such as harvest residues, hog fuels, and other unmerchantable wood sources is also expected to increase. However, the elevated presence of suspended char particulate (solids), as well as minerals and other ash components contained in pyrolytic liquids resulting from the conversion of these lower quality biomass residues may create new challenges for end-users. In light of this, two treatment pathways were investigated in this work: biomass pretreatment through sieving and acid washing, and post-condensation microfiltration of fast pyrolysis bio-oils. Selection of these two pathways was prioritized based on scarcity of published data, as well as the technical potential of both approaches for suspended char particulate and ash reduction in fast pyrolysis bio-oils. For biomass sieving and acid washing carried out at pilot scale, it was found that removing up to 80% of the ash contained in a hog fuel feedstock was possible by sieving out a fraction of the fines and subsequently washing with 0.1M nitric acid provided up to 40% increase in organic liquid yield after fast pyrolysis. Reaction water in the product was minimized when acid leaching was performed, while the solids content and ash content of the produced liquids were reduced by up to 80% and 87%, respectively. Cross-flow microfiltration of fast pyrolysis bio-oils produced principally from non-pretreated mill and harvest residues in the 1-40 µm range was performed. Microfiltration was found to remove between 80-95% of suspended solid particles, while only removing 4-45% of ash, presumably in the solid phase. To achieve high ash removal (>90%), microfiltration was combined with use of solid-phase adsorbents, such as Amberlyst 15, to remove cationic ash elements such as magnesium, calcium, iron, etc. The flux profiles from bio-oil cross-flow microfiltration were analyzed and consistently demonstrated a transient rapid and intermediate decline operating region, followed by a pseudo steady-state operating region. It was found that the initial flux of permeate in the transient operating region ranged from 100-1000 L m-2 h-1, while the pseudo steady-state flux ranged from 20-50 L m-2 h-1 for the experimental trials included in this study. It was determined that bio-oil temperatures of 50-60 ˚C, transmembrane pressures less than 1 bar and the addition of diluent solvents provided the highest pseudo steady-state fluxes of such a process. To improve the throughput of the process, different fouling remediation strategies were experimentally evaluated. The use of permeate, solvent and air backflushing confirmed that on-line cleaning strategies are suitable for active flux remediation, as fouling was found to be reversible over continuous operating periods up to 10 hours. Furthermore, it was found that the use of non-optimized on-line air backflushing resulted in increased throughput of low solids fast pyrolysis bio-oil from cross-flow microfiltration by 100%. Ultimately, the data produced from this work is intended to be used to generate design parameters and associated cost estimates for biomass washing and post-condensation microfiltration as processing strategies to generate high quality bio-oils from low cost biomass feedstocks.
83

Optical and Laser Spectroscopic Diagnostics for Energy Applications

Tripathi, Markandey Mani 12 May 2012 (has links)
The continuing need for greater energy security and energy independence has motivated researchers to develop new energy technologies for better energy resource management and efficient energy usage. The focus of this dissertation is the development of optical (spectroscopic) sensing methodologies for various fuels, and energy applications. A fiber-optic NIR sensing methodology was developed for predicting water content in bio-oil. The feasibility of using the designed near infrared (NIR) system for estimating water content in bio-oil was tested by applying multivariate analysis to NIR spectral data. The calibration results demonstrated that the spectral information can successfully predict the bio-oil water content (from 16% to 36%). The effect of ultraviolet (UV) light on the chemical stability of bio-oil was studied by employing laser-induced fluorescence (LIF) spectroscopy. To simulate the UV light exposure, a laser in the UV region (325 nm) was employed for bio-oil excitation. The LIF, as a signature of chemical change, was recorded from bio-oil. From this study, it was concluded that phenols present in the bio-oil show chemical instability, when exposed to UV light. A laser-induced breakdown spectroscopy (LIBS)-based optical sensor was designed, developed, and tested for detection of four important trace impurities in rocket fuel (hydrogen). The sensor can simultaneously measure the concentrations of nitrogen, argon, oxygen, and helium in hydrogen from storage tanks and supply lines. The sensor had estimated lower detection limits of 80 ppm for nitrogen, 97 ppm for argon, 10 ppm for oxygen, and 25 ppm for helium. A chemiluminescence-based spectroscopic diagnostics were performed to measure equivalence ratios in methane-air premixed flames. A partial least-squares regression (PLS-R)-based multivariate sensing methodology was investigated. It was found that the equivalence ratios predicted with the PLS-R-based multivariate calibration model matched with the experimentally measured equivalence ratios within 7 %. A comparative study was performed for equivalence ratios measurement in atmospheric premixed methane-air flames with ungated LIBS and chemiluminescence spectroscopy. It was reported that LIBS-based calibration, which carries spectroscopic information from a “point-like-volume,” provides better predictions of equivalence ratios compared to chemiluminescence-based calibration, which is essentially a “line-of-sight” measurement.
84

Screening pyrolysis bio-oil as binder for carbon anode in aluminium production / Undersökning av pyrolysbiobränsleolja som bindemedel för kolananod i aluminiumproduktion

Wang, Yazhe January 2023 (has links)
Den högkvalitativa stenkolstjäran, som används som anodbindemedel inom aluminiumindustrin, innebär utmaningar när det gäller att möta kraven på kolanod. Dess produktion är beroende av ohållbara fossila bränslen, vilket bidrar till ökade koldioxidutsläpp. Följaktligen är det ett iögonfallande forskningsämne att finna ett hållbart alternativ. Produkten av biooljauppgradering, så kallat biobeck, kan anses vara en genomförbar utmanare. Detta biobeck undersöks som ett potentiellt substitut för stenkolstjärabeck på grund av dess liknande reologiska egenskaper. Det primära syftet med denna studie är att utsätta tre biooljor från samma källa för olika värmebehandlingsmetoder och screena en riktig bioolja för vidare arbete. Karakteriseringen av dessa biooljor och deras destillationsprodukter syftar till att öka deras lämplighet som potentiella substitut för stenkolstjärabeck. Olika destillationsförhållanden ger olika resultat från de tre biooljorna. Fysiska och kemiska egenskapstester utförs på både bioolja och biobeck, såsom vattenhalt, FTIR, TGA och viskositet. Genom att jämföra dessa värden med karakteriserade koltjärabeckdata från litteraturen kan lämpliga biooljekandidater identifieras, och distinktionerna mellan biobeck och stenkolstjärabeck kan undersökas. Denna utforskning ger förståelse för att tillhandahålla justeringar i destillationsprocessen. / The high-quality coal-tar-pitch, used as an anode binder within the aluminum industry, poses challenges in meeting requirements of carbon anode. Its production relies on unsustainable fossil fuels, contributing to heightened carbon dioxide emissions. Consequently, It is an eye-catching research topic to distinguish a sustainable alternative. The product of upgrading bio-oil, named bio-pitch, can be considered a doable contender. This bio-pitch is being explored as a potential substitute for coal-tar pitch because of its similar rheological properties. The primary objective of this study is to subject three bio-oils from the same source to distinct heat treatment methods and screen a proper bio-oil for further work. The characterization of these bio-oils and their distilling products aims to raise their suitability as potential substitutes for coal-tar-pitch. Different distillation conditions yield varied bio-pitch outcomes from the three bio-oils. Physical and chemical property tests are conducted on both the bio-oil and bio-pitch, such as water content, FTIR, TGA, and viscosity. By comparing these values to characterized coal-tar-pitch data from the literature, suitable bio-oil candidates can be identified, and the distinctions between bio-pitch and coal-tar-pitch can be investigated. This exploration provides understanding to furnish adjustments in the distillation process.
85

Fractional Catalytic Pyrolysis Technology for the Production of Upgraded Bio-oil using FCC Catalyst

Mante, Nii Ofei Daku 06 January 2012 (has links)
Catalytic pyrolysis technology is one of the thermochemical platforms used to produce high quality bio-oil and chemicals from biomass feedstocks. In the catalytic pyrolysis process, the biomass is rapidly heated under inert atmosphere in the presence of an acid catalyst or zeolite to promote deoxygenation and cracking of the primary vapors into hydrocarbons and small oxygenates. This dissertation examines the utilization of conventional fluid catalytic cracking (FCC) catalyst in the fractional catalytic pyrolysis of hybrid poplar wood. The influence of Y-zeolite content, steam treatment, addition of ZSM-5 additive, process conditions (temperature, weight hourly space velocity (WHSV) and vapor residence time) and recycling of the non-condensable gases (NCG) on the product distribution and the quality of the bio-oil were investigated. The first part of the study demonstrates the influence of catalytic property of FCC catalyst on the product distribution and quality of the bio-oil. It was found that FCC catalyst with higher Y-zeolite content produces higher coke yield and lower organic liquid fraction (OLF). Conversely, FCC catalyst with lower Y-zeolite content results in lower coke yield and higher OLF. The results showed that higher Y-zeolite content extensively cracks dehydrated products from cellulose decomposition and demethoxylates phenolic compounds from lignin degradation. The Y-zeolite promoted both deoxygenation and coke forming reactions due to its high catalytic activity and large pore size. Higher Y-zeolite content increased the quality of the bio-oil with respect to higher heating value (HHV), pH, density, and viscosity. The steam treatment at 732 oC and 788 oC decreased the total BET surface area of the FCC catalyst. The findings suggest that steam treatment reduces the coking tendency of the FCC catalyst and enhances the yield of the OLF. Analysis of the bio-oils showed that the steamed FCC catalyst produces bio-oil with lower viscosity and density. Gas chromatography and 13C-NMR spectrometry suggest that steam treatment affect the catalyst selectivity in the formation of CO, CO2, H2, CH4, C2-C5 hydrocarbons and aromatic hydrocarbons. The addition of ZSM-5 additive to the FCC catalyst was found to alter the characteristic/functionality of the catalytic medium. The product slate showed decrease in coke yield and increase in OLF with increase in ZSM-5 additive. The FCC/ZSM-5 additive hybrid catalysts produced bio-oils with relatively lower viscosity and higher pH value. The formation of CO2, CH4, and H2 decreased whilst C5 and aromatic hydrocarbons increased with increase in ZSM-5 additive level. The second part of the work assesses the effect of operating conditions on the catalytic pyrolysis process. The response surface methodology study showed reaction temperature to be the most influential statistically significant independent variable on char/coke yield, concentration of non-condensable gases, carbon content, oxygen content, pH and viscosity of the bio-oils. The WHSV was the most important statistically significant independent variable that affects the yield of organic liquid and water. Adequate and statistically significant models were generated for the prediction of the responses with the exception of viscosity. Recycling of the NCG in the process was found to potentially increase the liquid yield and decrease char/coke yield. The experiments with the model fluidizing gases showed that CO/N2, CO2/N2, CO/CO2/N2 and H2/N2 increase the liquid yield and CO2/N2 decrease char/coke yield. The results showed that recycling of NCG increases the higher heating value and the pH of the bio-oil as well as decreases the viscosity and density. The concept of recycling the NCG in the catalytic cracking of biomass vapors with FCC catalyst improved the overall process. The evaluation of the reactivity of conventional FCC catalyst towards bio-based molecules provide essential direction for FCC catalyst formulation and design for the production of high quality bio-oils from catalytic pyrolysis of biomass. / Ph. D.
86

Catalytic Pyrolysis of Cellulose, Hemicellulose and Lignin Model Compounds

Atadana, Frederick Williams 10 March 2010 (has links)
The effect of HZSM-5 catalyst and NaOH pretreatment on the product distribution and bio oil properties from pyrolysis of cellulose, hemicellulose and lignin model compounds was investigated at 450 °C. NaOH pretreated and untreated cellulose was pyrolyzed on sand and the HZSM-5 catalysts; VPISU001 HZSM-5, BASF HZSM-5, and Sud-Chemie HZSM-5. The pyrolysis of cellulose on BASF and Sud-Chemie HZSM-5 catalysts increased the yields of the organic liquid fraction, total liquid and char while decreasing the gas yields. However the catalyst decreased the organic and char yields while increasing the water yields but there was no change in gas yields. The NaOH treatment caused a decrease in the organic and total oil yields relative to the control but the char yield increased. The change in gas yields was not significant. The characterization of the oils using FTIR and ¹³C−nmr showed that, the VPISU001 HZSM-5 with and without NaOH pretreatment caused elimination of the levoglucosan fraction while increasing the aromatic fraction. The NaOH pretreated cellulose pyrolyzed on sand reduced the levoglucosan groups while increasing the aromatic fraction of the bio oil. In the hemicellulose studies, birchwood xylan and NaOH treated xylan samples were pyrolyzed on sand and VPISU001 HZSM-5 catalyst. The organic liquid yields were very low and ranged from 3.3 wt% to 7.2 wt%, the water yields ranged from 17.8-25.7 wt%, the char yield were 17.8-25 wt% and gas yield were 40.9-49.6 wt%. The HZSM-5 catalysts increased the water and gas yields and produced the lowest char yield. NaOH pretreatment produced the lowest water yield while the char yield was the highest. The combined effect of NaOH pretreatment and HZSM-5 produced the lowest organic yield and highest char yield. The FTIR and ¹³C-nmr analyses of the organic liquids showed that the HZSM-5 catalyst promoted the formation of aromatic products, while the NaOH pretreatment promoted the formation of aliphatic hydrocarbons. The combined effect of NaOH pretreatment and HZSM-5 catalyst seem to promote the formation of anhydrosugars. The main gases evolved were CO, CO₂ and low molecular weight hydrocarbons. The HZSM-5 catalyst promoted CO formation while NaOH pretreatment promoted CO₂. The HZSM-5 catalyst produced the highest yield of low molecular weight hydrocarbon gases. The lignin and model compounds studies involved using low molecular weight kraft lignin, guaiacol, and syringol which were pyrolyzed on sand and VPISU001 HZSM-5 catalyst at 450 °C. The kraft lignin pyrolysis produced low liquid and gas yields and high char yields. The HZSM-5 catalysts increased the water yield and decreased the organic liquid yield. NaOH pretreatment increased the char yield and decreased the liquid products. NaOH and the HZSM-5 catalyst together decreased the char and increased the gas yields. The ¹³C-nmr and FTIR analysis showed that NaOH pretreatment promoted the formation of mainly guaiacol while the HZSM-5 catalyst formed different aromatic components. NaOH pretreatment promoted the formation of more CO₂ than CO whilst HZSM-5 catalyst promoted the formation of more CO than CO₂. Methane formation was enhanced by NaOH pretreatment. Other hydrocarbon gases were however enhanced by the HZSM-5 catalysts. Pyrolysis of the model compounds on the HSZM-5 catalyst showed an increase in pyrolytic water. The HZSM-5 catalyst promoted demethylation in syringol pyrolysis as compared to guaiacol. / Master of Science
87

Influence of a Biodegradable Litter Amendment on the Pyrolysis of Poultry Litter

Tarrant, Ryan Carl Allen 02 November 2010 (has links)
The effects of adding a biodegradable litter amendment (AmmoSoak), developed from steam exploded corncobs, to poultry litter prior to pyrolysis on the product yields and qualities were investigated. Mixtures of litter and AmmoSoak were pyrolyzed in a bench-scale fluidized bed reactor. The objective of the second phase was to start-up a pilot-scale fluidized bed reactor unit. The poultry litter had a lower higher heating value (HHV), higher moisture, ash, nitrogen, sulfur, and chlorine contents than AmmoSoak. Analysis of the poultry litter indicated a mixture of volatiles, hemicelluloses, cellulose, lignin, ash, and proteins. AmmoSoak had a simpler composition than the litter; mainly hemicelluloses, cellulose, and lignin. Bench-scale studies indicated that adding AmmoSoak affected the yields and characteristics of the products. Addition of Ammosoak increased the bio-oil and syngas yields and decreased char yields. Adding AmmoSoak to the feed decreased the pH, water contents, initial viscosity, and the rate at which the viscosity increased with time, while densities and HHVs increased. The addition of Ammosoak to poultry litter also increased the carbon and oxygen contents of the boi-oils while nitrogen, hydrogen, sulfur, chlorine and ash contents decreased. A pilot-scale fluidized bed reactor was designed, constructed, installed and investigated for the pyrolysis of poultry litter. Fluidization and thermal equilibrium of the reactor were successfully demonstrated. The reactor was heated by combustion of propane. To ensure complete combustion, the combustion water was collected and compared to the stoichiometric yield. Complete combustion was achieved. Bio-oil yields on the pilot scale were lower than those obtained on the bench-scale pyrolysis unit. The water soluble fractions of the bio-oils were rich in oxygen. Water insoluble fractions were rich in carbon and ash. / Master of Science
88

Uticaj procesnih parametara na pirolizu drvne biomase / Influence of process parameters on the pyrolysis of woody biomass

Kosanić Tijana 17 November 2015 (has links)
<p>U doktorskoj disertaciji vr&scaron;eno je istraživanje mogućnosti konverzije energije<br />različitih vrsta drvne biomase procesom pirolize. Ispitivanu drvnu biomasu<br />predstavljale su strugotina hrasta, bukve, tre&scaron;nje, oraha, jele, lipe, kao i<br />me&scaron;avina navedenih vrsta. Dobijeni eksperimentalni rezultati ukazuju da<br />prinos gasa, tečne i čvrste faze tokom odvijanja procesa pirolize zavise od<br />reakcionog vremena, temperature i brzine zagrevanja.</p> / <p>Doctoral dissertation investigates possibilities for energy conversion of<br />different woody biomass types through pyrolysis process. Investigated woody<br />biomass included oak, beech, cherry, walnut, fir, lime wood chips and their<br />mixture. Obtained experimental results imply that gas, liquid and solid phase<br />yields during pyrolysis process depend on reaction time, temperature and<br />heating rate.</p>
89

Mécanismes de transfert des inorganiques dans les procédés de pyrolyse rapide de la biomasse : Impacts de la variabilité des ressources lignocellulosiques sur la qualité des bio-huiles / Transfer mechnisms of inorganics in biomass fast pyrolysis processes : Impacts of lignocellulosic ressources variability on bio-oils quality

Jendoubi, Naoufel 18 October 2011 (has links)
La pyrolyse rapide de biomasse est un procédé de conversion thermochimique qui permet de produire principalement des huiles de pyrolyse valorisables dans le domaine de l’énergie. Les espèces inorganiques initialement présentes dans la biomasse sont à l’origine de problèmes d’instabilité des huiles, de dépôts et d’encrassement. L’objectif de ce travail consiste à mieux comprendre les mécanismes de transfert des inorganiques depuis la biomasse vers les huiles dans les procédés de pyrolyse rapide.Une méthodologie est mise au point afin de quantifier la répartition des alcalins et alcalino-terreux (K, Ca, Mg et Na), identifiés comme les plus néfastes, dans les produits (charbons et huiles) issus de pyrolyse de bois et de paille de blé. Deux dispositifs complémentaires sont utilisés, pour lesquels les bilans de matière bouclent de façon très satisfaisante: un réacteur pilote de pyrolyse rapide en lit fluidisé et un réacteur laboratoire en four tubulaire. Dans tous les cas, le charbon séquestre 99% des éléments minéraux issus de la biomasse. En outre, grâce à un dispositif original de condensation fractionnée des huiles, on démontre que plus de 60% des inorganiques restants dans les huiles de pyrolyse proviennent des aérosols, ce résultat ouvrant une discussion quant à leur origine. Les teneurs en inorganiques des huiles sont par ailleurs fortement liées à la présence de fines particules de charbon mal séparées dans le procédé. Les possibilités de traitement amont ou aval sont discutées, afin de diminuer ces concentrations.Enfin, des expériences parallèles associées à un modèle permettent de décrire quantitativement les mécanismes de transfert entre les particules de charbon et une phase liquide lors du stockage d’huiles de pyrolyse. / Biomass fast pyrolysis is a promising process for the preparation of bio-oils dedicated to energy production. Inorganic species originally present in biomass are known to induce problems such as bio-oil instability, deposits and fouling. The purpose of the present work is to better understand the mechanisms of inorganic species transfer from biomass to bio-oils in fast pyrolysis processes. A methodology is developed for quantifying alkali and alkali-earth species (K, Ca, Mg, Na) distribution in the products (chars and bio-oils) issued from wheat straw and beech wood fast pyrolysis. Two complementary devices are used: a pilot plant fluidized bed reactor, and a horizontal tubular reactor. Mass balances closures are accurately achieved. 99 wt.% of the inorganic species originally contained in biomass are recovered in the chars. Thanks to an original bio-oils fractional condensation device, it is shown that more than 60 wt.% of the inorganic content of overall bio-oil is contained in the aerosols. Different assumptions of possible origins of the aerosols are discussed. Inorganic content of bio-oil is strongly connected to the presence of fine chars particles which are not efficiently separated by the cyclones, and, hence recovered in the bio-oils. The possibilities of upstream or downstream treatments are discussed in order to lower inorganic content of bio-oils. Finally, the mechanisms of inorganics transfers between char particles and a liquid phase, during bio-oil storage, are quantitatively described on the basis of side experiments associated to a model.
90

Compositional and kinetic modeling of bio-oil from fast pyrolysis from lignocellulosic biomass / Modélisation compositionnelle et cinétique des bio-huiles de pyrolyse rapide issues de la biomasse lignocellulosique

Costa da Cruz, Ana Rita 25 January 2019 (has links)
La pyrolyse rapide est une des voies de conversion thermochimique qui permet la transformation de biomasse lignocellulosique en bio-huiles. Ces bio-huiles, différentes des coupes lourdes du pétrole ne peuvent pas être directement mélangés dans les procédés de valorisation. En effet, en raison de leur forte teneur en oxygène, les bio-huiles nécessitent une étape de pré-raffinage, telle que l’hydrotraitement, pour éliminer ces composants.L’objectif de ce travail est de comprendre la structure, la composition et la réactivité de la bio-huile grâce à la modélisation de données expérimentales. Pour comprendre leur structure et leur composition, des techniques de reconstruction moléculaire basées sur des données analytiques, ont été appliquées, générant un mélange synthétique, dont les propriétés correspondent à celles du mélange. Pour comprendre leur réactivité, l'hydrotraitement de molécules modèles a été étudié: gaïacol et furfural. Pour cela, un modèle déterministe et stochastique a été créé pour chacun d’eux. L’approche déterministe visait à récupérer une gamme de paramètres cinétiques, qui ont ensuite été affinés par l’approche stochastique créant un nouveau modèle. Cette approche a permis de générer un réseau de réactions en définissant et en utilisant un nombre limité de familles et règles des réactions. Finalement, le mélange synthétique a été utilisé dans la simulation stochastique de l’hydrotraitement de la bio-huile, étayée par la cinétique des molécules modèles.En conclusion, ce travail a permis de recréer la fraction légère de la bio-huile et de simuler leur l'hydrotraitement, via les paramètres cinétiques des composés modèles, qui prédisent de manière raisonnable les effluents de l'hydrotraitement de celles-ci, mais sont inadéquat pour le bio-huile / Fast pyrolysis is one of the thermochemical conversion routes that enable the transformation of solid lignocellulosic biomass into liquid bio-oils. These complex mixtures are different from oil fractions and cannot be directly integrated into existing petroleum upgrading facilities. Indeed, because of their high levels of oxygen compounds, bio-oils require a dedicated pre-refining step, such as hydrotreating, to remove these components.The aim of the present work is to understand the structure, composition and reactivity of bio-oil compounds through modeling of experimental data. To understand the structure and composition, molecular reconstruction techniques, based on analytical data, were applied generating a synthetic mixture, whose properties are consistent with the mixture properties. To understand the reactivity, the hydrotreating of two model molecules was studied: Guaiacol and Furfural. A deterministic and stochastic model were created for each compounds. The deterministic approach intended to retrieve a range of kinetic parameters, later on refined by the stochastic simulation approach into a new model. This approach generates an reaction network by defining and using a limited number of reaction classes and reaction rules. To consolidate the work, the synthetic mixture was used in the stochastic simulation of the hydrotreating of bio-oils, supported by the kinetics of the model compounds.In sum, the present work was able to recreate the light fraction of bio-oil and simulate the hydrotreating of bio-oils, via the kinetic parameters of model compounds, which can reasonably predict the effluents of the hydrotreating of these, but are unsuitable for bio-oil.Fast pyrolysis is one of the thermochemical conversion routes that enable the transformation of solid lignocellulosic biomass into liquid bio-oils. These complex mixtures are different from oil fractions and cannot be directly integrated into existing petroleum upgrading facilities. Indeed, because of their high levels of oxygen compounds, bio-oils require a dedicated pre-refining step, such as hydrotreating, to remove these components.The aim of the present work is to understand the structure, composition and reactivity of bio-oil compounds through modeling of experimental data. To understand the structure and composition, molecular reconstruction techniques, based on analytical data, were applied generating a synthetic mixture, whose properties are consistent with the mixture properties. To understand the reactivity, the hydrotreating of two model molecules was studied: Guaiacol and Furfural. A deterministic and stochastic model were created for each compounds. The deterministic approach intended to retrieve a range of kinetic parameters, later on refined by the stochastic simulation approach into a new model. This approach generates an reaction network by defining and using a limited number of reaction classes and reaction rules. To consolidate the work, the synthetic mixture was used in the stochastic simulation of the hydrotreating of bio-oils, supported by the kinetics of the model compounds.In sum, the present work was able to recreate the light fraction of bio-oil and simulate the hydrotreating of bio-oils, via the kinetic parameters of model compounds, which can reasonably predict the effluents of the hydrotreating of these, but are unsuitable for bio-oil

Page generated in 0.0678 seconds