Biomass conversion and catalytic hydrodeoxygenation of bio oil model compound doctor of philosophy major chemical engineering

Dissertation for the Degree of Doctor of Philosophy Biomass Conversion and Catalytic Hydrodeoxygenation of Bio-oil Model Compound VO THE KY Department of Chemical Engineering Graduate School Kyung Hee University Seoul, Korea August, 2018 Biomass Conversion and Catalytic Hydrodeoxygenation of Bio-oil Model Compound VO THE KY Department of Chemical Engineering Graduate School Kyung Hee University Seoul, Korea August, 2018 Biomass Conversion and Catalytic Hydrodeoxygenation of Bio-oil Model Compound by VO THE KY Supervised by Prof Jinsoo Kim Submitted to the Department of Chemical Engineering and the Faculty of the Graduate School of Kyung Hee University in partial fulfillment of the requirement for degree of Doctor of Philosophy Dissertation Committee: Chairman Prof Eun Yeol Lee………………………… Prof Jinsoo Kim…………………………… Prof Seung-Soo Kim………………… Prof Jae-Heung Ko………………………… Prof Bum Jun Park………………………… ABSTRACT Biomass Conversion and Catalytic Hydrodeoxygenation of Bio-oil Model Compound VO THE KY Department of Chemical Engineering Graduate School of Kyung Hee University Seoul, Korea Biomass –derived biofuel has attracted considerable attention as an alternative and renewable fuel owing to petroleum price instability and global warming Conversion of biomass such as lignocellulosic biomass or microalgae by thermal decomposition considered as feasible approaches for converting biomass into energy as well as valuable chemicals Recently, pyrolysis and hydrothermal liquefaction (HTL) have received growing attention on conversion of biomass compositions to produce biofuel Pyrolysis is the thermochemical process, in which dry biomass will be decomposed with the absence of oxygen While HTL converts wet biomass into gases, biocrude, aqueous –phase product and biochar through thermal and hydrolytic decompositions Lignocellulosic biomass has been studied extensively in terms of their pyrolysis characteristics as well as bio-oil yield and bio-oil compositions Most of these biomass were used as wild – type biomass Recently, transgenic biomass could be considered a promising biomass for production of bio-oil and valuable chemicals when its gene structure was modified from that of the wild-type to change the biochemical components (lignin, hemicellulose, cellulose) Hybrid poplar trees, which are valuable biomass feedstocks because they can grow very fast and are good candidates for genetic improvement with regard to bioenergy feedstock production A comparative study on pyrolysis characteristics and kinetic of the wild –type and genetically engineered hybrid poplar trees were conducted systematically to understand their thermal decomposition behaviors that were i necessary before using these feedstocks The obtained results indicated that transgenic biomass had lower activation energy and produced higher bio-oil yield compared to that of wild type under the same pyrolysis conditions In addition to this, chemical compositions of biocrude produced from genetic modified hybrid poplars had higher carbohydratederivatives but lower lignin-derivatives compared to those obtained from wild –type biomass Heterotrophic microalgae Aurantiochytrium sp is a promising feedstock for biofuel production due to its fast growth rates and high lipid content (50 wt % of dry biomass) Another kid of microalgae strain, Tetraselmis sp was cultivated successfully by artificial seawater semi-permeable membrane photobioreactor promising to provide an economic and sustainable biofuel production from microalgae Pyrolysis characteristics and kinetics of microalgae by means of thermogravimetric analysis (TGA) and pyrolysis on a micro-tubing reactor The thermal decomposition behaviors of biochemical compositions (carbohydrates, proteins, lipids) of microalgae were investigated and compared Freemodel methods such as Kissinger-Akahira-Sunose (KAS) and Flynn-Wall-Ozawa (FWO) were applied to estimate activation energy for pyrolysis of algal biomass These methods have widely used for the determination of activation energy since they can be used without knowledge of the reaction model A lumped kinetic model was applied for the expertiment data The obtained results indicated that the predominant pyrolysis reaction pathway of Aurantiochytrium sp was from biomass to bio-oil rather than from biomass to gas, indicating that the feasibility of converting this macroalgae biomass into bio-oil by fast pyrolysis Hydrothermal liquefaction of microalgae (Aurantiochytrium sp and Tetraselmis sp.) was conducted at different temperature (250 ~ 400 oC) and time (10~ 90 min) Under these conditions, the biochemical compositions in microalgae cells were decomposed to produce biocrude, gas, aqueous- phase product and biochar Biocrude with chemical compositions depend on the biomass feedstock as well as experimental conditions A reaction network that can generally describe the hydrothermal liquefaction of each carbohydrates, proteins and lipids in the biomass cell Besides, there exists interconversion between product phases as bio-oil and aqueous –phase, heavy –oil and light -oil were also included in the reaction network The results showed that microalgae were rapidly ii decomposed for first few minutes of reaction time With longer reaction time, the interconversion between products phases were predominant reactions Based on this reaction network, quantitative kinetic model for HTL of microalgae, which can be useful for design, control and optimization of HTL processes, was proposed The estimated reaction rates and activation energy suggested the dominant reaction pathways as well as the distribution of the biochemical compositions to the bio-oil phase Kinetic parameters were used to explore the parameter space in order to predict product yields as a function of reaction time and temperature Bio-oil obtained from pyrolysis and hydrothermal liquefaction of microalgae cannot be used directly since it is high viscosity, high acidity, and low heating value due to the presence of significant quantities of many oxygen-contain compounds such as acids, aldehydes, ketones and phenolic compounds Therefore, upgrading the quality of biomass – derived biocrude have attracted much attention for recent years Hydrodeoxygenation (HDO) reaction is one of the most potentially valuable processing routes to selectively cleave C – O and C – C bonds in oxygen-containing substances In this work, a novel method combining sol-gel and spray pyrolysis was applied to synthesize Mo/Al2O3 –TiO2 catalysts for upgrading of hexadecanoic acid (palmitic acid) that was found to be a major component (ca 50%) in the biocrude obtained from pyrolysis and HTL of microalgae Aurantiochytrium sp During spray pyrolysis process, the spherical composite particles were formed directly from the droplets containing a well-dispersed mixture of molybdenum salt, boehmite sol and titania sol through one-step pyrolysis The results obtained from catalytic activity studies on hydrodeoxygenation of palmitic acid showed that the Mo/Al2O3-TiO2 catalysts exhibited excellent catalytic performance as high HDO conversion (100%) and high saturated hydrocarbon selectivity (93.18%) These results were much better than those of catalyst derived from conventional impregnation method Effects of TiO2 concentration used to modify γ-Al2O3 on the catalytic activity was systematically investigated Reusability experiment results showed that there were a slight decrease in metal/metal oxides concentration ratio of reduced catalyst after four time uses iii Table of contents Abstract i List of Tables viii List of Figures ix CHAPTER - General Introduction 1.1 Background 1.2 Motivation 1.3 Research objectives 1.4 Dissertation overview 1.5 References 11 CHAPTER - Literature Review 2.1 Biomass concepts 16 2.1.1 Biomass 16 2.1.2 Biomass resources 16 2.1.3 Genetically engineered biomass 17 2.1.4 Microalgae 17 2.1.4.1 Microalgal Aurantiochytrium sp 17 2.1.4.2 Tetraselmis sp 18 2.1.5 Chemical compositions of microalgae 18 2.1.6 Biomass applications 20 2.1.7 Biomass into energy 20 2.2 Pyrolysis 23 2.2.1 Definition 23 2.2.2 Classification 23 2.2.3 Pyrolysis of biomass compositions 24 2.2.4 Kinetic models for pyrolysis of biomass 25 2.3 Hydrothermal liquefaction 26 2.3.1 Definition 26 iv 2.3.2 Reaction networks of HTL of microalgae 27 2.4 Hydrodeoxygenation (HDO) of bio-oil 29 2.5 References 32 CHAPTER - Pyrolysis Characteristics and Kinetics of Wild-Type and Genetically Engineered Hybrid Poplar Trees 3.1 Introduction 42 3.2 Experimental 44 3.2.1 Hybrid poplars and growth conditions 44 3.2.2 Characterizations of hybrid poplars 44 3.2.3 Pyrolysis of hybrid poplars in a micro-tubing reactor 45 3.3 Results and discussion 46 3.3.1 Material characterizations 46 3.3.2 Thermogravimetric analyses (TGA) 50 3.3.3 Pyrolysis kinetics of hybrid poplars 54 3.3.4 Pyrolysis product distributions and bio-oil analysis 59 3.3.5 Kinetic model for pyrolysis of hybrid poplars 65 3.3.6 Kinetic parameters analyses 69 3.3.7 Model predictions of pyrolytic products 71 3.4 Conclusions 73 3.5 References 74 CHAPTER - Pyrolysis Characteristics and Kinetics Studies of Microalgae by Nonisothermal and Isothermal Decompositions 4.1 Introduction 79 4.2 Materials and methods 81 4.2.1 Materials 81 4.2.2 TGA analysis 82 4.2.3 Pyrolysis in a micro-tubing reactor 82 4.2.4 Product analysis 83 4.3 Results and discussion 84 v 4.3.1 Material characterizations 84 4.3.2 TGA analyses of microalgae samples 88 4.3.3 Kinetic parameters of the pyrolysis of Aurantiochytrium sp KRS 92 4.3.4 Pyrolysis product distribution and bio-oil analyses 96 4.3.5 Kinetic model for pyrolysis of Aurantiochytrium sp KRS 100 4.4 Conclusions 105 4.5 References 106 CHAPTER 5- Hydrothermal Liquefaction of Microalgae 5.1 Introduction 110 5.2 Experimental 111 5.2.1 Methods and materials 111 5.2.1.1 Microalgae cultivation 111 5.2.1.2 Determination of the cellular compositions 112 5.2.2 Hydrothermal liquefaction 112 5.3 Results and discussion 116 5.3.1 Material characterizations 116 5.3.1.1 Biochemical compositions 116 5.3.1.2 FT-IR analyses 116 5.3.2 HTL product distributions and analyses 121 5.3.2.1 HTL of microalgae Aurantiochytrium sp 121 5.3.2.2 HTL of microalgae Tetraselmis sp 126 5.3.3 Kinetic models for HTL of microalgae 137 5.3.3.1 Kinetic models for HTL of Autrantiochytrium sp 137 a Reaction network and kinetic model 137 b Kinetic parameter analyses 141 c Model predictions of the liquefaction product distributions 144 5.3.3.2 Kinetic models for HTL of Tetralselmis sp 146 a Reaction network and kinetic model 146 b Kinetic parameter analyses 150 vi c Model predictions of the liquefaction product distributions 154 5.4 Conclusions 156 5.5 References 157 CHAPTER - Catalytic Hydrodeoxygenation of Microalgae –derived Bio-oil Model Compound 6.1 Introduction 162 6.2 Experimental 165 6.2.1 Synthesis of catalysts 165 6.2.2 Catalyst preparation 168 6.2.3 HDO of Palmitic acid and product analyses 169 6.3 Results and discussion 170 6.3.1 Textural properties 170 6.3.2 Morphologies analyses (SEM) 175 6.3.3 X-ray Diffraction studies (XRD) 178 6.3.4 FT-IR analyses 180 6.3.5 XPS analyses 182 6.3.6 H2 – TPR analyses 187 6.3.7 NH3 –TPD analyses 189 6.4 Hydrodeoxygenation of Palmitic acid 192 6.4.1 HDO with varied catalysts 192 6.4.2 Effects of reaction temperature 195 6.4.3 Catalyst stability studies 197 6.5 Conclusions 200 6.6 References 201 CHAPTER - Conclusions and Further Researches 7.1 Conclusions 208 7.2 Further researches 210 ACKNOWLEGEMENTS 212 vii [10, 11] They have been widely regarded as well-being resources of foods, bio-active compounds and animal feeds or fertilizer Besides, the residue after bio-actives extraction can be used as feedstock for chemical and biofuel production [12] Compared to terrestrial plants, algae biomass have many advantages as very fast growth rate, shorter harvesting cycle and high lipid content [1] Some photoautotrophic microalgae strains, such as Chlorella sp., Botryococcus sp., and Schizochytrium sp., can accumulate intracellular lipids up to 80% of dry biomass [13] Heterotrophic microalgae Aurantiochytrium sp can also accumulate large amounts of lipid, as high as 50% of dry biomass [14] Besides, microalgae have been found to have production yields higher than terrestrial oilseeds commonly used as biofuel feedstocks [1] and can capture CO2 emissions [2] or treat wastewater effluent during cultivation [3] Biochemical compositions in microalgae cells as carbohydrates, proteins and lipids can be converted into fuels (bio-alcohol and bio-oil), power and heat by two general processes including biological and thermochemical technologies, which are considered as feasible solutions [15] The biological technology refers to approaches involving digestion and fermentation of biodegradable biomass to produce bio-alcohols as bio-ethanol, biobutanol, biodiesel, and biogas [16] As for thermochemical conversion technology, these can be grouped in three distinct categories for fuel production: combustion, gasification, pyrolysis and solvolthermal liquefaction Among these approaches, combustion method is the simplest way to produce energy from biomass Nevertheless, this is not an environment-friendly method due to its low efficiency For gasification, however, is considered as one of the most effective methods for converting biomass into fuels, but it highly cost due to high technology requirements [17] Pyrolysis is a depolymerization process that produces liquid intermediates so-called pyrolytic oil or bio-oil with low cost and simple operation [18] Solvothermal liquefaction, which convert biomass with the presence of solvent as water or alcohol into gases, biocrude, solvent –soluble phase product and biochar A mong solvothermal liquefaction technuiqes, hydrothermal liquefaction has been wildely used with water as a solvent Pyrolysis is a process, in which the thermodecompostion of biomass in the absence of oxygen or in reduced air, typically in range of 400-650oC [19] Based on the heating rate and residence time, it can be classified as two approaches [20] Slow pyrolysis is performed at low heating rate and long residence time to produce mainly gas fuel and charcoal Meanwhile fast pyrolysis is conducted at high heating rate and short reaction time to yield mainly liquid (bio-oil) and gas products [19] The product distributions as well as bio-oil compositions depend on biomass resources and experimental conditions Hydrothermal liquefaction (HTL) is an emergent technology for converting wet algal biomass into an energy-dense biocrude oil Liquefaction of biomass obviates energy and resource-intensive steps, such as drying and solvent extraction that are common for other biofuel conversion routes as transesterification and pyrolysis [21] HTL has been known as a process involving the reaction of biomass in water at subcritical temperature (< 374 oC) and high pressure (> water vapor pressure) for a particular reaction with or without the presence of catalyst [22] Liquefaction conditions such as temperature, pressure, residence time and water density can affect on the product distribution as well as the chemical compostions Besides, the biomass loading also makes an effect on bio-oil yield and bio-oil composition The biocrude derived from pyrolysis have many advantages such as much easier handling and transport, flexibility of use over raw biomass, low nitrogen and sulfur content as compared with petroleum products Hence, bio-oils have been successfully tested in turbines, boilers and engines [23] However, the pyrolysis bio-oils usually contain high amount of oxygen (15~40 wt %) and water (~30 wt %) compared to fossil fuel The presence of high oxygen content in bio-oils can cause high acidity leading to corrosion of reactor, instability, high viscosity, low heating value, immiscibility with hydrocarbon fuels and thus reduce quality of the bio-oils [24, 25] Therefore, in order to make these biomassderived fuels comparable and compatible with petroleum fuels, the concentration of oxygen the bio-oil must be significantly reduced through elimination of oxygencontaining functional groups in the bio-oil component as alcohols, aldehydes, ketones or carboxylic acids Upgrading bio –oil model compound through the reaction that eliminates oxygen from functional gourps has been investigated by deoxygenation under hydrotreating using different catalysts or hydrodeoxyeganation (HDO) The HDO has been considered as one of the most potenitailly valuable processing approaches to selectively cleave C – O and C – C bonds in oxygen – containing compounds [26] There many kinds of HDO catalysts with various support and dopant materials have been reported recently Faba et al [27] investigated the HDO of acetone-furfural over Al2O3- supported noble metal (Ru, Rh, Pd, and Pt) catalysts Nguyen et al [28] studied the HDO of guaiacol over noble metal-based catalysts (Au, Rh, AuRh) supported on TiO2 They reported that the product selectivity depended on the metal dopant species and reaction temperature It is well-known that the exorbitant price of these noble metal-based catalysts may hinder their application on larger scales [29, 30] Therefore, the development of non-noble metal catalysts for HDO reaction has been thoroughly investigated by many researchers In recent years, Co, Ni, and Mo-based catalysts have been studied extensively These metals can be used as monometallic dopants (Co, Ni, Mo, etc.) or bimetallic dopants (NiMo, CoMo, etc.) on various catalyst supports for HDO [31-33] Also, catalysts of metal phosphides [34-38] or metal sulfide systems [32, 39, 40] have attracted tremendous attention due to their excellent properties in HDO However, these catalysts have disadvantages such as final products contamination due to dissolving of sulfur into reactants, water-evoked catalyst deactivation and coke formation [30] For doping metal or metal oxide on the support, impregnation, precipitation, and hydrothermal deposition techniques are usually used Among these approaches, impregnation has been extensively used for preparing catalysts [28, 31, 41-43] However, there exist two intrinsic disadvantages resulting from the impregnation route: (1) the lack of uniform particle and active species distribution due to the forced condensation of metal precursors on the support surface during the drying process, and (2) limited activity because of the limited amount of active metals deposited on the support surface [41, 44] Liu et al [42] compared the preparation route of NiMo/Al2O3 catalyst for HDS of dibenothiophene and found that the catalyst obtained from the coprecipitation method produced a homogenous distribution of metal sites, while that obtained from the impregnation method caused aggregated metal crystals It was reported that the catalyst preparation method had a major influence on the physicochemical properties of the catalysts and their activities [45, 43] Therefore, the development of a catalyst preparation route is an important factor that can improve catalytic activity Besides, a method that is sample and energy-efficient for preparation of a catalyst would be considered a promising strategy for industrial production of catalysts The spray pyrolysis has been used widely to prepared many kinds of and inorganic materials as iron oxide [46], Gd2O3/Eu3+[47], etc and organic material like macroporous carbon [48, 49] The spray pyrolysis is considered as a potential technique for the preparation because it has several advantages including continuous operation, one-step synthesis in a short time less than several seconds, spherical morphology and relatively narrow particle size distribution [49] Very recently, we have reported a study on the HDO of 2-furyl methyl ketone over catalysts (Ni, NiP, NiMo, Co, and CoP supported by γAl2O3) prepared by spray pyrolysis The results show that catalysts derived from spray pyrolysis had high catalytic activities compared to those derived from conventional impregnation method [50] 1.2 Motivation Biomass resources including lignocellulosic and algal biomass are being considered as alternative energy sources because they are inexpensive and renewable resources There are many kinds of biomass with various biochemical compositions Pyrolysis characteristics of lignocellulosic materials have been extensively studied for decades, indicating that their pyrolysis behaviors were different from species to species While study on pyrolysis characteristic as well as kinetics of transgenic biomass, whose gene structure was engineered to produce higher biomass content compared to the wildtype is still limited Clarification and comparison these characteristics of genetic modified biomass and its wild –type strain is necessary to figure out how they are different, and how the genetic modification technologies affect on their pyrolysis behaviors, bio-oil yield as well as bio-oil compositions Recently, microalgae biomass is considered as a promising alternative sources due to its fast growth, high production yields and capture of CO2 emissions Therefore, much paid attention to microalgae cultivation to increase the microalgae yields as well as to reduce production cost Heterotrophic microalgae Aurantiochytrium sp., which is cultivated in heterotrophic conditions, is a promising feedstock for biofuel production due to its fast growth rates and high lipid content (50 wt % of dry biomass) Recently, Tetraselmis sp., a microalgae was successfully cultivated in ocean medium found to reduce the production cost, providing an option for an economic biofuel production A transparent low-density polyethylene film-based floating photobioreactor was conceptualized and developed to culture microalgae in the ocean Microalgae were successfully cultured using floating photobioreactor without supply of any nutrients and additional power consumption In order to use these promising microalgae biomass as biomass resources for production of biofuel, their thermal decomposition characteristics and kinetics should be point out As conventional microalgae-derived biodiesel is only produced by means of lipid extraction followed by transesterification While, the biodiesel process can utilize only the lipid portion of the biomass, with the residual biomass representing a kind of waste In contrast, pyrolysis and hydrothermal liquefaction have been considered as a potential thermochemical processes to utilize all the components of microalgae for biofuel production, including carbohydrates, proteins, and lipids Microalgal liquefaction is found to produce high yields of biocrude, and capture as much as 90% of the energy content of the microalgal feedstock Recent studies of microalgal liquefaction have examined processing conditions as reaction time, temperature, feedstock, biomass loading and catalyst selection However, there still has been a lack of full knowledge on an entire reaction network for hydrothermal liquefaction of microalgae Besides, quantitative kinetic models based on the general reaction network will be needed for process design and optimization Developing such a model requires data from a systematic study of the influence of all the relevant process variables on liquefaction of microalgae The biocrude derived from thermochemical processes usually contains high oxygen content due to the presence of various kinds of oxygen-contain compounds These can cause some unwanted characteristics such as high acidity, low heating value (HV), high viscosity and immiscibility with hydrocarbon fuels The need of upgrading of biocrude to make its quality as close as that of engine fuel is still a challenge Therefore, various methods for upgrading the quality of biomass–derived biocrude have been studied for years aiming to find an effective solution for transportation fuels Among them, the hydrogedeoxyenation (HDO) reaction is one of the most potentially valuable processing routes to selectively cleave CO and CC bonds in oxygen–containing compounds Recently, much paid attentions to HDO of bio –oil model compounds by many kinds of catalysts derived from many approaches have been reported However, there is still a lack of catalyst preparation route that is not only high catalytic activity, but also simple and energy efficient 1.3 Research objectives This research have three main objectives as follows: 1) To understand pyrolysis characterstics of genetically modified hybrid poplar trees and compared to those of its wild –type The wild-type poplars were first genetically engineered to change its chemical biochemical compositions, in wich the content of hollocelluloses was increased while the lignin content was decreased, resulting in the biomass content of transgenic biomass was much higher than that of the wild-type Both of the wild-type and transgenic hybrid poplars were first studied on their pyrolysis characteristics by thermogravimetric analysis at different heating rates in inert gas Aterwards, thermal decomposition of these materials were conducted in a micro-tubing reactor to produce biocrude Effects of the processing varibles such as reaction time, temperature on pyrolytic product distributions as well as the bio-oil composition were symstematically investigated 2) To understand pyrolysis behaviors of heterotrophic microalgae Aurantiochytrium sp with high lipid content TGA analyses with different heating rates in N2 gas were performed for Aurantiochytrium sp and lipid – extracted Aurantiochytrium sp to compare Pyrolysis of Aurantiochytrium sp in micro-tubing reactor was conducted to produce biocrude and gas A lump-kinetic model was applied for the obtained data to figure out the predominant reaction pathway 3) To understand hydrothermal liquefaction of microalgae (Aurantiochytrium sp and Tetraselmis sp.) Liquefaction experiments were conducted at various temperature (250 ~ 400 oC) and reaction time (10 ~ 90 min) The biocrude includes heavy –oil (hexane – insoluble) and light- oil (hexane- soluble) and aqueous –phase product were analyzed A reaction network and a quantitative kinetic model were proposed for HTL of microalgae Estimation of activation energy and reaction rate for each reaction pathway suggested which reactions are predominant, and how the biochemical compositions contribute into each product phase In addition to this, the kinetic parameters were used to explore the parameter space in order to predict product yields as a function of reaction time and temperature 4) To develop a catalyst preparation that does not only produce a catalyst with high catalytic activity for HDO of palmitic acid as a bio-oil model compound, but also is an energy –efficient approach A combining sol-gel and spray pyrolysis that can allow to produce spherical catalyst particles with large quantity within a one-step pyrolysis Spray pyrolysis is a continuous process and the solution precursor can be added continuously, suggesting that this is a potential strategy for catalyst synthesis 1.4 Dissertation overview This dissertation consists of seven chapters, and the content of each chapter is as follows: Chaper 1, a general introduction Chapter 2, the basic definitions of biomass, pyrolysis and hydrothermal liquefaction were fully expressed to provide a fundamental knowledge Besides, the hydrodeoxygenation (HDO) review of model compounds over many kinds of catalysts was also mentioned Chapter 3, lignocellulosic biomass, namely hybrid poppar trees were first genetically engineered to change its chemical biochemical compositions resulting in the difference in biomass content of transgenic biomass compared to that the wild-type Both of the wild-type and transgenic hybrid poplars were first studied on their pyrolysis characteristics by thermogravimetric analysis at different heating rates in inert gas Aterwards, thermal decomposition of these materials were conducted in a micro-tubing reactor to produce biocrude Effects of the processing varibles such as reaction time, temperature on pyrolytic product distributions as well as the bio-oil composition were symstematically investigated In addition, a quantitative kinetic model was proposed for a better understanding of pyrolysis characteristics and reaction mechanisms both biomass Chapter 4, the pyrolysis characteristics and kinetics studies of microalgae microalgae Aurantiochytrium sp by means of TGA analysis and micro –tubing reactor Model –free method was applied to estimate activation energy for pyrolysis microalgae biomass Pyrolysis in micro-tubing reactor was conducted at various reaction time and temperature to capture its pyrolytic product distribution Additionally, a lumped –kinetic model was proposed for pyrolysis of microalgae in order to figure out the predominant reactions and activation energy for each reaction pathway Chapter 5, discussions about hydrothermal liquefaction of microalgae Aurantiochytrium sp and Tetraselmis sp Liquefaction of microalgae were conducted at various processing variables as time and reaction temperature The obtained reaction mixture was then underwent some extraction steps to collect heavy –oil, light –oil, aqueous –phase product, gas and biochar Bio-oil obtained at optimum condition was analyzed by GC-MS In order to explore hydrothermal liquefaction mechanism of microalgae, a reaction network was proposed, demonstrating the conversion of each biomass component (lipids, carbohydrates, proteins) to product as well as the interconversion between product phases during HTL process A quantitative kinetic model was applied for the obtained experimental data Estimation of reaction rate and activation energy suggest the dominant reaction as well as the contribution of each biochemical component into product phases Chapter 6, discussions about a development of a catalyst preparation for hydrodeoxygenation of a bio-oil model compound Molybdenum supported onto a binary Al2O3-TiO2 mixed support catalysts were prepared by a novel method combining sol-gel and spray pyrolysis The prepared catalysts were characterized by XRD, N2 adsorptiondesorption, SEM, XPS, FT-IR, H2 -TPR and NH3- TPD Catalytic activity of the prepared catalysts was examined by HDO reaction of palmitic acid, which is a main component of the obtained biocrude derived from pyrolysis and HTL of microalgae Aurantiochytrium sp This work developed a novel mehod combining of sol-gel and spray pyrolysis for synthesis of Mo/Al2O3-TiO2 catalysts with different TiO2 concentration The effects of TiO2 concentration used to modify γ-Al2O3 on catalyst activity was discussed deeply Besides, a comparison between catalytic activity of prepared catalyst and one derived from conventional impregnation approach was also performed Finally, one of the most important characteristics of catalyst is its reusability was also evaluated through studies on catalyst recycle Chapter 7, an overall summary of these research together with some suggestions for the future studies 10 1.5 References [1] Chisti Y Biodiesel from microalgae Biotechnol Adv 2007, 25(3):294-306 [2] Packer M Algal capture of carbon dioxide; biomass generation as a tool for greenhouse gas mitigation with reference to New Zealand energy strategy and policy Energ Policy 2009; 37:3428-37 [3] Mulbry W, Kondrad S, Pizarro C, Kebede-Westhead E Treatment of dairy manure effluent using freshwater algae: algal productivity and recovery of manure nutrients using pilot-scale algal turf scrubbers Bioresour Technol 2008; 99(17):8137-42 [4] D.J Cuff, W.J Young, U.S Energy atlas Free Press/McMillan Publishing Co NY 1980 [5]http://energy.converanet.com/cvn03/cachedhtml?hl=keywords&kw=s%3Acvc%5C.112 ZE&caceid=ds1- 9b24c1104e5e:4bdde224&scopeid=defLink [6] Mohan D, Pittman CU, Steele PH, Pyrolysis of wood/biomass for bio-oil: A critical review Energy Fuels 2006;20:848-89 [7] Ross AB, Anastasakis K, Kubacki ML, Jones JM, Investigation of the pyrolysis behaviour of brown algae before and after pre-treatment using PY-GC/MS and TGA, J Anal Appl Pyrolysis 2009;85:3-10 [8] Ross AB, Jones JM, Kubacki ML, Bridgman T Classification of macroalgae as fuel and its thermochemical behavior Bioresource Technol 2008;99(14):6494-504 [9] Alam F, Mobin S, Chowdhury H Third generation biofuel from Algae Procedia Eng 2015;105:763-8 [10] Medipally SR, Yusoff FM, Banerjee S, Shariff M Microalgae as sustainable renewable energy feedstock for biofuel production BioMed Res Int 2015;2015:519513 [11] Fei X Solving the coastal eutrophication problem by large scale seaweed cultivation Hydrobiologia 2004;512(1-3):145-51 [12] Lee JY, Lee MS, Choi JW, Shin TS, Woo HC, Kim HR, Dichloromethane fraction of Laminaria japonica ethanolic extract inhibits lipopolysaccharide-induced nitric oxide synthase and cyclooxygenase-2 expression in RAW 264.7 Cells via NF-ĸB pathway, 11 Inflammation 2012 [13] Lee, O.K., Kim, Y.H., Na, J.-G., Oh, Y.-K., Lee, E.Y 2013 Highly efficient extraction and lipase-catalyzed transesterification of triglycerides from Chlorella sp KR-1 for production of biodiesel Bioresource Technology, 147, 240-245 [14] Liu, B., Zhao, Z 2007 Biodiesel production by direct methanolysis of oleaginous microbial biomass Journal of Chemical Technology & Biotechnology, 82(8), 775780 [15] Sequeira CAC, Brito PSD, Mota AF, Carvalho JL, Rodrigues L, Santos DM, et al., Fermentation, gasificati JL on and pyrolysis of carbonaceous residues towards usage in fuel cells Energ Convers Manage 2007;48:2203-20 [16] Kraan S, Mass cultivation of carbohydrate rich microalgae, a possible solution for sustainable biofuel production Mitig Adapt Strateg Glob Change 2013;18:27-46 [17] Asian Biomass Handbook, Ministry of Agriculture Forestry and Fisheries, Japan with the help of Asia Biomass Association, 2008 [18] Bridgwater AV Renewable fuels and chemicals by thermal processing of biomass Chem Eng J 2003;91(2-3):87-102 [19] Dermibas A, Arin G An overview of biomass pyrolysis Energ Source 2002;24:47182 [20] Bridgwater AV, Peacocke GVC, Renew Sustain Energ Rev 2000;4:1-73 [21] Peter J Valdez, Michael C Nelson, Henry Y Wang, Xiaoxia Nina Lin, Phillip E Savage, Hydrothermal liquefaction of Nannochloropsis sp.: Systematic study of process variables and analysis of the product fractions Biomass Bioenegy, 2012, 46, 317-331 [22]Laura Garcia Alba, Cristian Torri, Chiara Samorì, Jaapjan van der Spek, Daniele Fabbri, Sascha R A Kersten,† and Derk W F (Wim) Brilman Hydrothermal Treatment (HTT) of Microalgae: Evaluation of the Process As Conversion Method in an Algae Biorefinery Concept Energy Fuels, 2012, 26(1), 642-657 [23] Czernik S, Bridgwater AV, Overview of Applications of Biomass Fast Pyrolysis Oil EnergyFuels, 2004;18:590-8 12 [24] He Z, Wang X, Hydrodeoxygenation of model compounds and catalytic systems for pyrolysis bio-oils upgrading Catal Sustain Energy 2012;1:28-52 [25] Huber GW, Iborra S, Corma A, Synthesis of transportation fuels from biomass: chemistry, catalysts, and engineering Chem Rev 2006;106:4044-98 [26] Ranran Ding, Yulong Wu, Yu Chen, Hao Chen, Jianlong Wang, Yanchun Shia and Mingde Yang Catalytic hydrodeoxygenation of palmitic acid over a bifunctional Codoped MoO2/CNTs catalyst: an insight into the promoting effect of cobalt Catal Sci Technol., 2016, 6, 1969-2452 [27] Faba L, Díaz E, Ordóđez S Hydrodeoxygenation of acetone–furfural condensation adducts over alumina-supported noble metal catalysts Applied Catalysis B: Environmental 2014; 160: 436-44 [28] Nguyen T-S, Laurenti D, Afanasiev P, Konuspayeva Z, Piccolo L Titania-supported gold-based nanoparticles efficiently catalyze the hydrodeoxygenation of guaiacol Journal of Catalysis 2016; 344: 136-40 [29] Cheng S, Wei L, Julson J, Rabnawaz M Upgrading pyrolysis bio-oil through hydrodeoxygenation (HDO) using non-sulfided Fe-Co/SiO2 catalyst Energy Convers Manage 2017; 150: 331-42 [30] Cheng S, Wei L, Julson J, Muthukumarappan K, Kharel P R Upgrading pyrolysis bio-oil to biofuel over bifunctional Co-Zn/HZSM-5 catalyst in supercritical methanol Energy Convers Manage 2017; 147: 19-28 [31] Le T A, Ly H V, Kim J, Kim S-S, Choi J H, Woo H-C, Othman M R Hydrodeoxygenation of 2-furyl methyl ketone as a model compound in bio-oil from pyrolysis of Saccharina Japonica Alga in fixed-bed reactor Chem Eng J 2014; 250: 157-63 [32] Bui V N, Laurenti D, Afanasiev P, Geantet C Hydrodeoxygenation of guaiacol with CoMo catalysts Part I: Promoting effect of cobalt on HDO selectivity and activity Applied Catalysis B: Environmental 2011; 101: 239-45 [33] Robinson A, Ferguson G A, Gallagher J R, Cheah S, Beckham G T, Schaidle J A, Hensley J E, Medlin J W Enhanced Hydrodeoxygenation of m-Cresol over Bimetallic 13 Pt–Mo Catalysts through an Oxophilic Metal-Induced Tautomerization Pathway ACS Catalysis 2016; 6: 4356-68 [34] Cecilia J A, Infantes-Molina A, Rodríguez-Castellón E, Jiménez-López A, Oyama S T Oxygen-removal of dibenzofuran as a model compound in biomass derived bio-oil on nickel phosphide catalysts: Role of phosphorus Applied Catalysis B: Environmental 2013; 136: 140-9 [35] Leiva K, Sepúlveda C, García R, Fierro J L G, Aguila G, Baeza P, Villarroel M, Escalona N Effect of P content in the conversion of guaiacol over Mo/γ-Al2O3 catalysts Applied Catalysis A: General 2013; 467: 568-74 [36] Bui P, Cecilia J A, Oyama S T, Takagaki A, Infantes-Molina A, Zhao H, Li D, Rodríguez-Castellón E, Jiménez López A Studies of the synthesis of transition metal phosphides and their activity in the hydrodeoxygenation of a biofuel model compound Journal of Catalysis 2012; 294: 184-98 [37] Berenguer A, Sankaranarayanan T M, Gomez G, Moreno I, Coronado J M, Pizarro P, Serrano D P Evaluation of transition metal phosphides supported on ordered mesoporous materials as catalysts for phenol hydrodeoxygenation Green Chem 2016; 18: 1938-51 [38] Ly H V, Galiwango E, Kim S-S, Kim J, Choi J H, Woo H C, Othman M R Hydrodeoxygenation of 2-furyl methyl ketone as a model compound of algal Saccharina Japonica bio-oil using iron phosphide catalyst Chem Eng J 2017; 317: 302-8 [39] Bui V N, Laurenti D, Delichère P, Geantet C Hydrodeoxygenation of guaiacol Applied Catalysis B: Environmental 2011; 101: 246-55 [40] Lin Y-C, Li C-L, Wan H-P, Lee H-T, Liu C-F Catalytic Hydrodeoxygenation of Guaiacol on Rh-Based and Sulfided CoMo and NiMo Catalysts Energy Fuels 2011; 25: 890-6 [41] de Souza P M, Rabelo-Neto R C, Borges L E P, Jacobs G, Davis B H, Resasco D E, Noronha F B Hydrodeoxygenation of Phenol over Pd Catalysts Effect of Support on Reaction Mechanism and Catalyst Deactivation ACS Catalysis 2017; 7: 2058-73 14 [42] Liu F, Xu S, Cao L, Chi Y, Zhang T, Xue D A Comparison of NiMo/Al2O3 Catalysts Prepared by Impregnation and Coprecipitation Methods for Hydrodesulfurization of Dibenzothiophene The Journal of Physical Chemistry C 2007; 111: 7396-402 [43] Wei R, Zhu Q, Han F, Guan Q, Li W Comparison of four different synthetic routes of Ni2P/TiO2-Al2O3 catalysts for hydrodesulfurization of dibenzothiophene RSC Advances 2015; 5: 38774-82 [44] Han W, Yuan P, Fan Y, Shi G, Liu H, Bai D, Bao X Preparation of supported hydrodesulfurization catalysts with enhanced performance using Mo-based inorganicorganic hybrid nanocrystals as a superior precursor Journal of Materials Chemistry 2012; 22: 25340-53 [45] Maity S K, Ancheyta J, Soberanis L, Alonso F Alumina-silica binary mixed oxide used as support of catalysts for hydrotreating of Maya heavy crude Applied Catalysis A: General 2003; 250: 231-8 [46] J.W Overcash, K.S Suslick High Surface Area Iron Oxide Microspheres via Ultrasonic Spray Pyrolysis of Ferritin Core Analogues Chem Mater, 27 (2015), pp 3564-7 [47] J.S Cho, K.Y Jung, Y.C Kang Yolk-shell structured Gd2O3:Eu3+ phosphor prepared by spray pyrolysis: the effect of preparation conditions on microstructure and luminescence properties PCCP, 17 (2015), pp 1325-31 [48] A.F Arif, Y Chikuchi, R Balgis, T Ogi, K Okuyama Synthesis of nitrogenfunctionalized macroporous carbon particles via spray pyrolysis of melamine-resin RSC Advances, (2016), pp 83421-8 [49] B.H Min, K.Y Jung Improved porosity and ionic sorption capacity of carbon particles prepared by spray pyrolysis from an aqueous sucrose/NaHCO3/TEOS solution RSC Advances, (2017), pp 21314-22 [50] Ly H V, Im K, Go Y, Galiwango E, Kim S-S, Kim J, Choi J H, Woo H C Spray pyrolysis synthesis of γ-Al2O3 supported metal and metal phosphide catalysts and their activity in the hydrodeoxygenation of a bio-oil model compound Energy Convers Manage 2016; 127: 545-53 15 CHAPTER Literature Review 2.1 Biomass concepts 2.1.1 Biomass Biomass most often refers to plants or plan-based materials that are not used for food or feedsuch as wood, short rotation woody crops, agricultural wastes, short-rotation herbaceous species, wood wastes, bagasse, bio solids, industrial residues, waste paper, sawdust, municipal solid waste, bio solids, grass, waste from food processing, aquatic plants and algae, animal wastes, and a host of other materials [1, 2] Biomass exist in many kinds forms depending on its sources (animal or plant) or phases (solid, liquid or gaseous) 2.1.2 Biomass resources Biomass resoures can be categorized into the first, the second and the third generation [3]  The first biomass generation is derived from food crops such as corn, vegetable oils, sugars, palm oil, and animal fats [4] The use of these resources can cause food crisis in the world [5, 6] because they may push up the price of food to some extents [5]  The second bimass generation includes lignocellulosic biomass or forest residue, which are also used for biofuel production [3, 4] These feedstocks not compete with food, have higher energy yield with less agrochemicals being used leading to higher greenhouse gas reduction potential and have significantly less water requirements [5, 7]  Macroalgae biomass have been considered as a third-generation biofuel feedstock to compensate for the drawbacks of using first- or second-generation biofuel 16 ... Prof Seung-Soo Kim………………… Prof Jae-Heung Ko………………………… Prof Bum Jun Park………………………… ABSTRACT Biomass Conversion and Catalytic Hydrodeoxygenation of Bio-oil Model Compound VO THE KY Department of. .. Biomass Conversion and Catalytic Hydrodeoxygenation of Bio-oil Model Compound by VO THE KY Supervised by Prof Jinsoo Kim Submitted to the Department of Chemical Engineering and the Faculty of the.. .Biomass Conversion and Catalytic Hydrodeoxygenation of Bio-oil Model Compound VO THE KY Department of Chemical Engineering Graduate School Kyung Hee University Seoul, Korea August, 2018 Biomass