Pyrolysis Of Sawdust Research Articles

Development of a novel bio char for CO2 capture and biogas upgrade: Static and dynamic testing

The optimization of the pyrolysis of the spruce sawdust was conducted based on the yield, textural properties, and static capture capacity of the chars to generate a new micro porous char for biogas upgrade. The nature of the precursor (C: 45.68 %, H: 6.08 %, N: 0.15 %, and 0.34 % ash content) helped to tune the porosity of the char for capturing CO2 from gas streams and biogas. The optimization of the pyrolysis at 700 °C, a heating rate of 10 °C / min and holding time of 1 hour, produced a microporous char with high yield, CO2 capture capacity and CO2/CH4 selectivity. The presence of the oxygen and nitrogen-containing functional groups in the optimum char help in the selective capture of CO2. The static CO2 capture capacity of the optimum char was 1.98 mmol/g at atmospheric pressure and 25 °C (90 % CO2 stream). The CSD (700−10−60) have capture capacity of 1.50 mmol/g (at a feed gas stream of 50 % CO2 and adsorption temperature of 25 °C and 120 kPa) which is equivalent to Norit C and Calgon BPL. Hence, spruce sawdust can be used to produce efficient biochar for biogas upgrade (CO2 capture) owing to high capture capacity and CO2/CH4 selectivity (around 3) and easy regeneration of the biochar for 10 consecutive cycles.

Catalytic fast pyrolysis of jujube sawdust over two core–shell micro/mesoporous zeolites: Impact of mesoporous structure and aluminum sources

Core–shell zeolites have been used to improve bio-oil quality in biomass catalytic fast pyrolysis (CFP), yet research on shell materials remains limited. This study explores ZSM-5@MCM-41 and ZSM-5@SBA-15 core–shell micro/mesoporous zeolites, including their Al-containing variants synthesized with sodium aluminate (SA), aluminum sulfate (AS), and aluminum isopropoxide (AI) as Al sources, for improving bio-oil quality during biomass CFP. The samples were thoroughly characterized using powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, N2 adsorption–desorption, and NH3-TPD techniques. CFP experiments using jujube sawdust examined the impact of mesoporous structure and Al sources on bio-oil yield and quality. Results indicated that ZSM-5@MCM-41, with a smaller mesoporous structure and higher acid strength, showed 1.7 times greater hydrocarbon selectivity compared to ZSM-5@SBA-15 (20.6 % vs. 12.4 % by area). The incorporation of Al into the MCM-41 shell led to a decrease in bio-oil yield, with the order being ZSM-5@MCM-41 > ZSM-5@MCM-41-AI > ZSM-5@MCM-41-AS > ZSM-5@MCM-41-SA, owing to the combined effects of strong acid sites and mesoporosity. However, the hydrocarbon selectivity of ZSM-5@Al-MCM-41 catalysts decreased by 15.6–19.5 % owing to reduced mesoporous volume. Conversely, while the incorporation of Al in the SBA-15 shell also reduced bio-oil yield, it increased hydrocarbon production by 27.0–47.6 %. Also, the hydrocarbons selectivity was related to the acid strength of the ZSM-5@Al-SBA-15 catalysts, demonstrating that strong acid sites are more effective in regulating bio-oil quality than porosity.

Revealing the delithiation process of spent LiMn2O4 and LiNi0.6Co0.2Mn0.2O2 batteries during the biomass-assisted gasthermal and carbothermal reduction

The utilization of biomass-assisted pyrolysis in the recycling of spent lithium-ion batteries has emerged as a promising and reliable process. This article furnishes theoretical underpinnings and analytical insights into this method, showcasing sawdust pyrolysis reduction as an efficient means to recycle spent LiMn2O4 and LiNi0.6Co0.2Mn0.2O2 batteries. Through advanced thermogravimetry-gas chromatography-mass spectrometry analysis complemented by traditional thermodynamic demonstration, the synergistic effects of biomass pyrolysis reduction are elucidated, with minor autodecomposition and major carbothermal and gasthermal reduction pathways identified. The controlled manipulation of transition metals has demonstrated the capability to modulate surface pyrolysis gas catalytic reactions and facilitate the preparation of composite materials with diverse morphologies. Optimization of process conditions has culminated in recovery efficiency exceeding 99.0 % for LiMn2O4 and 99.5 % for LiNi0.6Co0.2Mn0.2O2. Economic and environmental analyses underscore the advantages of biomass reduction and recycling for these two types of spent LIBs: low energy consumption, environmental compatibility, and high economic viability.

Can Glycerol Carbonate be Synthesized Without a Catalyst?

Abstract: Biodiesel and oleo-chemical industries have been producing huge quantities of glycerol as a by-product. Value-added products can be synthesized from glycerol through different chemical and enzymatic reactions, such as oxidation, carbonylation, reforming, acetalyzation, etherification, dehydration, hydrogenolysis, hydrolysis, esterification, and transesterification. Glycerol is a low-cost polyol that can be converted into glycerol carbonate, which has potential applications in polymer and biobased non-isocyanate polyurethanes industries (Bio-NIPUs). The present contribution is the first of its kind to report on the synthesis of glycerol carbonate via catalyst and solvent-free transesterification of glycerol with dimethyl carbonate under conventional as well as microwave heating. Additionally, a comparative study of conventional and microwave-assisted transesterification was performed. Under conventional heating, 78% glycerol carbonate is obtained at 120oC in 36 hours, whereas, using microwaves, 92% of glycerol carbonate can be achieved in 30 minutes. Presently, biomass-based heterogeneous materials are used in catalysis due to their importance within the context of sustainability. In line with this, in this work, a series of green catalysts, namely, molecular sieves (MS, 4Å), Hβ- Zeolite, Montmorillonite K-10 clay, activated carbon prepared from the shell of groundnut (Arachis hypogaea), and biochar from sawdust pyrolysis were successfully employed. Glycerol carbonate was thoroughly characterized by 1H and 13C NMR, FT-IR and MS. The method described here is facile and green since the utilization of bioresource (glycerol) for the production of glycerol carbonate is performed under microwave.

Pyrolysis and catalytic upgrading of pine wood sawdust over modified biochar catalyst in a tandem microreactor

A series of novel catalysts were prepared by modifying biochar (BC) with different metal loading (Fe, Zn) and thermal activation in different atmospheres (CO2, H2O). The catalysts were further used to upgrade the pyrolysis vapor from pine wood sawdust, aiming to produce high-quality bio-oil. The modified biochar catalyst exhibited strong deoxygenation ability to acids and ketones in bio-oil and effectively converted lignin-derived compounds into aromatic hydrocarbons and phenols. Subsequently, the catalyst (BC-Fe-CO2) demonstrating the highest yields of phenols and aromatics was selected for condition optimization. Different catalytic temperatures and biomass-to-catalyst ratios were compared to determine the optimal conditions for producing high-quality bio-oil. Phenolics and aromatic hydrocarbons content in the bio-oil reached 70 % at the optimal condition and the selectivity of monocyclic aromatic hydrocarbons in aromatic hydrocarbons reached 77 %. The properties of the biochar catalysts were characterized using BET, SEM, XRD, and XPS. The superior performance of the modified BC catalysts not only relied on its enhanced surface area and porous structure but also due to active Fe sites. The detail reaction pathways of the bio-oil catalytic upgrading were also proposed. These findings underscore the potential of modified biochar in pyrolysis and catalytic upgrading for bio-oil with improved quality.

Biomass valorization toward sustainable bio-oil obtained by pyrolysis of lignocellulosic raw materials for bitumen modification

The quality and durability of road surfaces have long been an area of interest for researchers all over the world, who are trying to prolong life of service of roads and cut the additional expenses. The quality of bitumen, one of the most important parts of road building materials, can be improved with various modifiers, lots of which have been introduced and used commercially for a long time. This paper studies bio-oil obtained in the process of slow pyrolysis of sawdust as a sustainable modifier for bitumen production. Adhesive properties of bitumen produced by different methods of bio-oil introduction into the material are studied, as well as some of the no-harm characteristics. It was found that introducing both bio-oil and its fraction boiling above 350 °С directly into bitumen leads to a rise in adhesion rate (up to 91.52 % for unfractionated bio-oil and 79.98 % for bio-oil >350 °С fraction vs. 62.88 % for base bitumen). However, adding >350 °С fraction of bio-oil proved to deteriorate the bitumen’s rheological characteristics, such as ductility and penetration, while adding bio-oil made bitumen fail the ageing test (mass change). The addition of bio-oil in the amount of 1 wt% into vacuum, residue showed to have a limited effect on the adhesion properties of the resulting oxidized bitumen, while passing both no-harm and ageing tests. The results reported that the optimal concentration of bio-oil added to bitumen in the case of the current study was 2–3 wt%, since it is at this share of the modifier that the binder shows peak adhesion indicators of the adhesion with the mineral surface.

Deactivation of nickel/biochar catalyst through metal-volatiles interaction in pyrolysis of poplar sawdust loaded with nickel salt

Metal/biochar is an important category of catalyst that can be prepared via direct impregnation of metal salt to a biomass feedstock. However, during pyrolysis of metal salt@biomass for catalyst preparation, metal-volatiles interaction might affect exposure or dispersion of metal species. To verify this, loading of nickel acetate to poplar sawdust directly and to the sawdust-derived biochar was conducted to prepare Ni/biochar and biochar/Ni at 500 or 750 °C, aiming to understand the effect of metal-volatiles interaction on exposure of nickel species in resulting Ni/biochar. The results indicated Ni species catalyzed cracking, dehydrogenation, and reforming reactions in sawdust pyrolysis, producing more bio-oil/gases at the expense of biochar and also making biochar of higher aromatic degree with improved thermal stability. The in-situ IR characterizations also evidenced high activity of Ni towards dehydration and cracking of carbonyls for enhancing aromatization of biochar. In biochar/Ni catalysts prepared via loading nickel to biochar, little metal-volatiles interaction existed and nickel species weakly interacted with the biochar, resulting in remarkable migration and agglomeration of nickel, forming nickel size of 2–3 times larger than that in Ni/biochar. However, biochar/Ni possessed higher capability for adsorption/activation of H2, thus exhibiting superior catalytic activity than Ni/biochar for hydrogenation of phenolics.

Novel Staged Free-Fall Reactor for the (Catalytic) Pyrolysis of Lignocellulosic Biomass and Waste Plastics.

Pyrolysis of lignocellulosic biomass and waste plastics has been intensely studied in the last few decades to obtain renewable fuels and chemicals. Various pyrolysis devices have been developed for use in a laboratory setting, operated either in batch or continuously at scales ranging from milligrams per hour to tenths of g per hour. We report here the design and operation of a novel staged free-fall (catalytic) pyrolysis unit and demonstrate that the concept works very well for the (catalytic) pyrolysis of pinewood sawdust, paper sludge, and polypropylene as representative feeds. The unit consists of a vertical tube with a pretreatment section, a pyrolysis section, a solid residue collection section, a gas-liquid separation/collection section, and a catalytic reaction section to optionally perform ex situ catalytic upgrading of the pyrolysis vapor. The sample is placed in a tube, which is transported by gravity through various sections of the unit. It allows for rapid testing with semicontinuous feeding (e.g., 50 g h-1) and the opportunity to perform reactions under an (inert) gas (e.g., N2) at atmospheric as well as elevated pressure (e.g., 50 bar). Liquid yields for noncatalytic sawdust pyrolysis at optimized conditions (475 °C and atmospheric pressure) were 63 wt % on biomass intake. A lower yield of 51 wt % (on a biomass basis) was obtained for the noncatalytic pyrolysis of paper sludge, likely due to the presence of minerals (e.g., CaCO3) in the feed. The possibility of using the unit for ex situ catalytic pyrolysis (pyrolysis at 475 °C and catalytic upgrading at 550 °C) was also successfully demonstrated using paper sludge as the feed and H-ZSM-5 as the catalyst (21 wt % catalyst on biomass). This resulted in a biphasic liquid product with 25.6 wt % of an aqueous phase and 11 wt % of an oil phase. The yield of benzene, toluene, and xylenes was 1.9 wt % (on a biomass basis). Finally, the concept was also proven for a representative polyolefin (polypropylene), both noncatalytic as well as in situ catalytic pyrolysis using H-ZSM-5 as the catalyst at 500 °C. The liquid yield of thermal, noncatalytic plastic pyrolysis was as high as 77 wt % on plastic intake, while in situ catalytic pyrolysis gave a combined 7.8 wt % yield of benzene, toluene, and xylenes on plastic intake.

Analysis of the Propagation of Temperature and Thermal Conductivity of Sawdust Pyrolysis Process with Modeling Fea and Experiment

The study uses densified sawdust with heat propagation and thermal conductivity to achieve better pyrolysis and gasification processes. Analysis of sawdust's heat propagation and thermal conductivity during pyrolysis was developed with Finite Element Analysis (FEA). The thermal conductivity values of sawdust (k) obtained from FEA are 1.49, 1.3, 1.1, and 0.7 W/m C considering the sawdust heated with a triggering temperature (T0) 535 ºC and reaches a constant temperature of T1 = 265 ºC, T2 = 165 ºC, T3 = 115, and T4 = 95 ºC respectively after 20 minutes. The temperature distribution of sawdust heated shows between the experimental and FEA results is quite the same; however, differences on graph T1 show the experimental thermal conductivity (k) value is distinct from the simulated thermal conductivity (k) value due to a significant change that occurred as sawdust transformed into charcoal at minute 70, where the distance between point T1 and the trigger point (T0) is 40mm and after 180 minutes the sawdust had turned into charcoal completely. Furthermore, 31 grams (6.46%) of sawdust underwent pyrolysis in this experiment. The findings can aid future research and development in this field and provide valuable insight into the duration of time a bio stove utilizing compacted sawdust can produce a sustainable flame and be used as a reference for future experiments.

Catalytic pyrolysis of poplar sawdust pretreated with combined leaching and torrefaction over Fe–Ni/ZSM-5 for aromatic-rich bio-oil production

High oxygen content and alkali and alkaline earth metals (AAEMs) naturally present in biomass exhibit detrimental effects on biomass pyrolysis. Hence, effective pretreatment methods are essential for enriching the desired pyrolytic products (aromatics). In this study, poplar sawdust (PS) pretreated with a combination of acid leaching and torrefaction was catalytically pyrolyzed using Fe–Ni/ZSM-5 for enhanced aromatic production. The findings show that the coupled pretreatment effectively removed AAEMs while also lowering the H/C and O/C ratios. The combined pretreatment method increases the activation energy of the raw sample from 126.38 kJ mol−1 to 154.38–158.33 kJ mol−1. The enrichment of aromatics in bio-oils was significantly aided by the pretreatment process, with benzene, toluene, and xylene increasing from 82.24 mg g−1 of raw PS catalytic pyrolysis to 97.48–103.83 mg g−1 of the pretreated PS. This study demonstrates that combined pretreatments of biomass enhanced the quality of pyrolytic products, which could be a valuable framework for practical application.

Oxidative pyrolysis of poplar sawdust: Probing the influence of oxidation reactions on property of biochar

Partial oxidation of some organics is desirable in some scenarios for compensation of the heat required for pyrolysis, which, however, impacts not only composition of bio-oil but also possibly property of biochar. This was investigated herein by oxidative pyrolysis of poplar sawdust from 300 to 600 °C and further analysis of the pyrolytic products, especially biochar. The results showed that O2 could oxidize some organics on surface of biochar, forming more volatiles below 400 °C. Above this temperature the excessive oxidation of the light and heavy organics with π-conjugated structures in bio-oil dominated, producing more gases. Weight loss of biochar from oxidation of organics on its surface was only remarkable at 300 °C, while some weight gain was observed from introduction of additional oxygen-containing functionalities from the oxidation. The removal of aromatic structures on biochar at 500 or 600 °C via oxidation was rather difficult. However, the oxidation reactions did make the biochar oxygen-rich but hydrogen-deficient, which, in overall, improved thermal stability and comprehensive combustion performance of the biochar. Additionally, oxygen presence enhanced aromatic degree of biochar by increasing regularity of (100) facet of carbon crystals while narrowing interplanar spacing of (002) facets. The oxygen-rich nature also made the biochar from the oxidative pyrolysis more hydrophilic while the removal of some organics via oxidation promoted development of the pore structures.

Catalytic pyrolysis of poplar sawdust over biochar of varied origin: Impact of volatile-char interactions

Volatile-char interaction is almost unavoidable in pyrolysis, which is part of the process shaping composition of bio-oil/gases and properties of char. In this study, the influence of the char from sawdust/spinach/rice/spirulina/pig manure on pyrolysis of poplar sawdust was investigated at 500 °C, aiming to understand the impact of the char of same or varied origin on formation of volatiles/gases and change of the char catalysts themselves from the volatile-char interaction. The results suggested that the sawdust-, spinach- or rice-char catalyzed cracking of volatiles, reducing formation of heavy tar, decreasing production of bio-oil (28.6–35.5 % vs 49.4%) while enhancing gases generation (36.9–44.0 % vs 22.4%). The spirulina- and manure-char enhanced secondary condensation of volatiles, producing more heavy tar, more bio-oil, and additional oxygen-rich carbonaceous deposit with highly aliphatic nature. This reduced thermal stability, the C/O ratio of the char catalyst, and also led to coverage of char surface, especially for the manure-char catalyst. The in-situ IR techniques showed that manure-char catalyzed formation of abundant ketones and esters/lactones in intermediates, which further involved in polymerization. In comparison, the sawdust-char catalyst catalyzed cracking and aromatization of the volatiles of same origin, producing carbon- and hydrogen-rich carbonaceous solid, enhancing aromatic nature of the char catalyst, which was actually a real process for evolution of structure of biochar in pyrolysis of the sawdust.

Comparison Study by using Pyrolysis of Kenna Sugarcane Bagasse and Sawdust in Sudan

Today the request for save energy and addressing emissions has become a primary concern for every country aiming to achieve sustainable development while preserving its environment. The demand for energy is steadily rising, driven by rapid population growth and industrial development. Fossil fuels continue to play a major role in fulfilling these energy needs., but their combustion is linked to rising environmental issues. There are many sources of energy use to solve the environmental problems and fossil fuel shorted such as biomass. This paper aims to explore the potential of biomass to provide significantly higher amounts of useful energy while reducing pollutant emissions compared to fossil fuels. In this research the two samples of sugar cane bagasse and sawdust is study by slow pyrolysis. Two samples are presented—one from Kenana bagasse and the other from sawdust. Bio-oil is a product of the slow pyrolysis process, and its calorific value, determined through laboratory analysis, is significantly high compared to previous studies. This indicates that bio-oil emits fewer pollutants than fossil fuels, making it suitable for use in transportation and various industrial sectors.

Catalytic fast pyrolysis of waste pine sawdust over solid base, acid and base-acid tandem catalysts

Catalytic pyrolysis is an effective means for high-value utilization of biomass. This study investigated the effect of solid base catalysts (CaO, calcium aluminate catalysts CaAl-1, CaAl-2, CaAl-3), acid zeolite catalysts (ZSM-5, Fe/ZSM-5, Co/ZSM-5, Ni/ZSM-5, Cu/ZSM-5, Zn/ZSM-5) and base-acid tandem catalysts on pine sawdust pyrolysis using Py-GC/MS. Acid zeolite catalysts exhibited robust deoxidation and aromatization capabilities, favoring aromatics, while solid base catalysts yielded more phenols and ketones. Among the solid base catalysts, CaAl-3 (CaO-Ca12Al14O33) showed comparable deoxygenation activity to CaO and optimal aromatic selectivity with structural stability. Zn/ZSM-5 excelled in deoxygenation and aromatic selectivity (70.42%) among metal-modified ZSM-5 catalysts. Base-acid tandem catalysis promoted the formation of aliphatics and BTX (benzene, toluene, xylene) while suppressing polycyclic aromatics. The highest BTX content (44.35%) was achieved with CaO-Ca12Al14O33&Zn/ZSM-5 tandem catalysts in a 1:3 ratio. This work demonstrates base-acid tandem catalysis as a promising approach for converting pine sawdust into valuable chemicals.

Fractional condensation of bio-oil vapors from pyrolysis of various sawdust wastes in a bench-scale bubbling fluidized bed reactor

The use of lignocellulosic waste as an energy source for substituting fossil fuels has attracted lots of attention, and pyrolysis has been established as an effective technology for this purpose. However, the utilization of bio-oil derived from non-catalytic pyrolysis faces certain constraints, making it impractical for direct application in advanced sectors. This study has focused on overcoming these challenges by employing fractional condensation of pyrolytic vapors at distinct temperatures. The potential of five types of sawdust for producing high-quality bio-oil through pyrolysis conducted with a bench-scale bubbling fluidized bed reactor was investigated for the first time. The highest yield of bio-oil (61.94 wt%) was produced using sample 3 (damaged timber). Remarkably, phenolic compounds were majorly gathered in the 1st and 2nd condensers at temperatures of 200 °C and 150 °C, respectively, attributing to their higher boiling points. Whereas, carboxylic acid, ketones, and furans were mainly collected in the 3rd (−5 °C) and 4th (−20 °C) condensers, having high water content in the range of 35.33%–65.09%. The separation of acidic nature compounds such as acetic acid in the 3rd and 4th was evidenced by its low pH in the range of 4–5, while the pH of liquid collected in the 1st and 2nd condensers exhibited higher pH (6–7). The well-separated bio-oil derived from biomass pyrolysis facilitates its wide usage in various applications, proposing a unique approach toward carbon neutrality. In particular, achieving efficient separation of phenolic compounds in bio-oil is important, as these compounds can undergo further upgrading to generate hydrocarbons and diesel fuel.

Addition of Hydrocarbon Components to Products in the Catalytic Pyrolysis of Sawdust by Natural Catalysts

Addition of Hydrocarbon Components to Products in the Catalytic Pyrolysis of Sawdust by Natural Catalysts

Investigation of interactions of nickel with pyrolytic products in pyrolysis of poplar with nickel acetate via furnace or microwave heating

Metal/biochar is an important catalyst with feature of easy recovering of metal via combustion of biochar carrier. During preparation of metal/biochar, interaction of metal with biochar affects evolution of pyrolytic products and dispersion of metal. Heating mode could influence interaction of metal with pyrolytic products. This was investigated by pyrolysis of sawdust loaded with nickel acetate at 400 or 600 °C with furnace and microwave heating, respectively. The results showed that cracking of biochar and volatiles was effectively promoted with Ni, generating more gases while reducing aliphatic organics and heavy phenolics in bio-oil. The enhanced cracking facilitated aromatization in microwave heating, forming biochar of higher thermostability and gases with more hydrogen. However, the furnace heating at 600 °C formed Ni/biochar of more developed pores than from microwave heating (409.1 versus 385.0 m2g−1). Microwave heating could induce merging of micropores on biochar, resulting in migration and aggregation of Ni. This led to lower capability for chemical adsorption of hydrogen and dispersion of nickel, further leading to inferior activity of Ni/biochar from microwave heating for hydrogenation of vanillin or furfural. The in-situ IR characterization of the pyrolysis showed the furnace heating reserved more oxygen-containing organics and aliphatic structures, promoting dispersion of nickel.

Exchange of organics with homogenous volatiles shapes nature of biochar of varied aspects

During pyrolysis of biomass, contact between volatiles and nascent biochar is inevitable, and the volatile-char interactions are highly dependent on not only composition of volatiles but also surface property of biochar. Herein, the potential interactions of the biochar produced at varied temperatures (500, 600 or 700 °C) with the volatiles generated at 500 °C from pyrolysis of poplar sawdust were investigated, aiming to probe the exchange of organics on the varied biochar from the interactions. The results showed that biochar-600 or biochar-700 catalyzed cracking of phenols, sugars and sugar-derivatives to generate more gases. Biochar-500, in comparison, catalyzed aromatization of volatiles to form more phenols of single or multiple rings and enhanced tar content in bio-oil, relating to catalytic effects of its abundant oxygen-containing species. During the catalysis, some organics on surface of the biochar were removed while some carbonaceous deposit from the volatiles deposited, resulting in relative increase of ash content, reduced thermal stability, filling of micropores and formation of fragmented morphology of the spent biochar. The in-situ IR characterization showed that biochar-500 could maintain higher abundance of the intermediates bearing oxygen-containing species, facilitating their subsequent condensation, while biochar-700 catalyzed rapid cracking of these oxygen-containing organics.

Catalytic upgradation of pyrolytic products by catalytic pyrolysis of sawdust using a synthesized composite catalyst of NiO and Ni (II) aluminates

A significant comparative study was done on thermal and catalytic pyrolysis of sawdust via metal-induced active site NiO and Ni (II) aluminates composite catalyst by integrating sawdust into a fixed-bed reactor and assessing product profile distribution from a temperature range of 773–873 K at 30 K min−1 heating rate under nitrogen purge gas (300 mL min−1). With an increase in temperature from 773 to 873 K, bio-oil yield was increased with a decrease in the yield of biochar. From thermal bio-oil characterization, it was observed that d-Allose was the prominent compound along with Beta-d-Glucopyranose-1,6-Anhydro with a remarkable Cp value of 2.0 Jg-1 K−1 and an ignition temperature of 397.95 K. Catalytic upgradation of bio-oil using 10 % and 20 % catalyst resulted in phosphonic acid, (p-hydroxyphenyl)- and 6-Hepten-3-one, 5-Hydroxy-4-Methyl- as the candidate compounds with slightly decreased Cp values of 0.095 Jg-1 K−1 and 0.826 Jg-1 K−1 respectively due to catalytic tar cracking of polyaromatic hydrocarbons present in the bio-oil. Biochar revealed amorphous graphitic multilayer nanosheets with polycrystalline and hexagonal crystal systems of the lattice structure with the presence of aromatic ring structures and –CN stretching as evident from FTIR analysis.

Techno-economic analysis and environmental impact assessment of biodiesel production from bio-oil derived from microwave-assisted pyrolysis of pine sawdust

Pyrolysis stands out as a highly promising technology for converting biomass. Upgrading the bio-oil to meet the requirements for fuelling internal combustion engines is indispensable. This study evaluates the economic viability of microwave-assisted pyrolysis (MAP) of pine sawdust, followed by bio-oil esterification for the production of biodiesel. Aspen Plus® was used to simulate a facility that processed 2000 metric tonnes of pine sawdust per day. The minimum fuel selling price (MFSP) of biodiesel was established through the use of a discounted cash flow analysis. A life cycle assessment approach was used to evaluate the environmental impact assessment of biodiesel production. Process modelling findings revealed that the pyrolysis section yielded 65.8 wt% bio-oil, 8.9 wt% biochar, and 25.3 wt% NCGs. The biodiesel product yield was 48 wt% of the raw bio-oil, yielding 631.7 tonnes per day of biodiesel. With the cost of methanol playing a significant role, the overall capital investment was $286.1 MM and the total yearly operating expenses were $164.9 MM. The predicted MFSP for biodiesel is $2.31/L, with yearly operational expenses and biodiesel output being the most important factors. The emission from the biodiesel production process resulted in a global warming potential of 70.97 kg CO2eq. With an anticipated MFSP that is competitive with traditional diesel fuel, the study concludes that the method is economically viable. The results underline how crucial it is to optimize crucial process variables in order to increase the process's economic viability.