Pyrolysis of Date palm waste in a fixed-bed reactor: Characterization of pyrolytic products

Metallurgical Properties of Biocarbon in Ferroalloy Production-A Review

The significant volume of CO2 emissions contributes to global warming, which has drawn substantial attention. Metallurgical processes contribute to around 30% of these emissions, with ferroalloy smelting alone equivalent to the collective mean CO2 emissions from 11.8 million people. Biocarbon emerges as a promising substitute for fossil reductants, and its research and industrial application have the potential to significantly curtail emissions on a relatively short time scale. As a result, extensive research has been conducted on biobased carbon materials and their practical utilization in metal production processes. In this review, an overview of the methodologies employed to assess the CO2 reactivity, electrical conductivity, reactivity toward slag and SiO, and mechanical strength is illustrated. The impact of characterizations on its behavior within furnaces is concluded. Furthermore, the ongoing efforts to substitute traditional fuels with these environmentally friendly materials in the sintering process are introduced. The metallurgical properties of biocarbon are closely related to its chemical composition and physical characteristics, such as porosity, surface area, and internal structure. It has higher CO2 reactivity, lower electrical conductivity, higher SiO reactivity, and lower mechanical strength than conventional coke. Some of the drawbacks can be addressed through techniques such as densification, pyrolysis, carbonization, and agglomeration, effectively mitigating these limitations. Additionally, the current application situation on sintering has demonstrated that the substitution of specific coke amounts with biobased reductants in the ore agglomeration process can save energy. The incorporation of biocarbon in metallurgy is a feasible and potential way to reduce CO2 emissions, and this work deserves a valuable and significant endeavor.

Co-Pyrolysis of Date Palm Waste and Salicornia Bigelovii: Insights for Bioenergy Development in Arid and Semi-Arid Regions

Bioenergy is predicted to significantly contribute to the global energy needs of both developed and developing economies. Co-pyrolysis of halophytes offers a solution for a sustainable supply of feedstock in coastal and water-scarce regions. This novel research introduces an experimental investigation of co-pyrolysis of saline-tolerant flora (date palm waste and Salicornia bigelovii) to address sustainable waste management, bioenergy production, and efficient resource utilization in xeric regions. To examine the impact of the thermic condition on the pyrolysis products (bio-oil, biochar, and gas), the experiments have been conducted at three different temperatures (400, 500, and 600 °C). This pioneering study revealed that the co-feed bio-oil is acidic (pH 3.76-4.39) and has a high energy content (HHV 32.29-36.29 MJ/kg) that surpasses most woody biomass. The produced biochar was chemically stable, high in ash (40.09-47.62 wt %), high in fixed carbon (30.12-38.12 wt %), highly alkaline (pH 9.37-10.69), and low in HHV (16.30-17.2 MJ/kg). Increased pyrolysis temperature enhances biochar stability and fixed carbon, thus benefiting long-term carbon sequestration if applied in the soil. However, due to its high alkalinity, the application of this biochar in naturally alkaline sandy soils, such as in coastal deserts, requires careful monitoring. The hydrogen content in the gaseous phase significantly improves with rising temperature, reaching HHV = 24.12 MJ/kg at 600 °C, due to the enhanced ash catalytic effect. Overall, this study constitutes an important contribution to advancing bioenergy, sustainable feedstock, carbon capture, and waste management strategies in drought-prone areas.

Preparation and Characterization of Date Palm Bio-Oil Modified Phenolic Foam

In this work, the potential of biomass-derived date palm bio-oil as a partial substitute for phenol in the phenolic resin was evaluated. Date palm bio-oils derived from date palm were used for the partial substitution of phenol in the preparation of phenolic foam (PF) insulation materials. Date palm waste material was processed using pyrolysis at 525 °C to produce bio-oil rich in phenolic compounds. The bio-oil was used to partially replace phenol in the synthesis of phenolic resin, which was subsequently used to prepare foams. The resulting changes in the physical, mechanical, and thermal properties of the foams were studied. The substituted foams exhibited 93%, 181%, and 40% improvement in compressive strength with 10%, 15%, and 20% bio-oil substitution, respectively. Due to the incorporation of biomass waste material, the partial reduction in phenol uses, and the favorable properties, the date palm bio-oil substituted phenolic foams are considered more environmentally benign alternatives to traditional phenolic foams.

Biochar from date palm (Phoenix dactylifera L.) residues—a critical review

Biochar, a carbon rich organic amendment, derived from organic biomass by pyrolysis under high-temperature and zero oxygen condition, is a soil amendment to enrich soil with essential nutrients. Biochar is multidimensional in its benefits, including increase in soil carbon sequestration, reduction in green house emission, improved soil fertility, and prolonged soil moisture retention capability to overcome drought. Biochar can be produced from a wide array of biological residues, contributed by plants as well as animals. Date palm a common plant in Gulf region, leave enormous quantity of residues, which are disposed or burnt as waste in farms, that acts as a source of pollution in date-producing nations. The residual biomass from dates is utilized in cattle feed production in some countries. Disposing these residues without harming the environment is a challenge and the perfect solution is biochar. Based on the unique abatement potential of biochar and its functions to improve soil health and soil carbon sequestration, biochar can be considered as long-term agriculture adaptation strategy. This comprehensive review highlights the production of biochar from date palm biomass, the influence of different date palm parts in biochar production, and their potential benefits to the community. It is realized that the knowledge of biochar from date palm residues is still in its infancy which requires concerted efforts to educate the date palm farming community to utilize the valuable biomass from date palm for transformation to a nutritious and eco-friendly product, biochar.

Mesoporous Activated Carbon from Leaf Sheath Date Palm Fibers by Microwave-Assisted Phosphoric Acid Activation for Efficient Dye Adsorption

Remazol Brilliant Blue R (RBBR) is a common dye used in the industry, and its presence in wastewater and discharge into the environment can create a serious concern for the ecosystem and human health. Activated carbon produced from crop residues has emerged as a promising technique for removing contaminants from wastewater. In this study, leaf sheath date palm fiber-based activated carbon (LSDAC) was synthesized via phosphoric acid, H₃PO₄, treatment, followed by a microwave-induced carbonization process. The produced LSDAC was found to have a BET surface area of 604.61 m²/g, a Langmuir surface area of 922.05 m²/g, a total pore volume of 0.35 cm³/g, and an average pore size of 2.75 nm. The highest removal of RBBR was achieved at a solution pH of 3 (92.56 mg/g) and a solution temperature of 50 °C (90.37 mg/g). Adsorption of RBBR onto LSDAC followed the Langmuir isotherm model with a maximum monolayer capacity, Q _m, of 243.43 mg/g, whereas in terms of kinetics, this adsorption system was best described by the pseudo-first-order (PFO) model. The calculated thermodynamic parameters ΔH°, ΔS°, ΔG°, and Arrhenius activation energy, E _a, were 4.71 kJ/mol, 0.10 kJ/mol·K, -26.25 kJ/mol, and 5.88 kJ/mol, respectively, indicating that the adsorption of RBBR onto LSDAC was endothermic in nature, exhibited increased randomness at the solid-liquid interface, and was spontaneous and controlled by physisorption.

An Overview on Co-Pyrolysis of Biodegradable and Non-Biodegradable Wastes

Continuous urbanization and modernization have increased the burning of fossil fuels to meet energy needs across the globe, emanating environmental pollution and depleting fossil fuels. Therefore, a shift towards sustainable and renewable energy is necessary. Several techniques to exploit biomass to yield energy are trending, with pyrolysis one of them. Usually, a single feedstock is employed in pyrolysis for anoxygenic generation of biochar together with bio-oil at elevated temperatures (350–600 °C). Bio-oil produced through pyrolysis can be upgraded to crude oil after some modification. However, these modifications of bio-oil are one of the major drawbacks for its large-scale adoption, as upgradation increases the overall cost. Therefore, in recent years the scientific community has been researching co-pyrolysis technology that involves the pyrolysis of lignocellulosic biomass waste with non-biodegradable waste. Co-pyrolysis reduces the need for post-modification of bio-oil, unlike pyrolysis of a single feedstock. This review article discusses the recent advancements and technological challenges in waste biomass co-pyrolysis, the mechanism of co-pyrolysis, and factors that affect co-pyrolysis. The current study critically analyzes different recent research articles presented in databases such as PubMed, MDPI, ScienceDirect, Springer, etc. Hence, this review is one-of-a-kind in that it attempts to explain each and every aspect of the co-pyrolysis process and its current progress in the scientific field. Consequently, this review also compiles the remarkable achievements in co-pyrolysis and recommendations for the future.

Valorization of rubberwood sawdust and sewage sludge by pyrolysis and co-pyrolysis using agitated bed reactor for producing biofuel or value-added products

This study investigated experimentally pyrolysis of rubberwood sawdust (RWS), sewage sludge (SS), and their blends (25:75, 50:50, and 75:25 by weight) in an agitated bed pyrolysis reactor. The yields and characteristics of liquid product and biochar were determined for pyrolysis at 450, 500, and 550 °C and were affected both by temperature and feedstock type. The liquid and biochar yields were in the ranges 27.30-52.42 and 21.43-49.66 (wt%). Pyrolysis of RWS at 550 °C provided the highest liquid yield, while SS gave a high biochar yield. Co-pyrolysis of SS with RWS improved yield and quality of liquid and biochar products. The liquid product had 57.54-70.70 wt% of water and a low hydrocarbon content. The higher heating value (HHV) of water-free liquid product was 14.73-22.45 MJ/kg. The major compounds of liquid product included acetic acid, 2-propanone, 1-hydroxy, and phenols according to GC-MS. The biochar from RWS had a high carbon content (83.37 wt%) and a high HHV (33.57 MJ/kg), while SS biochar was mainly ash (67.62 wt%) with low carbon content. The SS biochar also had high contents of Si, Ca, Fe, K, and Mg as determined by XRF. Co-pyrolysis of SS with RWS improved the biochar by increasing its carbon content and reducing ash and inorganic elements. The surface of RWS biochar was more porous, while SS biochar had the larger specific surface according to SEM and BET. Based on these results, co-pyrolysis of 75:25 feedstock mix is recommended for further studies on applications of liquid product and biochar.

Utilization of the UAE date palm leaf biochar in carbon dioxide capture and sequestration processes

This paper evaluates the potential use of date palm leaf biochar as a climate change solution through CO₂ capture and sequestration. The pyrolysis of date palm leaf was performed at different temperatures 300°, 400°, 500°, and 600 °C. The physicochemical characteristics of the synthesized biochar were examined using Scanning Electron Microscopy (SEM) with Energy Dispersive X-Ray Analysis (EDX), Fourier transforms infrared spectroscopy (FTIR), Thermogravimetric analysis (TGA), and X-ray diffraction analysis (XRD). Direct gas-solid interaction was carried out in an integrated Fluidized Bed Reactor (FBR), connected with a gas analyzer for maximum and effective mixing between the biochar and CO₂. LabView program was used as data acquisition for an instantaneous calculation of CO₂ adsorption. This study showed that the date palm biochar as porous carbon-based materials has high CO₂ adsorption capacity through physisorption and chemisorption progressions. The adsorption results showed a maximum CO₂ capture percentage of 0.09 kg CO₂/kg, 0.15 kg CO₂/kg, 0.20 kg CO₂/kg, and 0.25 kg CO₂/kg palm biochar synthesized at 300 °C, 400 °C, 500 °C, and 600 °C, respectively. This paper paid attention to the inexpensive technology applied in CO₂ sequestration, where fluidization provides well mixing of biochar particles with low operation cost.

Activated carbons from biomass-based sources for CO2 capture applications

In an ever-growing attempt to reduce the excessive anthropogenic CO₂ emissions, several CO₂ capture technologies have been developed in recent years. Adsorption using solid carbonaceous materials is one of the many promising examples of these technologies. Carbon-based materials, notably activated carbons, are considered very attractive adsorbents for this purpose given their exceptional thermal stability and excellent adsorption capacities. More importantly, the ability to obtain activated carbons from agricultural wastes and other biomass that are readily available makes them good candidates for several industrial applications ranging from wastewater treatment to CO₂ adsorption, among others. Activated carbons from biomass can be prepared using various techniques, resulting in a range of textual properties. They can also be functionalized by adding nitrogen-based groups to their structure that facilitates faster and more efficient CO₂ capture. This review provides a detailed overview of the recent work reported in this field, highlighting the different preparation methods and their differences and effects on the textual properties such as pore size, surface area, and adsorption performance in terms of the CO₂ adsorption capacity and isosteric heats. The prospect of activated carbon functionalization and its effect on CO₂ capture performance is also included. Finally, the review covers some of the pilot-plant scale processes in which these materials have been tested. Some identified gaps in the field have been highlighted, leading to the perspectives for future work.

Techno-Economic Analysis of Fast Pyrolysis of Date Palm Waste for Adoption in Saudi Arabia

Date palm trees, being an important source of nutrition, are grown at a large scale in Saudi Arabia. The biomass waste of date palm, discarded of in a non-environmentally-friendly manner at present, can be used for biofuel generation through the fast pyrolysis technique. This technique is considered viable for thermochemical conversion of solid biomass into biofuels in terms of the initial investment, production cost, and operational cost, as well as power consumption and thermal application cost. In this study, a techno-economic analysis has been performed to assess the feasibility of converting date palm waste into bio-oil, char, and burnable gases by defining the optimum reactor design and thermal profile. Previous studies concluded that at an optimum temperature of 525 °C, the maximum bio-oil, char and gases obtained from pyrolysis of date palm waste contributed 38.8, 37.2 and 24% of the used feed stock material (on weight basis), respectively, while fluidized bed reactor exhibited high suitability for fast pyrolysis. Based on the pyrolysis product percentage, the economic analysis estimated the net saving of USD 556.8 per ton of the date palm waste processed in the pyrolysis unit. It was further estimated that Saudi Arabia could earn USD 44.77 million per annum, approximately, if 50% of the total date palm waste were processed through fast pyrolysis, with a payback time of 2.57 years. Besides that, this intervention will reduce 2029 tons of greenhouse gas emissions annually, contributing towards a lower carbon footprint.

Mesoporous Carbon from Optimized Date Stone Hydrochar by Catalytic Hydrothermal Carbonization Using Response Surface Methodology: Application to Dyes Adsorption

Providing efficient and environmental friendly ways to recover lignocellulosic waste remains a challenge around the world. In this study, citric acid-catalyzed hydrothermal carbonization (CHTC) was coupled with pyrolysis to convert date seed (Ds) into adsorbent material. In this regard, a central composite design (CCD) using response surface methodology (RSM) was developed to examine the influence of temperature, reaction time, and catalyst dose on the mass yield (Ym(%)) and carbon retention rate (CRR(%)) in the produced hydrochars. The optimized hydrochar (OHC-Ds) was obtained under optimal conditions (200°C, 120 min, 20 mg) and characterized by a Ym(%) and CRR(%) of 59.71% and 75.84%, respectively. Chemical activation by KOH of OHC-Ds followed by pyrolysis at 600°C resulted in an active material (AOHC-Ds) rich in carbon and characterized by a high specific surface area of 1251.5 m2/g, with the dominance of mesopores, as well as an amorphous structure comparable to graphite shown by X-ray diffraction (XRD) analysis. Adsorption experiments of two dyes on AOHC-Ds showed a high maximum adsorption capacity (Qm) of 657.89 mg g−1 for methylene blue (MB) and 384.61 mg g−1 for methyl orange (MO) compared to other conventional adsorbents. This result is due to the low acidity (pHpzc) of the surface of AOHC-Ds, which equals 6.75, and its surface, which is also rich in oxygenated functional groups such as (-OH), (C=O), and (C-O) shown by FTIR analysis. These results suggest that the coupling of CHTC and KOH activation followed by pyrolysis is an encouraging way to prepare an efficient and inexpensive adsorbent to remove dyes in wastewater.

Biosorption potential of Phoenix dactylifera coir wastes for toxic hexavalent chromium sequestration

Valorization of waste phytomass into valuable components provide new functionality to these biowastes and annul problems associated with their safe disposal. In this study, date palm (Phoenix dactylifera) coir (DPC) waste was tested for its toxic hexavalent chromium (Cr(VI)) ions biosorption. The DPC biosorbent was subjected to SEM, EDX, FTIR, TGA and N₂ adsorption/desorption characterization studies. Results showed that the cellulose-rich DPC surface contained mesopores with a wide number of functional groups and possessed suitable surface attributes for Cr(VI) ions sequestration. Batch biosorption tests established the Cr(VI) ions sequestration potential of the DPC biosorbent with a maximum chromium removal efficiency of 87.2% for a 100 ppm initial feed concentration at pH 2, dosage 0.3 g, temperature 30 °C, contact time 60 min and agitation speed 100 rpm. Langmuir isotherm fitted well (R² = 0.9955) with the experimental data while the kinetic analysis showed that Cr(VI) ions sequestration by DPC followed the pseudo-second order model. Biosorption thermodynamics revealed the exothermic nature and low-temperature preference for the effective binding of chromium ions on DPC. Regeneration of the biosorbent using NaOH wash showed a nearly steady Cr(VI) ions removal efficiency (with a loss <10%) by the DPC till four recycle runs. Economic analysis showed a very low production cost of $1.09/kg for the DPC biosorbent with a total cost of $4.36/m³ for a scale-up batch process wastewater treatment plant. Thus, a low-cost, effectual and sustainable biosorbent for effective treatment of Cr(VI) ions polluted water streams has been reported.

Catalytic Depolymerization of Date Palm Waste to Valuable C5–C12 Compounds

Lignin depolymerization often requires multiple isolation steps to convert a lignocellulose matrix into high-value chemicals. In addition, lignin structural modification, low yields, and poor product characteristics remain challenges. Direct catalytic depolymerization of lignocellulose from date palm biomass was investigated. Production of high value chemicals heavily depends on optimization of different parameters and method of conversion. The goal of the study was to elucidate the role of different parameters on direct conversion of date palm waste in a bench reactor, targeting valuable C5–C12 compounds. The catalytic performance results demonstrated better liquid yields using a commercial alloy catalyst than with laboratory-prepared transition metal phosphide catalysts made using nickel, cobalt, and iron. According to the gas chromatography-mass spectrometry results, C7–C8 compounds were the largest product fraction. The yield improved from 3.6% without a catalyst to 68.0% with a catalyst. The total lignin product yield was lower without a catalyst (16.0%) than with a catalyst (76.0%). There were substantial differences between the carbon distributions from the commercial alloy catalyst, supported transition metal phosphide catalyst, and catalyst-free processes. This may be due to differences between reaction pathways. Lab-made catalysts cracked the biomass to produce more gases than the alloy catalyst. The final pressure rose from 2 bar at the start of the experiment to 146.15 bar and 46.50 bar after the respective reactions. The particle size, solvent type, time, temperature, gas, and catalytic loading conditions were 180 µm, methanol, 6 h, 300 °C, nitrogen, and 5 wt %, respectively. The results from this study provide a deep understanding of the role of different process parameters, the positive attributes of the direct conversion method, and viability of date palm waste as a potential lignocellulose for production of high-value chemicals.

Comparative Investigation of Yield and Quality of Bio-Oil and Biochar from Pyrolysis of Woody and Non-Woody Biomasses

This study investigated the quantitative and qualitative attributes of liquid product and biochar obtained from pyrolysis of woody biomass (rubberwood sawdust (RWS)) and non-woody biomasses (oil palm trunk (OPT) and oil palm fronds (OPF)). The prepared biomass was pyrolyzed at temperatures of 500 °C, 550 °C, and 600 °C by using an agitated bed pyrolysis reactor, and then the yields and characteristics of liquid product and biochar were determined. The results showed that liquid product and biochar yields were in the respective ranges of 35.94–54.40% and 23.46–25.98% (wt.). Pyrolysis of RWS at 550 °C provided the highest liquid yield. The energy content of the water free liquid product was in the range 12.19–22.32 MJ/kg. The liquid product had a low pH and it mainly contained phenol groups as indicated by GC-MS. The biochars had high carbon contents (75.07–82.02%), while their oxygen contents were low (14.22–22%). The higher heating value (HHV) of biochar was in the range 26.42–29.33 MJ/kg. XRF analysis revealed that inorganic elements had higher contents in biochar than in the original biomass. The slagging and fouling indexes of biochar were also different from those of the biomass. High carbon content of the biochar confirms potential for its use in carbon sequestration. The specific surface of biochar was lower than that of biomass, while the average pore diameter of biochar was larger than for raw biomass as revealed by BET and SEM. These results on liquid product and biochar obtained from RWS, OPT, and OPF demonstrate that they are promising feedstocks for biofuels and other value-added products.

Investigation of Non-Isothermal Kinetics and Thermodynamic Parameters for the Pyrolysis of Different Date Palm Parts

Using the thermalgravimetric technique, we investigated the non-isothermal combustion kinetics of abundant and low-cost date palm wastes (leaflet, rachis, fibers, and their composite) as potential biomass energy sources. The kinetic and thermodynamic parameters were determined by Flynn–Wall–Ozawa (FWO), Kissinger–Akahila–Sunose (KAS), and Starink methods. Thermogravimetric analysis results showed a major peak for the degradation of volatiles between 127–138 °C with average percentage mass loss of 68.04 ± 1.5, 65.57 ± 0.6, 62.97 ± 5.5, and 59.26 ± 3.2, for rachis, composite, leaflet, and fibers, respectively. The FWO model showed the lowest activation energy, Eα, of 157 ± 25.6, 158 ± 25.7, 164 ± 40.1, and 169 ± 51.8 kJ mol−1 for the composite, rachis, leaflet, and fibers, respectively. The positive enthalpy values confirmed an endothermic pyrolysis reaction. For all models, a minimal difference of 4.40, 5.57, 6.55, and 7.51 kJ mol−1 between activation energy and enthalpy for rachis, fibers, composite, and leaflet ensued, respectively. The KAS model was best suited to describe chemical equilibrium with average ΔG values of 90.3 ± 28.8, 99.3 ± 34.9, 178.9 ± 27.3, and 186.5 ± 38.2 kJ mol−1 for rachis, fibers, composite, and leaflet, respectively. The reaction mechanism by the Malek and Popescu methods was ((g(α)=[−ln(1−α)]14) across the conversion range of 0.1–0.9 for all heating rates. The high energy content and volatile matter combined with low energy barriers make date palm waste a potential candidate in a biorefinery.

Energy and Economic Analysis of Date Palm Biomass Feedstock for Biofuel Production in UAE: Pyrolysis, Gasification and Fermentation

This work evaluates date palm waste as a cheap and available biomass feedstock in UAE for the production of biofuels. The thermochemical and biochemical routes including pyrolysis, gasification, and fermentation were investigated. Simulations were done to produce biofuels from biomass via Aspen Plus v.10. The simulation results showed that for a tonne of biomass feed, gasification produced 56 kg of hydrogen and fermentation yielded 233 kg of ethanol. Process energy requirements, however, proved to offset the bioethanol product value. For 1 tonne of biomass feed, the net duty for pyrolysis was 37 kJ, for gasification was 725 kJ, and for fermentation was 7481.5 kJ. Furthermore, for 1 tonne of date palm waste feed, pyrolysis generated a returned USD $768, gasification generated USD 166, but fermentation required an expenditure of USD 763, rendering it unfeasible. The fermentation economic analysis showed that reducing the system’s net duty to 6500 kJ/tonne biomass and converting 30% hemicellulose along with the cellulose content will result in a breakeven bioethanol fuel price of 1.85 USD/L. This fuel price falls within the acceptable 0.8–2.4 USD/L commercial feasibility range and is competitive with bioethanol produced in other processes. The economic analysis indicated that pyrolysis and gasification are economically more feasible than fermentation. To maximize profits, the wasted hemicellulose and lignin from fermentation are proposed to be used in thermochemical processes for further fuel production.

Pyrolysis of date palm waste to biochar using concentrated solar thermal energy: Economic and sustainability implications

A system of concentrated solar energy for pyrolysis of date palm waste to biochar is designed and simulated using SuperPro Designer v8.5. Both economic and environmental sustainability implications are evaluated by bench-marking with the conventional process (electric heating-based pyrolysis). Economic analysis shows that this process is more economically viable than the conventional process, with payback time (PBT) of 4 years and 132 days, internal rate of return (IRR) of 14.8%, return on investment (ROI) of 22.9% and gross margin of 35.5%. Environmental impact assessment shows that CO₂ emissions from concentrated solar energy-based pyrolysis accounts for only 38% of that of the conventional pyrolysis, indicating that concentrated solar energy pyrolysis is more environmentally friendly. Sensitivity analysis shows that PBT is more sensitive to changes in biochar selling price than changes in the cost of acquiring date palm waste. This process presents sustainable opportunities for biochar production while reducing life cycle emissions and costs.

Comparative study on characteristics of the bio-oil from microwave-assisted pyrolysis of lignocellulose and triacylglycerol

Microwave-assisted pyrolysis of Camellia oleifera shell (COS) and stillingia oil (SO) was performed in the temperature range of 400-600 °C. The effects of feedstock and pyrolysis temperatures on product yield and bio-oil composition were discussed in detail. The bio-oil yield from COS pyrolysis varied from 37.30 wt% to 40.27 wt%, which was 11.32 wt% to 21.62 wt% lower than that from SO pyrolysis. Gas chromatography-mass spectrometry analysis indicated that SO bio-oil was rich in hydrocarbons, whereas COS pyrolysis produced mainly oxygen-containing compounds predominantly comprising phenols and acids. Fourier transform infrared and ¹H-nuclear magnetic resonance spectra showed significant differences in the chemical structure of bio-oils from COS and SO pyrolysis. Elemental-composition and physical-property analyses further revealed that SO bio-oils were similar to gasoline and heavy fuel oil.

Experimental process parameters optimization and in-depth product characterizations for teak sawdust pyrolysis

Pyrolysis is an efficient thermochemical route to obtain biofuels in the form of bio-oil, biochar and pyrolytic gas from the processing of biomass. Pyrolysis experiments were performed with teak sawdust to determine the yield and main characteristics of solid, liquid and gaseous products. Experiments were carried out in the temperature range of 400-700 °C in 100 °C intervals, nitrogen flow rate of 150-250 mL/min, packed bed height in between 2 and 8 cm and particle size in between 0.18 and 0.60 mm. The maximum bio-oil and biochar yield were observed at 600 °C (48.8%) and 400 °C (37.42%), respectively. Physical properties (viscosity, density, carbon residue, pH and HHV) of bio-oil were determined and the chemical properties were investigated using FTIR and GC-MS. Further, biochar was characterized with proximate, ultimate, HHV, FTIR, SEM-EDX, BET surface area and XRD analysis. Non-condensable gases coming out during pyrolysis were analyzed using gas chromatography and amount of H₂, CH₄, CO and CO₂ were determined. According to characterization results, bio-oil can be used as biofuel after up gradation or as source of valuable chemicals, biochar can be utilized as solid fuel or seems to be suitable in waste stream purification as it has very high BET surface area. In addition, pyrolytic gases have significant amount of methane and hydrogen that provides good combustion properties.