Agroforestry Residues Research Articles

The potential application of agroforestry residues in the adsorption of aniline

A low-cost activated carbon based on agroforestry residues (AAC) was synthesized and characterized to remove aniline (AN), a healthy and environmentally toxic substance. The batch adsorption assays were used to assess the effect of contact time (1, 2, 6, 12, and 24 h), pH (2, 4, 6, and 8), and with 1, 5, and 10 mg/L AN concentration. The adsorption mechanism of AN on ACC and commercial carbons (GAP and PAC) was evaluated and compared through Langmuir, Freundlich, and Temkin isotherms. The results show that AN removal increases with decreasing pH, reaching a maximum removal capacity of AAC of 90 %. AAC resulted in similar efficiency to GAC > 90 % to 1 and 5 mg/L. Langmuir shows the best-fit model reaching an R2 of 0.98. These models explain that the adsorption mechanism of AN on ACC is homogeneous, and monolayer adsorption occurs, achieving a maximum capacity of 1.20 and 1.16 mg/g for ACC and PAC, respectively, with a possible endothermic mechanism suggested by Temkin. The results showed that AAC could be considered an effective and economical adsorbent in removing the AN.

Life cycle greenhouse gas emissions assessment: converting an early retirement coal-fired power plant to a biomass power plant

Decommissioning aging coal-fired power plants (CFPPs) represents an effective strategy for reducing greenhouse gas (GHG) emissions, accelerating energy mix diversification, and achieving nationally determined contributions and net-zero emissions targets. However, dismantling the CFPP and building a renewable energy-based power plant with a capacity equal to a dismantled CFPP could burden state finances. Therefore, converting coal to 100% biomass fuel in the aging CFPP is one of the proposals that needs to be studied. This study conducted an environmental assessment concerning the Life Cycle Greenhouse Gas (LC GHG) emissions, encompassing raw material extraction and power plant operation. Five scenarios were analyzed. Two scenarios related to using sawdust and agroforestry residue for biomass fuel in the aging CFPP. The other three scenarios used biomass fuel from Calliandra wood harvested from tropical forests, production forests, and marginal land, which produced GHG emissions from Land Use Change (LUC). This study demonstrates that sawdust and agroforestry residue can reduce global warming impacts compared to coal. The LUC in higher carbon stock land will increase global warming impacts, while the LUC in lower carbon stock land will reduce global warming impacts. A decrease in the aging CFPP efficiency, when coal is converted to 100% biomass, will cause an increase in global warming impacts.

Investigations of thermal effects during pyrolysis of agro-forestry biomass and physicochemical characterizations of biofuel products

The development of biofuels from waste residues is critical due to higher emissions of greenhouse gases from petroleum and coal and rising energy demand. Converting agricultural and forestry biomass into biofuel products efficiently is a practical approach for simultaneously addressing renewable energy security and waste management challenges. This study examines the physicochemical characteristics of several agro-forestry residues such as camelina meal, mustard meal, flax straw, hemp straw and spruce wood to assess their suitability as feedstocks for pyrolysis to generate biochar, bio-oil and gases. An analysis was conducted to evaluate the influence of temperature (300–525 °C), heating rate (5–35 °C/min) and reaction time (30–75 min) to assess their impact on conversion efficiency and product distribution during pyrolysis. The optimal temperature, heating rate and reaction time for pyrolysis of camelina meal as a model biomass were determined to be 450 °C, 5 °C/min and 30 min, respectively. Physicochemical characteristics of biochar and bio-oil were analyzed to determine the impact of controlled thermal breakdown through slow pyrolysis. As the temperature increased, the calorific value, carbon content and thermal stability of biochar increased due to the removal of volatile matter and the development of aromatic carbon and phenolic features.

Characterization of Several Pellets from Agroforestry Residues: A Comparative Analysis of Physical and Energy Efficiency

The use of agroforestry biomass provides several advantages, both from an environmental point of view, in terms of the mitigation of global warming, and in terms of a circular economy for agricultural or agroforestry companies that reuse pruning residues as a source of energy. However, even if the use of energy pellets resulting from the pruning residues of various agroforestry species has excellent potential for the valorization of agricultural by-products, the physicochemical characteristics of these pellets have been scarcely studied by the scientific community. In this context, this study aims to assess the valorization potential of various lignocellulosic material residues produced during agroforestry activities. The objectives of the study include evaluating the chemical and physical characteristics of pellets produced with different mixtures of agroforestry biomass (olive, citrus, black locust, poplar, paulownia, etc.) in order to determine the optimal pellet blend from an energy and physicochemical perspective. The results of this study demonstrate that this comprehensive analysis provides valuable information on the optimization of biomass mixtures for better energy valorization, addressing both compositional and combustion-related challenges. In fact, it is observed that the addition of citrus and olive biomass to the various mixtures increases their energy potential. Furthermore, all of the pellets analyzed are found to possess an adequate and useful durability index (PDI) for their handling during storage and transport operations. This study demonstrates that olive and citrus pruning residues can be used to improve biomasses that have poor suitability in energetic, physical, and chemical terms. Further studies could be useful to understand which specific interaction mechanisms have an influence on emissions in order to optimize mixtures using different biomass sources for sustainable energy production.

Economics of sustainable lignocellulose biomass and biofuel logistics in Malaysia

Lignocellulose biomass is an inedible and renewable resource that can be used to produce biofuels sustainably and thus help to mitigate climate change while helping to ensure energy security. Tropical countries like Malaysia are assumed to have abundant biomass resources, but the fragmented farming landscapes common in Southeast Asia raise challenges for biofuel production, which largely stem from logistics operations and have an adverse impact on economies of scale and the viability of biorefineries. This thesis seeks to understand the costs and supplies associated with biomass transport, assess the impacts of landscape fragmentation on biorefineries, and identify optimum biorefinery locations. Ten sources of biomass (agroforestry residues from fields, sawmills, and processing plants) were considered, taking into account various logistical factors, supply scenarios, and impacts of landscape fragmentation. The study began with a simulation of biomass transport across Peninsular Malaysia, using GRASS GIS software to estimate costs and supplies. Eighty-nine points within each district were designated as potential locations. Biomass transport was recorded as a major cost component in operational expenditures. The capital expenditures for various conversion pathways and biorefinery operations were estimated across relevant orders of magnitude, with the biofuel supplies also being simulated. The study identified four optimum locations for various types of biomass, presenting detailed cost and supply structures. The two most competitive biomass types are rice straw and pressed palm fibre (PPF). Costs ranged a) from 130.6 to 206.3 USD/tonne, yielding 0.47 to 0.97 million tonnes of PPF fermented biofuel per year, and b) 123.2 to 207.8 USD/tonne for rice straw, yielding 0.49 to 0.56 million tonnes of fermented biofuel per year. In tonnes of oil equivalent (toe), both together amounted to 5–7% of Malaysia’s annual petroleum consumption. Surprisingly, the findings suggest that an abundance of biomass does not necessarily result in lower biofuel costs, because factors such as spatial fragmentation and moisture content amplify transport costs. Our analysis emphasises the need for strategic planning, including the use of larger trucks, early moisture removal, and the establishment of local consolidation centres to manage biomass effectively. It highlights the need for a more holistic and strategic approach in order to understand supply zone specifics with a view to unlocking Malaysia’s potential for sustainable biofuel production.

Polyethylene terephthalate (PET) as a recycled raw material for particleboards produced from pinus wood and biopolymer resin

Considering the significant demands for construction products and the increasing disposals of plastic and agroforestry residues, this research evaluated the influence of recycled particles of polyethylene terephthalate (PET) inserted in the manufacture of five particleboard prototypes based on Pinus elliottii wood and castor-oil-based polyurethane resin (CPUR). The following panel traits were obtained: 100% pine wood, 0% PET and 10% CPUR (M100P-0PET-10C); 70% pine, 30% PET, and 10% CPUR (M70P-30PET-10C); 50% pine, 50% PET, and 10% CPUR (M50P-50PET-10C); 70% pine, 30% PET, and 5% CPUR (M70P-30PET-5C); and, 50% pine, 50% PET, and 5% CPUR (M50P-50PET-5C). Panels were evaluated according to physical (density, moisture content, thickness swelling, and water absorption), mechanical (modulus of rupture, modulus of elasticity, perpendicular tensile), and morphological tests (scanning electron microscope). M50P-50PET-10C particleboards revealed the best performance in the physical and mechanical tests, as well as M70P-30PET-10C and M50P-50PET-5C panels showed equivalent results. The findings suggested a notable environmental contribution and a great economic feasibility. Thus, it is possible to obtain wood-based particleboards manufactured from recycled PET, reusing this highly discarded non-biodegradable plastic and using a smaller volume of adhesive, with physical-mechanical properties that meet the expected performance for this bioresource-based product.

An integrated PROMETHEE II-Roadmap model: Application to the recovery of residual agroforestry biomass in Portugal

Rural fires are currently one of the main global disasters, and Portugal is among the countries that have suffered from them for decades. These fires pose economic, environmental, and social threats to the country. A primary cause of rural fires is the burning of biomass to clear agroforestry residues. Thus, combating rural fires requires more effective forest management, particularly the removal of forest residues that serve as fuel. These residues, also known as biomass, have significant potential for energy production and biofuel use. This paper proposes a model that integrates the PROMETHEE decision-making method with the roadmapping. This proposed model includes 7 steps, including the planning of the roadmap, the definition of the decision problem, gathering information and building the roadmap. The proposed model was applied to develop a roadmap proposal for the recovery of surplus agroforestry biomass in Portugal, identifying the most emerging conversion technologies in the national context. With the roadmap developed, it was possible to understand that the recovery of surplus agroforestry biomass in Portugal involves several sectors. The energy sector is one of those that can benefit from the recovery of leftover agroforestry biomass, both from the point of view of carbon neutrality and energy independence. Forestry management is another of the great advantages of recovering leftover forestry biomass and, consequently, reducing the number of fires. In the context of recovery, combustion is the most widely used technology for producing energy or heat. The technology identified as most emerging in the upcoming years is gasification. Investment in scientific research is essential for the success of this sector, as is the development of public incentive policies and more engagement from all stakeholders. This paper conclude that valorizing agroforestry residues can reduce rural fire risks while promoting energy independence, sustainable regional development, and innovation in Portugal.

Performance of Particleboard Made of Agroforestry Residues Bonded with Thermosetting Adhesive Derived from Waste Styrofoam.

This paper investigated the upcycling process of thermoplastic waste polystyrene (WPS) into thermosetting particleboard adhesive using two cross-linkers, namely methylene diphenyl diisocyanate (MDI) and maleic anhydride (MA). The WPS was dissolved in an organic co-solvent. The weight ratio of WPS/co-solvent was 1:9, and 10% of cross-linkers based on the WPS solids content were added subsequently at 60 °C under continuous stirring for 30 min. The adhesive properties, cohesion strength, and thermo-mechanical properties of WPS-based adhesives were examined to investigate the change of thermoplastic WPS to thermosetting adhesives. The bonding strength of WPS-based adhesives was evaluated in particleboard made of sengon (Falcataria moluccana (Miq.) Barneby & J.W. Grimes) wood and rice straw particles at different weight ratios according to the Japanese Industrial Standard (JIS) A 5908:2003. Rheology and Dynamic Mechanical Analysis revealed that modification with MDI and MA resulted in thermosetting properties in WPS-based adhesives by increasing the viscosity at a temperature above 72.7 °C and reaching the maximum storage modulus above 90.8 °C. WPS modified with MDI had a lower activation energy (Ea) value (83.4 kJ/mole) compared to the WPS modified with MA (150.8 kJ/mole), indicating the cross-linking with MDI was much faster compared with MA. Particleboard fabricated from 100% sengon wood particles bonded with WPS modified with MDI fulfilled the minimum requirement of JIS A 5908:2003 for interior applications.

Preparation of TiO2/Lignin Composites with Agave sisalana Residue for Bisphenol-A Removal

Composites prepared from metal oxides and materials derived from agroforestry residues have been successfully applied to remove emerging contaminants. The lignin properties, high surface area and number of functional groups, are beneficial in the preparation of TiO2 composites. In the present work, sisal residue was used as a source of lignin, and after extraction, the lignin was applied in the preparation of an adsorbent composite with TiO2 to remove bisphenol-A. The optimal conditions for lignin extraction resulted in a lignin purity of 73%. Characterization proved that the synthesized composites have a high surface area (> 100 m2 g-1), homogeneous distribution of TiO2 particles and stable surface charge. Such characteristics resulted in a lignin/TiO2 composite with a maximum adsorption capacity of 13.7 mg L-1, capable of removing up to 97% of bisphenol-A. The adsorbent can be used in six cycles, removing over 70% by the third cycle, which indicates good stability.

Sustainable reduction of sulfate contained in gypsum waste: perspectives and applications for agroforestry waste and sanitary sewage

This review article explores sustainable biotechnological strategies for converting sulfate compounds and lignocellulosic waste, focusing on using sulfate-reducing bacteria (SRB) and the valorization of agroforestry residues and sanitary sewage. SRB show potential in effluent treatment, mine drainage, and the removal of sulfate and heavy metals from wastewater, with their metabolic activity being influenced by factors such as pH, temperature, and chemical oxygen demand/sulfate (COD/SO4=) ratio. In the context of a sustainable bioeconomy, the challenge of converting lignocellulosic waste into value-added products is addressed through physical pretreatment techniques such as milling, extrusion, microwave irradiation, and ultrasound, which are efficient in valorizing waste from urban tree pruning. The article highlights the importance of bioreactors in transforming raw materials into desirable biochemical products, discussing different types of bioreactors, such as batch, continuous stirred tank, airlift, fluidized bed, upflow anaerobic sludge blanket (UASB), and bubble column, and their specific advantages and disadvantages. Sustainable sulfate reduction is the central focus, integrating the application of SRB and the conversion of lignocellulosic waste in a way that complements the objectives of the work and promotes a more cohesive flow in the summary. Thus, the interrelationship between effluent treatment strategies and waste valorization is emphasized from an environmental sustainability perspective, highlighting the relevance of this study in the broader context of a sustainable bioeconomy.

Biomass from Allelopathic Agroforestry and Invasive Plant Species as Soil Amendments for Weed Control—A Review

Effective weed management faces increasing legislative restrictions for the use of herbicides due to their toxicity and environmental persistence. In addition, the linear increase in resistant weeds threatens to render authorized herbicides useless. In a post-herbicide era, under the IWM strategy, allelopathy can play a relevant role since many plants can produce a variety of allelochemicals with different structures and modes of action, capable of inhibiting the germination and growth of different weed species. Inspired by green manuring with cover crops, the use of allelopathic biomass from weeds, invasive species, residues of forestry plantations, and other abundant wild plants has some advantages over green manures grown in situ or other alternatives such as applying plant extracts or essential oils. Beyond the ecosystem services provided by green manures, the potential use of allelopathic biomass offers extra opportunities for the science and practice of holistically integrated weed management because (i) the investment of resources and time for producing cover crops would be alleviated, and (ii), new use of agroforestry residues and a sink for harmful weed biomass is provided. In this review, we compile the current knowledge of those allelopathic species whose biomass, used as soil amendment, effectively controlled weeds. In addition, the complex allelopathic processes underlying the effectiveness of cover crops and allelopathic biomass used as green manures for weed control are revisited.

Synergistic effects and products yield analyses based on co-pyrolysis of poplar tree and rape stalks with polyethylene terephthalate and polypropylene

In this study, results from co-pyrolysis of poplar tree, rape stalks (biomass) and polyethylene terephthalate, polypropylene (plastics) are reported using thermogravimetric analyzer, Fourier transform infrared spectroscopy and Pyrolyzer-Gas chromatograph/Mass spectrometry. The individual samples, and their mixtures (in 1:1 mass mixture ratios) were investigated to evaluate their co-pyrolysis behavior. TGA results showed the decomposition of agroforestry residues and plastic mixtures having three main stages of moisture evaporation, volatilization, and solid decomposition. The volatilization stage was important in the process. FTIR results showed the presence of poplar tree and rape stalks promoted the pyrolysis of plastics, which also supported the results of TGA. The same absorption bands at the same wavenumbers, indicated the presence of similar chemical functional groups. Py-GC/MS results showed co-pyrolysis of agroforestry residues and PET promoted formation of aromatic and acid while with PP, it promoted hydrocarbons and alcohol at 700 °C.

Preparation of water-insoluble lignin nanoparticles by deep eutectic solvent and its application as a versatile and biocompatible support for the immobilization of α-amylase

As one of the most abundant biopolymers, lignin is a widely available resource. However, its potential largely remains untapped, with most of it ending up as waste from industries like paper production, pulp processing, and bio-refining. The research undertaken in this study focused on the extraction of lignin from agroforestry waste using a deep eutectic solvent (DES) as a carrier for α-amylase immobilization, resulting in high stability and reusability. Several techniques, including Nuclear Magnetic Resonance (NMR), Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDS), and the Brunauer-Emmett-Teller (BET) method were employed to examine the structure and morphology of both the extracted lignin and the immobilized enzyme. The temperature used to recover lignin by DES would affect immobilization efficiency and enzyme loading by influencing its specific surface area, pore size, and volume distribution. Investigations using Nuclear Overhauser Effect Spectroscopy (NOESY) uncovered that the hydroxyl groups in G, H, and S units and the β-O-4 structure of lignin primarily serve as binding sites for enzyme molecules. Immobilized α-amylase demonstrated a higher pH and thermal stability level, with an optimal pH of 7.0 and temperature of 100 °C, compared to the free enzyme, which exhibited optimal activity at a pH of 6.5 and temperature of 90 °C. Importantly, immobilized α-amylase retained >80 % of its initial activity even after 28 days at room temperature, and it maintained 70 % of its activity after being reused 12 times. These findings strongly suggest that lignin derived from agroforestry residues holds promising potential as a future versatile immobilization material, a prospect integral to society's sustainable development.

Polyethyleneimine functionalized cellulose-rich agroforestry residues for removing perfluorooctanoic acid: adsorption performance and mechanism

Polyethyleneimine functionalized cellulose-rich agroforestry residues for removing perfluorooctanoic acid: adsorption performance and mechanism

Durability and resistance of eco-friendly particleboards produced from agroforestry residues

Durability and resistance of eco-friendly particleboards produced from agroforestry residues

RECYCLING OF CATTLE MANURE ASSOCIATED WITH RICE HUSK AS VERMICOMPOST VIA THE EISENIA FÉTIDA EARTHWORM

Agro-silvopastoral residues such as cattle manure and rice husks are abundant in the southeastern region of Pará. As an alternative aimed at sustainability, recycling through vermicomposting has advantages such as low cost, easy and fast application, besides the production of a material rich in nutrients. The objective of the work was to analyze the use of the vermicomposting technique in the degradation of agroforestry residues for the construction of organic fertilizer. The research method used was hypothetical-deductive, of quanti-qualitative scope under applied nature and descriptive, exploratory and experimental procedures, with standardized techniques of data collection and systematic observation on the processes of the study. Within this, the study followed within a greenhouse environment under open sides, located in the back of the Pará State University, Marabá campus, Pará. The materials used were rice husk from a rice mill in the municipality, along with black soil and bovine manure. For the initial stages, the manure needed to go through a washing process (tanning), and the rice husk by carbonization of the material, transforming it into ash. A pre-composting was performed for a period of 36 days before the increment of Eisenia fétida earthworms. The experimental design was employed with the use of 4 treatments, T1 - Cattle manure + rice husk in natura + Soil (composted), T2 - Cattle manure + rice husk in natura + Soil (Vermicompost), T3 - Cattle manure + rice husk ash + Soil (composted), T4 - Cattle manure + rice husk ash + Soil (Vermicompost). To measure pH and temperature data, the AMT-300® equipment was used, while soil moisture was measured using a soil hygrometer sensor connected to the Arduino UNO R3 board. At the end, samples of the organic compost were analyzed in the soil laboratory of Embrapa Amazonia Occidental, with data submitted to descriptive statistics and comparison of means using the Tukey 5% test. The pre-composting required 36 days, a period considered long due to the problem of assembling the beds during the rainy season in Marabá. They had pH values suitable for worm casting (5.5 - 6.9) and temperatures < 30°C, considered suitable environments for the development of Eisenia fétida. T2 and T4 presented a significant difference in moisture and chemical composition compared to T1 and T3, with moisture levels above 70% and organic matter contents 40% higher. T4 was the one with the highest C/N ratio, with values higher than the other treatments. The nutritional gain observed in the organic composts from vermicomposting in the pilot experiment, supports the need for implementation of vermicomposting on a larger quantitative scale in the evaluation of the of Eisenia fetida earthworms and their potential for degradation of agroforestry residues, resulting in ecological alternatives for the southeastern region of Pará.

Thermochemical Properties for Valorization of Amazonian Biomass as Fuel

The use of agroforestry residues for energy purposes has long been a reality in Brazil. About 84.8% of the produced electricity comes from renewable resources; vegetable biomass contributes 9.1% to this total. This percentage has the potential to increase if Amazon biomass residues are processed to be used as fuel. The major difficulty for this scenario is the lack of available information on energy properties, mainly the HHVs for Amazon agroforestry biomass types. Considering that there are important deviations in the equations for predicting the HHVs of Amazon biomass types in the literature, the main objective of this work was to propose equations to determine the HHVs of these biomass types using the proximate or ultimate analysis results as input. The methodology adopted to develop such equations was simple and multiple linear regression methods, using experimental results for HHVs and proximate and ultimate analyses for biomass types from the north region of Brazil. Four distinct equations were considered based on ranges from the proximate and ultimate analyses of the biomass types to deliver better results. The obtained equations were validated by application to 28 other biomass types from the same region. The proposed HHV equations presented good agreement between predicted and experimental values, with errors below 5% for equations based on proximate analysis and below 3% for equations based on ultimate analysis.

Caracterización fisicoquímica, compuestos bioactivos y capacidad antioxidante del jugo y harina de cladodios secundarios de Opuntia ficus-indica

Prickly pears (Opuntia ficus-indica) are one of the most valued species due to their ability to develop on soils with low access to nutrients and water and great nutritional value in their fruits and leaves. However, the frequent pruning of "secondary cladodes" generates agroforestry residues thatdonothave a secondaryuse, hence the present study sought to characterize the nutritional and bioactive properties of the "secondary cladodes" from the district of Santiago de Tunato develop a baseline for its possible ulterioruse as raw material. For the assays, two types of samples were used: the juice and the flour of the cladode, in which a proximate analysis was conducted, and the concentration of polyphenols, Vitamin C, flavonoids, and antioxidant activity were determined. The juice presented a yield of 53% while the flour of 7.3%. Both the juice and the flour presented considerable amountsof polyphenols (105.1 mg GAE/100g -769 GAE/100g), vitamin C (56.2 mg AA mg/100g -114.6 mg AA mg/100g) and antioxidant capacity (1247.94 μmol Trolox/g -2585 μmol Trolox/g). Therefore, the results indicated that cladodes can be used to develop products with exciting potentialin the food industry.

"GANODERMA LUCIDUM AND G. TSUGAE – A WELL-KNOWN LIGNIN DEGRADING SPECIES AS TRANSFORMATORS OF INSUFFICIENTLY UTILIZED LIGNOCELLULOSIC WASTE"

"The present study aimed to determine the capacity of Ganoderma lucidum and G. tsugae for pretreatment of common agroforestry residues. G. lucidum dominated in Mn-dependent peroxidase activity (1625.00 U L-1) after corn stalks fermentation, while the peak of Mn-independent peroxidase activity (2458.33 U L-1) was detected on raspberry sawdust fermented by G. tsugae. Laccases were dominant in the ligninolytic cocktail, with the maximal activity of 42480.09 U L-1 synthetized by G. lucidum cultivated on plum sawdust. The reduction of the lignocellulosic dry matter ranged between 11.00% and 33.00% in oak sawdust and wheat straw, respectively, fermented by G. tsugae, while the highest extent of lignin, cellulose and hemicellulose consumption (54.78%, 40.30% and 54.91%, respectively) was obtained on corn stalks. On the other hand, the smallest cellulose removal (6.26%) was detected after raspberry sawdust fermentation by G. lucidum, which, besides moderate ligninolysis, induced the highest selectivity index (2.87). The obtained differences in enzyme activities and lignocellulosics degradation extent could be the consequence of the different composition of the studied residues, especially macro- and microelements content. The obtained results clearly indicated the huge potential of G. lucidum and G. tsugae enzyme cocktails for the transformation of lignocellulosic residues that present abundant sources of numerous value-added products."

Product distribution from pyrolysis of large biomass particle: Effects of intraparticle secondary reactions

Thermochemical conversion provides promising approaches for utilization of agroforestry residues as energy sources in rural areas, such as decentralized biomass combustion and gasification. Understanding of the pyrolysis characteristics are crucial for the design of reactors and optimization of working conditions, but in these scenarios, utilization of centimeter-sized large fuel particles will bring challenges in predicting the evolution of pyrolytic products owing to the intraparticle secondary reactions. In this work, the product distribution of biomass pyrolysis was investigated in wide ranges of temperatures and particle sizes, and special attention was paid to the pyrolysis of centimeter-sized fuel particles under medium to high temperatures (500 °C – 900 °C). The yields of solid/liquid/gas-phase products were quantified, and the composition of tar and gas products were qualitatively and quantitatively evaluated, aiming at illustrating the effects of intraparticle secondary reactions. The results have shown that the differences between the product distribution of sawdust (<1 mm) and centimeter-sized wood cubes were significant over the whole temperature range, but the differences between wood cubes with varying sizes (1 cm, 1.5 cm and 2 cm) were dependent with the external temperature, indicating that the extent of intraparticle secondary reactions was simultaneously determined by external temperature and particle size. The evolution of tar composition indicated that the intraparticle secondary reactions could be divided into two distinctive steps. Increasing the particle size would firstly result in fast consumption of primary tar species and emergence of secondary tar species, while the second step would lead to the formation of simple phenols and aromatics, and large quantities of PAHs were released for centimeter-sized fuel particle under high temperatures (≥800 °C). Kinetic analysis further revealed that the first step was mainly transport controlled and sensitive to particle size, while the second step was jointly controlled by kinetics and transport, which appeared to be significant only if the particle size was large and simultaneously the temperature was sufficiently high.